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Trimethoprim and Sulfamethoxazole Residues in Untreated Wastewater used for Irrigation in Peri-urban Farms in Nairobi County, Kenya

Untreated wastewater is often recycled in peri-urban subsistence farming. This water may contain residues of pharmaceutically active compounds discharged into the wastewater. Of concern are the residues of trimethoprim and sulfamethoxazole which are administered synergistically under the brand name septrin or cotrimoxazole. These two antibiotics are administered to both humans and livestock and belong to the group of medicines called ‘anti-infectives’. This being the case, they are administered routinely to HIV-AIDS patients and to poultry and livestock as growth promoters, prophylaxis and to control microbial infections. Application of irrigation water with pharmaceutically active compounds may predispose microbial life to significant doses of the antibiotics for a non-limited span of time. This has been known to induce microbial resistance and thus minimize the drug sensitivity upon administration, an outcome that is harmful to human health and the environment. This study was carried out to determine if there are pharmaceutically active residues of these antibiotics by the use of high performance liquid chromatography coupled to spectroscopy. Untreated wastewater used for irrigation was collected during the dry season from various peri-urban farms in Ruai and Njiru from small scale farms along Ngong River. In the untreated wastewater, sulfamethoxazole levels ranged from 62.09 to 88.66 ng/L while trimethoprim levels ranged from 24.71 to 27.52 ng/L. In all cases the results in the farms upstream were higher than in those downstream. From these findings, it is recommended that wastewater should be treated prior to recycling in farms.

Scholastica Gatwiri Mathenge, Ruth Nduta Wanjau and Glaston Mwangi Kenji

Effect of Immobilized Bacteria on TAN Suppression, Survival Rate, and Biomass Harvest of Pacific White Shrimp, Litopenaeus vannamei, Grown in Biofloc Culture System

In this study, immobilized bacteria (Nitrosomonas, Nitrobacter and Nitrospira) were added into three shrimp ponds in a concentration of 2´106 cfu mL-1 that equals to 20 kg beads ha-1. The other three ponds were used as control treatment. All ponds were stocked with PL’s (Post Larvae) of Pacific white shrimp at a density of 100 PL’s m-2. Shrimps were fed with a commercial diet containing 36% crude protein, 7% fat, 10% ash, and 2% crude fibre. Oxygen was kept near saturation through paddle-wheels. Secchi disc depth, pH and temperature were monitored daily. Total ammonia nitrogen (TAN), nitrite and nitrate were measured every 10 days together with sampling for shrimp body weight and feed adaptation. Average TAN concentration of ponds with nitrifying bacteria was 0.12±0.144 mg L-1, one fourth of the control ponds (0.523±0.564 mg L-1). Average nitrite concentration in control ponds (0.058±0.045 mg L-1) was also significantly higher than the ponds added with immobilized bacteria (0.037±0.038 mg L-1). However, the end product of nitrate was not significantly different (a = 0.607) among the ponds. Although not affecting shrimp growth, TAN suppression significantly increases the survival rate and finally resulted in higher (a = 0.043) biomass harvest, from 12.37 t ha-1 (control ponds) to 18.87±2.91 t ha-1 at treatment ponds. This study concluded the importance of transforming TAN concentration into nitrate, particularly in intensive culture system. To do this, the presence of immobile nitrifying bacteria is needed.

A. M. Hariati, Aulaniam, E. Y. Herawati and D. G. R. Wiadnya

Nitrogen Transformation and Loss During the Composting Process of Livestock and Poultry Manure With or Without Bio-fermentation Agent

The composting experiment using chicken manure, pig manure, fungus chaff and biogas residue as mixed media was conducted for 30 days with or without amendment of the bio-fermentation agent. The nitrogen transformation, changes of compost temperature and organic carbon in the mixture were investigated during the whole process. The results demonstrated that addition of the bio-fermentation agent improved the compost temperature, prolonged the high-temperature stage, expedited the process of organic carbon decomposition and lowered the C/N ratio. The amendment of bio-fermentation agent was beneficial to the transformation of organic nitrogen to ammonium (NH4+-N) in the early composting stage (the first 9 d), but to the form of nitrate (NO3--N) afterwards. Compared to the non-bio-fermentation agent treatment, the composting process was reduced by 9 d to maturity. The acid hydrolysis organic nitrogen (THN) was increased with the addition of bio-fermentation agent during the early composting period by increasing the hydrolysis of the protein. The formation of amino acid nitrogen (AAN) and amide nitrogen (AN) in the compost, with amendment of bio-fermentation agent in early stage, revealed the reason why the mineralization of organic N was fast during the composting process. Although the addition of fermentation agent accelerated the organic nitrogen to transform into available forms, it did not cause massive N loss in the whole composting process.

Liu Shuai and Wang Xudong

Co-metabolic Biodegradation of Nitrified Old Landfill Leachate with Nitrate-N in Anoxic Sequencing Batch Biofilm Reactors (ASBBRs)

In consideration of the high concentration of ammonia and refractory organics, co-metabolic biotreatment system of old landfill leachate after bio-nitrification was constructed in ASBBRs with nitrate-N as growth substrate. Under the conditions of 0.25 kg COD/(m3·d) and 0.20 kg NO3--N/(m3·d), the degradation rates of chemical oxygen demand (COD), total organic carbon (TOC), NO3--N and colour index, after the operation for 67 d were 67.60%, 53.78%, 45.54% and 53.57%, respectively, while the BOD5/COD value of old landfill leachate was 0.068. Analyses of molecular weight cut off (MWCO) showed that micro-molecular refractory organics of 5~10 KDa in inflow were effectively degraded, of which parts of organics became more difficult to be biodegraded with smaller molecular weight. Fourier transforms infrared spectroscopy (FTIR) analysis demonstrated that aldehydes, aliphatics, phenols and alcohols, etc. decreased and O-H functional group increased in the effluent. A majority of bacteria in the co-metabolic system were discovered to be globular and short-bar-shaped, with a few disc-shaped bacteria by scanning electric microscopy (SEM) testing. Moreover, benzene and toluene, as particular pollutants in old landfill leachate, were researched in different co-metabolic systems with nitrate-N. The result showed that the dehydrogenase concentration might accelerate the degradation of refractory organics.

Yancheng Li, Benzhou Gong, Yingmu Wang, Jiale Wang and Jian Zhou

Removal Kinetics and Performance Evaluation of 3D Rotating Cylindrical Anode Reactor for Textile Wastewater Treatment

The removal kinetics of a batch electrocoagulation 3D rotating cylindrical anode reactor for reactive dye effluent was investigated. The cell used a new type of electrode arrangement having a rotating 3D Al cylinder as anode and long rod of aluminium as cathode. The performance of the reactor was studied via various operating parameters, such as current density, anode rotation speed, duration of electrolysis, nature of supporting electrolyte and rate of reaction. The dye removal process in this innovative system follows a second order kinetics with maximum COD removal of 96.40% in a pH range of 6-8 and having a current density of 6 mA/cm2. The anode rotation provides the turbulence which helps in removal process.

