不同固体浓度下不同菌去除重金属效果

在污泥中分别接种10％的氧化硫硫杆菌菌液与氧化亚铁硫杆菌菌液，研究了不同菌种情况下，10g／L到40g／L梯度的污泥浓度对生物淋滤重金属Zn和Cu的影响。实验表明，在不同固体浓度下两种菌对污泥中Zn和Cu的去除率都很高，污泥浓度越低，污泥中重金属的去除率越高。淋滤过程中，低固体浓度污泥，氮、磷、钾及有机质等营养物质流失量比高固体浓度污泥明显增多；而同浓度下，氧化硫硫杆菌在去除污泥中重金属的同时，营养物质的损失小于氧化亚铁硫杆菌。     

施用城市污泥对土壤中重金属积累和迁移的影响

目的 了解城市污泥农用后土壤重金属的积累和迁移。方法 于1998年分不同季节，从苏州、无锡、常州3个城市污水处理厂采集污泥样本，用原子吸收光谱仪分析样本中重金属(Pb、Zn、Cu、Cd、Hg、As)含量和不同形态含量，分析污泥农用后土壤重金属积累及迁移特性。结果 城市污泥重金属含量远高于土壤背景值，3城市污泥中Zn含量均超标，分别达到1199，00、784．00、1216．00mg／kg。长期施用能导致土壤重金属积累。污泥中重金属具有一定的活性和潜在迁移性。结论 城市污泥农用可能会导致土壤和生物体重金属积累，存在着一定的环境重金属积累风险。     

三峡库区消落区土壤沉积物中重金属的形态及其环境影响分析

为了解不同的库岸生产活动对土壤重金属形态分布情况的影响,从而为三峡库区消落区的环境规划和保护提供科学依据,于2009年1—3月期间,从小江开县段消落区选取临江、竹溪、镇安、桃花溪、丰乐、开县调节坝6个断面进行土壤沉积物的采集。采用原子吸收光谱法测定土样中的Pb、Cu、Cd、Zn4种重金属的含量。采用Tessier形态分类法分析消落区土壤沉积物中痕量重金属元素Cu、Pb、Zn、Cr的存在形态。结果表明,三峡库区消落区土壤沉积物中Cd、Cu、Pb、Zn的含量分别为1.02、21.62、126.98、76.23mg/kg,三峡库区消落区6个采样点土壤中重金属主要以残渣晶格结合态为主,但Cd和Cu的金属可交换态构成比较高,很容易进入植物生态系统和水环境威胁库区环境。     

医疗垃圾焚烧过程中重金属污染物分布特征研究

分别选取回转窑窑尾、布袋除尘器灰斗、洗涤塔塔底和烟囱口采集炉渣、飞灰、淋洗液和烟气样品,探究医疗垃圾焚烧时重金属污染物在整个回转窑焚烧系统中的空间分布特征。结果显示:医疗垃圾样品中Zn占36%、Fe占29%、Pb占19%、Cd占10%、Cu占4%、Mn占2%。炉渣、飞灰、淋洗液和烟气中重金属含量分布差异较大,分别占总量的10%、60%、30%、不到万分之一。像Cd、Zn、Pb和Cu等低沸点重金属随着烟气在焚烧系统中的迁移,其分布规律基本相同,主要集中在飞灰中;而对Fe这类熔沸点相对较高的重金属来说,在炉渣、飞灰和淋洗液中的分布相对比较平均,其中淋洗液中Fe的含量最高。     

