Time filter

Source Type

Gan L.,Guilin University of Technology | Gan L.,Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology | Gan L.,CAS Nanjing Institute of Soil Science | Gan L.,University of Kiel | And 3 more authors.
Soil Science | Year: 2013

To better understand the effects of different grazing intensities on soil-water dynamics and its budget in Inner Mongalia, China, five sites, under two representative vegetation types, Leymus chinensis (LC) and Stipa grandis (SG), were investigated: ungrazed sites since 1979, LCUG79 and SGUG79, a winter grazed site (LCWG), a continuously grazed site (SGCG) defined as a moderate grazing intensity, and a heavily grazed site (LCHG). Soil, plant, and meteorological data were collected for use in modeling soil-water content and its budget during growing seasons from 2008 to 2009 using the HYDRUS-1D. The soil-water content in 2010 was simulated using annually averaged values of initial and boundary conditions. Our results showed that grazing reduced total pores and saturated hydraulic conductivity but ungrazed sites benefited from natural recovery. Greater transpiration was observed at the SGCG site when compared with the LCWG and LCHG sites. At the two ungrazed sites, transpiration was greater in the SG region as compared with the LC region. Rainfall reduced the difference between potential and actual evapotranspiration through increasing plant-available water. The simulation of soil water in 2010 using annually averaged parameters was determined to be an acceptable alternative to actual on-site observation. Our data suggest that selection of an appropriate grazing intensity may be possible via simulation modeling for use in making land management decision, especially in the absence of on-site observations as often is the case from such remote regions. Copyright © 2013 by Lippincott Williams & Wilkins. Source

Li H.,Guilin University of Technology | Xie Q.,Guilin University of Technology | Xie Q.,Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology | Chen N.,Guilin University of Technology | And 2 more authors.
Key Engineering Materials | Year: 2016

Pollution of heavy metals has become a serious environmental problem and it needs to be solved as soon as possible. Diatomite is a kind of biogenic rock and it is siliceous and sedimentary. There is abundant diatomite resource in China. Diatomite has distinctive structure of diatom monoblock. It has strong adsorbability, its specific area is large and it has high porosity. Its surface adheres a lot of active groups and negative charge. Diatomite with proper modification would show outstanding absorption effect of heavy metal ions. This paper reviewed the absorption efficiency of heavy metal ions on diatomite modified by metallic oxide, acids and bases, acticarbon, calcium carbonate and organics, the results would offer references for related researches. At last, this paper takes the outlook for the modified methods and application prospects of diatomite in wastewater treatment of heavy metals. © 2016 Trans Tech Publications, Switzerland. Source

Song B.,Guilin University of Technology | Song B.,Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology | Zeng W.,Guilin University of Technology
Chinese Journal of Environmental Engineering | Year: 2016

The transform and stabilization process of external lead in red and gray soil of southern part of China were studied through 60 days of soil incubation. The results show that after the additions of high concentrations of external lead, soil available Pb showed a tendency of decrease at first and stable at last during soil incubation and soil DTPA-Pb showed a stable trend during the first 30 days. The results of the Form-BAC risk evaluation method show that the concentrations of Pb significantly decreased in the exchangeable and carbonate fractions lowering the risk of human health and ecology in tested soil under natural conditions, and provide the scientific basis for the engineering application of remediation of lead contaminated soil. © 2016, Science Press. All right reserved. Source

Wu X.H.,Guilin University of Technology | Wu X.H.,Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology | Zhang J.,Guilin University of Technology
Applied Mechanics and Materials | Year: 2014

overmuch heavy metal is one major restrictive factor for land application of sewage sludge. The environmental behavior of heavy metals depends strongly on their specific chemical fraction or binding state in sludge. The present paper gives an overview of recent researches about the chemical speciation of heavy metals in sludge. A detailed discussion was also made on the various problems associated with the distribution of chemical fractions of heavy metals in sewage sludge, which need to be addressed while exploring more efficient treatment of removing heavy metal. © (2014) Trans Tech Publications, Switzerland. Source

Liu B.,Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology | Liu B.,Chongqing University | Peng X.Y.,Chongqing University | Tian Q.,Chongqing University | Zhao H.,Chongqing University
Applied Mechanics and Materials | Year: 2014

Landfill leachate treatment is a major problem to be solved in the field of environmental protection, and ammonia nitrogen is one of the major pollutants in landfill leachate, whose processing technology needs further improvement. In this paper, ultrasound/ultraviolet co-oxidation technology was directly applied to the treatment of high concentration landfill leachate without the pretreatment operations of dilution, filter, and adjusting the pH conditions. The results showed that: ultrasonic and ultraviolet had certain effects on the ammonia nitrogen removal, and the ammonia nitrogen removing effects became better when the ultrasonic power was greater, or the ultraviolet wavelength was shorter. When the ultrasonic power was 100 W, the ammonia nitrogen removal efficiency was 25.2%, and the UV of 254 nm could decompose 20.2% of the ammonia nitrogen in landfill leathate. In the condition of aeration, ultrasonic and ultraviolet had good synergistic effect on leachate ammonia nitrogen treatment. When the ultrasonic power was 100 W, UV wavelength was 254 nm, and the aeration rate was 150 L/h, the ammonia removal efficiency of high concentration leachate (ammonia nitrogen concentration of 1800 mg/L) reached 98.5% after 6 hours. The paper's research results provide a useful reference for the removal of landfill leachate ammonia nitrogen. © (2014) Trans Tech Publications, Switzerland. Source

Discover hidden collaborations