碳纳米管催化电极处理难降解有机物研究进展

难降解有机物严重污染环境和威胁人类身体健康,因此难降解有机物的治理技术研究是目前水污染防治研究的热点与难点。碳纳米管(CNTs)由于具有独特的一维结构、良好的化学稳定性、优异的电荷传导性能以及独特的电学性能,近些年被广泛应用做电极材料。介绍了碳纳米管的电化学特性,对碳纳米管催化电极的制备、催化反应机理及其在有机污染物处理过程中的应用进行了概述,并对其应用前景进行了展望。     

Environmental effects and risk control of antibiotic resistance genes in the organic solid waste aerobic composting system: A review

• ARGs were detected in livestock manure, sludge, food waste and fermentation dregs. • The succession of microbial community is an important factor affecting ARGs. • Horizontal transfer mechanism of ARGs during composting should be further studied. Antibiotic resistance genes (ARGs) have been diffusely detected in several kinds of organic solid waste, such as livestock manure, sludge, antibiotic fermentation residues, and food waste, thus attracting great attention. Aerobic composting, which is an effective, harmless treatment method for organic solid waste to promote recycling, has been identified to also aid in ARG reduction. However, the effect of composting in removing ARGs from organic solid waste has recently become controversial. Thus, this article summarizes and reviews the research on ARGs in relation to composting in the past 5 years. ARGs in organic solid waste could spread in different environmental media, including soil and the atmosphere, which could widen environmental risks. However, the conventional composting technology had limited effect on ARGs removal from organic solid waste. Improved composting processes, such as hyperthermophilic temperature composting, could effectively remove ARGs, and the HGT of ARGs and the microbial communities are identified as vital influencing factors. Currently, during the composting process, ARGs were mainly affected by three response pathways, (I) “Microenvironment-ARGs”; (II) “Microenvironment-microorganisms-ARGs”; (III) “Microorganisms-horizontal gene transfer-ARGs”, respectively. Response pathway II had been studied the most which was believed that microbial community was an important factor affecting ARGs. In response pathway III, mainly believed that MGEs played an important role and paid less attention to eARGs. Further research on the role and impact of eARGs in ARGs may be considered in the future. It aims to provide support for further research on environmental risk control of ARGs in organic solid waste.     

生物炭对土壤水肥热效应的影响试验研究

本文通过野外大田小区试验以番茄（Lycopersicon esculentum Mill）为供试作物,通过在土壤中施加不同含量生物炭（Biochar）研究生物炭对土壤含水率、有机碳、速效养分含量和土壤温度的影响,从而寻求一个较为合适的施用量,为生物炭在内蒙古地区的大面积推广提供科学的理论依据。试验共设5个处理,3个重复：不施加生物炭（CK）,生物炭使用量分别为10 t·hm^-2（A）,20 t·hm^-2（B）,40 t·hm^-2（C）,60 t·hm^-2（D）,在各生育期取土样测定土壤含水率、有机碳、速效养分含量,并在各生育期连续3天测定土壤地表温度。试验结果表明：不同处理下土壤含水率随生物炭施用量增加呈先增加后减小的趋势,且均高于对照组,其中施炭量为40 t·hm^-2处理的土壤含水率增幅最明显,0～10 cm土层各生育期土壤含水率较对照组最大增幅分别为20.8%、13.7%、21.8%,10～20 cm土层各生育期土壤含水率较对照组最大增幅分别为33.9%、17.1%、21.3%;不同处理下土壤温度随着生物炭施用量的增加而升高,两者具有显著的正相关关系,各生育期各处理土壤地表温度较对照组最大增幅分别为58.1%、31.3%、55.8%;不同处理土壤有机碳含量随着生物炭施用量的增加而增大,番茄各生育期各处理土壤有机碳含量较对照组最大增幅分别为80.9%、62.7%、63.9%;不同处理土壤中碱解氮、速效钾、速效磷含量均随生物炭施用量的增加而呈现先增大后减小的趋势,且均大于对照组,各生育期各处理土壤碱解氮较对照组最大增幅分别为92.7%、45.7%、106.5%,速效磷最大增幅分别为120.1%、39.3%、250.4%,速效钾最大增幅分别为86.2%、118.5%、203.4%。综上所述,生物炭对于砂壤土具有保水、保肥、保温的特性,对于提高土壤水肥利用效率,增加土壤有机碳具有重要的作用,而且通过试验验证40 t·hm^-2的施?     

