Sorption behavior of dibutyl phthalate and dioctyl phthalate by aged refuse

Sorption is a fundamental process controlling the transformation, fate, degradation, and biological activity of hydrophobic organic contaminants in the environment. We investigated the kinetics, isotherms, and potential mechanisms for the sorption of two phthalic acid esters (PAEs), dibutyl phthalate (DBP) and dioctyl phthalate (DOP), on aged refuse. A two-compartment first-order model performed better than a one-compartment first-order model in describing the kinetic sorption of PAEs, with a fast sorption process dominating. Both the Freundlich and Dubinin–Astakhov (DA) models fit the sorption isotherms of DBP and DOP, with the DA model being of a better fit over the range of apparent equilibrium concentrations. The values of the fitting parameters (n, b, E) of the PAEs suggest nonlinear sorption characteristics. Higher predicted partition coefficient values and saturated sorption capacity existed in refuse containing larger quantities of organic matter. The sorption capacity of DOP was significantly higher than that of DBP. PAE sorption was dependent on liquid phase pH. Desorption hysteresis occurred in PAE desorption experiments, especially for the long-chain DOP. PAEs may therefore be a potential environmental risk in landfill.     

Enhanced reductive dechlorination of polychlorinated biphenyl-contaminated soil by in-vessel anaerobic composting with zero-valent iron

Anaerobic dechlorination is an effective degradation pathway for higher chlorinated polychlorinated biphenyls (PCBs). The enhanced reductive dechlorination of PCB-contaminated soil by anaerobic composting with zero-valent iron (ZVI) was studied, and preliminary reasons for the enhanced reductive dechlorination with ZVI were investigated. The results show that the addition of nanoscale ZVI can enhance dechlorination during in-vessel anaerobic composting. After 140 days, the average number of removed Cl per biphenyl with 10 mg g^?1 of added nanoscale ZVI was 0.63, enhancing the dechlorination by 34 % and improving the initial dechlorination speed. The ZVI enhances dechlorination by providing a suitable acid base environment, reducing volatile fatty acid inhibition and stimulating the microorganisms. The C/N ratios for treatments with the highest rate of ZVI addition were smaller than for the control, indicating that ZVI addition can promote compost maturity.     

印染生化尾水反渗透深度处理工艺膜污染成因分析

为阐明印染生化尾水反渗透膜处理时膜污染的成因,使用小试装置进行40h膜污染实验,研究膜污染速率、污染程度以及可逆性,同时应用扫描电子显微镜一EDS能谱仪、傅里叶变换红外光谱仪、电感耦合等离子发射光谱仪、总有机碳测定仪等仪器对进水水质、膜表面污染物的形态和组成等进行表征。结果表明,膜表面主要是碳酸钙无机污染和钙与有机物络合污染,无机污染占主导,且可逆性差,有机污染物主要含有--OH和～c-c官能团;单一去除废水中有机物污染物（TOC去除率达88％）对膜污染缓解不明显,但钙离子的去除可显著缓解膜污染,膜通量可增加72．6％;同时去除有机物和钙离子,膜通量可增加80．4％。     

印染生化尾水反渗透深度处理工艺膜污染成因分析简

为阐明印染生化尾水反渗透膜处理时膜污染的成因,使用小试装置进行40 h膜污染实验,研究膜污染速率、污染程度以及可逆性,同时应用扫描电子显微镜-EDS能谱仪、傅里叶变换红外光谱仪、电感耦合等离子发射光谱仪、总有机碳测定仪等仪器对进水水质、膜表面污染物的形态和组成等进行表征。结果表明,膜表面主要是碳酸钙无机污染和钙与有机物络合污染,无机污染占主导,且可逆性差,有机污染物主要含有—OH和—CC官能团;单一去除废水中有机物污染物（TOC去除率达88%）对膜污染缓解不明显,但钙离子的去除可显著缓解膜污染,膜通量可增加72.6%;同时去除有机物和钙离子,膜通量可增加80.4%。     

