Comparison of homologous and heterologous formats in nanocolloidal gold-based immunoassays for parathion residue determination

The effectiveness of homologous and heterologous formats in a nanocolloidal gold-based immunoassay for pesticide residue determination was investigated. Parathion, one of the most toxic organophosphorus pesticides, was used as the target analyte. One-step homologous and heterologous test strips based on a nanocolloidal gold-labeled monoclonal antibody were developed for the rapid detection of parathion residues. The results showed that the heterologous format was more effective than the homologous format, being more sensitive, more specific to parathion and more tolerant of matrix interferences. The best competitive hapten was found to have a moderate heterology and the opposite electronic distribution to the immunizing hapten. The detection limits for parathion using the preferred heterologous strip were 1 μg/L in water samples and 5 μg/kg in soil and food samples.     

脱氮吸附剂深度脱除模拟含氮油中氮化物的研究

将磷钨酸、甲醛气体负载于介孔分子筛SBA-15中制备脱氮吸附剂,其中SBA-15、磷钨酸、甲醛的质量比为10∶7∶3.以喹啉、吲哚和咔唑为目标氮化物,二甲苯及二甲苯和十二烷的混合液为溶剂配制模拟含氮油,考察了反应温度、氮化物类型对脱氮反应速率的影响以及磷钨酸、甲醛的脱氮机制.结果表明,磷钨酸可以有效脱除碱性氮化物和低浓度非碱性氮化物,甲醛能强化吸附剂对非碱性氮化物的选择性.在70℃、脱氮吸附剂与高浓度模拟含氮油质量比为2.0∶30.0的条件下,模拟含氮油中的氮化物在90 min内可以被深度脱除.磷钨酸对碱性氮化物的脱除机制为磷钨酸和碱性氮化物间的配合作用和酸碱反应,磷钨酸对非碱性氮化物的脱除机制为氮化物和甲醛在酸催化下缩合反应生成聚合物.反应吸附剂再生回用后的脱氮能力随氮化物碱性的增强而减弱.     

Emission of volatile organic sulfur compounds (VOSCs) during aerobic decomposition of food wastes

Food wastes collected from typical urban residential communities were investigated for the emission of volatile organic sulfur compounds (VOSCs) during laboratory-controlled aerobic decomposition in an incubator for a period of 41 days. Emission of VOSCs from the food wastes totaled 409.9 mg kg^?1 (dry weight), and dimethyl disulfide (DMDS), dimethyl sulfide (DMS), methyl 2-propenyl disulfide, carbonyl sulfide and methyl 1-propenyl sulfide were the five most abundant VOSCs, with shares of 75.5%, 13.5%, 4.8%, 2.2% and 1.3% in total 15 VOSCs released, respectively. The emission fluxes of major VOSCs were very low at the beginning (day 0). They peaked at days 2–4 and then decreased sharply until they leveled off after 10 days of incubation. For most VOSCs, over 95% of their emission occurred in the first 10 days. The time series of VOSC emission fluxes, as well as their significant correlation with internal food waste temperature (p < 0.05) during incubation, suggested that production of VOSC species was induced mainly by microbial activities during the aerobic decomposition instead of as inherited. Released VOSCs accounted for 5.3% of sulfur content in the food wastes, implying that during aerobic decomposition considerable portion of sulfur in food wastes would be released into the atmosphere as VOSCs, primarily as DMDS, which is very short-lived in the atmosphere and thus usually less considered in the sources and sinks of reduced sulfur gases.     

Chemisorption and Physical Adsorption Roles in Cadmium Biosorption by Chlamydomonas Reinhardtii

The aim of this study was to investigate the mechanism of cadmium (Cd) adsorbed by microalgae Chlamydomonas reinhardtii (C.reinhardtii). The kinetic and adsorption isotherm of the process could be well described by mathematical models. Chemical modification experiments and Fourier transform infrared spectra indicated that carboxyl and amine groups were the important functional groups for adsorption of Cd. The maximum contribution of physical adsorption in the overall adsorption process was evaluated as 5.5%...     

高碱度水库水混凝过程中残留铝控制

针对高碱度水库水源的某水厂残留铝超标问题,选取碱化度(B)与Alb含量不同的3种铝盐絮凝剂,研究不同投量与pH值下混凝效果与残留铝浓度水平。结果表明,碱化度和Alb含量显著影响混凝效果。DOC和浊度的去除率随着3种絮凝剂AlCl3(B=0)、PACl-1(B=1.2)、PACl-2(B=2.2)投量增大而升高。3种絮凝剂投量在1.5～2.0 mg/L(以铝计)范围内,总铝和溶解铝含量最低。对于该水厂自制的絮凝剂PACl-2,可通过降低絮凝剂碱化度,或将水的pH值降低至7～7.5之间,以此可以提高PACl-2混凝效果,而且可以降低出厂水残留铝浓度。考虑工程应用可行性,可优先考虑调整絮凝剂生产工艺。     

