Time filter

Source Type

Zhao X.,Chinese Research Academy of Environmental Sciences | Zhao X.,State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution | Zhao X.,Beijing Normal University | He X.,Chinese Research Academy of Environmental Sciences | And 11 more authors.
Waste Management | Year: 2016

The humification of water extractable organic matter (WEOM) by microorganisms is widely used for assessing compost maturity and quality. However, the effect of bacterial and fungal community dynamics on humification of WEOM was not yet explored fully. Here, we used canonical correspondence analysis (CCA) and redundancy analysis (RDA) to investigate the link between bacterial and fungal community dynamics and humification process of WEOM, respectively. Results showed that water-soluble carbon (WSC), humification degree, molecule weight and abundance of aromatic carbon were significantly related to bacterial community (p . <. 0.05), while the protein-like materials were statistically influenced by fungal community (p . <. 0.05). Both bacterial and fungal communities significantly affected the abundance of oxygen-containing functional groups and humic-like materials (p . <. 0.05). These humification parameters were most likely to be influenced by some of bacterial and fungal species at different composting stages. . Lactobacillus, . Aspergillus fumigatus and . Galactomyces geotrichum can enhance the degradation of WSC and protein-like materials at the early composting. . Bacteroidetes and . Firmicutes could promote the increase of aromatic carbon, oxygen-containing functional groups, humification degree and molecular weight of WEOM during the initial fermentation stage. . Cladosporium herbarum and . Chaetomium globosum could be the dominant controllers at the second fermentation for accelerating. the formation of oxygen-containing functional groups and humic-like materials of WEOM, respectively. Our results suggested that regulation for the dynamics of these special bacterial and fungal species at different composting stages might be a potential way to accelerate humification of municipal solid waste composting. © 2016. Source

Yu M.,State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution | Yu M.,Chinese Research Academy of Environmental Sciences | Yu M.,Changzhou University | Zhang H.,Chinese Research Academy of Environmental Sciences | And 7 more authors.
Chinese Journal of Environmental Engineering | Year: 2016

In this study, field investigations and laboratory analyses were combined to analyze the concentrations and pollution levels of Cr, Ni, Cu, Zn, Cd, Pb, As, and Hg in typical agricultural soils in the southern part of Jiangsu Province, China. The ecological risk of heavy metals in farmland soils was assessed using single-factor pollution, Nemerow pollution, and potential ecological risk indices. Three major factors were further selected after principal component analysis to determine the possible origins of heavy metals in soil. Our results showed that the concentrations of all heavy metals in farmland soils are above the threshold values, and that the pollution level in the topsoil is higher than that in the subsoil. The pollution levels of all heavy metals based on the single-factor pollution index reflected clean levels. The Nemerow pollution index was 0.46, which indicates low pollution levels. Potential ecological risk assessment indicated moderate risk of soil pollution by heavy metals, and the risk by pollutant species was in the order: Cd>Hg>As>Cu>Pb>Ni>Cr>Zn. Principal component analysis revealed that Hg, As, and Cr pollution of soils is mainly caused by industrial emissions, whereas Cd and Pb pollution is mainly caused by extreme agricultural and residential activities. Ni, Zn, and Cu pollution can be attributed to natural causes. Comprehensive evaluation showed that heavy-metal pollution in the study area has reached alarming levels, and that heavy metals are concentrated in farmland soils that experience urbanization and long-term modern farming activities. Thus, effective farmland soil management is necessary to ensure security production, control soil pollution sources, and implement standard agricultural production. © 2016, Science Press. All right reserved. Source

Li J.,Beijing Normal University | Li J.,Chinese Research Academy of Environmental Sciences | Li J.,State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution | Yang Y.,Beijing Normal University | And 17 more authors.
Science of the Total Environment | Year: 2016

This paper presents a system for determining the evaluation and gradation indices of groundwater pollution intensity (GPI). Considering the characteristics of the vadose zone and pollution sources, the system decides which anti-seepage measures should be implemented at the contaminated site. The pollution sources hazards (PSH) and groundwater intrinsic vulnerability (GIV) are graded by the revised Nemerow Pollution Index and an improved DRTAS model, respectively. GPI is evaluated and graded by a double-sided multi-factor coupling model, which is constructed by the matrix method. The contaminated sites are categorized as prior, ordinary, or common sites. From the GPI results, we develop guiding principles for preventing and removing pollution sources, procedural interruption and remediation, and end treatment and monitoring. Thus, we can select appropriate prevention and control technologies (PCT). To screen the technological schemes and optimize the traditional analytical hierarchy process (AHP), we adopt the technique for order preference by the similarity to ideal solution (TOPSIS) method. Our GPI approach and PCT screening are applied to three types of pollution sites: the refuse dump of a rare earth mine development project (a potential pollution source), a chromium slag dump, and a landfill (existing pollution sources). These three sites are identified as ordinary, prior, and ordinary sites, respectively. The anti-seepage materials at the refuse dump should perform as effectively as a 1.5-m-thick clay bed. The chromium slag dump should be preferentially treated by soil flushing and in situ chemical remediation. The landfill should be treated by natural attenuation technology. The proposed PCT screening approach was compared with conventional screening methods results at the three sites and proved feasible and effective. The proposed method can provide technical support for the monitoring and management of groundwater pollution in China. © 2015. Source

Yu M.-D.,State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution | Yu M.-D.,Changzhou University | Yu M.-D.,Chinese Research Academy of Environmental Sciences | He X.-S.,State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution | And 15 more authors.
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2016

Typical urban polluted city river-Hebei Xiao River water CDOM of the source, spatial and temporal distribution characteristics were studied by fluorescence excitation-emission matrix spectra (EEM), ultraviolet-visible (UV-vis) combine with parallel analysis (PARAFAC), principal component analysis (PCA), and the correlation of CDOM and water chemical indicators was investigated as well. The results showed that Xiao River water CDOM was mainly microbial-derived for rencent human emission of water. The concentration of CDOM was at higher level in fall (August) and winter (November), but low in the spring (February) and summer (May). Variation characteristics of space redered on first increase and then decreases from upstream to downstream. Four florescence components were identified, and component 1 (fulvic acid), component 2 (humic) and component 3 (humic acid) originated from humic-like substance, while component 4ascribed to protein-like materials. The components had difference source and distribution was variable and changed with time. In addition to summer the protein-like and humic-like components had similar sources, especially with the humic acid components. The concentration of protein-like was higher in spring and winter, but lower in the summer and autumn. In the Xiao River fluorescent substance had greatly contribution of ammonia and nitrite, and the humic-like had an important influence of chemical oxygen demand. The results demonstrated that, EEM and UV-vis spectra coupled with PARAFAC, PCA and cluster analysis can be used to analyze the seasonal variation of the CDOM and identify the spatial distribution of pollution in the Xiao River. © 2016, Chinese Society for Environmental Sciences. All right reserved. Source

Discover hidden collaborations