Adsorption of microcystins by carbon nanotubes

The production of cyanobacterial toxins microcystins (MCs) by cyanobacterial bloom which may promote the growth of tumor in human liver is a growing environmental problem worldwide. In this paper, the adsorption of MC-RR and LR, which were extracted from cyanobacterial cells in Dianchi Lake in China, by carbon nanotubes (CNTs), wood-based activated carbon (ACs) and clays were investigated. Compared with ACs and clay materials of sepiolite, kaolinite and talc tested, CNTs were found to have a strong ability in the adsorption of MCs. At the concentrations of 21.5 mg l(-1) MC-RR and 9.6 mg l(-1) MC-LR in 50 mmol phosphate buffer solution (pH 7.0), the adsorption amounts of MCs by CNTs with the range of outside diameter from 2 to 10nm were 14.8 and 5.9 mg g(-1), which were about four times higher than those by other adsorbents tested. It was shown that with the decrease of CNTs outside diameters from 60 to 2 nm, the adsorption amount of MCs was apparently increased, however the size of CNTs particles formed in solution declined. This result implies that the size of CNTs tube pore that is fit for the molecular dimension of MCs plays a dominant role. Furthermore the specific surface area of CNTs was also found to be a factor in the adsorption of MCs. The results suggested that the selection of suitable size of CNTs as a kind of adsorbent is very important in the efficient eliminating MCs from drinking water in future.     

纳米银诱导细胞自噬的分子机制和生物效应

细胞自噬对维持细胞的生长代谢以及细胞内环境稳态具有重要意义。近年来,纳米银(silver nanoparticles, AgNPs)与细胞自噬的关系逐渐被揭示。深入了解AgNPs诱导的细胞自噬效应有助于其在医药领域的进一步应用,也能为全面评估AgNPs的纳米毒性提供科学依据。本文重点介绍AgNPs诱导细胞自噬的机制及其涉及的主要信号通路,通过探讨不同理化性质的AgNPs诱导自噬的不同结果及机制,归纳总结AgNPs诱导细胞自噬的生物效应,以期为全面认识AgNPs的自噬效应提供科学依据。     

珠江口和邻近海域沉积有机质的来源及其沉积通量的时空变化

分析了珠江口和邻近海域沉积有机质(OM)的总有机碳(TOC)、总氮(TN)及稳定碳同位素组成〔δ(13C)〕等地球化学参数,并对有机质的来源和沉积通量进行了研究. 结果表明,珠江口沉积有机质来自大陆(52%)和水生(48%)混合来源;而邻近海域沉积有机质主要为水生来源(93%). 珠江口陆源有机质含量〔w(T－OC)为5.4 　mg/g〕远远高于邻近海域(0.49 　mg/g),近年来珠江口TOC和陆源有机质(T-OC)的平均沉积通量分别为5.57和2.2～3.6 mg/(cm2·a),说明珠江河口接受了大量的陆源有机物的输入,这是由于自20世纪后期的几十年以来,华南地区经济快速增长造成大量土地开垦,以及工农业生产和生活污水的排放所致. 珠江口和邻近海域的水生有机质沉积通量在近年均呈增加趋势,在珠江口达到最大值3.6 mg/(cm2·a),说明大量的营养物质导致水体的富营养化,从而促使水域初级生产力的增长.      

焦炉装煤车烟气净化节能技术改造

焦炉装煤车烟气净化是焦化厂烟气净化的重点之一。介绍了把装煤车烟气的湿法净化改造为干法净化方法和节能、节水和降噪效果。     

水体中氨氮测定方法的比较——纳氏试剂光度法、靛酚蓝比色法

纳氏试剂光度法是氨氮的经典测定方法,但该方法的灵敏度不高。靛酚蓝比色法对氨氮具有特殊的敏感性和相关性,具有较高的准确度、精确度和敏感度。同时用两种方法对水样进行了测定,结果显示无显著性差异,但是靛酚蓝比色法较为方便,准确,易于操作,极大地减轻了分析人员的劳动强度,具有积极的现实意义。     

面向未来的污水处理厂关键技术研发与工程实践专栏序言

污水处理行业碳排放水平约占全社会碳排放水平的1%～2%,为实现行业碳达峰、碳中和目标以及满足建设面向未来污水处理厂的需要,污水处理行业碳减排技术的开发及碳中和路线图的搭建迫在眉睫.本文是国家水专项“面向未来污水处理厂关键技术研发与工程示范”课题近年来科研成果的总结,致力于构建面向未来污水处理技术体系,从污水处理厂“碳减排”和“碳中和”角度出发,在污水“碳转向”、污水处理过程“碳减排”、基于大数据和云平台的智慧水务3个关键技术的研究以及对面向未来污水处理厂工程实践等方面进行了总结凝练,以期为我国污水处理行业的“碳减排”及“碳中和”提供技术支撑.     