湖北“人口-经济-空间”城市化及其层级结构

城市化的内在协调性是城市（区域乃至国家）综合竞争力、国民生计及可持续发展能力的综合体现。基于对城市化概念与内涵的认知--城市化是一个“人口 经济 空间”三维一体的过程,其中人是行为主体,经济是驱动力,空间是载体,构建了城市化综合测度指标,并运用时序全局主成分分析法,对2000年以来湖北省12个地级市的城市化层级结构演变过程及趋势进行了分析。结果表明湖北省城市化具有如下特征：① 城市化总量时序演变上呈现出明显的上升趋势,且存在经济城市化>空间城市化>综合城市化>人口城市化的变化趋势,但也表现出一定程度的粗放增长的内在特征;② 整个城市化过程是一个由人口城市化导向型向经济城市化导向型转变的过程;③ 城市化相关系数的时序演变与人口城市化集聚程度>空间城市化集聚程度>经济城市化集聚程度的演变趋势密切相关,表明综合城市化与人口城市化的地域协调性最高,而与经济的最低;④ 城市化等级体系空间结构及其时序演变具有首位度城市层级结构、城市层级结构动态演变,以及城市化地域协调性不强等特征;最后就城市化的协调发展提出对策和建议。为我国城市化可持续发展研究以及湖北省今后的城市化发展战略提供了理论借鉴和实践指导     

膜生物反应器(MBR)-反渗透(RO)工艺深度处理印染废水的实验研究

采用膜生物反应器（MBR）-反渗透（RO）工艺对印染废水进行了深度处理实验。原水经MBR系统处理后,COD去除率、ss去除率和色度去除率分别达89．9％、100％和87．5％。MBR系统处理出水进入反渗透（RO）系统进行处理,硬度去除率和除盐率分别达99．62％和99．64％,同时可进一步除去剩余的COD、色度。系统出水水质满足生产回用的要求。     

HFBM工艺处理三羟甲基丙烷废水的中试研究

采用厌氧滤池+HFBM工艺处理三羟甲基丙烷废水,在进水CODCr浓度小于10 000 mg.L-1、水力停留时间为96 h条件下,出水CODCr浓度稳定在500 mg.L-1以下,在进水中含0.5%甲醛条件下,经过7 d的冲击试验,出水CODCr浓度仍能保证在500 mg.L-1以下,中试试验直接运行费用为6.96元/t废水。     

A sensitive monoclonal antibody-based enzyme-linked immunosorbent assay for chlorpyrifos residue determination in Chinese agricultural samples

A monoclonal antibody-based competitive antibody-coated enzyme-linked immunosorbent assay (ELISA) was developed and optimized for determining chlorpyrifos residue in agricultural products. The IC(50) and IC(10) of this ELISA were 3.3 ng/mL and 0.1 ng/mL respectively. The average recoveries in six agricultural products were between 79.5% and 118.0%, with the intra-assay coefficient of variation being less than 8 %. The limit of detection for all tested products was 30 ng/g. To the best of our knowledge, this assay has the best specificity among all the published research on ELISAs for chlorpyrifos.     

Hexachlorocyclohexane (HCH) as new Stockholm Convention POPs��a global perspective on the management of Lindane and its waste isomers

Purpose

Hexachlorocyclohexane (HCH) isomers (??-, ??- and ??- (Lindane)) were recently included as new persistent organic pollutants (POPs) in the Stockholm Convention, and therefore, the legacy of HCH and Lindane production became a contemporary topic of global relevance. This article wants to briefly summarise the outcomes of the Stockholm Convention process and make an estimation of the amount of HCH waste generated and dumped in the former Lindane/HCH-producing countries.

Results

In a preliminary assessment, the countries and the respective amount of HCH residues stored and deposited from Lindane production are estimated. Between 4 and 7 million tonnes of wastes of toxic, persistent and bioaccumulative residues (largely consisting of alpha- (approx. 80%) and beta-HCH) are estimated to have been produced and discarded around the globe during 60 years of Lindane production. For approximately 1.9 million tonnes, information is available regarding deposition. Countries are: Austria, Brazil, China, Czech Republic, France, Germany, Hungary, India, Italy, Japan, Macedonia, Nigeria, Poland, Romania, Slovakia, South Africa, Spain, Switzerland, Turkey, The Netherlands, UK, USA, and former USSR. The paper highlights the environmental relevance of deposited HCH wastes and the related POPs?? contaminated sites and provides suggestions for further steps to address the challenge of the legacy of HCH/Lindane production.

Conclusion

It can be expected that most locations where HCH waste was discarded/stockpiled are not secured and that critical environmental impacts are resulting from leaching and volatilisation. As parties to the Stockholm Convention are legally required to take action to stop further POPs pollution, identification and evaluation of such sites are necessary.