A. Choudhary and S. Mathur

Monsoonal Floods Affecting Cochin Backwater Ecosystem

The samples were collected in five sampling campaigns conducted during postmonsoon 2008, premonsoon 2009, monsoon 2009, postmonsoon 2009 and premonsoon 2010. The phytoplankton species dominant in premonsoon were mainly species of Chorella, Asterionella, Ceratium, Coscinodiscus, Nitzschia and Trichodesmium. During monsoon, species of Arthodesmus, Chaetoceros, Closterium, Dinorhysis and Spirogyra were abundant. Species of Volvox, Closterium, Peridinium and Ceratium were mostly represented. Copepods the main secondary producers were represented by species belonging to Acartia, Pseudodiaptomus, Paracalanus, Oithona and Coryceus. Copepods have indicated increase in carnivorous species namely Tortanus, Oithona, Oncaea and Corycaeus spp. The main fish species studied were Oreochromis mossambicus, Mugil cephalus, Channa striatus and Etroplus suratensis. Enumeration of the fish species in 2008 reported only 50 species as against 160 species observed in 1970’s. The changes in hydrochemical properties indicate environmental degradation with the increase of nutrient load. Eutrophication and harmful algal blooms are also observed. The recent reports of octopus in the fishing nets operating in the backwater suggest that salinity of backwater is on par with that of the Arabian Sea during premonsoon period. There is marked alteration in the predator components in the coastal fishery showing a significant rise in puffer fish. Recently, scientists from Central Marine Research Institute have spotted many dolphins in the CBW. Climate change and temperature rise in coastal waters cause damage to marine, estuarine and inland fishes. Vulnerability of plankton and fish in CBW exposed to floods and salinity ingress is causing serious threat to many traditional species.

R. Radhika

Analysis of the Relationship Between Land Surface Temperature and Land Cover Changes Using Multi-temporal Satellite Data

Rapid urbanization, coupled with the tremendous growth in population and built-up areas in cities, leads to problems associated with global climate change impacts, such as urban heat island effect, which influences regional climate, urban environmental pollution, and socio-economic development. This study aims to detect the spatial variation of land surface temperature (LST) and determine its quantitative relationship with land cover types using the techniques of remote sensing and geographic information system. Taking the city of Zhengzhou as the study area, we utilized four Landsat TM images from 1988 to 2017 to classify land cover types by maximum likelihood classification and retrieve the LST by using a mono-window algorithm. Results show that the urban heat island areas have an expanding trend from 1988 to 2017 in general. Moreover, the spatial distribution pattern and extension of the urban heat islands are consistent with urban sprawl. Changes in land cover type altered the spatial distribution characteristics of LST from 1988 to 2017. In various land cover types, the construction land and bare land showed the highest temperature, and they significantly contributed to the heat island effect. Green land and water can effectively relieve the heat island effect. Finally, constructive strategies and measures to alleviate the urban heat island effect are proposed from different aspects. Therefore, this work provides a scientific reference for decision making to improve the thermal environment and achieve sustainable development in the future.

Qingkong Cai, Erjun Li and Ruibo Jiang

Prediction of NOx Emissions from Coal-Fired Boilers Based on Support Vector Machines and BP Neural Networks

The BP neural network and support vector machine (SVM) are respectively employed using operation test data to establish models describing the NOx emission characteristics of a coal-fired boiler with the assistance of the intelligent MATLAB toolbox. The momentum method is employed to improve existing problems within the BP neural network, and to choose the optimal kernel function of the SVM prediction model and the corresponding parameters c and g. The maximum error of the prediction model of the improved BP neural network is 9.85% with an average error of 4.2%; the maximum error of the SVM prediction model after parameter optimization simulation is 4.57% with an average error of 2.15%. Results indicate that both modelling methods demonstrate improved accuracy and generalization. Finally, quantitative comparison analysis of the simulation and prediction results of the two models indicate that the supporting vector machine model is greatly superior to the neural network model in terms of computing speed, fit and generalizability while requiring fewer thermal state data samples from boiler operation.

Ting-fang Yu, Lei Liao† and Ran Liu

Seasonal Changes in Soil Microbial Biomass Carbon and Nitrogen of Different Vegetation Types in the Mu Us Sandland, Northwestern China

The aim of the study is to determine the seasonal changes in sand soil microbial biomass carbon (C) and nitrogen (N) and to identify the pattern of sand soil microbial biomass of four vegetation types in the Mu Us Sandland in northwestern China. Four types of psammophyte plots were established in a desert botanical garden. Soil samples were collected at the depths of 0-10, 10-20 and 20-40 cm, before the 10th of each month, from April to October 2015. The microbial biomass C (MBC) and microbial biomass N (MBN) concentrations were determined using chloroform fumigation extraction. The concentration of MBC did not show consistent patterns as the soil depth increased from 0-10 cm to 20- 40 cm, although it was higher in the top layer than in the other layers in some stands (p<0.05). There was also a consistent pattern in different soil layers. All of the top layers showed similar changes from August to October. The MBN concentration in the middle layer was maximal in April, which experiences different types of vegetation, and was significantly higher in the Pinus sylvestris L. var. mongholica Litv and Salix cheilophila stands (p<0.05). Seasonal changes in desert soil MBC and MBN concentrations were obvious in the top soil layer. The peak MBC and MBN concentrations occurred during different seasons, with MBN higher during the colder months.

Wang Yue, Li Xu, Guo-Dong Ding, Gao Guanglei, Zhao Yuanyuan and Yu Minghan

Bacterial Community Composition Associated with Freshwater Cyanobacterial Blooms of Intensive Culture Ponds

To determine the composition of the bacterial communities associated with cyanobacteria in the freshwater ponds of Channa argus in intensive culture in the late culture period, we examined the bacterial community of non-cyanobacterial blooms freshwater ponds (C) and cyanobacterial blooms freshwater ponds (CB) using PCR-denaturing gradient gel electrophoresis (PCR-DGGE) and 16S rDNA clone library. DGGE profiles showed that Microcystis sp. (JX391871.1), Leptospira sp. (JX067673.1) and Verrucomicrobium sp. (FN668203.2) existed only in CB, whereas Sphingomonas sp. (AB681542.1) and Paenibacillus sp. (JQ659563.1) were the C-specific bacteria. The 16S rDNA clone libraries of pond water showed that Actinobacteria (15 OTUs, 31.9%), Bacteroidetes (13 OTUs, 28.7%), Fibrobacteres (7 OTUs, 14.9%) and Proteobacteria (5 OTUs, 10.0%) were the dominant groups in C; the four dominant groups in CB were Bacteroidetes (17 OTUs, 34.7%), Actinobacteria (9 OTUs, 18.4%), Fibrobacteres (6 OTUs, 12.2%) and Proteobacteria (8 OTUs, 16.2%). In the clone library, distribution of sequences belonging to Fibrobacter in CB (22.2% of the 99 clones) was twice as that of C (11.1% of the 99 clones). In both DGGE map and 16S rDNA clone library the Firmicutes group (JQ659563.1 in DGGE and 3 OTUs in C library) existed only in C. These results suggested that the composition of bacterial communities changed with the cyanobacterial blooms in Channa argus intensive culture freshwater ponds, and whether the change of the Firmicutes-to-Bacteroidetes ratio could be used to predict cyanobacterial blooms in these types of ponds required further validation.