再生水中优先控制有毒污染物的筛查方法

建立了一种适用于再生水中优先控制有毒有机污染物筛查的方法.针对样品前处理方法中的固相萃取柱的选择和洗脱剂条件等进行了优化设计,利用保留时间锁定和谱图解卷积技术分辨复杂系统中的目标污染物,并利用有毒化合物数据库进行有毒污染物甄别.结果表明,采用C18柱串联HLB柱的方法进行富集,用1:1(V/V)的正己烷/二氯甲烷混合溶剂和4:1(V/V)的二氯甲烷/甲醇混合溶剂进行分级洗脱的前处理方法,对分配系数(logKow)在1.48~6.41之间的30种化合物平均回收率在52.1%~138%之间,相对标准偏差值均<13.6%.将该方法应用于天津空港地区再生水中有毒有机污染物的筛查,2007~2008年度2次采集样品分别筛查出30种有毒有机污染物,其中有7种属于《城镇污水处理厂污染物排放标准》中已列入监管范围的污染物,11种未列入排放标准监测范围.比较污水处理厂进、出水以及地表水中检出污染物,发现现有污水处理工艺对筛查出的优先有机污染物处理效果不佳.     

Toxic substances: Measures and measurements†

The formulation of a sound policy for environmental protection and toxic substances control requires knowledge of the presence and concentration of environmental contaminants. For this reason monitoring programs have been set up in the Netherlands for water, drinking water, and air pollution. The Netherlands system for air pollution, monitoring of the substances SO2, NOχ, CO, O₃ is now fully automated. Some examples will be given to show the acquisition and management and interpretation of air pollution measurements.

Various smaller projects, supported by the Department of Health and Environmental Protection include measurement of indoor air‐contaminants, contaminants in soil and hazardous waste sites, and contaminants in biotic samples such as for instance PCB's in eels and seals and mussels. Moreover a Coordinating Committee regularly collects measurements from various sources in the Netherlands regarding pesticide residues and contaminants in food.

For cost‐effective monitoring the accuracy of the measurements must be chosen with regard to the biological effect concentration of the pollutant. The necessity of proper control measurements to establish background levels and the necessity of ring‐tests to increase interlaboratory reproducibility is discussed. In cost‐effective monitoring the minimum number of measurements, which are necessary to check the effect of environmental protection measures, must be defined through proper sampling.     

It's a dirty job but someone has to do it: The role of marine benthic macrofauna in organic matter turnover and nutrient recycling to the water column

Benthic macrofaunal populations through their feeding, bioturbation, burrow construction and sediment irrigation activities have profound influences on organic matter inputs to marine sediments (biodeposition) and on the vertical distribution of deposited organic matter within the sediment. These effects in turn influence the rates and pathways of organic matter mineralisation, and element cycles. Similarly, bioturbation, burrow construction and burrow irrigation are major determinants of sediment-water column fluxes of oxygen and nutrients.

In this review, I discuss the influences of the different benthic macrofaunal feeding (functional) groups on mineralisation processes and sediment-water column fluxes of particulate and dissolved nutrients. How these effects influence diagenic processes, the balance between aerobic and anaerobic processes, and the redox status of the surficial sediments. Finally, I discuss some of the limitations of the predominantly laboratory techniques which have been used to study “macrofaunal effects” and how this hinders the inclusion of the effects in quantitative sediment biogeochemical models.     

