污泥混配土淋溶液中pH、氮磷及重金属含量的动态变化

以北京市大兴区庞各庄镇污水处理厂的堆肥污泥、生污泥和通州区的熟土为对象,探讨污泥混配土淋溶液中相关指标的动态变化.结果表明,生污泥、堆肥污泥和熟土混配后可降低土壤pH值,增加土壤全氮、全磷含量,同时也增加了土壤中重金属As、Cd、Ni、Cu、Ph的含量,生污泥系列淋滤液中Pb对地下水造成污染的可能性最大;堆肥污泥系列淋滤液中给地下水带来污染可能性最大的因子是As.但各处理中重金属的污染程度都很低,基本符合国家第II类地下水水质标准,因此淋滤液中的重金属基本不会对地下水造成污染.     

稀土对缓解油菜镉胁迫的研究

长期利用污水灌溉、污泥改良土壤以及化学农药和化肥的不合理施用,会使农用土壤受到重金属不同程度的污染[1] ,且以重金属镉(Cd)污染最为普遍关注.     

污泥与施污土壤重金属生物活性及生态风险评价

将城市污泥以不同质量比施于土壤中构成污泥混合土壤,研究各污泥配比土壤中重金属的生物活性,并采用三种重金属评价方法(地累积指数法、潜在生态风险指数法、综合毒性指数模型)和黑麦草对重金属的吸收富集效果来对施污土壤中重金属具有的生态风险性进行评价。结果表明:污泥的添加使土壤中生物活性态Cd、Cu和Zn含量显著增加,对三种重金属具有活化作用,但对Pb却起到钝化作用。生态风险评价结果表明:污泥的添加使土壤中Pb呈现无污染和低生态风险;Cu和Zn呈现中度污染和低生态风险;Cd达到强度污染和重度生态风险,重金属潜在生态风险(RI)总体处于强度生态风险水平。当污泥添加比例大于6:10(污泥S3处理)时,施污土壤中重金属的综合毒性指数高于土壤对照。黑麦草对Cd、Pb、Cu和Zn的富集浓度与施污土壤中对应重金属的生物活性态含量存在显著正幂指数关系,同时黑麦草对施污土壤中Cd、Cu和Pb的富集能力大小与地累积指数法和潜在生态风险指数法对三种重金属具有的生态风险性的评价结果具有一致性。     

城市污水污泥和固体生活废弃物堆肥的利用

<正> 在研制城市污水污泥和固体生活废弃物堆肥的利用技术时,首先要测定其成分中的重金属对土壤可能产生的生态污染的程度。把城市污水污泥和固体生活废弃物堆肥施于作物,在重金属含量极低时,作物的增产将最高。     

长江三角洲地区污水污泥与健康安全风险研究 Ⅲ. 苏、杭二城市污水污泥所施土壤中Cu和Zn的释放动态及其环境风险

未经处理的污泥农业利用后,不仅会增加土壤中污染物的含量,而且会威胁人类和其他生物的健康。室内培养试验结果表明,污泥中的重金属进入土壤后,表现出先释放,后固定的变化趋势,而且随培养时间的增加,施污泥土壤中EDTA和CaCl2提取态Cu和Zn含量逐渐增加,150d时其含量达到最高。与对照处理相比,施污泥土壤中EDTA提取态Cu和Zn含量分别增加了21.4mgkg-1和26.1mgkg-1,而CaCl2提取态Cu和Zn含量分别增加了0.10mgkg-1和3.37mgkg-1。重金属不合格的污泥农业利用存在一定程度的重金属污染风险,且其风险大小与土壤类型、污泥种类和培养时间及污泥的土壤施用量等因素密切相关。选择适宜的土壤类型、污泥种类、施用时间及控制污泥施用量等,能够在一定程度上降低污泥中重金属农业利用的环境风险。     

城市污泥及其堆肥对土壤重金属积累的影响

与对照相比,在城市污泥及其堆肥的作用下,土壤耕层的重金属含量在一定程度上增加。耕层土壤在试验0的处理(3)、(4),即施城市污泥30 t hm-2和60 t hm-2和试验1的处理(4)即施污泥堆肥60 t hm-2的情况下,根据污染等级,土壤处于重度污染等级,其他处理的土壤耕层处于中等污染等级。在作用后效方面,两个试验中,对于土壤中全量和可吸收态的重金属元素得到下面递减排列:CdZnCuNiPb。比较试验各处理的Zc和土壤污染等级,试验0和试验1的处理4使土壤产生重度污染,其他处理导致试验土壤产生中度污染。     

污泥农用对植物系统的影响及其潜在性污染

本研究的主要目标是确定:(1)高施用量的污泥施入Sassafras砂壤土后对地下水产生的潜在威胁,(2)施用污泥后,土壤中盐分和金属的积累;(3)施用污泥后,重金属在植物组织中的积累,(4)根据对地下水污染方面的考虑,确定污泥的最大施用量。     