Yun Xia, Ermeng Yu, Zhifei Li, Deguang Yu, Guangjun Wang, Jun Xie†, Wangbao Gong and Kai Zhang

Pollution Assessment of Various Heavy Metals in the Surface Sediment of Kendari Bay, Indonesia

The concentration and pollution level of heavy metals in the surface sediments of Kendari Bay, Indonesia were measured. Sediments samples from 25 sites, ranging from the inshore (Wanggu River) to the offshore regions of the bay, were analysed for metal concentrations (i.e., Mn, Fe, Co, Ni, Cu and Zn), sediment type and TOC. The results demonstrate that the heavy metal Fe had the highest concentrations (1100 to 29800 μg/g) followed by Mn (34.39 to 399.59 μg/g), Zn (2.58 to 129.70 μg/g), Ni (1.14 to 15.34 μg/g), Cu (0.6 to 15.81 μg/g), and Co (0.24 to 7.33 μg/g). Moreover, results of both Pearson correlation analysis and PCA suggest the similar distinctiveness of Fe, Co and Ni in 25 sampling sites. The measurement results of index of geoaccumulation (Igeo) suggest that the Kendari Bay surface sediment is considered an unpolluted area for each of the heavy metals investigated in this study.

Alrum Armid, Ryuichi Shinjo, Siti Hadijah Sabarwati and Ruslan Ruslan

Does Nuclear Energy Consumption Improve Environment? Empirical Evidence From India

This paper attempts to investigate the long run and short run relationship between nuclear energy consumption and carbon dioxide emission in India within energy consumption growth-environment deterioration framework, over the period of 1969-2014 using a multivariate model wherein coal consumption, oil consumption and trade openness are also included as additional variables. The empirical results indicate that there is a long run relationship among the competing variables. We find that nuclear energy consumption indeed reduces CO2 emission in both short run and long run in India. On the other hand, non-renewable energy sources (oil and coal) increase CO2 emission in both long run and short run. Based on these findings, it is suggested that government should shift from nonrenewable energy sources to nuclear energy to attain faster, inclusive and sustained economic growth.

Ritu Rani and Naresh Kumar

Assessment of DNA Damage in Agricultural Workers Exposed to Mixture of Pesticides in Assam (India)

In agricultural fields, pesticides are used to protect the crops, but they pose a potential hazard to the farmers and the environment. The aim of the present study is to investigate the relationship between the occupational exposure of different kinds of pesticides and DNA damage of an individual due to directly spraying the pesticides in the agricultural field. Blood samples of 70 exposed workers (after a day long spraying) and 70 control subjects belonging to Kolgochia Area of Barpeta district of Assam, were evaluated using the comet assay. Significant differences were found in the DNA damage among freshly exposed workers and controls group. The two groups had similar mean ages and smoking habits. Mean comet tail length was used to measure the DNA damage. Length of duration of pesticide exposure on the workers had significantly large tail length (62.75±21.97, 63.48±20.15, P=0.05). There was a significant increase in the comet parameters, viz., mean comet length and frequency of cells showing migration in exposed workers as compared to the control (20.73± 20.23 vs. 63.48±20.15, P=0.054641 and 31,07±23.81 vs. 62.75±21.97 P=0.043). Confiding factors during pesticide exposure, such as age, smoking, drinking and dietary habit were expected to modulate the damage. The evidence of genetic hazard related to exposure, resulting from the exposure of pesticides, is the matter of concern. There is a need for educational programs in agriculture to reduce the use of such chemicals.

Ranjit Hazarika and Purbajyoti Deka

Environment Pollution State and Improvement Measures in Rural Areas of Heilongjiang, China

With the development of social economy and industrialization, environment pollution in rural areas is increasingly serious and the rural ecological environment is destroyed continuously, which have become constraints against the sound and sustainable development of rural economy in China. Existing studies on rural environment pollution state were reviewed to further analyse the rural environment pollution state and then to introduce corresponding suggestions. The rural environment pollution state in Heilongjiang Province was analysed. In the past decade, industrial waste gas and industrial solid waste outputs of township enterprises have increased by 3.81% and 18.72% respectively. Random livestock excrement disposal, low straw utilization, and continuous growth of household garbage throughput are important manifestations of rural environment pollution. Poor environment protection consciousness of peasant, poor monitoring of rural environment pollution and imperfect management systems are the most prominent problems in rural environment pollution control. Finally, specific measures to control rural environment pollution were proposed, including increasing attention to environment protection, forming effective environment protection mechanism, increasing financial input to environment protection, and strengthening legal monitoring. Conclusions obtained in the study can provide significant references to explore further countermeasures to rural environment pollution that conform to actual situations in Heilongjiang of China.

Yanli Yang and Jun Meng

Modelling the Spatial Variation of Hydrology in Volta River Basin of West Africa Under Climate Change

Spatial variability in Volta basin’s climate coupled with climate change increases unpredictability and unreliability of rain-fed agriculture, putting livelihoods of the inhabitants under severe risk. Though there have been numerous studies on the hydrological response of the basin to climate change, only a few have dealt into its spatial variation. To fill up the existing gap, the spatial variation of hydrology of Volta basin under projected impacts of climate change is investigated using high resolution (0.3°~3 km) National Centers for Environmental Prediction (NCEP) Climate Forecast System Reanalysis (CFSR) data as observational data, Global Climate Model HadCM3, IPCC A1B emissions scenario and Soil, and Water Assessment Tool (SWAT). Calibration results from flow stations Dapola (R2 =0.74, NSE=0.72), Nawuni (R2 =0.86, NSE=0.88), and Bamboi (R2 =0.82, NSE=0.80) show reasonable simulation of the basin’s hydrology, in general. Overall the simulation indicates higher spatial variability, with variability much higher at the end of the century (2071-2100). There is a greater average increase in rainfall and surface runoff in northern catchments compared to the south with average potential evapotranspiration and evapotranspiration much higher in southern catchments compared to the north. Contrary to projected increase in rainfall in the basin, some sub-basins in north and south show a decrease. Decrease ranges from 2% to 10%, whilst increase in surface runoff is in the range of 16% to 76% in some sub-basins is far greater than the basin-wide range of increase i.e., 9% to 14%. This might impact negatively on the rain-fed agriculture and also intensify flood events, respectively, in these sub-basins. There is, therefore, a call for a decentralized approach in the basin’s water resources management that incorporates the spatial variability of the hydrologic cycle into local climate change adaptation mechanisms.

Sulemana Abubakari, Xiaohua Dong, Bob Su, Xiaonong Hu, Ji Liu, Yinghai Li, Tao Peng, Haibo Ma, Kai Wang and Shijin Xu

Nitrogen Degradation Kinetic Analysis in Different Subsurface Constructed Wetlands

In this study, the kinetic models of pollutant degradation in different wetlands were studied. The kinetic equations were deduced and the kinetic simulation of the main pollutants such as NH3-N and TN was completed by the experimental data, and the dynamics of the pollutant degradation simulation model were applied to simulate the effect of the reaction kinetics model on the removal of contaminants in horizontal steel slag subsurface wetland (HSSSW) and horizontal volcanic subsurface wetland (HVSW). The results showed that the first order reaction kinetics model could obviously simulate the effect of main pollutants such as NH3-N and TN in two kinds of subsurface wetlands. The correlation coefficient R2 of the dynamic linear model was 0.9640 and 0.9600 in HSSSW, respectively, and the correlation coefficient R2 of the HVSW was 0.9365 and 0.9709, respectively. The degree of fitting and correlation was very good. Besides, the simulation results showed that the degradation of the main pollutant was of great reference value for the design and operation of the practical subsurface wetland.

