Insights into reactive oxygen species formation induced by water-soluble organic compounds and transition metals using spectroscopic method

Ambient particulate matter (PM) can cause adverse health effects via their ability to produce Reactive Oxygen Species (ROS). Water-Soluble Organic Compounds (WSOCs), a complex mixture of organic compounds which usually coexist with Transition Metals (TMs) in PM, have been found to contribute to ROS formation. However, the interaction between WSOCs and TMs and its effect on ROS generation are still unknown. In this study, we examined the ROS concentrations of V, Zn, Suwannee River Fulvic Acid (SRFA), Suwannee River Humic Acid (SRHA) and the mixtures of V/Zn and SRFA/SRHA by using a cell-free 2′,7′-Dichlorodihydrofluorescein (DCFH) assay. The results showed that V or Zn synergistically promoted ROS generated by SRFA, but had an antagonistic effect on ROS generated by SRHA. Fluorescence quenching experiments indicated that V and Zn were more prone to form stable complexes with aromatic humic acid-like component (C1) and fulvic acid-like component (C3) in SRFA and SRHA. Results suggested that the underlying mechanism involving the fulvic acid-like component in SRFA more tending to complex with TMs to facilitate ROS generation through π electron transfer. Our work showed that the complexing ability and complexing stability of atmospheric PM organics with metals could significantly affect ROS generation. It is recommended that the research deploying multiple analytical methods to quantify the impact of PM components on public health and environment is needed in the future.     

产酸脱硫反应器中限制性生态因子的定量化研究

采用产酸脱硫反应器进行连续流试验并配合静态试验 ,从群体生态学角度考察限制性生态因子———COD SO2 -4 比、硫酸盐负荷率 (Ns)、pH值、氧化还原电位 (ORP)和碱度 (ALK)的定量化对产酸脱硫生态系统的影响 .提出COD SO2 -4 比大于2 0 ,Ns 小于 7 5kg(SO2 -4 ) (m3·d) ,pH =6 0— 6 2 ,ORP =- 32 0— - 42 0mV ,ALK =15 0 0— 2 0 0 0mg L是维持硫酸盐还原菌(SRB)较高活性和生态系统稳定性的标志 ,硫酸盐去除率可达 80 %— 90 %     

零价铁还原降解2,4-二硝基甲苯研究

研究了零价铁对2，4-二硝基甲苯(2，4-DNT)的还原降解情况。实验结果表明，2,4-DNT的还原降解率与溶液初始pH值、初始浓度、溶解氧含量和铁粉投加量等因素有关。2，4-DNT在还原过程中先生成2-氨基-4-硝基甲苯(2A4NT)和4-氨基-2-硝基甲苯(4A2NT)，最后被还原成2，4-二氨基甲苯(2，4-DAT)。     

氧化絮凝复合床预处理印染废水的试验研究

在传统铁屑内电解的基础上,提出了氧化絮凝复合床的新技术,并使用该方法对印染废水预处理进行研究,确定了pH值,反应时间等工艺参数的影响。实验结果显示,在酸性条件下,pH为6左右,停留时间为30～45min,处理效果基本达到稳定。COD的去除率可达30%～90%,色度去除率均可达95%以上,且可提高废水的可生化性,为后续生化处理创造了有利条件。另外还研究了加盐Na2CO3,催化剂MnO2,TiO2对印染废水的处理效果。研究表明加以上添加剂后,处理效果均有所提高。该工艺以其设备简单,成本低,操作方便,预处理效果好,以废治废等优点而广受青睐,具有较好的研究价值和工程使用前景。     

生物砂滤池对有机物和氨氮的去除

当在常规工艺前加生物预处理并取消预加氯时,砂滤池就成为生物砂滤池。与普通砂滤池相比其对有机物、氨氮和浊度的去除率都有很大的提高。实验以珠江源水为水源研究了生物砂滤池对高锰酸盐指数、NH3-N、NO2--N和浊度的去除,在实验期间生物砂滤池出水高锰酸盐指数、NH3-N、浊度平均值分别为1.32mg/L、0.098mg/L、0.171NTU,其相对于沉淀池出水的高锰酸盐指数、NH3-N、浊度的平均去除率分别为18.52%、72.93%、64.45%,而砂滤池出水NO2--N几乎检测不出来。滤池进水与出水溶解氧的变化也证明了砂滤池中生物的存在,并且生长状况良好。     

膜分离技术处理电镀废水的实验研究

采用纳滤＋反渗透2级处理系统浓缩回收电镀铜漂洗废水。实验结果显示：在△P=1．5MPa条件下进行浓缩．纳滤膜可以使料液浓缩近10倍。纳滤膜对Cu^2＋的截留率在96％以上，对COD的截留率在57％以上。在△P=3．0MPa条件下进行浓缩，反渗透膜可以使料液浓缩近10倍。反渗透膜对Cu^2＋的截留率在98％以上，对COD的截留率在67％以上。随着料液浓度的增加，纳滤膜和反渗透膜的截留率会降低。     

分光光度法测定水样中铬

在ｐＨ４．４ＨＡＣ－ＮａＡｃ缓冲介质及乳化剂ＯＰ存在下，Ｃｒ６＋与二溴羟基苯基荧光酮（ＤＢＨＰＦ）显色反应生成桔红色络合物．该络合物最大吸收位于４８２ｎｍ波长处，表现摩尔吸光系数εｍａｘ＝３．４７×１０４．络合物配位比为Ｃｒ６＋：ＤＢＨＰＦ＝２：３，Ｃｒ６＋在０－１６μｇ／２５ｍＬ范围内遵守比耳定律．方法已用于水样中微量铬的测定，结果满意．     

Analysis of relationship between economic growth and environment in Benxi Shiqiaozi Development Zone

ＡｎａｌｙｓｉｓｏｆｒｅｌａｔｉｏｎｓｈｉｐｂｅｔｗｅｅｎｅｃｏｎｏｍｉｃｇｒｏｗｔｈａｎｄｅｎｖｉｒｏｎｍｅｎｔｉｎＢｅｎｘｉＳｈｉｑｉａｏｚｉＤｅｖｅｌｏｐｍｅｎｔＺｏｎｅ￥ＬｉＢｉｎ；ＲｕＪｉａｎｇ；ＹｅＷｅｎｈｕ；ＸｕＹｕｎｌｉｎ（Ｃｅｎｔｅ...     

光化学反应的环境效应

光化学反应具有良好的环境效应，本文概述了有机合成和环境化学中光化学反应对环境的影响。