施用城市和市郊污泥对大麦吸收锌与镉的影响

污泥施入土壤既有助于作物基本养分的供应,又可确保污泥处理系统不污染环境。但是由于大量工业废水排入处理系统,使污泥不但含有珍贵的植物养分,也含有有害物质,尤其是重金属对植物可能造成危害,且一旦进入食物链也可能会危及人畜。     

污泥中重金属的环境活性及生态风险评估

研究了湖南省长沙市、株洲市和常德市10个污水处理厂剩余污泥中As,Cd,Cu,Ni,Pb,Zn的含量和形态特征,并利用潜在生态危害指数法对污泥农用过程中重金属的生态风险进行了综合评价。结果表明,城市污泥中富含有机质及N,P,K等养分,然而,污泥表现为以Cd为主的多金属污染,不能直接农用。污泥中Cd含量为1.43～260mg/kg,以可还原态为主,占全量比例高于28.9%;As,Pb的可还原态,Ni,Zn的酸可溶态和可还原态,Cu可还原态和氧化态所占比例较高,表明污泥中重金属的潜在环境活性较高。风险指数评价结果表明,污泥中Cd和As是潜在的强生态风险元素;以工业废水处理为主的污水处理厂污泥重金属单因子生态风险相对较高,且综合潜在生态风险严重。     

外源亚精胺对受重金属污染的城市污泥植物修复的影响

研究外施浓度为1mmol/L的亚精胺（spd）对美洲商陆修复受重金属污染城市污泥的影响。结果表明,外施spd能使美洲商陆根系生长及其生物量均增加1.5倍以上;同时能增加叶绿素a的含量和叶绿素总量,减少叶绿素的流失。外施1mmol/L spd还能明显促进美洲商陆各器官对城市污泥中Cd、Hg重金属的吸收、转运和富集,但对Cu和Zn的吸收差异不明显。上述结果表明,spd增强了美洲商陆对Cd、Hg污染的城市污泥的修复作用,并在一定程度上缓解了城市污泥中Cd2＋、Hg2＋对美洲商陆的毒害作用。     

污泥及其复合肥对蔬菜产量及重金属积累的影响

通过盆栽和小区试验初步探讨了污泥复合肥对蔬菜的增产效应及其对蔬菜吸收累积重金属的影响。结果表明 ,污泥复合肥可显著提高蔬菜产量 ,蔬菜可食部分中的Cu、Zn、Cd含量均在国家食品卫生标准范围内 ,但Pb的含量超出了国家食品卫生标准     

污泥农用对土壤和作物重金属累积及作物产量的影响

以3 a定位试验为基础,比较3种不同处理的污泥肥料（消化污泥、污泥堆肥及污泥复混肥）农田施用下土壤养分、土壤和作物籽粒中Mn、Cu、Zn、Pb、Cd 5种重金属的积累以及作物产量的变化情况,以阐明污泥农用对土壤及作物的影响。研究表明,3种污泥肥料提高了土壤中氮素和有机质的含量;与空白和普通化肥处理相比,3种污泥肥料增加了土壤中Mn和Cu的含量,而对土壤交换态重金属含量没有显著影响;3种污泥处理均增加了小麦籽粒中Zn的含量;相对普通化肥处理,3种污泥肥料处理对小麦和玉米产量均无显著影响。合理施用污泥肥料可以有效地提高作物产量;污泥肥料施用对土壤重金属有一定累积效应,但短期施用对土壤比较安全。     

蚯蚓活动对城市生活污泥重金属的影响

采用塑料温棚内垄式堆积污泥培养蚯蚓方式,研究了蚯蚓处理对污泥重金属的影响。结果表明,污泥经蚯蚓处理后,理化性质发生了显著的变化,污泥的pH值、有机质、总氮和总磷都有不同程度的降低;蚯蚓能吸收富集污泥中的重金属,其中对重金属Cd有较强的富集能力;蚯蚓处理使污泥中重金属含量均出现不同程度的下降,重金属Cr、Zn、Pb、Cd、Cu、Ni分别减少27.98%、31.46%、32.81%、13.85%、23.86%和22.92%。利用盆栽试验,研究了污泥施用于土壤后生菜体内重金属积累的情况,结果表明,生菜体内重金属Zn、Cu、Pb和Ni的含量为污泥处理高于蚓粪处理;Cr和Cd则分别为差异不显著和略有降低。     

Determination of mobile heavy metal fraction in soil: Results of a pot experiment with sewage sludge