Hao Wang, Can Tian, Huiyuan Zhong, Xiaoqing An and Bingxu Quan

Soil Microbial Diversity of Marshes Covered by Suaeda salsa and Spartina alternifora in Yancheng Wetland

The introduction of invasive species, Spartina alternifora, in the tidal marshes of Yancheng wetland has been considered deleterious to habitat quality. However, the extent to which the replacement of Suaeda salsa by S. alternifora affects the soil environment is unknown. In this study, we examined the soil physicochemical characteristics and microbial communities of rhizosphere and non-rhizosphere in soils adjacent to Spartina and Suaeda marshes. The dynamics of microbial community were similar in both the types of plants, and the roots were conducive to microbial growth. The total number of microorganisms and microbial activity showed a seasonal fluctuation, increasing from spring through summer and then declining gradually to the lowest in spring. The data provided herein also indicated that values of organic carbon, biomass carbon, size of microbial populations, and activity were higher in Suaeda than in Spartina marsh, which suggests that differences in vegetation cover significantly affect the soil environment and microbial community. Therefore, we suggest that the policy to introduce S. alternifora into this area should be reconsidered.

Hongmei Zhang, Bairen Yang, Aihui Chen and Huixing Liang

The Glycerol Effect on Mechanical Behaviour of Biodegradable Plastic from the Walur (Amorphophallus paenifolius Var. sylvestris)

Bioplastic material development by utilizing indigenous commodity is a trend to overcome the environment damage by plastic and as a sustainable resource. As a home of broad biodiversity, Indonesia has more species of Amorphophallus that are still unexplored. One of species among them that is possible to explore as bioplastic material is Walur. The aim of this work is to study the behaviour of bioplastics with the Walur corm as a raw material and glycerol as a plasticizer. Glycerol portion is varied in 7 levels and in a range of 6% to 30%. The result showed that glycerol has significantly affected the tensile strength, elongation and modulus elasticity of the Walur plastics. Glycerol could decrease both, elongation and elasticity of Walur plastic despite increasing effect on elongation behaviour.

Musthofa Lutfi, Sumardi Hadi Sumarlan, Bambang Susilo, Wignyanto, Risma Zenata and Lita Puspita R. Perdana

Utilization of Agrowastes for Vermicomposting and its Impact on Growth and Reproduction of Selected Earthworm Species in Puducherry, India

Ecofriendly vermicomposting technology is used for utilizing the locally available agrowastes. Three different combinations of locally abundant agrowastes- banana waste (BW), mixed farm waste (MFW) and cow dung (CD) were fed to two different earthworm species, Perionyx excavatus and Eudrilus eugeniae in vermibins under controlled laboratory conditions for 90 days. Standard physicochemical parameters of vermicompost were evaluated for seven different treatments along with the impacts on growth and reproduction of the selected earthworm species. The decomposition rate of substrate in E. eugeniae in T3, T5 and T7 (70.3±2.1 days, 76.3±2.5 days and 75.7±1.5 days respectively) and in P. excavatus in T2, T4 and T6 of same combination of substrates (81.7±1.2, 84.3±2.5 and 83.7±1.5 days) have been recorded. Earthworm growth and biomass production by weight of E. eugeniae was higher (68.5%) than P. excavates (66.9%). Further, the individual weight gain was higher in E. eugeniae than P. excavatus in all the three wastes with a significant difference (p<0.05). The production of cocoons and juveniles at the intervals of 30th, 60th and 90th days were found higher in E. eugeniae than P. excavatus in all the three agrowaste combinations. The results indicate that Eudrilus eugeniae outperformed Perionyx excavatus in growth and decomposition rate of substrates and proves to be a better species for vermicomposting. Therefore, vermicomposting may be an efficient management approach for the locally available agrowastes to convert them into enriched manure for sustainable agriculture.

R. Kamalraj, M. Nandhivarman, Pynkhlainbor Thongni, M. Pradheeps and G. Poyyamoli

Performance of Recycled E-waste as Aggregates in Green Concrete

This study is focused to improve strength and durability properties of green concrete with E-waste as fine (10%, 20% and 30%) and coarse aggregates (5%, 10% and 15%) replacement in fibre reinforced green concrete with 30% of ground granulated blast furnace slag (GGBS) for the replacement of cement. Since the reuse of electronic waste and the waste industrial by-product GGBS was used in this study, this also aims to design a green concrete with E-waste. The findings from this study show that E-waste as fine aggregate attained lesser compressive strength, whereas E-waste as coarse aggregate replacement exhibited similar compressive strength compared to control concrete. The results of splitting tensile strength and flexural strength of E-waste as fine and coarse aggregate replacement mixtures were superior to that of normal concrete. The chloride ion penetration of control concrete was low, whereas for E-waste concrete mixtures moderate chloride ion penetration was observed. The overall performance of E-waste as fine and coarse aggregates replacement in compressive strength, splitting tensile strength, flexural strength and chloride ion penetration was due to the combined pozzolanic action of GGBS, increase in the tensile behaviour due to the presence of steel fibres and good bonding of E-waste aggregates.

A. Arun Kumar and R. Senthamizh Selvan

Hazards, Sources and Control Measures of Heavy Metal Pollution of Forest Soil: Taking Jin-Jing-Ji Region of China as an Example

Forest is a complex system of woods, plants, animals, and other environmental components. However, owing to unsustainable population growth and rapid economic development, large quantities of poisonous heavy metal elements are directly or indirectly released into forests by human activities, which has damaged the soil quality. This study took Jin-Jing-Ji region of China as an example to analyze the hazards and sources of heavy metals in forest soil. Related literature on heavy metal pollution of forest soil was analyzed. Subsequently, control measures were proposed to overturn the current polluted state of the above region’s forest. Results show that the effect strength, urbanization, and industrialization level of human activities are closely related to the degree of heavy metal pollution of forest soil. The hazards of heavy metals pollution to forest soil manifest in four aspects: plants, soil animals, soil enzymes, and people dwelling around the forest. Meanwhile, the main sources of heavy metal pollution are atmospheric dry and wet deposition, industrial activities and transportation, fertilization of man-made forest, and mining activities. The current state can be improved by employing control measures such as economic and industrial structural adjustments, strengthening the environmental awareness of individuals, strict control of pollution sources through prevention management, and strict control of atmospheric deposition and forest pollution. The findings of this study can serve as a significant reference for relevant regions when analyzing the state of heavy metal pollution to their respective forest soils and when conducting environmental diagnosis and forest protection activities.

Zhen Li and Zhi Liu

The Research on The Ecological Environment of Green Building

Increasing emphasis has been placed on the concern of buildings’ effects on the wind, making it an essential aspect in considering the surrounding environment. It has a profound influence on aspects such as pedestrian’s comfort, safety, natural ventilation, and reducing building energy consumption. Outdoor wind environment is related to natural and artificial geographical features, and the wind direction, which all play an important role in the user comfort in and around a building. The prediction from the simulation of the wind environment can guide the layout of the buildings to enhance the wind environment effectively. The research looks at a block of land in the new district of Yuexi County. By using the wind environment simulation software Fluent, the research explores the prediction of wind environment for the building, as well as possible methods of analysis, designing process and the influence brought by the large-scale project. It supplies reference to enhance the wind environment of buildings in the designing process for both planners and architects to create a more enjoyable and safe building environment.

