Effect of surfactants at low concentrations on the sorption of atrazine by natural sediment.

A series of experiments were carried out to determine the effect of surfactants at low concentrations on the sorption of atrazine by natural sediments. With surfactant concentrations ranging from 0 to 20 mg/ L, anionic and cationic surfactants appreciably reduce the adsorption of atrazine, while nonionic surfactant decreases the adsorption of atrazine at concentrations equal to or less than 1 mg/L and increases adsorption at higher concentrations. Desorption of atrazine in the presence of different sodium dodecylbenzene sulfonate (SDBS) concentrations shows that a portion of the bound pesticide resists desorption in the SDBS free system. However, the addition of SDBS accelerates the desorption of atrazine. Furthermore, the nature of sediment and the contacting sequence of SDBS, at 10 mg/L, with the sediment, also influence the adsorption of atrazine. The conclusions in this study could be explained partially by the effect of the type and concentration of surfactants and the characteristics of sediments.     

交联壳聚糖冠醚的合成及其对金属离子的吸附性能

本文合成了交联壳聚糖苯并－１５－冠－５醚和交联壳聚糖苯并－１８－冠－６醚,研究了它们对Ａｇ（Ⅰ）Ｐｄ（Ⅱ）,Ｐｂ（Ⅱ）,Ｃｄ（Ⅱ）,Ｃｒ（Ⅲ）等金属离子的吸附性能和选择性,实验结果表明：无论是在单一金属离子体系还是在二元或三元金属离子体系中,ＣＣＴＳ－ＢＸ和ＣＣＴＳ－ＢＹ对Ａｇ（Ⅰ）和Ｐｄ（Ⅱ）者有较高的吸附选择性。     

Occurrence and volatility of several trace elements in pulverized coal boiler

The contents of eight trace elements(Mn, Cr, Pb, As, Se, Zn, Cd, Hg) in raw coal, bottom ash and fly ash were measured in a 220 t/h pulverized coal boiler. Factors affecting distribution of trace elements were investigated, including fly ash diameter, furnace temperature, oxygen content and trace elements‘ characters. One coefficient of Meij was also improved to more directly show element enrichment in combustion products. These elements may be classified into three groups according to their distribution: Group 1. Hg, which is very volatile. Group 2: Pb, Zn, Cd, which are partially volatile. Group 3: Mn, which is hardly volatile. Se may be located between groups 1 and 2. Cr has properties of both group ! and 3. In addition, the smaller diameter of fly ash, the more relative enrichment of trace elements (except Mn). The fly ash showed different adsorption mechanisms of trace elements and the volatilization of trace elements rises with furnace temperature. Relative enrichments of trace elements(except Mn and Cr) in fly ash are larger than that in bottom ash. Low oxygen content can not always improve the volatilization of trace elements. Pb is easier to form chloride than Cd during coal combustion. Trace elements should be classified in accordance with factors.     

Kinetics study of aqueous sorption of phenanthrene to humic acids and sediments

IntroductionThesorptionofhydrophobicorganiccontaminants(HOCs)onnaturalgeosorbentsplaysasignificantroleintheirtransport,degradationandultimatefateintheaquaticenvironment (Alexander,1995 ;Luthy ,1997;Weber,2 0 0 1) .Sincethelate 1970s,theorganicmatter(OM)ha…     

Progress in quantitative research on the relationship between atmospheric oxidation and air quality

Atmospheric oxidizing capacity (AOC) is an essential driving force of troposphere chemistry and self-cleaning, but the definition of AOC and its quantitative representation remain uncertain. Driven by national demand for air pollution control in recent years, Chinese scholars have carried out studies on theories of atmospheric chemistry and have made considerable progress in AOC research. This paper will give a brief review of these developments. First, AOC indexes were established that represent apparent atmospheric oxidizing ability (AOIe) and potential atmospheric oxidizing ability (AOIp) based on aspects of macrothermodynamics and microdynamics, respectively. A closed study refined the quantitative contributions of heterogeneous chemistry to AOC in Beijing, and these AOC methods were further applied in Beijing-Tianjin-Hebei and key areas across the country. In addition, the detection of ground or vertical profiles for atmospheric OH·, HO₂·, NO₃· radicals and reservoir molecules can now be obtained with domestic instruments in diverse environments. Moreover, laboratory smoke chamber simulations revealed heterogeneous processes involving reactions of O₃ and NO₂, which are typical oxidants in the surface/interface atmosphere, and the evolutionary and budgetary implications of atmospheric oxidants reacting under multispecies, multiphase and multi-interface conditions were obtained. Finally, based on the GRAPES-CUACE adjoint model improved by Chinese scholars, simulations of key substances affecting atmospheric oxidation and secondary organic and inorganic aerosol formation have been optimized. Normalized numerical simulations of AOIe and AOIp were performed, and regional coordination of AOC was adjusted. An optimized plan for controlling O₃ and PM_2.5 was analyzed by scenario simulation.     

久效磷对海洋微藻毒性机理的初步研究III.超氧化物歧化酶和过氧化物酶活性的变化

报道了久效磷对3种海洋微藻细胞内2种清除活性氧的关键性酶--超氧化物歧化酶和过氧化物酶活性的影响.结果显示:1.在久效磷的胁迫下,扁藻和三角褐指藻细胞的超氧化物歧化酶(SOD)活性均表现出下降的总变化趋势,而叉鞭金藻细胞的SOD活性时而上升,时而下降,在整个胁迫过程中呈现出无规律性的变化.2.随着久效磷胁迫时间的延长,3种微藻细胞的过氧化物酶活性均逐渐下降,表现出相同的变化规律性.这说明不同的藻种,久效磷对其细胞内酶活性的影响不尽相同.推测超氧化物歧化酶和过氧化物酶(POD)活性的降低是微藻细胞内过量产生活性氧,进而引起藻细胞膜脂过氧化伤害的主要原因之一.     

2,4,6—三硝基甲苯废水治理技术的研究进展

论述了２，４，６－三硝基甲苯废水中化学耗氧量和色度的研究进展情况，指出生化法中白腐菌综合治理２，４，６－三硝基甲苯废水的处理方法是目前极有前途的有效的技术。     

治理油类污染军港的一种新型处理系统

本文概述了设计集油污水接纳，分离处理，分析监控于一体的军港舰船油污水处理系统。该系统能全方位，快速安全地解决舰船油污水的接纳难题。该系统分离技术可靠，工艺设计合理，实用性好，适用性强，运用费用低，处理效果佳，达到了防止军港污染，保护海洋环境这一目的，收到了较好的环境，社会和经济效益。