THE IMPACT OF URBANIZATION ON THE DISTRIBUTION OF HEAVY METALS IN BOTTOM SEDIMENTS OF THE SADDLE RIVER1

ABSTRACT: A three-year study has been conducted on a 4.6 mile stretch of the Saddle River near Lodi, New Jersey. The primary objectives of this investigation were (1) to provide baseline information on the concentration and distribution of heavy metals in bottom sediments of the Saddle River; (2) to qualitatively evaluate which parameters affect this distribution; and (3) to determine the effect of urbanization on the concentration and distribution of these materials. Significant enrichments of several heavy metals were observed in bottom sediments of the lower Saddle River near Lodi, New Jersey, as compared to the upper Saddle River. Attempts to correlate metal concentrations in bottom sediments with chemical-oxygen demand were not successful in demonstrating a relationship between these two factors. Metal concentrations were found to be strongly dependent upon particle size. In general, metal concentrations in bottom sediments increased with decreasing partical diameter. However, metals enrichment was observed to be considerably greater in the larger sediment fractions studied (>420μ) than the smaller sediment fractions as one proceeded downstream through the urban area. Since the larger sediment fractions are least effected by scour and transport they may best reflect the effect of urbanization on the distribution of heavy metals over an extended period of time at a given location.     

Lead adsorption capacities of different components in natural surface coatings

Pb adsorption capacities of Fe oxide, Mn oxide and organic materials in natural surface coatings (biofilms and associated minerals) collected in three lakes, two ponds and a river in Jilin Province, China and Cayuga Lake in US were studied. A novel extraction technique was employed to remove one or more component(s) from the surface coatings. Pb adsorption to surface coatings before and after extraction was performed to determine the adsorptive properties of the extracted component(s). The statistical analysis of observed Pb adsorption was carried out using nonlinear least squares fitting (NLSF) to estimate the Pb adsorption capacity of each component of surface coatings. For each body of water, the estimated Pb adsorption capacity of Mn oxide( mol Pb/mol Mn) was significantly higher than that of Fe oxide( mol Pb/ mol Fe). The value of estimated adsorption capacities of organic materials with the unit mol Pb per kg COD was similar to or less than that of Fe oxides with the unit mol Pb per mol Fe. Comparison of components of surface coatings in different waters showed that the estimated Pb adsorption capacities of components in surface coatings developed in different natural waters were different,especially for Mn oxides.     

废干电池中锌和汞的分布及其处理

由于民众缺乏环境意识和国家没有相应法规 ,大多数废干电池都随手丢弃 ,回收的废电池处于不同程度的腐蚀状态。介绍了锌、汞在废干电池中的分布状态以及腐蚀对其分布的影响 ,并根据它们的分布特点提出用真空法回收废干电池中的锌、汞。     

铜锰型催化剂对低浓度乙醇的催化燃烧性能

乙醇汽油车尾气中除了传统汽油车的三大常规污染物（CO、NO_x和HCs）,还含有导致光化学烟雾和臭氧污染的醇醛类非常规有机物。采用共沉淀法制备了CuO_x、MnO_x和CuMnO_x催化剂用于乙醇汽油车冷启动排放的低浓度乙醇的催化燃烧,同时采用氮气吸附脱附技术（BET）、X射线衍射（XRD）、氢气程序升温还原（H₂-TPR）、扫描电子显微镜（SEM）、X射线光电子能谱（XPS）对催化剂进行了表征。研究表明,CuMnO_x催化剂对低浓度乙醇具有较好的低温催化活性;当反应温度为185 ℃时,CO₂产率可达86%,优于单一的CuO_x催化剂（约20%）;同时,CuMnO_x比MnO_x具有较高的CO₂选择性。Cu、Mn之间的相互作用改变了催化剂的织构、结构和氧化性能,引起了催化剂表面晶貌和电子环境的变化,使得CuMnO_x催化剂表面具有大量的氧缺陷位,有利于氧分子在其表面的吸附,进而活化成表面活性氧物种。

     

逆流流动注射在线萃取火焰原子吸收法测定水样中的铜、铁、铅、锰

采用逆流流动注射在线萃取,用ＡＰＤＣ＋ＤＤＴＣ为络合剂,ＭＩＢＫ作萃取剂,与火焰原子吸收光谱仪联用测定Ｃｕ、Ｆｅ、Ｐｂ、和Ｍｎ的灵敏度,分别提高了３５．７、３４．３、４８．７和４１．６倍,检测限分别为１．６、７．５、３．３、２．１μｇ／Ｌ,该法用于含这些重金属很低的饮用水和环境水样的测定,获得了满意的结果。     