Li Yang and Feng Qian

Bioadsorbents and Filters for Removal of Heavy Metals in Different Environmental Samples-A Brief Review

To eliminate the problem of heavy metals, there are naturally occurring materials that are locally and commonly found and are very much encouraged as low cost adsorbents such as industrial and agricultural wastes. Several agricultural and industrial wastes as potential adsorbents have been viewed, which includes wood ash and bone ash, cassava waste, chitosan-g-poly (butyl acrylate)/bentonite nano composite, Eucalyptus tereticornis bark, sarooj clay, orange fruit peel, fly ash, potato peels, coconut shell charcoal, pecan shells, bagasse fly ash, waste sludge, pith and saw dust, maize cob and husk, hazelnut shell, soybean hull, jackfruit, crab shell, neem leaves, cooked tea dust, teak leaves, cashewnut shells, aerogel carbon, sewage sludge ash and lignite-based fly ash. The adsorption details of these adsorbents have been keenly viewed and judged in batch studies mostly. The judgment is on the basis of adsorption isotherms, thermodynamics and parameters like contact time, adsorbent dosage, pH, initial metal concentration and adsorption capacity. Hence, it is proved from the review of these adsorbents that they are highly selective in terms of separation, thermally and mechanically stable and do not foul, regenerative and less soluble in liquids. They are commonly available and are very less costly with removal efficiency up to 99%. The usage of these adsorbents is better applicable at low pH and oxidized or carbonized or activated before using them as adsorbents to remove heavy metal ions from agricultural, industrial and municipal wastes.

Hirra Rashid and Ghazala Yaqub

Study on the R-Based Dynamic Construction Techniques for Stand Density Management Diagrams

With an investigation into the procedure and techniques involved in constructing a stand density management diagram (SDMD) and in light of users’ real needs, this study designs a system for the dynamic construction of SDMDs based on R language, for the purpose of overcoming the complexities of model fitting in producing a diagram, the difficulties in constructing a diagram and the high demands for users’ expertise. The interactive modelling technique between C# language and R language is applied to the research, with which different sets of model fitting results are compared and optimal results are chosen. The whole procedure, from data collection, model fitting (including outlier data elimination, prototype model fitting and model testing) and diagram construction, is streamlined and automated. Continuous forest inventory data for the Larix principis-rupprechtii plantation in China’s Inner Mongolia is used and two sets of prototype fitting results of the SDMD are compared. With equivalent height curves as the example, this paper makes the goodness of fit of the binomial theory of density effect (R2=0.9231) better than that of the power theory of density effect (R2=0.8354). The model with the best goodness of fit is finally selected for the dynamic construction of a SDMD. Application of this generated SDMD indicates a relatively high accuracy and practical value.

Chengde Wang, Baoguo Wu, Chen Dong and Jiancheng Liu

Applied Problems of Selecting Synthetic Polymer Waste as Raw Material For Production of Active Carbon

The widespread use of polymers in engineering and for household needs is accompanied by the formation of large amounts of waste, which leads to the necessity of solving the problem of their utilization and recycling. This paper shows the results of studies on thermal processing of synthetic large-tonnage polymeric wastes with receipt of active carbons (AC). AC of synthetic polymeric materials are characterized by high purity, low ash content, regular structure, and the possibility of direct forming of porous structure. Sorption properties of AC depend on physical and chemical properties of polymeric wastes. The aims of the present work are to study the processes of thermal degradation of polymeric materials with different chemical structures and physical and chemical properties to obtain carbon sorbents and to develop requirements for chemical composition of waste synthetic polymers as a raw material for the production of AC. Samples of polymer materials, widely used in business activities and having different chemical structure and physical and chemical properties, such as technical polypropylene, polycarbonate based on bis-phenol A, granulated polystyrene, bound rubber on the base of styrene and butadiene copolymer, textile laminate (cotton fabric reinforced with phenol resin and pressed), filled polymer impregnated and cured with epoxy resin, were selected for this study. The influence of the structure of polymer structural unit and its physical and chemical properties on AC porous structure formation has been defined, and requirements to chemical composition of polymer wastes as raw material for AC production have been proved. These requirements include: polymer aromatic structure, location of benzene rings in polymer backbone, presence of heteroatoms (oxygen, nitrogen), high aromaticity index and oxygen mass content in the polymer composition.

Glushankova Irina, Vaisman Yakov, Surkov Alexandr and Dokuchaeva Darya

Formulation and Characterization of Pyrolytic Oil from Waste Tyre and Waste Plastic: A Comparative Study

Elimination of solid waste generated by the engineering sector is the need of the present world. In this study, a comparative analysis has been made to formulate a petro-diesel like fuel from the waste tyre (WTPO) and waste plastic (WPPO), which is derived from unusable tyre and plastic waste materials, by the thermal pyrolytic reaction. A pyrolysis reactor is designed and fabricated to transform the solid waste into the pyrolytic oil through thermal cracking. The characterization of WTPO and WPPO is carried out using the gas chromatography, mass spectrometry, Fourier transform infra-red and elemental analysis. The GC-MS analysis of both WPTO and WPPO indicated the presence of naphtha and limonene compounds at higher concentration levels. The content of sulphur in WTPO is at higher level. The physico-chemical properties are also determined based on IS:1448 and it is found to be comparable with the commercial petro-diesel.

V. Hariram, S. Seralathan and A. Mohammed Raffiq

Alterations in Haematological and Biochemical Profile of Freshwater Fish, Cirrhinus mrigala (Hamilton) Exposed to Sub-lethal Concentrations of Chlorpyrifos

Pesticide pollution in aquatic ecosystems is an environmental issue throughout the world. Chlorpyrifos is the most widely used organophosphate pesticide against pests in agricultural farms, orchards of fruit trees and household purposes. Herein, we investigated the impact of sublethal toxicity of this organophosphate on some haematological and biochemical parameters of freshwater fish Cirrhinus mrigala. The acute median lethal concentration (LC50) value of chlorpyrifos calculated by probit analysis was found to be 0.44 mg L-1. On the basis of LC50 value, the fingerlings were exposed to three sublethal concentrations (1/20th, 1/10th, 1/5th) of chlorpyrifos. During the prolonged treatment, haematological parameters including RBC, Hb and Hct values were found to decrease, whereas WBC count was found to increase in pesticide treated fishes. Similarly, indices like MCH and MCHC were significantly lower and MCV was significantly higher when compared to control. In the biochemical study, values of plasma glucose showed a gradual increase, whereas plasma protein levels, albumin and globulin showed a gradual decrease with increase in dose of chlorpyrifos at the end of experimental period. Results of the study clearly revealed that chlorpyrifos can disrupt the haematological and biochemical parameters of Cirrhinus mrigala and these can be used as non specific biomarkers in pesticide contaminated aquatic ecosystems.

Anita Bhatnagar, Navneet Cheema and Abhay Singh Yadav

Study on Ecological Safety Monitoring Practice of County Cultivated Land: A Case Study from Huanghua City, Hebei Province of China

Degradation of ecological environment and health functions of cultivated land can cause great threats to food safety. In order to effectively promote ecological safety monitoring and protection practices of county cultivated land, factors influencing cultivated land ecological environment in Huanghua City (Hebei Province) were analysed. An ecological security monitoring index system for current cultivated land utilization in China was constructed. A database was constructed, and a safety evaluation was carried out based on the agricultural land classification platform by using the single index evaluation method. Evaluation results overlapped in terms of the spatial consistency between management technologies and monitoring results. Cultivated lands were divided according to safety monitoring results. Corresponding management and monitoring measures were proposed. Results demonstrate the excessive application of chemical fertilizer is the leading threat to cultivated land ecological environment in Huanghua City. Arsenic and Ni content have low safety levels in a part of the region. High attention can be paid to their real-time monitoring. Moreover, cultivated land shortage, low unit yield, and small reserves all intensify pressure on cultivated land ecological environment in Huanghua City. Insufficient soil fertility and freshwater shortage are caused by poor physical and chemical properties of soil, and because of this cultivated land ecological environment in Huanghua City has no material basis. The study provides references to set up ecological safety monitoring system for the county cultivated land and practices.

