扫频脉冲电磁场对污水的杀菌性能

将直流脉冲与变频扫频技术相结合开发研制出扫频直流脉冲装置,利用其产生的脉冲电磁场对生活污水进行了电磁杀菌试验研究,探讨了影响杀菌效果的相关因素.试验结果表明,在扫频范围400Hz～60kHz、输出功率20W、电流1～2A条件下,脉冲电磁场对生活污水具有一定的灭菌作用,其杀菌性能随作用时间、pH值、温度、原水菌数的升高而升高.当温度为25℃,pH为7.47时,原水经电磁处理4h后,细菌总数从7.2×10⁶个·mL^-1下降到2.2×10⁴个·mL^-1,去除率为99.7%;大肠杆菌数从9.2×10⁵个·mL^-1下降到3.5×10⁴个·mL^-1,去除率为96.2%.     

柔性电解去污技术概述

为保护人员健康和环境安全,核设施长期运行及未来退役时必须高度重视放射性污染防治。柔性电解去污技术一直是电解去污技术研究发展方向之一,是去除金属表面放射性污染的有效方法。本文介绍了电解去污技术特别是柔性电解去污技术在日本的发展,概述了几种具有代表性的技术应用实例。通过与中国电解去污技术发展水平的比较,提出未来中国电解去污技术的研究发展应该与其它去污技术整和、与现场条件相结合,建议开发硝酸体系的系列电解液配方和柔性电解去污装置。     

Biosynthesis of gold nanoparticles by Trichoderma sp. WL-Go for azo dyes decolorization

Developing an eco-friendly approach for metallic nanoparticles synthesis is important in current nanotechnology research. In this study, green synthesis of gold nanoparticles(AuNPs) was carried out by a newly isolated strain Trichoderma sp. WL-Go. UV–vis spectra of Au NPs showed a surface plasmon resonance peak at 550 nm, and transmission electron microscopy images revealed that the Au NPs were of varied shape with well dispersibility.The optimal conditions for Au NPs synthesis were HAuCl_4 1.0 mmol/L, biomass 0.5 g and pH 7–11. Moreover, the bio-Au NPs could efficiently catalyze the decolorization of various azo dyes. This research provided a new microbial resource candidate for green synthesis of Au NPs and demonstrated the potential application of bio-Au NPs for azo dye decolorization.     

The effects of hydrogen peroxide pre-oxidation on ultrafiltration membrane biofouling alleviation in drinking water treatment

Pre-oxidation is widely used to reduce ultrafiltration membrane fouling.However,the variation in the composition of microbial communities and extracellular polymeric substances(EPSs) accompanying pre-oxidation in drinking water treatment has received little attention.In this study,hydrogen peroxide(H_2O_2) was used in a coagulationultrafiltration process with Al_2(SO_4)_3·18H_2O.A long-term reactor experiment(60 d) showed that pre-oxidation alleviated membrane fouling,mainly due to its inhibition of microbial growth,as observed by flow cytometry measurements of the membrane tank water.Further analysis of the formed cake layer demonstrated that the corresponding levels of EPS released from the microbes were lower with than without H_2O_2 treatment.In comparison to polysaccharides,proteins dominated the EPS.2 D-electrophoresis showed little difference(p 0.05,Student's t-test) in the composition of proteins in the cake layer between the treatments with and without H_2O_2.The molecular weights of proteins ranged from approximately 30–50 kDa and the majority of isoelectric points ranged from 6 to 8.Highthroughput sequencing showed that the predominant bacteria were Proteobacteria,Bacteroidetes,and Verrucomicrobia in both cake layers.However,the relative abundance of Planctomycetes was higher in the cake layer with H_2O_2 pre-oxidation,which was likely probably due to the strong oxidative resistance of its cell wall.Overall,our findings clarify the fundamental molecular mechanism in H_2O_2 pre-oxidation for ultrafiltration membrane bio-fouling alleviation in drinking water treatment.     