微生物对砷的氧化还原竞争

滤池被广泛运用于饮用水厂中,前期研究发现某水厂生物滤池处理含砷地下水时,一方面三价砷可被生物氧化锰氧化为五价砷,另一方面滤池系统中存在的微生物砷还原酶可促使五价砷还原为三价砷,而滤池表面存在的这种微生物竞争关系会影响滤池的稳定性及处理效率.为探讨其内在机制,本研究选取1株锰氧化模式菌(Pseudomonas sp.QJX-1)和1株砷还原模式菌(Brevibacterium sp.LSJ-9),考察在Mn2+、As(As3+、As5+)共存时,两菌株对空间、营养物质以及对砷氧化/还原的竞争关系.结果表明,不同的反应时间,Mn、As质量浓度/价态不同,三价及五价砷体系中,Pseudomonas sp.QJX-1生成的锰氧化物在砷的氧化还原反应中占主导地位,即能迅速氧化本身存在的As3+(三价砷体系)和砷还原菌产生的As3+(五价砷体系),最终两体系中砷都主要以As5+的形式存在.PCR及RT-PCR结果表明,反应过程中锰氧化菌功能基因(cum A)抑制了砷还原酶(ars C)的表达,锰氧化菌16S rRNA表达量始终比砷还原菌高两个数量级,即锰氧化菌在生长竞争过程中占优势.实验结果表明滤池的水力停留时间是决定出水中砷价态的一个重要因素.     

文山县饮用水水源铁锰超标调查研究、处理方法及建议

结合文山县当前饮用水源中铁锰超标的实际情况,分析了周边环境对文山县饮用水水源地的影响,阐述了饮用水中铁、锰超标对人体健康的危害,提出了解决饮用水中铁锰超标问题的必要性和可行方法,并提出相关的对策和建议。     

浅谈地下水净化厂除铁除锰试验及应用

通过对齐齐哈尔市自来水公司铁锋水厂除铁、锰工艺的分析,得出曝气接触氧化除铁、锰是一种好方法.     

钱塘江杭州段沉积物中铁锰的分布特征

针对钱塘江杭州段水污染现状,对钱塘江杭州段12个采样断面的沉积物进行了系统研究。结果表明,沉积物Fe、Mn的平均含量分别为2.05%,449 mg/kg,变异系数分别为16%、27%。主成分分析结果表明,Fe、Mn、K具有一定的同源性,代表沉积物的自然来源,Fe、Al的分布情况反映两者之间可能存在一定的同源性。相关性分析结果表明,Fe、Al、K均与粘粒显著或极显著相关,反映了地球化学作用和水文条件相互作用的结果;Mn与有机污染(OM)呈显著负相关,说明Mn的污染源与OM不存在同源性,相反,有机质污染导致沉积物锰含量有所降低,两者可能存在密切关系。     

洱海沉积物有机质、铁、锰对磷的赋存特征和释放影响

利用SMT磷连续提取分级方法研究了洱海表层沉积物中磷的赋存特征,探讨有机质(OM),Fe和Mn对磷赋存形态及释放的影响,同时评估了洱海沉积物磷的释放风险. 结果表明:洱海表层沉积物w(TP)为710.3～1 961.2 mg/kg,其中w(Ca-P)最高(占36.9%～59.2%),w(OP)次之(占24.6%～36.9%),w(Fe/Al-P)最低(占9.8%～20.7%);w(OM)为25.0～119.6 mg/g,与w(TP)和w(Ca-P)呈显著负相关;w(总锰)为0.8～3.8 mg/g,w(总铁)为34.3～127.2 mg/g,均与w(TP)及其各形态磷含量呈显著正相关. 沉积物中w(Fe/Al-P)/w(Ca-P)比低于0.5,且w(总铁)/w(TP)远大于20,表明磷释放强度小,但w(TOC)/w(OP)<200,说明有机磷的潜在释放风险较大. w(TP)及其各形态磷含量均与无定形铁氧化物(Feo-Fep)含量呈显著正相关,而与结晶态铁氧化物(Fed-Feo)含量的相关性不显著,且全湖沉积物中的铁氧化物以Feo-Fep为主,表明洱海沉积物磷释放主要受Feo-Fep控制.