Zhang Guijun, Zhou Zhi, Zhang Pengtao and Zhang Yigong

Feasibility of Banana (Musa sapientum) Trunk Biofibres for Treating Kitchen Wastewater

Kitchen wastewater that is discharged to the environment is one of the contributing factors to water pollution in Malaysia and other developing countries. Various techniques have been employed to remove the pollutants namely, physical, chemical and biological treatment. Biosorption is one of the biological treatments that has emerged as a new technology for the removal and recovery of pollutants, which is more environmental friendly. This study focuses on the effectiveness of the kitchen wastewater treatment systems using low-cost natural fibre of banana trunk (Musa sapientum) as biofibre to remove COD, ammonia nitrogen, suspended solids, turbidity, colour, and oil and grease from kitchen wastewater. The optimum adsorption capacities of banana trunk biofibres were investigated under several conditions, namely, pH, absorbent dosage, speed and contact time. The optimum pH was found to be 6. The experimental results obtained were satisfactory at a dosage of 2 g at 150 rpm. The banana fibres show satisfactory COD removal of 88%, ammonia nitrogen of 84%, suspended solids of 83%, turbidity of 75%, the colour of 67% and oil and grease of 68% respectively. Maximum removal was achieved at 2 hours contact time. The study reveals that the banana fibres could be acceptable for efficient removal of organics and nutrients present in the kitchen wastewater.

Zawawi Daud, Noorain Suhani, Radin Maya Saphira Radin Mohamed and Halizah Awang

Investigation of Landform Classes in Geomorphology Units (Case Study: South of Isfahan, Fars Province, Iran)

The aim of this study is to perform landform classification in the south of Isfahan, Iran. In order to make landform classification, Digital Elevation Models (DEMs) with 30 m resolution and Topographic Position Index (TPI) were used. Also, the percentage of each landforms classes in geomorphological units was determined. The results show that there were ten classes for the study area that consist of classes of canyons, shallow valleys, upland drainages, U-shaped valleys, plains small, open slopes, upper slopes, hills in valleys, midslope ridges and mountain tops. Also, the results show that the highest area of landform was for the classes of plain small for Playa unit. While for pediment unit, the area of landform was canyons, streams, U-shaped valleys, mountain tops and plains small. It was also determined that the highest area of landform for mountain units was mountain tops, canyons and stream landforms.

Mehran Shaygan and Marzieh Mokarram

Geochemical Study of the Groundwater from Coal Bearing Aquifer in Zhuxianzhuang Coal Mine, Northern Anhui Province, China

Major ion concentrations were measured in 22 groundwater samples collected from a coal bearing aquifer in Zhuxianzhuang coal mine, northern Anhui Province, and the ion source and geochemical characteristics were discussed by the methods such as traditional graphic and multivariate statistic analysis. The results showed the presence of three water types, i.e., HCO3-Na, Cl-Na and SO4-Na. The surrounding rock weathering and evaporation, both controlled the chemical characteristics of groundwater, evidenced by the Gibb’s diagrams. In detail, the features of ion ratios such as Ca/Na, HCO3/Na and Mg/Na show that the evaporate dissolution and silicate weathering were the dominant water-rock interactions. Multivariate analysis, such as correlation analysis, cluster analysis and FA analysis were also conducted to reveal the ion source in groundwater, and the Ca2+ and Mg2+ were mainly released from the dissolution of gypsum and/or magnesium and/or anorthite; while the Na+ is influenced by the weathering of feldspar and halite, with the cation exchange in a certain extent. In contrast, the Cl-, HCO3 - and SO4 2- are also controlled by the halite dissolution, silicate mineral weathering and sulphate mineral dissolution, respectively. In addition, the SO4 2- in groundwater could be influenced by the oxidation of pyrite, which is abundant in the coal bearing aquifers.

Jie Ma, Lin-hua Sun, Song Chen, He-rong Gui and Hai-tao-Zhang

Study on Water Environmental Carrying Capacity Based on Improved Catastrophe Theory

The improved catastrophe theory is introduced into the study of water environment carrying capacity. With coupling of 4 subsystems which are, water resource factors, ecological environment factors, social resources allocation capacity factors, social and economic factors as the basic framework, 12 indexes were selected to construct the model of water environment carrying capacity. Based on the characteristics of normalization formula of aggregation, the rating scale refinement method was used to improve conventional catastrophe theory and to obtain the adjusted comprehensive value. Then according to the evaluation habits, fuzzy judgment was selected to determine the evaluation threshold, five grade evaluation was used to evaluate water environment carrying capacity. At the last, the water environment carrying capacity in Yichang city was evaluated, the results show that: during 2010-2015, water environmental carrying capacity in Yichang city was on the rise, but in 2020 the Yichang city water environmental carrying capacity will decrease sharply. We need to strengthen environmental protection and governance level.

Xin Huang, Hai-tao Chen and Zheng-ying Guan

Radiation Dose to the Populace in Southern Peninsular India Through Foodstuff

In an environment with the presence of elevated levels of primordial radionuclides, food is an important route by which radionuclides enter the body. The primary aim of the study was to estimate the dose characteristics received by typical members of the society with average food habits and living in the high background radiation area. The concentrations of 226Ra, 238U, 228Ra, 232Th and 40K were determined in food crops, fish, drinking water and soil. Analyses of food samples were done using gamma ray spectrometry. The estimated total annual average effective dose due to the ingestion of 238U, 232Th and 40K in fruits, vegetables, cereals, pulses and fish was 0.57 ± 0.1 mSv/y based on the dietary habits of the population in the area.

Reeba Maria Jose and Jojo P. J.

Study on Sources, Causes and Countermeasures of Water Pollution in Rural Areas of Guangxi in China

With the gradual acceleration of urbanization and industrialization, considerable changes have taken place in the production and lifestyle of peasants. However, industrial wastes, domestic and production wastes, and livestock effluent discharge are increasing gradually, thereby intensifying water pollution in rural areas day by day. Water pollution sources and causes in rural areas of Guangxi Autonomous Region were analysed in the research, and the countermeasures were proposed from multiple perspectives. Results demonstrate that wastewater and waste gas emission by township enterprises, wanton production of livestock breeding, large-scale generation of agricultural nonpoint source pollutions, and rural domestic sewage and waste are the main sources of water pollution in rural areas. The long-term existences of an urban-rural dual economic structure, imperfect laws and management systems, and restrictions on rural development have created the current conditions of the water environment in rural areas. Management strategies for the rural water environment are proposed, such as coordinating economic development and environmental protection, improving treatment efficiency of rural domestic waste sewage, increasing the technological content of agricultural production, and enhancing pollution regulation of township enterprises. The conclusions in this study expand the research perspectives and enrich the research content on water pollution problems in rural areas.

