Modulation of the DNA repair system and ATR-p53 mediated apoptosis is relevant for tributyltininduced genotoxic effects in human hepatoma G2 cells

The toxic effects of tributyltin (TBT) have been extensively documented in several types of cells, but the molecular mechanisms related to the genotoxic effects of TBT have still not been fully elucidated. Our study showed that exposure of human hepatoma G2 cells to 1-4 μmol/L TBT for 3 hr caused severe DNA damage in a concentration-dependent manner. Moreover, the expression levels of key DNA damage sensor genes such as the replication factor C, proliferating cell nuclear antigen and poly (ADP-ribose) polymerase-1 were inhabited in a concentration-dependent manner. We further demonstrated that TBT induced cell apoptosis via the p53-mediated pathway, which was most likely activated by the ataxia telangiectasia mutated and rad-3 related (ATR) protein kinase. The results also showed that cytochrome c, caspase-3, caspase-8, caspase-9, and the B-cell lymphoma 2 were involved in this process. Taken together, we demonstrated for the first time that the inhibition of the DNA repair system might be more responsible for TBT-induced genotoxic effects in cells. Then the generated DNA damage induced by TBT initiated ATR-p53-mediated apoptosis.     

水中六六六与五氯苯酚的光催化氧化

以高压汞灯不光泊,ＴｉＯ２为催化剂,研究了水中低浓度六六六五与五氯苯酚的光催化氧化。六六六易被光催化氧化,其４种异构体的半衰期十分接近,均在２０ｍｉｎ左右。ＰＨ中性条件下γ六六六的氧化速率较高。六六六光催化氧化存在含氯中物,并可逐渐被氧化去除。五氯苯酚光催化氧化速率明显高于光分解。３０ｍｉｎ之内五氯苯酚即可完全脱氯。随反应过程的继续,五氯苯酚被氧化成简单的小分子直至完全矿化。该法在饮用水深度处理中     

改性凹凸棒土对水溶液中苯的吸附研究

研究了改性凹凸棒土对水溶液中苯的吸附规律。结果表明，改性凹凸棒土对苯的吸附量和去除率提高了２倍多，ｐＨ值对吸附量的影响甚小，吸附量随温度上升而增加，改进的ＢＥＴ方程能较好地描述实验等温线，其吸附机理可能为表面的疏水作用与化学吸附和进入内部孔道吸附。     

华南地区土壤中不同结合态腐殖质的三卤甲烷生成潜能

通过提取土壤中各结合态腐殖酸组分 ,研究华南地区不同土壤类型、不同结合态腐殖酸的三卤甲烷生成潜能 (THMFP) .结果表明 :①稳结态腐殖酸 (H2)的 THMFP最大 ,其次是松结态腐殖酸 (H1) ,紧结态腐殖酸 (H3)的 THMFP最小 ;②各土样不同结合态腐殖酸中 ,基本上是富里酸 (FA)的 THMFP大于胡敏酸 (HA)的 THMFP;③同属铁铝土纲的麻红壤、赤红壤和砖红壤 3者中 ,砖红壤各结合态腐殖酸的 CHCl₃生成量最小 ;④水稻土和湿潮土两者各结合态腐殖酸的 CHCl₃生成量的变化规律基本一致 .     

环境行政公益诉讼——以美、印经验为借鉴

环境行政公益诉讼的建立在我国具有理论上的依据,但是具体的构建尚需要借鉴成熟经验.本文介绍了世界公益诉讼的典范--美国环境的公民诉讼和具有巨大创造性的印度环境行政公益诉讼,这两个国家在环境公益诉讼上的经验,给我国建构环境行政公益诉讼提供了借鉴.     