猪粪、底泥和土壤中6种重金属测定与污染情况分析

目的 了解猪粪、底泥和土壤中的重金属污染情况。方法 采集某县2个不同规模生猪养殖场的猪粪、附近水源水底淤泥和农田土壤样品，参照GB/T 17141—1997,采用酸消化法对样品进行消化处理，通过测定标准物质确定和优化测定方法后，采用石墨炉原子吸收光谱法(GF-AAS)测定重金属Cd,电感耦合等离子体发射光谱法测定重金属元素Pb、Cu、Zn、Cr、Ni等，绘制标准曲线，计算方法的检出限和定量限，测定30份样品含量后对其重金属含量进行评估。结果 Pb在0～500μg/L,Cd在0～10μg/L,Cu、Ni、Cr、Zn在0～1 000μg/L质量浓度范围内线性良好，相关系数均>0.999;相对标准偏差(RSD):Cd为1.50%～5.12%,Pb、Cr、Cu、Zn、Ni为1.25%～3.52%;方法检出限：Cd为0.042 mg/kg, Pb、Cr、Cu、Zn、Ni分别为0.038、0.048、0.162、0.044、0.384 mg/kg。与底泥和土壤样品相比，猪粪样品中Cu、Zn、Cd的含量较高，Pb、Cr、Ni含量较低，差异均有统计学意义(t值分别为6.78～36.12,P值均&...     

公路交通对土壤重金属污染的研究

目的评价公路交通引起的土壤中重金属污染。方法选择320国道马龙路段进行耕作土采样,用原子吸收光谱法和分光光度法分析土壤中重金属Cu、Cd、Pb、Zn、Cr、As、Ni含量,采用清洁对照区土壤剖面重金属含量作为参比值,应用地积累指数法对重金属污染叠加进行评价。结果研究区土壤中Cu、CA、Pb、Zn、Cr、As、Ni的含量显著高于对照区（P〈0．01）。Cd为中等污染～强污染,Pb为中等污染,Cr和Cu为轻污染～中等污染。污染晕带沿公路延伸方向展开,自公路起向其两侧强度运渐减弱,扩散范围约为150m。土壤对重金属元素的吸收及污染程度;Cd〉Pb〉Cr〉Cu〉As〉Zn〉Ni。结论公路旁土壤重金属污染以Cd、Pb和Cr为主,污染叠加重金属来源主要为机动车燃料、轮胎、机械中所含微量重金属成分。     

山东某大学116例学生头发中重金属含量调查

目的调查山东某大学学生头发中重金属的含量及可能的影响因素。方法采集山东某大学116位大学生的头发样本,测定其中Pb、Cd、Cu、Zn的含量,并用统计分析的方法从性别、生源地及是否染发等方面分析影响头发中重金属元素含量的可能因素。结果样本中Pb含量平均值为8.99μg/g,Cd为0.44μg/g,Cu为8.87μg/g,Zn为50.49μg/g,其中Zn含量低于建议值,染发同学头发中的Pb含量明显高于非染发同学头发中的含量;男女生4种重金属元素含量差异不显著;不同生源地学生头发中Cu、Zn含量差异不显著,但来自淄博地区的学生头发样本中Cd、Pb含量均显著高于其他地区;城市生源学生头发中重金属含量高于农村生源学生,Pb、Cu、Zn 3种重金属在组间存在显著差异性。结论样本中4种重金属元素含量与正常值相比均未超标,但大学生存在缺Zn问题;性别、生源地(除淄博外)不是影响头发中重金属元素含量的可能因素;城市源或农村源是影响头发中Pb、Cu、Zn含量的可能因素;是否染发是影响头发中重金属元素含量Pb的可能因素,这进一步证实染发对人体健康有潜在危害。     

铁浆法回收垃圾焚烧飞灰中重金属的实验研究

为考察铁浆法回收生活垃圾焚烧飞尘中重金属的可行性,研究了NaCl浓度、铁粉/飞尘、pH及处理时间对重金属回收率的影响,结果表明:铁浆法回收生活垃圾焚烧飞尘中的重金属是可行的。在最佳参数为NaCl浓度0.5mol/L、pH为4、铁粉/飞尘为2、处理时间2 h条件下,飞尘中Pb、Cu、Zn、Cd等重金属回收率可分别达到88.6%、86.7%、90.3%、83.3%。     

太原市晋源区土壤中重金属及微量元素与畸胎发生率的关系

目的探讨太原市晋源区先天性畸胎发生率高的原因.方法以土壤及蔬菜中重金属和微量元素含量为指标,在晋源区和对照区采土壤和蔬菜样品,用原子吸收分光光度仪测定Cd、Pb、Mn、Zn、Cu的含量.结果晋源区土壤和蔬菜中Zn、Mn含量低,Cd、Pb含量高,Cu含量未见显著性差异.结论土壤和蔬菜中Cd、Pb含量高,Zn含量低可能是导致畸胎发生率高的原因,Mn含量低是否可导致畸胎还需进一步研究.     