Yanli Peng

Methane Capturing Using Anaerobic Digestion Technology: A Way Towards Mitigating Green House Gases in Limpopo Province, South Africa

South Africa is not only a contributor to greenhouse gas emissions (GHG), it is also particularly vulnerable to the effects of climate change on health, livelihoods, water and food, with a disproportionate impact on the poor, especially women and children. One of the mandates of the national government is to reduce GHG emissions by 34% by 2020 and 43% by 2025. Global anthropogenic emissions of CH4 are estimated at 323 Mt in 2005 and expected to increase by 28% to 414 Mt in 2030, when assuming no further implementation of control. Globally, efforts are being made to control GHG emission from various sources. The methane that is exhaled by the ruminant animals is impossible to capture, but a large proportion of methane produced by the manure of these animals can be captured through anaerobic digestion technology. The use of traditional fuels, like wood, animal waste and crop residues has local environmental impacts due to significant emission of pollutants. To overcome the above, biogas program has been established through research study which covers the whole province of Limpopo. This study focuses on knowledge dissemination of methane recovery projects in the province with the intention of reducing inefficient sources for energy use. The study also considers pollutants that are contributing to global warming resulted from GHG emitted from activities that generate waste. It also shows some contribution made by various organization and departments in mitigating GHG emissions in South Africa in general, and in particular Limpopo province.

Vhutshilo Nekhubvi and David Tinarwo

Equilibrium and Kinetic Studies on Removal of Cd2+ Ion in Aqueous Solution by the Multiple Modified Diatomite

The problem of metal pollution was regarded by many researchers for a long time. The wastewater containing metal ions must be treated. A composite modification technology of acid activating, sodium hydroxide and baking was applied to improve the diatomite adsorption ability, and a modified diatomite was prepared. The adsorption experiment of the metal wastewater by the modified diatomite was carried out in detail. The modified diatomite owned the high adsorption capacity of the Cd2+ ion. The operating parameters, such as contact time, concentration of Cd2+ ion and reaction temperature, had an important effect on the removal of the Cd2+ ion in aqueous solution. The adsorption of Cd2+ ions onto the modified diatomite was 9.65 mg/g. The adsorption process fits well with the Langmuir isotherm model and the pseudo-second-order kinetics model and it implied that the adsorption was mainly a physical process. The adsorption process is chemisorption, which involves a sharing of electrons between the adsorbate and the surface of the adsorbent.

Hai Wang, Chengcai Huang, Muqing Qiu and Chunxia Hu

Different Types of Inoculated Sludge for Chemical Wastewater Treatment: Acclimation and Microbial Community

A laboratory-scale reactor for hydrolytic acidification-biological contact oxidation (A/O) was constructed and inoculated with different types of sludge to treat synthetic chemical wastewater. Biodegradation of degradation-resistant organic matters, such as epoxy propane, glycerol and aniline, in saline water were evaluated, and acclimation of chemical and sewage seeding sludge was contrastively analysed. An average COD reduction rate of 93% by A/O reactor was achieved after the 22 d and 31 d of acclimation of chemical and sewage seeding sludge, respectively. Salt-tolerance acclimation of chemical seeding sludge required 35 d and 14 g/L NaCl for effective pollution degradation, whereas, chemical sludge required 32 d and had salt-tolerance of 16 g/L NaCl. The microbial community structure differed between chemical and sewage seeding sludge. Sewage sludge presented higher average Shannon diversity index (3.34) and more uniform microbial distribution than chemical sludge. The results can provide the basis for selection, cultivation and acclimation of inoculation sludge for field debugging of treating chemical wastewater through biological membrane method.

Dong Yingbo and Lin Hai

Analysis on Sensitivity of Parameters in Numerical Simulation of Dissolved Gas Supersaturated in Spillway Discharges

High concentration of total dissolved gas (TDG) in the tailrace of high dam may induce gas bubble disease to the fish for lethal effect. Thus, the distribution of the TDG concentration in the plunge pool and immediately in the downstream of dam becomes critical. In order to proves to be effective and convenient, but the determination of the model parameter relies on field observed data and the calibration of the parameter is time-consuming. In this paper, the predictive relationship of the parameter in the TDG transport equation with a source term is developed. Observed field data from six spillways in China were used to fit the source parameter that the predictive relationship needed. The inclusion in the predictive relationship will allow for the estimation of the source parameter representing the mass transfer between bubble/water interfaces and may give an insight into the mitigation of high TDG concentration downstream of spillways.

Hui-xia Yang, Ran Li and Juan Wei

Effects of Combined Pretreatment of Sewage Sludge on Biogas Production in Anaerobic Digestion Process

Biogas recovery by anaerobic digestion was seen as an ideal way to treat biomass waste-sewage sludge, but has some limitations, such as the low efficient biogas production. In this paper, the combined (alkaline and ultrasonic) pretreatment was proposed for effective sludge anaerobic digestion and the effect of these pretreatments was investigated. It can be seen that this treatment effectively led to the increase of soluble chemical oxygen demand (SCOD) and volatile fatty acids (VFA) concentration. The high concentration of VFA led to an increase in biogas production. Under the optimum combined pretreatment condition (under 6000 kJ/kg TS and with 0.15 mol/L NaOH), the biogas production was nearly 8 times higher than the raw sample. Besides, the SV of sludge was reduced and the settling characteristics of sludge were improved. The results indicated that the combined pretreatment could be an effective method for improving biogas yield.

Wei Na

Improvement and Compilation of Density Management Diagram of Larix principis-rupprechtii Mayr Forest in Northern Hebei

Stand density management diagram is an average stand model that indicates forest growth at different stages, providing a scientific basis for the mastery of stand density, the prediction of forest growth, the control of water conservation and the measurement of carbon storage. Larch forests in northern China, that is faced with such environmental problems as sand storm and smog, serve the functions of wind break and sand fixation as well as water conservation. This paper makes some improvement to the density management diagram by adding a crown width line to obtain appropriate stand density. In this research: 1. A stand density management diagram is constructed to show growth information in Saihanba Forestry, Hebei province, into which contour lines of constant tree height, degree of closeness, natural thinning, diameter at breast height and crown width are included. 2. The planting density should be set at 3,000 plants.hm-2 and 300 m3 timbers are expected to be obtained from harvest cuttings. Two harvest cuttings should be arranged between 16 and 29 years, with cutting intensities of 28.4% and 36.4%, respectively. The density management diagram is to be constructed to predict the growth of Larch forests in northern China, so as to provide reference for the making of forest management plans and the reasonable arrangement of stand density.

Jiancheng Liu, Baoguo Wu and Chen Dong

Decomposition of Inorganic Nutrient Nitrogenous Matter from Lightly Polluted Wastewater Using Electrochemical System

In this research, electrochemical system was adapted to decompose lightly polluted wastewater (LPW). The major pollutants of LPW were removed and its removal effects were investigated. Meanwhile, courses of the electrochemical reaction for nitrogen and phosphorus were discussed. Experiments results exhibited that the best removal rates of NH3-N and TN respectively were 100% and 90.9% after dosing NaCl. In addition, under the condition of different electrolysis time, removal of pollution was better than without NaCl, namely, the pollution was removed rapidly through electrolysis when other experimental conditions remained invariable. Meanwhile, the optimal operation condition could be confirmed while the current density was 7.4mA/cm2, the cell voltage was 6 V, electrolysis time was 30 min, the plate distance was 1cm and the ratios of concentration of NH4 + and Cl- were 1:3, respectively. Besides, the removal effects for nitrogenous compounds as the change of the chloride concentration were investigated, too. And the results exhibited that higher the chloride concentration in the wastewater was, the higher the removal rate for nitrogenous compounds was. The removal rates of nitrogenous compounds increased with the increasing of cell voltage. Therefore, the influence of every factor could be obtained through considering the power consumption of per ton wastewater treatment.

