膜生物法降解TNT弹药销毁废水的重要影响因素

采用水解酸化一好氧膜生物工艺对弹药销毁废水中TNT进行降解试验研究。结果表明,共代谢外加碳源对TNT的生物降解影响显著。无共代谢外加碳源的情况下,HRT=40h,TNT的去除率仅为53．4％。有共代谢外加碳源的情况下,外加碳源COD与TNT提供COD比值宜大于4．8,系统对TNT的去除率可高达99％。温度对水解酸化影响重大,当温度低于15℃时,水解酸化对TNT去除率低于33．3％,而当温度高于20℃时,水解酸化对TNT的去除率不小于83％。     

气液混合脉冲放电等离子体再生活性炭系统优化研究

为了丰富活性炭再生方法,并拓宽脉冲放电等离子体技术的应用范围,研究建立了气液混合的脉冲放电等离子体体系,将其用于吸附酸性橙II (AO7)饱和活性炭的再生。通过实验,考察了气液混合方式、脉冲电压、脉冲频率和电极间距等关键参数对活性炭再生效果的影响规律,进而对该再生体系进行优化。研究结果表明,气液分离式的气液混合方式较利于该脉冲放电等离子体体系中活性炭的优化;在一定范围内提高脉冲电压,可以提高其中活性炭的再生效果;高的脉冲频率下活性炭再生效果好;气液混合脉冲放电等离子体体系中适宜于活性炭再生的电极间距为20 mm。     

Characterization of coal gangue and coal gangue-based sodalite and their adsorption properties for Cd2+ ion and methylene blue from aqueous solution

Journal of Material Cycles and Waste Management - Synthesis and development of high-efficiency and low-cost adsorbents for treating of the wastewater containing heavy metal ions and/or dyes has...     

Preparation of hydrogen-rich gas from waste polyurethane foam by steam gasification and catalytic reforming in a two-stage fixed bed reactor

Journal of Material Cycles and Waste Management - The reclamation of waste rigid polyurethane foam (WRPUF) is capable of realizing both circulations of waste and protection of the environment. In...     

NO oxidation performance and kinetics analysis of BaMO3 (M=Mn,Co) perovskite catalysts

Environmental Science and Pollution Research - Perovskite is an efficient and emerging catalyst for NO oxidation. In this study, BaMnO3 and BaCoO3 perovskite catalysts were synthesized by the...     

Antibiotic contamination in a typical water-rich city in southeast China: a concern for drinking water resource safety

Abstract

The occurrence and distribution in the aquatic environment of Nanjing of 49 antibiotics from seven therapeutic classes were investigated using an improved analytical method developed for multiclass target analysis. The results showed that these antibiotics are widely present in the water bodies of this city, with a total concentration of up to 1.958?μg L^?1. The most abundant class was tetracyclines, contributing 43.7% to the total antibiotic burden. Lincomycin was detected in all samples, and the detection rate of clindamycin was 90.5%. An exploratory analysis of the data points was performed by unsupervised pattern recognition (hierarchical cluster analysis, HCA) in an attempt to clarify the pollution level in different sampling areas, and robust cluster solutions grouped the data according to their different antibiotic contaminant profiles. The safety of drinking water resources was emphasized, and the rivers, as the main receiving water body for treated and untreated wastewater in this city, were more seriously contaminated than the surrounding lakes and reservoir, not only in concentration but also in detection frequency, in our study as well as in similar research studies. A correlation analysis between the presence of antibiotics and the environmental factors was conducted, and it was found that antibiotic contamination and water quality were closely connected; the better the water quality, the lower the antibiotic contamination. Positive correlations existed between the antibiotics and tested heavy metals, as well as between antibiotics and boron and arsenic. However, whether these correlations resulted from their reaction or a common source was difficult to determine, and the mechanism requires further exploration.     

Performance of Streptomyces pactum–assisted phytoextraction of Cd and Pb: in view of soil properties,element bioavailability,and phytoextraction indices

Environmental Science and Pollution Research - Microbe-assisted phytoremediation provides an eco-friendly and cost-effective approach to reclaim Cd- and Pb-contaminated soils. In this work,...     

Nitrogen removal from recycled landfill leachate by ex situ nitrification and in situ denitrification

A three-compartment system, comprising a landfill column with fresh municipal solid waste, a column with a well-decomposed refuse layer as methane producer, and a sequential batch reactor as ex situ nitrifying reactor, was employed to remove nitrogen from municipal solid waste leachate. Since food waste comprised a major portion of refuse collected in Shanghai, an intense hydrolysis reaction occurred and caused the rapid accumulation of ammonia nitrogen (NH(3)-N) and total organic carbon in the leachate. This paper discusses the role of the three mentioned units and the design and operation of the proposed system. With most NH(3)-N being converted to nitrite nitrogen (NO(2)(-)-N) or nitrate nitrogen (NO(3)(-)-N) by the nitrifying reactor, and with the well-decomposed refuse layer transforming most dissolved organic compounds to CO(2), carbonates and methane, it was found that the fresh refuse column could efficiently denitrify the hydrolyzed nitrogen to N(2) gas. The role of the three mentioned units and comments on the design and operation of the proposed system are also discussed.     

Depth-dependent changes in chlorophyll fluorescence number at a Sargasso Sea station

Chlorophyll a-specific in vivo fluorescence exhibited depth-dependent changes in a Sargasso Sea phytoplankton community, decreasing from a maximum value at the surface to a minimum at 90m, and then increasing again below 90 m. This distribution pattern was not explained by irradiance conditions, diurnal variability, senescence in the deep population, or changes in light-absorption efficiency of chlorophyll a. However, a significant positive correlation was found between mean phytoplankton cell size and fluorescence number in the upper euphotic zone, where nutrient concentrations were low. We hypothesize that the direct cause for this observed correlation was nutrient limitation. In this picoplankton-dominated community, packaging effect was minimal. Under nutrient-limiting conditions, as mean cell size increases photosynthetic efficiency decreases and therefore fluorescence number increases. In the lower euphotic zone where nutrients were not limiting, changes in fluorescence number exhibited weak size-dependence and appeared to be related to species compositional changes.