A、B两污灌农田土壤重金属含量分析及污染评价

[目的]通过对A、B两污灌农田土壤中重金属元素镉(Cd)、铬(Cr)、铜(Cd)、镍(Ni)、锌(Zn)、铅(Pb)含量调查与分析,评价其污染程度,了解其重金属污染现状. [方法]土壤样品经王水+HCLO4消化彻底后,采用电感耦合等离子体原子发射光谱法(ICP-AES)测定重金属含量,并采用重金属单项污染指数法和综合污染指数法对污染状况进行评价. [结果]A区域土壤的Cd、Cu、Pb、Zn含量超标;B区域土壤的Cd、Zn含量超标. [结论]A、B两区域土壤重金属污染均为重度污染(P＞3),土壤受污染已相当严重.     

Evaluation for Agricultural Usage with Speciation of Heavy Metals in a Municipal Sewage Sludge

This study was carried out to evaluate the agricultural usage of an anaerobically digested sludge in the contents and fractions of heavy metals. Therefore, a sequential extraction scheme according to the BCR's (Community Bureau of Reference) guidelines and total acid digestion were applied to sewage sludge samples. The results of total heavy metal concentrations in sewage sludge showed that the highest total concentrations were Fe, Zn and Mn. When Turkish, Europe and US EPA directives were compared with each other by depending on the use of sludge for agricultural purposes, all the heavy metals determined for this sludge were below the maximum permitted levels, except for Cd. This sludge should not be applied to land due to its high Cd content. The results of heavy metal fractions indicated that some metals (Cd, Mn, Pb, and Fe) distributed mainly in the residual fraction. All fractions of Zn showed no variation. Cu and Cr were most abundant in the oxidizable phase while Ni was in exchangeable phase. Although total content of Ni in the sludge is lower than the maximum levels allowed by all the directives, it tends to be easily moved and dispersed in the environment. Due to its high mobility, the examined sewage sludge may cause phyto-toxicity after its agricultural application.     

延安市污水处理厂各工段重金属元素的含量分析

采取延安市污水处理厂各工段污水,利用电感耦合等离子体发射光谱法(ICP-AES),对其中Zn、Cu、Pb、Mn和Cr 5种重金属元素的总量进行测定,结果表明部分活性污泥回流到厌氧池后,几种重金属元素在厌氧池和氧化沟中的去除率都较高。     

Composition of toxicants and other constituents in yard or sludge composts from the same community as a function of time-of-waste-collection

Samples of yard waste compost and sewage sludge compost were analyzed for toxic and nutrient elements and PCBs to assess variations in their concentrations as a function of the time of delivery of the initial organic material to the same composting site. In general, the variations in composition found were remarkably small. Generally, the samples of sludge compost were higher in Ca, Cd, Cu, Fe, Hg, Mo, Na, P, Pb, S, Se, Zn, and PCBs than those of the yard waste compost. The latter was higher in Cr, Ni, K, Mg, and Si. Possible factors affecting compost composition are discussed.     