Hao Wang, Bingxu Quan, Huiyuan Zhong, Shan Yan and Meiyuan Yang

Study on Preparation and Adsorption Properties of Diatomite-Based Porous Ceramsite

Using diatomite as the main material, diatomite-based porous ceramsite was prepared by wet grinding, molding by rolling and high-temperature calcinations. The structure and properties were characterized by X-ray diffraction, Scanning Electron Microscope, Mercury Injection Apparatus and so on. The ultraviolet-visible spectrophotometer was used to analyse the adsorption properties of diatomitebased porous ceramsite on Cu2+. The results show that the pore size distribution of materials is 300~3500 nm, the specific surface area is 6.14 m2/g, and the pore porosity is 47.8%. Plenty of unsaturated bonds, such as -OH, Si-O-Si and O-Si-O, cluster on the surface of ceramsite. The removal rate of Cu2+ reaches 92.5%.

Ruqin Gao, Yiming Gu , Guoting Li and Qian Sun

Disturbance Status of Secondary Forest of Castanopsis on Jiangle Forest Farm, Fujian Province, China

The study was conducted on the secondary forest of Castanopsis on Jiangle Forest Farm in Sanming City, Fujian Province, China to determine the vegetation disturbance status. Twenty one quadrats (20 m × 30 m) were sampled and recorded the vegetation parameters such as DBH, height, seedling and sapling density of woody species, and location and altitude of each quadrat. An evaluation system was established to assess the disturbance to the secondary forest based on the standard quadrat of the Jiangle Forest Farm. Using the evaluation system, we found that the Castanopsis forests on the farm were mostly pristine or sustained minor disturbance. These results suggest that secondary forests of Castanopsis must be managed and protected according to the disturbance status. More basic and applied researches should be conducted, for sustainable development of the forest and its products.

Zuo Zheng and Zheng Xiao-xian

China’s Carbon Emission Productivity and its Development Tendency from an Environmental Protection Perspective

Burning coal, oil, natural gas and trees produce large amounts of carbon dioxide and methane. After these gases enter the atmosphere, the earth heats up and the carbon cycle becomes unbalanced, thereby resulting in global warming and deterioration of the ecological environment. To further analyse China’s carbon emissions, this study calculated China’s carbon emission productivity and predicted China’s carbon emission productivity level and growth rate for a certain period. Results show that in 1990-2016, China’s carbon emission productivity has continued to grow, and the actual GDP brought by unit carbon emissions has increased continuously. Moreover, China’s carbon emission productivity is expected to continuously increase. China can increase carbon emission productivity by improving energy efficiency, formulating and implementing carbon budget programs at the micro level, and implementing carbon taxes. Here, we expand the research perspective of carbon emissions, which has a certain reference value to further study China’s carbon emissions and protect the environment.

Jian Jin, Xiaoyi Ma and Yashuo Gao

Spatial Assessment of Ecological Vulnerability in Fuzhou District in China Using Remote Sensing and GIS

With the growth of global population and intense land use changes, the problem of ecological vulnerability has become prominent. Assessment of ecological vulnerability bears significance in protection and restoration of the ecological environment. Assessment results for a given area can reveal regional characteristic differences in system vulnerability and provide basis for the rational use and protection of the natural environment. To analyse the ecological vulnerability in Fuzhou district in China and its causes, systematic assessment and zoning of ecosystem vulnerability were proposed. Using the remote sensing and geographic information system technologies, ecological vulnerability was spatially, explicitly, and comprehensively assessed. Results showed that the most vulnerable areas of Fuzhou district include Pingtan Comprehensive Experimental Area, Fuqing City, Fuzhou City and Changle City. Counties of Yongtai, Minhou and Minqing feature good vegetation coverages and low ecological vulnerability. In Fuzhou City, three zones, namely, Taijiang, Gulou and Cangshan Zones, feature high or extremely high percentage vulnerability. The other two zones comprise better ecosystems. Analysis of correlation coefficients between vulnerability value and various indices showed distinct factors of ecological vulnerability for each region. The main factors affecting the ecosystems in Fuqing, Jin’an Zone, and Changle City include climate, vegetation and soil, respectively, whereas the factors that simultaneously affect the ecosystem in Cangshan Zone consist of soil, land use, topography and vegetation. The key challenge in improving ecological vulnerability of these areas is optimization and coordination of land use/coverage under natural conditions. The results can provide basis and reference for future research and relevant formulation, such as the mode of selection of resource utilization and environmental protection, and improvement of key factors.

Hongmei Zhang, Jiwen Wu, Yang Gao and Zhuo Chen

Using Bio-mulch for Dust Stabilization (Case Study: Semnan Province, Iran)

The use of bio-mulches to stabilize dust has gained worldwide attention during the last five decades. We report herein on a study of the application of 20 new types of bio-mulches as stabilizing agents. To understand the effect of new bio-mulches on dust stabilization, several tests have been applied for strength, structural stability and wind erosion. Fourier Transforms Infrared and Scanning Electron Microscopy have been applied on untreated and treated soil samples. Bio-mulch modified mechanisms have been analysed. Wind erosion and aggregate stability test results clearly indicate that certain biomulch specimens were useful in controlling dust in relatively arid and semiarid areas. The Scanning Electron Microscopy images show that when bio-mulches were applied to sandy soil, some voids in the soil were filled, while other parts stayed on the surface of soil aggregates. The molecular structure of polyelectrolyte groups reacted chemically with positive ions of the clay grain and created physicochemical bonds between molecules and soil aggregates with ionic, hydrogen or Vander Waals bonds. Untreated samples had no bonds between molecules and soil aggregate, and the strength and erosion resistance were weak.

Davood Namdar Khojasteh, Hossein Ali Bahrami, Mehran Kianirad and William Sprigg

The Mechanism of Denitrification by Plasma with Different Background Gases in Clearing of the Flue Gas for NOX

The denitrification rate of NO by using dielectric barrier discharge plasma method with four different background gases, such as N2/NO/O2, N2/NO/O2/NH3, N2/NO/O2/NH3/SO2 and N2/NO was studied. The results showed that the denitrification rate of four kinds of background gas increases with the increase of power and the increase of the 20W~40W range was obvious. The NO was dislodged by active species N which was electrolysed from N2 in the N2/NO system. The greater the initial concentration of NO, the lower the initial denitrification rate. But the stable NO removal rate reached almost 100%. The greater the concentration of O2, the lower removal rate of NO and show that the removal of NO was blocked by O2 in the N2/NO/O2 system. Compared to the N2/NO system, the denitrification rate was decreased when added O2 in the system. The higher the concentration of NH3, the higher denitrification rate in the N2/NO/O2/NH3 system. And the NO was removed by NH and NH2 that was electrolysed from NH3. The removal rate was significantly improved compared with the N2/NO/O2 system. The competitive existence between SO2 and NO in the electrolysis reaction, resulted the denitrification rate decrease in the N2/NO/O2/NH3/SO2 system. And the greater the concentration of SO2, the lower the denitrification rate of NO.

Zhang Lei, Chen Jihao, Sha Xiangling, Zhang Lei, He Huibin, Ma Zhenhua and Yang Dan