孔径对微孔曝气充氧性能的影响

孔径是微孔曝气产品最重要的参数之一,研究孔径对微孔曝气氧传质的影响对于提高微孔曝气器充氧性能有重要意义。本研究在1.5 m水深条件下对不同大小孔径的钟罩型塑料微孔曝气器充氧性能进行评价。结果发现,在实验条件下,微孔曝气器的阻力损失RL、标准氧总转移系数KLas、标准氧转移速率SOTR,标准氧转移效率SOTE及理论动力效率E随孔径增大而显著减小。     

Theoretical and exploratory research on sustainability mental model of the public in China: based on a typical survey in Guangdong province

This article aims to investigate the public’s sustainability mental model (SMM), which can reveal the sustainability dilemma from the public respective, other than enterprise or government. In this article, SMM is defined as one’s cognitive structure, thinking mode, and behavior tendency when someone deals with sustainability issues. After theoretical analysis, the authors developed reliable and valid measures systematically and conducted a typical survey with 581 participants from college students’ families in Guangdong province in China. Based on those samples, the author used the exploratory factor analysis and confirmatory factor analysis to construct a measurement model of SMM, which includes three dimensions, i.e. sustainable cognition, sustainable thinking, and sustainable behavior intention. According to SMM survey and clustering analysis, the results indicate that SMM of those participants is inactive. Even though those samples do not represent the whole country comprehensively, but this survey was sampled typically and they came from around China. So, the authors consider the SMM scores can reflect Chinese people to some extent, leading to the assumption that SMM of Chinese people is not active presently.     

Deciphering biodegradable chelant-enhanced phytoremediation through microbes and nitrogen transformation in contaminated soils

Biodegradable chelant-enhanced phytoremediation offers an alternative treatment technique for metal contaminated soils, but most studies to date have addressed on phytoextraction efficiency rather than comprehensive understanding of the interactions among plant, soil microbes, and biodegradable chelants. In the present study, we investigated the impacts of biodegradable chelants, including nitrilotriacetate, S,S-ethylenediaminedisuccinic acid (EDDS), and citric acid on soil microbes, nitrogen transformation, and metal removal from contaminated soils. The EDDS addition to soil showed the strongest ability to promote the nitrogen cycling in soil, ryegrass tissue, and microbial metabolism in comparison with other chelants. Both bacterial community-level physiological profiles and soil mass specific heat rates demonstrated that soil microbial activity was inhibited after the EDDS application (between day 2 and 10), but this effect completely vanished on day 30, indicating the revitalization of microbial activity and community structure in the soil system. The results of quantitative real-time PCR revealed that the EDDS application stimulated denitrification in soil by increasing nitrite reductase genes, especially nirS. These new findings demonstrated that the nitrogen release capacity of biodegradable chelants plays an important role in accelerating nitrogen transformation, enhancing soil microbial structure and activity, and improving phytoextraction efficiency in contaminated soil.     

水产养殖中水环境污染的原因与防控探微

水产养殖在水产业中的比重日益提高,但养殖期间受各种因素影响导致水环境受到污染,富营养化、饲料污染等现象在一定程度上影响了水产养殖的可持续发展。对此,为推动我国水产养殖发展,本文将结合水产养殖中水环境污染的原因探讨相关防控措施。     

复方头孢氨苄胶囊荧光熄灭法测定水中的铬(Ⅵ)

基于铬(Ⅵ)对复方头孢氨苄胶囊(CCC)的荧光熄灭,建立了测定水中铬(Ⅵ)的方法。在pH为4.2的HCl-NaAc缓冲溶液中,最大激发波长和发射波长分别为351nm和433nm、CCC加入量为100mg/L时,铬(Ⅵ)浓度的测定范围为2.00×10-6~5.00×10-3mol/L,检出限为6.25×10-7mol/L。该法受共存物的干扰相对较小,可用于测定环境水样中的铬(Ⅵ)浓度。