Bioaccumulation of Heavy Metals by Aquatic Macrophytes around Wroc aw, Poland

Studies were made of heavy metal accumulation in aquatic macrophytes growing in streams and ponds around Wroc aw, Poland, partly affected by atmospheric pollution, effluents of chemical factories, and groundwater contaminated by slagdumps from a smelter and power station. The highest concentrations of Cd, Co, Cr, Cu, Hg, Ni, Pb, and Zn in surface water and aquatic macrophytes surpass the average values established for background reference sites. Significant positive correlations were found between Cu contents in water and Cu, Cd, and Zn contents in plants, between Cu and Cd in plants, between Co and Ni in plants, between Ni contents in water and Ni and Cu contents in plants, between Zn in water and Cu in plants, and between Cd and Ni in plants. Negative correlations were found between Cd contents in water and Zn contents in plants, between Co in water and Cd in plants, and between Zn in water and Co in plants. Experiments with the liverwortScapania undulataoriginating from a clean, forested, mountain stream and cultivated in solutions containing 70–100% sewage from a chemical factory demonstrated an increase in lead content (85 times in 100% sewage and 58 times in 70% sewage) and in mercury content (40 times in 100% sewage and 20 times in 70% sewage), and also an increase in contents of Cd, Cr, Cu, and Ni. Exposure to 70% sewage concentration during the 14 days of the experiment may be recognized as harmless forS. undulata,so this liverwort could be used in biotechnical purification of water.     

Effects of Composting Process and Fly Ash Amendment on Phytotoxicity of Sewage Sludge

With the increasingly growing global production of sewage sludge, evaluation of its applicability in agriculture and land restoration is essential. This study assessed the potential effects of composting process and fly ash amendment on soil-ameliorating properties of sewage sludge. The metal availability and phytotoxicity of ash-amended sludge compost (AS, mature sewage sludge compost mixed with fresh lagoon ash) and sludge-ash co-compost (SA, co-composted mixture of sewage sludge and lagoon ash) were compared. The results of this work suggested that both composts favored the applicability of sewage sludge for land application by reducing Cd, Cu, Pb, and Zn availability. The SA co-compost stimulated seed germination at ash amendment rates of ≤10%, whereas various treatments of AS compost inhibited germination at an extract dilution of 50%. Amendment of lagoon ash before or after sludge composting increased electrical conductivity (EC) and volatilization of NH₄-N, but lowered availability of PO₄-P. Together with the results of phytotoxicity, an optimal ash amendment rate of 5% for AS and 10% for SA were most desirable. Alkaline amendment prior to sludge composting was recommended, because it could be more effective in reducing soluble and plant-available metal concentrations through the composting process. Received: 1 October 1999/Accepted: 31 May 2000     

Phytotoxicity of municipal sewage sludge composts related to physico-chemical properties, PAHs and heavy metals

The aim of the study was to determine the influence of the composting on the phytotoxicity of sewage sludge in relation to their physical-chemical properties, heavy metals and polycyclic aromatic hydrocarbons content. Four municipal sewage sludges were composted for 76 days. A Phytotoxkit Test and pot experiment with Lepidium sativum were used for bioassay. The total PAH content in sludges ranged from 3674.1 to 11236.3 microg kg(-1). Heavy metals content was in the range Cd (1.9-76 mg kg(-1)), Cr (27.6-120 mg kg(-1)), Cu (156-335 mg kg(-1)), Pb (37.5-59.5 mg kg(-1)), Ni (21.7-155 mg kg(-1)) and Zn (1015-1385 mg kg(-1)). The results showed a varied toxicity of sewage sludge in relation to the plant tested. In the case of two sludges a 100% inhibition of seed germination were noted. Sludge composting limited their negative influence on most of the phytotoxicity parameters. Only chlorophyll concentration was often lower than in the plant bred on compost obtained from sludge.     

Survey of toxicants and nutrients in composted waste materials

Currently, there is much activity in composting yard wastes (leaves, twigs, grass), sewage sludge and portions of municipal solid wastes (MSW) in the United States. The resultant compost is typically applied to agricultural or recreational land. A nationwide analytical survey was therefore conducted of 21 toxic and nutrient elements, polychlorinated biphenyls (PCBs) and gamma emission in 26 composts sampled nationwide in 1991. Those composts produced solely from sludge or MSW tended to be higher in metals such as Cd, Cu, Hg, and Zn as compared to totally yard waste compost. Molybdenum, P and Se were higher in composted sewage sludge and Na and Pb in composted MSW than in yard waste compost. PCBs and gamma emission were low or not detectable in most compost samples. Shards of metal and glass found particularly in MSW-containing composts would detract from its application especially in recreational areas. References dealing with the reactions of metals in composts and environmental effects of compost application to land are cited.     