Abstract

The development of a method using a chelating resin to assess heavy metal mobility in soil and the first results obtained from a pot experiment with sewage sludge additions were studied. The resin was Chelex 100 with the calcium (Ca)‐form of the resin proving to be best suited for the extraction. The efficiency of recovery of the heavy metals from an aqueous solution ranged from 81.2% for cadmium (Cd) to 102% for copper (Cu) within 24 hours. For heavy metal extractions from a soil sample, a 96 hour extraction period was found to be optimum. The extracted heavy metal portion was comparable with the results obtained with an ammonium acetate (NH₄AOc) extraction. Total heavy metal contents in the substrate of the pot experiment did not show a significant influence due to the sewage sludge treatments, although considerable amounts of heavy metals were added by the sewage sludge. This effect can be both due to the incomplete recovery of heavy metals by an aqua regia extraction and leaching losses of these elements from the pots. Rape (Raphanus sativus L.) plants did not have any heavy metal contents which might indicate a high availability in soil, with the Cd and Cr contents in the rape biomass being partly lower in the sewage sludge‐treated pots than in the control plants; however, zinc (Zn) uptake slightly increased with increasing sewage sludge treatments. The Chelex 100 extraction procedure was correlated with Cd plant uptake, while the NH₄AOc extraction procedure was better related to the Zn uptake by rape plants.     

Influence of sewage sludge and heavy metals on nematodes in an arable soil

Summary The abundance of nematodes was investigated in agricultural plots treated in three different ways, the first with no treatment, the second with 300 m³ ha^-1 a^-1 raw sewage sludge and the third with 300 m³ ha^-1 a^-1 sewage sludge with the addition of heavy metals. The nematodes were determined down to the genus and were assigned to five feeding groups. Total nematode numbers were highest in the site treated with sewage sludge and heavy metals. The smallest total numbers were found in the control site. The plant-feeding nematode genera showed different patterns of abundance depending on the sludge treatment and heavy metal content. For the mycophagic and bacteriophagic nematodes, numbers increased with the amount of sludge, especially in the sites with a higher heavy metal content. The family Rhabditidae was the most numerous group in the sludge plus heavy metals treatment. In contrast to these findings, the omnivorous nematodes were very rare in the sludgetreated plots and were completely absent in plots treated with sludge plus heavy metals, whereas predatory nematodes were numerous only after the application of sludge alone.     

剩余污泥厌氧消化过程重金属形态转化及生物有效性分析

为研究污泥厌氧消化过程中物理化学性质的变化对典型重金属形态转化的影响,对其农用的可行性及生物有效性进行评估,对取自某城市污水处理厂的剩余污泥进行了序批式厌氧消化实验,在试验过程中测定了污泥理化学性质,采用Tessier分步提取法提取了污泥样品中的典型重金属,并采用电感耦合等离子发射光谱仪（ICP-OES）测定各形态重金属含量及总量。结果表明,厌氧消化过程中重金属的形态发生了显著变化,由不稳定态向比较稳定的残渣态和有机结合态转变,某些重金属形态与污泥理化性质如pH、碱度、VS/TS及氨氮显著相关。厌氧消化可以有效地降低污泥中重金属的潜在迁移能力和生物有效性,经厌氧消化后污泥可以更好地进行土地利用。     

The influence of process parameters on the removal of heavy metals in activated sludge

The behavior of six heavy metals in an activated sludge pilot plant under conditions of normal and elevated influent metal concentrations has been studied. Percentage heavy metal removals at sludge ages of 4, 9, and 12 d were more consistent when metals were added to the system, possibly as a result of lesser variations in heavy metal speciation in the settled sewage, and the greatest degree of accumulation of heavy metals by the biomass occurred at the 12 d sludge age. When shock loads of heavy metals were introduced into the system, their concentrations in the effluent did not immediately rise in proportion; however, heavy metal removal efficiencies were similar under steady state conditions of normal and elevated influent metal concentrations. Cadmium, Cu, and Ni were largely soluble in the effluent samples, but Cr, Pb, and Zn were predominantly insoluble, indicating that particulate forms of these metals may escape removal in secondary sedimentation. The high degree of Ni solubility in the settled sewage and final effluent reflected its consistently poor removal in the process. The two most soluble metals, Cu and Ni, appeared to be associated to a large degree with high molecular weight substances in the settled sewage and final effluent, possibly influencing their availability for uptake by the biomass.     

辽宁省污灌区土壤重金属污染特征与生态风险评价

针对当前污灌区土壤污染研究中存在的问题,提出了一种模糊识别模型评价土壤综合环境质量,并对潜在生态风险指数法进行改进,用以计量重金属潜在生态风险。采用建立的方法对辽宁省污灌区土壤环境质量和重金属潜在生态风险进行了评价,结果显示:Cd是辽宁省污灌区首要重金属污染物,而Hg、Pb、Ni污染较为普遍;重金属的来源主要是灌溉污水和农田施肥;以工业废水为灌溉用水的灌区污染情况比以河水为灌溉用水的灌区污染严重;污灌区重金属元素污染程度大小依次为:Cd>Pb>Ni>Hg>Cu>Cr>As,而重金属潜在生态风险从大到小则依次为:Cd>Hg>Pb>Cu>Ni>As>Cr。总体来看,辽宁省污灌区存在一定程度的重金属污染,且具有较为明显的复合型污染特点,其潜在生态风险超出警戒水平,各灌区应根据各自污染特点和风险等级制定相应的污染防治对策。