我国废物进口综合管理技术对策研究

随着废物进口数量的增长、废物再生利用行业的成长、废物越境转移形势的变化和环境保护事业的不断发展,废物进口环境管理经历了从无到有并且逐步完善的过程,成为我国固体废物环境管理工作的重要内容。当前我国废物进口管理还存在着部分种类废物进口行业利用水平较低、废物非法越境转移压力长期存在和能力建设步伐与管理需求不相适应等问题。针对存在的问题,采取合理有效的应对措施,进一步完善相关法律、法规,推进“圈区管理”,鼓励统一管理和污染集中防治,探索建立企业环保信誉管理机制,加强源头风险控制,完善国际合作机制,使我国进口废物管理向兼顾环境、经济协调发展的综合管理模式转变。     

Simultaneous adsorption of lead and cadmium on MnO2-loaded resin

MnO2-loaded D301 weak basic anion exchange resin has been used as adsorbent to simultaneously remove lead and cadmium ions from aqueous solution. The e ects of adsorbent dosage, solution pH and the coexistent ions on the adsorption were investigated. Experimental results showed that with the adsorbent dosage more than 0.6 g/L, both Pb2+ and Cd2+ were simultaneously removed at pH range 5–6. Except for HPO4 2??, the high concentration coexistent ions such as Na+, K+, Cl??, NO3??, SO4 2?? and HCO3??, showed no significant e ect on the removal e ciency of both Pb2+ and Cd2+ under the experimental conditions. The coexistence of Mg2+, Ca2+ caused the reduction of Cd2+ removal, but not for Pb2+. The adsorption equilibrium for Pb2+ and Cd2+ could be excellently described by the Langmuir isotherm model with R2 > 0.99. The maximum adsorption capacity was calculated as 80.64 mg/g for Pb2+ and 21.45 mg/g for Cd2+. The adsorption processes followed the pseudo first-order kinetics model. MnO2-loaded D301 resin has been shown to have a potential to be used as an e ective adsorbent for simultaneous removal of lead and cadmium ions from aqueous solution.     

白色污染的外部性及其管控措施

随着经济的快速发展,白色污染造成的危害日益凸显.中国政府于1999年开始陆续颁布了一系列条例,限制"白色垃圾"的生产、销售和使用.但是,白色污染仍日趋严重.文章首先从分析白色污染的外部性入手,并且重点从经济学的角度讨论其外部性的具体表现.通过对现行政府征收排污税制度和实行排污许可证交易制度的效率比较,得出排污许可证交易是有效率的环境管控措施.     

公共资源类旅游景区水环境承载力研究 ——以武汉市东湖风景区为例

公共资源类旅游景区水环境受到社会经济系统和旅游系统两方面影响,本文通过选取人口、GDP、灌溉面积、游客量、宾馆日接待人数、TP、COD、BOD等指标,构建水环境承载力多目标模型.同时,选取水果湖、汤菱湖和郭郑湖3个子湖对东湖风景区水环境承载力进行评价,并运用层次分析法(AHP)确定各指标对东湖风景区水环境承载力的权重,采用典型水环境承载力概念模型计算了2011年武汉市东湖风景区水环境承载力.结果表明,东湖风景区水资源承载力表现为灌溉面积和GDP承载度超标,而人口和旅游指标承载度未达到饱和,水质承载力各指标的承载度超标.水果湖、汤菱湖和郭郑湖的水环境承载力分别为4.03、3.86、3.95,均大大超出负荷.     

UASB启动及不同浓度垃圾渗滤液的处理效果

在UASB反应器中接种好氧污泥培养厌氧颗粒污泥进行启动,研究不同浓度老龄(13年)垃圾渗滤液对处理效果的影响情况。通过保持进水COD浓度不变、逐步缩短HRT从而提高容积负荷到20 g COD/(L.d)的方法,可以培育出直径为1～3 mm颗粒污泥,最终产气量稳定在60～70 L/d,甲烷含量在50%～70%之间,COD去除率保持在90%左右,污泥层最底部MLSS为50 g/L。逐步提高进水中渗滤液的含量考察其对处理效果的影响,当进水为100%渗滤液时日产气量为500 mL/d、COD去除率仅为10%,表明渗滤液中多为难降解性有机物质。