Solubility of Trace Elements and Heavy Metals from Stabilized Sewage Sludge by Fly Ash

Stabilized sewage sludge (SS) by fly ash (FA) and alkaline mine tailing as artificial soil, to be applied on the ecological rehabilitation at mining junkyard, offers a potential viable utilization of the industrial by-product, as well as solves the shortage of soil resource in mine area. In this study, trace element and heavy metal soil solution concentrations arising from fly ash, sewage sludge, mine tailing, and artificial soil mixtures were investigated in a laboratory incubation. It was found that total Cd, Pb, and Zn contents in artificial soils were significantly lower than the control standards for pollutants in sludges from agricultural use (GB 4284-84). Soil solution Cd and Pb concentrations were obviously reduced by mixing sewage sludge with alkaline fly ash. Initial soil solution Cd, Pb, and Zn concentrations in artificial soils were 1.773–14.672, 4.05–24.95, and 133–608 μg L⁻¹, respectively, and after 35-days incubation, soil solution Cd, Pb, and Zn concentrations gradually decreased and were approaching control levels by the end of the experiment, and finial soil solution were decreased to 0.037–0.365, 2.12–7.34, and 29–509 μg L⁻¹, respectively.     

Metal-metal interactions of dietary cadmium, copper and zinc in rainbow trout, Oncorhynchus mykiss

The influence of metal-metal interactions on uptake, accumulation, plasma transport and chronic toxicity of dietary Cu, Cd and Zn in rainbow trout (Oncorhynchus mykiss) was explored. Juvenile rainbow trout were fed diets supplemented with (μg/g) 500 Cu, 1000 Zn and 500 Cd singly and as a ternary mixture at 2.5% body weight daily ration for 28 days. Complex interactions among the metals dependent on the tissue/organ, metals ratios and duration of exposure were observed. While Zn did not accumulate, whole-body Cd and Cu concentrations increased following linear and saturation patterns, respectively. Early enhanced whole-body Cu accumulation in fish exposed to the metals mixture was correlated with reduced Cd concentration whereas late enhancement of Cd accumulation corresponded with elevated Cd concentration. This suggests early mutual antagonism and late cooperation between Cd and Cu probably due to interactions at temporally variable metal accumulation sites. At the level of uptake, Cd and Cu were either antagonistic or mutually increased the concentrations of each other depending on the duration of exposure and section of the gut. At the level of transport, enhanced Cd accumulation in plasma was closely correlated with reduced concentrations of both Zn and Cu indicating competitive binding to plasma proteins and/or antagonism at uptake sites. Compared to the Cu alone exposure, Cu concentrations were either lower (gills and carcasses) or higher (liver and kidney) in fish exposed to the metals mixture. On the other hand, Cd accumulation was enhanced in livers and carcasses of fish exposed to the mixture compared to those exposed to Cd alone, while Zn stimulated Cu accumulation in gills. Chronic toxicity was demonstrated by elevated malondialdehyde levels in livers and reduced concentrations of Zn and Cu in plasma. Overall, interactions of Cd, Cu and Zn are not always consistent with the isomorphous competitive binding theory.     

某大型医院污水处理净化效果

目的了解膜生物反应池和次氯酸钠消毒对医院污水的净化效果.方法于2005年5月,检测天津医科大学总医院污水处理站的污水处理效果.在污水经膜生物反应池处理前后及次氯酸钠消毒后分别取水样测定pH值、悬浮物、CODCr、BOD5,氨氮、粪大肠菌群及余氯.结果经膜生物反应池处理后,悬浮物、CODCr、BOD5、氨氮、粪大肠菌群的去除率分别为82.25%,80.25%,75.52%,75.84%,96.75%;经次氯酸钠消毒后,水中粪大肠菌群的去除率为99.96%,余氯为3.4mg/L.结论膜生物反应器结合次氯酸钠消毒的方法对医院污水有很好的净化效果,达到GB 8978-1996《污水综合排放标准》二级标准.