The levels and distribution of organochlorine pesticides (OCPs) in sediments from the Haihe River, China

The levels and distribution patterns of the selected organochlorine pesticides (OCPs=p,p'-DDT, o,p'-DDT, p,p'-DDE, p,p'-DDD, alpha-, beta-, gamma- and delta-HCH) in surficial sediments from the Haihe River and Dagu Drainage River of Tianjin were investigated by means of gas chromatography coupled with micro-electronic capture detector (GC-microECD). Concentrations of OCPs in the sediments from the Haihe River ranged from 1.88 to 18.76ng g(-1) (mean 7.33ng g(-1)) for sum HCH, 0.32-80.18ng g(-1) (mean 15.94ng g(-1)) for sum DDT. Compared with the Haihe River, the Dagu Drainage River was much more contaminated by HCHs and DDTs, wherein sum HCH ranged from 33.24 to 141.03ng g(-1) (mean 87.74ng g(-1)) and sum DDT ranged from 3.60 to 83.49ng g(-1) with a mean value of 35.52ng g(-1). The concentration distribution of sum DDT and sum HCH was different indicated their different contamination sources. Composition analyses indicated that a recent usage or discharge of HCH and DDT into the Dagu Drainage River.     

应用概率物种敏感度分布法研究太湖铜水生生物水质基准

运用概率物种敏感度分布法获得太湖水体中铜的急性水质基准值为14.57μg·L-1,慢性水质基准值为3.26μg·L-1;不同类别物种敏感性存在差异,无脊椎动物较脊椎动物更敏感,甲壳类敏感性大于鱼类。概率物种敏感度分布法与传统的物种敏感度分布法相比,更全面合理地考虑多种毒性效应,曲线拟合效果好,受数据量大小影响较小,结果更加稳定。研究结论可为铜水质标准的修订和太湖流域水环境管理提供技术支持。     

A straightforward green synthesis of N-(tert-butylsulfinyl)imines

A straightforward and environment-friendly protocol for the synthesis of valuable chiral N-(tert-butylsulfinyl)imines has been developed. Different from traditional process with benzaldehydes as substrates, arylmethyl alcohols, benzylthiol, dibenzyl ether, thioether, and disulfide are used as alternative substrates to react with tert-butanesulfinamide in the presence of KO^tBu under air for the synthesis of chiral N-(tert-butylsulfinyl)imines. This is a transition metal-free, mild, cost-effective, and simple process.     

典型石化企业排放有毒有害大气污染物人体健康风险评估

石化行业生产过程中会产生有毒有害大气污染物,并可能对人体健康产生危害。为贯彻落实《大气污染防治法》第七十八条中对有毒有害大气污染物(hazardous air pollutants,HAPs)实行风险管理,评估环境风险的要求,有必要开展石化企业排放HAPs的人体健康风险评估。本研究采用美国环境保护局(US EPA)发布的人体健康风险评估手册F部分吸入风险评估指南中的方法,推算出HAPs物质对人体健康的致癌风险值和非致癌风险值;通过CALPUFF模型模拟预测出典型石化企业HAPs物质扩散范围及空气中的浓度,并将模拟预测得到的污染物浓度与推算得到的风险值进行比较,进而表征园区内该企业排放HAPs对人体健康的风险。结果表明,基于最坏情况分析,该石化企业排放的HAPs致癌风险值为0.421μg·m-3,非致癌风险值为2.212μg·m-3,CALPUFF模拟预测空气中污染物浓度最大为0.62μg·m-3,且模型预测的月均浓度均未超过致癌和非致癌风险值,风险表征结果表明,该石化企业排放的HAPs物质对人体健康不存在致癌和非致癌风险。但本研究仅针对某石化企业开展人体健康风险评估,并不能代表石化行业排放有毒有害大气污染物对人体健康风险的整体水平。