接枝羧基壳聚糖的合成及其对重金属离子的吸附性能

以壳聚糖为基体,经环氧氯丙烷交联,制备了水不溶性交联壳聚糖,然后以Ｆｅ＾２＋－Ｈ２Ｏ２为引发剂,将丙烯腈单体接枝到ＣＣＴＳ分子骨架上,经皂化制得了水溶性接枝羧基壳聚糖聚合物。     

重庆缙云山四川大头茶常绿阔叶林重金属元素的累积与生物循环

四川大头茶,常绿阔叶林,重金属,循环,净化     

鄱阳湖流域重金属污染评价与分析

为分析评价鄱阳湖流域重金属积累污染情况,采集流域内沉积物及土壤样品,测定其Cu、Pb、Zn、Cr、Cd、As、Hg含量以及pH、氧化还原电位(Eh)、有机质(SOM)以及黏粒含量等理化参数,采用地累积指数法、潜在生态危害指数法评价流域内沉积物及土壤的重金属污染水平,利用相关性分析法及主成分分析法解析重金属污染的影响因素...     

高分子重金属絮凝剂对 Hg2+的捕集及性能

以含Hg^2 废水作为处理对象,研究了几个影响高分子重金属絮凝剂去除水中Hg^2 的因素,实验表明：(1)pH值对Hg^2 的去除率影响不大;(2)水中某些二价离子的存在不仅不会消耗高分子重金属絮凝剂的用量,而且会促进螯合体MHM-Hg^2 絮凝沉淀,Hg^2 的去除率在99％以上,而一价金属离子对处理效果影响不大;(3)Hg^2 和致浊物质会互相促进彼此的去除,浊度的去除率在98％以上,Hg^2 的去除率在99％以上;(4)高分子重金属絮凝剂对重金属离子具有选择性,可将部分重金属离子从其它离子中分离开、回收再利用．     

Environmental risk assessment for trisodium [S,S]-ethylene diamine disuccinate, a biodegradable chelator used in detergent applications

Environmental safety data are presented for [S,S]-Ethylene Diamine Disuccinate ([S,S]EDDS), a new, biodegradable, strong transition metal chelator. An environmental risk assessment for its use in detergent applications, which takes into account the chelating properties of [S,S]-EDDS, is proposed.

A property of [S,S]-EDDS that distinguishes it from other strong transition metal chelators is its, “ready” and transparent (no recalcitrant metabolites) biodegradation profile. Because its sorption to activated sludge solids is low ( Kp of 40 1/kg), removal of [S,S]EDDS during sewage treatment, which is greater than 96% as determined by the Continuous Activated Sludge test , is mainly ascribed to biodegradation. At projected use volumes in detergent applications [S,S] - EDDS predicted steady-state concentration in rivers leaving the mixing zone will be below 5 pg/I due to rapid biodegradation. [S,S]-EDDS exhibits low toxicity to fish and Daphnia ( both EC₅₀s> 1000 mg/l). By contrast, due to limitation of the algal test for chelators apparent toxicity was observed (EC₅₀ = 0.290 mg/l, NOEC - No observable Effect Concentration = 0.125 mg/l). Schowanek et al. [1] demonstrated that this is not toxicity sensu stricto but a chelation effect of trace metals in the test medium and of resulting essential nutrients limitation. This requires specific attention when the results of algal toxicity are to be extrapolated to a field situation to perform realistic risk assessment. Metal speciation calculations, using MINEQL+, show that at the predicted environmental concentrations of [S,S] - EDDS (1–5 μg/l), such a chelation effect would be insignificant. These calculations allow to estimate the NOEC for chelation effects in the field to be in the range of 0.250-0.500 mg/l, depending on the background water chemistry. These values are well above the laboratory NOEC.

An environmental risk assessment was performed using the EUSES (1.0) program. EUSES is currently the EU recommended tool for conducting risk assessments (TGD 1995). It was applied to estimate the river water and soil concentrations from production, formulation and private use life stages. The estimated PEC/PNEC ratio in all relevant environmental compartments is smaller than 1, indicating “no immediate concern” at the anticipated usage level.     

焦作市中马村矿土壤重金属污染调查评价

对焦作市中马村矿矸石山周围土壤中5种重金属(Cu、Cr、Pb、Zn、Mn)的含量、分布特征及其污染状况进行了调查与评价。结果表明,矿区土壤不同程度地受到5种重金属的污染,依次为Zn>Pb>Cu>Cr>Mn;土壤综合污染指数为1. 74,属轻污染; 5种重金属元素中Zn、Pb相关性显著,其余均为低度相关。     

重金属螯合剂在废水治理中的应用研究

研究重金属螯合剂的实验室合成及其捕集重金属的机理,对其处理重金属废水的效果与无机稳定化药剂Ｎａ２Ｓ进行了实验比较。     

污染稻、麦籽实中Cd、Cu、Pb的分布及其存在形态初探

采用组织化学及溶剂提取法研究了污染水稻、小麦籽实中Cd、Cu、Pb的分布及存在形态．结果表明,3种金属元素在水稻、小麦籽实各形态结构中的浓度具有明显不均一性,胚中浓度显著高于胚乳,颖壳,皮层中浓度也较高;糙米、麦粒中的Cd、Cu、Pb在去离子水、0.1mol EDTA、1％醋酸、2.5％　NaCl、0.2％NaOH、70％乙醇中的溶出比例有显著差异;综合2项试验结果可以看出Cd、Cu、Pb在籽实中主要与谷物成分结合形成配合物,其优势形态是蛋白质结合态．     

CuO对贵金属/CeO2/Al2O3催化剂的作用

制备含少量贵金属Ｐｔ、Ｐｄ的不同Ｃｕ和Ｃｅ摩尔含量比（０：１０,１：９,２：８）的催化剂,实验条件十加入ＣｕＯ可以提高Ｐｔ催化剂的二效活性;加入Ｃｕ：Ｃｅ＝２：８的ＣｕＯ降低了Ｐｄ催化剂的顾效性能,然而Ｃｕ：Ｃｅ＝１：９时可以改善Ｐｄ催化剂的三效催化性能。通过结构分析,认为ＣｕＯ的存在可以提高ｄ催化剂的比表面积,ＰｄＯ的分散度。     

矿山土复垦利用试验

利用分层随机取样法取得开滦矿区范矿南矸石回填复土区不同复土方式、不同复土年份、不同土地利用形式及不同深度的矿山土样品,对矿山土的养分状况、酸性污染与重金属污染规律进行了研究．结果表明,矸石回填复土区完全可以种植白菜、白薯、大豆、葡萄、紫穗槐等植物;此类矿山土的酸性污染可以通过条带式复土、全面复土方式得到有效地控制,而穴植法效果不佳,养分状况可通过种植紫穗槐或牧草得到改善;重金属元素含量没有超标,但试验点的矿山土培肥及表土受空气与粉尘污染造成表土的重金属元素含量高于30cm处土壤．