Sediment organic matter and meiofauna community response to long-term fish-farm impact in the Ligurian Sea (Western Mediterranean)

Quantitative and qualitative changes in meiofauna community structure were investigated to assess the impact of a fish farm, which was operating continuously for 15 years (La Spezia Gulf, W Mediterranean). Sediment samples were collected in June, July, September, October 2000 and February 2001 for the analysis of phytopigments (chlorophyll-a and phaeopigments), the biochemical composition of organic matter (proteins, carbohydrates and lipids) and related to meiofaunal parameters.

Sediment organic matter reached extremely high concentrations beneath the fish cages when compared to the control. Particularly lipids, carbohydrates and chlorophyll-a were significantly higher in fish-farm sediments. On a long-term basis meiofauna displayed adaptations in sediments beneath the cages resulting in an increase of density. Organic impact on meiofaunal community structure was evident in terms of an increase of the nematodes to copepods (Ne/Co) and nauplius to copepods (Na/Co) ratios in fish farm sediments. Cumaceans and kinorhynchs were encountered in control sediments, but disappeared in fish-farm samples. These data suggest that meiofauna is a sensitive tool for evaluating the effects of organic enrichment in fish farm impacted areas.     

Biodegradability of organic substances by ATP test

The aerobic biodegradability of organic substances in water is characterized by determination of energy change ‐ ATP content in microbial cells during biodegradation. A satisfactory result is obtained under the following conditions: the initial concentration of tested substance is 100mg/l (as DOC), the amount of the inoculum in the biological medium is 500mg/l (as MLSS), and the duration of test time is 14 days. The evaluating system (peak time, peak height and IA index) is proposed to assess the biodegradability of 46 organic compounds and 7 wastewaters.     

基于TLSER和QSPR关系预测PAHs和PCBs的LDPE膜-空气分配系数

有机污染物在被动采样材料与环境介质之间的平衡分配系数(K_P),是测定环境中有机污染物浓度的重要参数,但K_P值大部分都需要经过繁琐的实验测定获取,无法逐个测定数量繁多的污染物,因此需开发一种预测K_P值的方法。为此,搜集整理了一些多环芳香烃(PAHs)和多氯联苯(PCBs)的低密度聚乙烯(LDPE)-空气分配系数(K_PA)的实测值,基于理论线性溶解能(TLSER)和定量结构性质关系(QSPR),利用逐步多元线性回归(MLR)分别构建了预测K_PA值的模型。模型的决定系数R2adj分别为0.927和0.956,交叉验证系数Q2LOO分别为0.915和0.946,外部系数Q2ext分别为0.913和0.960。结果表明,2种模型具有良好的拟合优度、稳健性和预测能力,并解释了模型的机理。所构建的2种模型均可用来预测应用域内有机污染物的LDPE膜-空气分配系数。     

The temporal changes of the concentration level of typical toxic organics in the river sediments around Beijing

In this study, the current situation of five types of toxic organics and endocrine disrupters in the sediments of rivers around Beijing, i.e., polycyclic aromatic hydrocarbons (PAHs), phthalic acid esters (PAEs), organic chlorinated pesticides (OCPs), estrogens (Es), and bisphenol A (BPA), which included 56 contaminants, was analyzed and compared with that registered by the historical literatures. The ecological risks were also assessed. The total concentration of PAHs, PAEs, OCPs, Es, and BPA ranged from 232.5 ng·g^–1 to 5429.7 ng·g^–1, 2047.2 ng·g^–1 to 18051.5 ng·g^–1, 4.5 ng·g^–1 to 11.7 ng·g^–1, 18.1 ng·g^–1 to 105.2 ng·g^–1, and 36.3 ng·g^–1 to 69.6 ng·g^–1, respectively. Among these five types of organic compounds, the concentration levels of PAHs and OCPs have decreased significantly in the last ten years, while those of PAEs and Es had an upward trend compared with the previous studies. BPA still remained at a moderately high level, as it was ten years ago. The risks of the PAEs in all of the sample sites, and fluoranthene, benzo[a]anthrene, and benzo[a]pyrene in the Wenyu River sediment, were relatively high. These results supplemented the database of toxic organics’ concentration levels in the sediments of Beijing rivers.

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