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.     

载La(Ⅲ)-和Fe(Ⅲ)-氨基膦酸型螯合树脂对氟吸附性能的比较

研究并比较了载La（Ⅲ）和载Fe（Ⅲ）大孔氨基膦酸型螯合树脂对饮用水中氟离子的吸附特性。氟在载La（Ⅲ）和载Fe（Ⅲ）的螯合树脂上的吸附不随pH的变化而改变,载金属螯合树脂对氟的饱和吸附容量分别为3.78、3.55mg/g,吸附方式符合Freundlich吸附等温式,代表性竞争离子不影响氟在螯合树脂上的吸附。结果表明载Fe（Ⅲ）和载La（Ⅲ）的螯合树脂是一种有前景的饮水氟去除吸附剂。     

直接法测定大气中的非甲烷烃

介绍了在２个监测点，用直接法测定大气中的非甲烷烃。测定方法的检出限可达０．００６５ｍｇ／ｍ＾３，在线性范围０－１０ｍｇ／ｍ＾３时，线性相关系数为０．９９９５，相对标准焦虑差为２．８％。结果表明，由于大气逆温层、工业排放源、汽车排气对非甲烷烃的浓度变化产生影响，其日变化曲线呈双峰形。     

Characteristics of phosphorus chemistry and its geographical distribution in the Haihe River valley,North China

ＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｐｈｏｓｐｈｏｒｕｓｃｈｅｍｉｓｔｒｙａｎｄｉｔｓｇｅｏｇｒａｐｈｉｃａｌｄｉｓｔｒｉｂｕｔｉｏｎｉｎｔｈｅＨａｉｈｅＲｉｖｅｒｖａｌｌｅｙ，ＮｏｒｔｈＣｈｉｎａＪｉａｎｇＧａｏｍｉｎｇ；ＨｕａｎｇＹｉｎｘｉａｏ；Ｌ...     

二级出水中磷的混凝处理研究

以北京市某污水处理厂的二级出水中总磷为去除对象,通过混凝的静态烧杯实验[1],确定了二级出水除磷效果较好的絮凝剂聚合氯化铁(PFC)[2]和Al2(SO4)3[3]混合使用的最佳投药量,使出水中磷(TP)符合再生水水质标准的要求.絮凝剂组合时静态混凝烧杯实验表明:PFC-Al2(SO4)3体积比1∶1时,最佳投药量离子浓度比为:Fe3 /Al3 ∶9.9/7(mg·L-1),此时TP去除率为93%,浊度去除率为33%.PFC-Al2(SO4)3体积比1:2时,最佳投药量离子浓度比为:Fe3 /Al3 ∶4.95/7(mg·L-1),此时TP去除率为88%,浊度去除率为71%.     

处理含油废水絮凝剂最佳配方的筛选

针对含油废水，选择合适种类的絮凝剂，通过评价絮凝剂的除油效果，筛选出适合处理石油化工行业含油废水的絮凝剂最佳配方．其主要特点是投加量少、除油效果好、价格适宜。     

乡镇企业环境保护工作初探

近年来，乡镇企业蓬勃发展的趋势要求我们必须重视其环境保护工作．笔者通过联系当地的实际情况力图阐明自己对于如何搞好乡镇企业环境保护工作的一些观点。     

基于GIS的海洋环境质量评价图编制

本文介绍了采用地理信息系统技术制作海洋环境质量评价图的基本内容，重点阐述了图件的表现形式、编制过程和具体的操作方法，为海洋环境质量评价图的制作提供了一种新的方法。     

草履虫──针杆藻群落对混合印染废水净化作用的条件实验

本文对混合印染废水的静态净化过程，进行了生物群落观察和条件实验。发现废水净化初期以大量细菌和草履虫（以 Ｐ． Ｃａｕｄａｔｕｍ为主）繁殖为特征，同时伴生着少量浮游藻类。随着净化过程的进行，细菌和草履虫数量下降，以针杆藻（以 Ｓ． ａｕｃｓ为主）为建群种的浮游藻类群落占优势。化学分析表明，净化作用与温度、光照条件及废水起始浓度有关。     

Analysis and improving ways for water condition in winter wheat field of dryland in subhumid areas of the loess plateau

Based on the soil moisture data from the locating experiments from 1986-1990, and using the water balance method, the water supply and demand state in the field of winter wheat, and the ways for improving water condition in dryland of subhumid by dry area of the Loess Plateau were studied. The results suggested that a low precipitation satisfying ratio of 42.9%-58.8% appears in the growing period of winter wheat, and the yield, to a great extent depends on the water that was stored in deep soil layer in the previous rainy season. The filed trial results showed that tillage in the summer fallow period,straw cover, soil moisture regulation with adequate fertilization, crop rotation and proper croppingsystem could be the efficient ways for improving the water condition,and for the exploitation and utilization of natural water resources(both precipitation and soil water) in the winter wheat field of dryland.