Characteristics and formation mechanism of regional haze episodes in the Pearl River Delta of China

To investigate the characteristics and the specific mechanism of continuous haze,comprehensive measurements were conducted from 15 October to 19 November in the Atmospheric Environment Monitoring Super-Station in Heshan of Guangdong province.Five haze episodes occurred in October and November 2014 in the Pearl River Delta(PRD)region. The meteorological parameters, gas data, chemical compositions, and optical parameters of the aerosols were obtained. Among these events, the second haze episode,with the highest concentration of PM2.5 of 187.51 μg/m~3, was the most severe. NO~3-was always higher than SO_4~(2-), which indicated that motor vehicles played an important role in the haze, even though the oxidation rate from SO_2 to SO_4~(2-)was faster than that of NOXto NO_3~-. The difference between the hourly averages of Na+and K+during the haze episode and clean days was small, implying that straw combustion and sea salt had no significant effect on the occurrence of haze, and the backward trajectories of the air masses also conformed with this result. The air pollutants were difficult to disperse because of the significant decrease in the planetary boundary layer(PBL) height. Relative humidity played a crucial role in the formation of haze by leading to hygroscopic growth of the diameter of aerosols.     

汽柴油加氢装置分馏塔进料/反应产物换热器管束腐蚀原因分析

对汽柴油加氢装置分馏塔进料/反应产物换热器E-102/1、2腐蚀穿孔的原因进行了分析,采用XRD、金相分析、细菌培养试验等方法,分析了工艺、设备、设计3个方面的原因,认为停工保护与变更管理制度不完善是造成换热器腐蚀穿孔的根本原因,碱洗管理制度不完善、氯化物引起的点蚀以及微生物腐蚀等原因共同作用导致了换热器的腐蚀穿孔。     

Migration of manganese and iron during the adsorption-regeneration cycles for arsenic removal

Fe-Mn binary oxide incorporated into porous diatomite (FMBO-diatomite) was prepared in situ and regenerated in a fixed-bed column for arsenite [As(III)] and arsenate [As(V)] removal. Four consecutive adsorption cycles were operated under the following conditions: Initial arsenic concentration of 0.1 mg·L⁻¹, empty bed contact time of 5 min, and pH 7.0. About 3000, 3300, 3800, and 4500 bed volumes of eligible effluent (arsenic concentration ⩽ 0.01 mg·L⁻¹) were obtained in four As (III) adsorption cycles; while about 2000, 2300, 2500, and 3100 bed volumes of eligible effluent were obtained in four As(V) adsorption cycles. The dissection results of FMBO-diatomite fixed-bed exhibited that small amounts of manganese and iron were transferred from the top of the fixed-bed to the bottom of the fixed-bed during As(III) removal process. Compared to the extremely low concentration of iron (<0.01 mg·L⁻¹), the fluctuation concentration of Mn²⁺ in effluent of the As(III) removal column was in a range of 0.01–0.08 mg·L⁻¹. The release of manganese suggested that manganese oxides played an important role in As(III) oxidation. Determined with the US EPA toxicity characteristic leaching procedure (TCLP), the leaching risk of As(III) on exhausted FMBO-diatomite was lower than that of As(V).     

环境质量监测常规数据管理措施的探讨

环境质量常规监测数据是指在人类活动中产生的与环境相关的原始性、基础性数据,以及按照不同需求系统加工整理的各类数据集。只有加强环境质量常规监测数据（资料）使用的规范化,才能发挥环境质量常规监测数据在各项环境建设、经济和社会发展中的作用,更好地为环境保护事业服务。     

城市内城河污染如何进行点源排查及针对性治理的探讨

经济的高速发展,使人们的生活水平不断提高,从而对所生活的城市空间的要求也越来越高.内城河作为城市景观风貌和休闲空间的重要组成部分,近年来由于水体黑臭,表面脏物漂流,已成为群众投诉较多的社会热点问题,如何对内城河水体进行整治,是目前亟需解决的问题.以靖江市内城河渔婆港治理为例,探讨如何从河道沿线排查,以及根据排查情况提出具体的针对性治理措施,以此切实有效地处理群众反响较大的内城河污染,从根本上改善内城河周边环境,提升群众生活质量.     

流域水生态功能分区方法与指标体系探讨

水生态功能分区是识别流域水生态系统特征、结构与功能的主要依据,它能够反映区域水生态系统的主要生态功能状况及其所面临的潜在压力。因此,建立基于生态功能分区的水质管理技术体系,是中国水生态管理的必然发展趋势,也是国际水质管理的前沿方向。拟从水生态功能分区的研究现状,比较国内外相关的研究工作,探讨不同等级生态分区方法及指标体系的构建依据。