污泥肥和生活垃圾肥对小麦-玉米重金属累积及产量的影响

以肥料定位试验为基础,比较了污泥肥、生活垃圾肥和常见农用肥料(化肥、鸡粪肥)农田施用下土壤和作物籽粒、秸秆中Cd、Cr、Pb、Hg、As、Cu、Zn、和Ni八种重金属的积累以及作物产量的变化情况,用来阐明污泥肥和生活垃圾肥施用对土壤和作物籽粒以及产量的动态影响规律。研究表明,与化肥和鸡粪肥分别比较,施用生活垃圾肥可以显著带来作物的增产,而污泥肥处理作物增产效果不明显;根据国家粮食卫生标准(GB 2715-2005)、MPCC以及《食品卫生标准》(GB2762-2005)的规定,施用污泥肥和生活垃圾肥处理的作物籽粒重金属含量均在其标准限量值范围之内,完全符合安全标准;污泥肥和生活垃圾肥比化肥、鸡粪显著增加了土壤Cr和Hg含量。所有处理的土壤重金属含量均在土壤环境质量一级标准(GB15618-1995)的重金属限量值(pH>7.5)范围内。     

肥料重金属含量状况及施肥对土壤和作物重金属富集的影响

本文对肥料中重金属的含量状况以及施肥对土壤和农作物重金属累积影响的研究进展进行了系统分析和总结。过磷酸钙中锌（Zn）、 铜（Cu）、 镉（Cd）、 铅（Pb）含量高于氮肥、 钾肥和三元复合肥,有机-无机复混肥料中的Pb含量高于其他化肥。有机肥如畜禽粪便、 污泥及其堆肥中的重金属含量高于化肥,猪粪中的Cu、 Zn、 砷（As）、 Cd含量明显高于其他有机废弃物,鸡粪中铬（Cr）含量高;污泥和垃圾堆肥中Pb或汞（Hg）含量高。商品有机肥Zn、 Pb和镍（Ni）含量高于堆肥,Hg含量高于畜禽粪便。多数研究表明,氮磷钾配施与不施肥相比土壤Cd和Pb含量增加,施用有机肥比不施肥提高土壤Cu、 Zn、 Pb、 Cd含量。施用化肥对农作物重金属富集的影响不明确,而施用有机肥可提高作物可食部位Cu、 Zn、 Cd、 Pb 的含量,影响大小与有机肥种类、 用量、 土壤类型和pH以及作物种类等有很大关系。在今后的研究中应着重以下几个方面, 1）典型种植体系下土壤重金属的投入/产出平衡; 2）不同种植体系下长期不同施肥措施对土壤重金属含量、 有效性影响的动态趋势; 3）典型种植体系和施肥措施下土壤对重金属的最高承载年限; 4）现有施肥措施下肥料中重金属的最高限量标准。     

施用河道污泥对水稻和土壤重金属含量及 水稻氮素利用的影响

2013—2014年以苏州市相城区望亭镇某河道污泥为研究对象,以农田施用污泥20 kg?m~(-2)和不施用污泥为主处理,以施氮肥120 kg(N)?hm~(-2)(LN)和240 kg(N)?hm~(-2)(NN)为副处理,连续两季种植粳稻品种‘武运粳24’,研究河道污泥农田施用对水稻和土壤重金属含量及水稻氮素利用的影响。结果表明:1)河道污泥农田施用,显著提高了稻田土壤有机质含量、速效氮含量和重金属Cu、Zn、Pb含量,水稻产量平均增加7.05%,水稻籽粒中重金属Cu、Zn、Pb含量分别增加53.66%、18.71%和802.29%,水稻吸氮量显著增加,氮素利用效率显著降低。2)河道污泥施用后,较高施氮量(NN)增加了稻田土壤有机质含量和速效氮含量,对稻田土壤重金属含量和水稻籽粒中重金属含量影响不大,水稻产量、水稻吸氮量显著增加,但氮素利用效率显著降低。3)污泥处理条件下,与第1季相比较,第2季稻田土壤重金属Cu、Zn、Pb含量平均下降5.0%左右、籽粒中重金属Cu、Zn、Pb含量下降7.27%~12.65%,但均显著大于不施河道污泥的对照处理。4)污泥×氮肥、污泥×年度、氮肥×年度和污泥×氮肥×年度的互作效应对稻田土壤养分含量、重金属含量,水稻产量、籽粒重金属含量和水稻氮素吸收利用的影响均未达显著水平。     

污泥堆肥对盐碱土土壤环境和作物生长的影响

以城市污水处理厂污泥堆肥为研究对象,采用盆栽试验方法研究不同用量(0%,5%,10%,20%)污泥堆肥施入盐碱土后,对玉米、大豆生长情况及土壤环境的影响。结果表明,施用污泥堆肥可降低盐碱土pH值和总盐含量,提高土壤养分及酶活,增加土壤微生物量碳、微生物量氮,同时施用污泥堆肥土壤重金属Zn、Cu含量增加,当施用量为20%时,土壤Zn含量超标。另外,玉米和大豆在污泥堆肥施用比例分别为10%和5%时长势最佳,且作物籽粒中重金属含量在国家食品卫生标准范围内。     

兰州市城市污泥施用对小麦生长和重金属富集的影响

以兰州市安宁区污水处理厂污泥为研究对象,采用盆栽的方法研究污泥土地利用后对土壤中重金属含量以及对3种小麦生长和重金属富集的影响。结果表明,污泥施用后使污泥混合土壤中重金属Pb、Cu、Zn含量显著增加,但3种重金属含量均未超过我国土壤环境质量二级标准(GB15618-1995)中的限制性标准值。污泥土地施用后,小麦获得了良好的生长响应。污泥低施入量(污泥在混配土壤中的干重比为5%、10%、15%)时不同程度的促进了小麦的生长发育,使3种小麦出苗率提高,植株更高,生物量增加。污泥高施入量(污泥在混配土壤中的干重比为25%、35%)时,小麦的出苗率和根长受抑制明显。污泥的施用使小麦籽实中的Pb、Cu、Zn的含量显著升高,呈现递增趋势,污泥在混配土壤中的干重比超过25%时,籽实中Cu和Pb含量相对国家无公害食品标准有超标现象。综合考虑污泥对小麦生长和重金属富集的影响及土壤中重金属含量的变化,对小麦的耕种土壤中一次性施用污泥时,污泥在混配土壤中的干重比应限量在25%以下。     

植物处理后的城市污泥农用对玉米生长的影响

采用东南景天单种、东南景天与香芋套种对污泥进行植物处理,将植物处理后的污泥作为肥料与上层土壤混合后种植玉米,并设不同的肥料处理来研究对玉米生长的影响。结果表明,利用植物处理后的污泥作为肥料种植玉米,玉米生长良好,且长势和产量明显优于对照和施用化肥的处理,其中单种东南景天处理后的污泥与土壤混合种植的玉米籽粒的产量最高,分别是对照和化肥处理的3.26和2.66倍;利用植物处理后的污泥作为肥料所生产的玉米籽粒中Zn、Cd、Cu、Pb的含量符合国家饲料卫生安全标准,作为饲料是安全的。     

长期肥料试验对土壤和水稻微量元素及重金属含量的影响

长期肥料试验会影响土壤中微量元素和重金属状况以及作物对微量元素和重金属的吸收。本文研究了长期的不同施肥处理对土壤、糙米中微量元素Cu、Zn、Fe、Mn和重金属Pb、Cd含量的影响,结果表明:经17a连续施用猪粪及秸秆还田显著增加了土壤Cu、Zn和Cd全量,而土壤Fe、Mn和Pb全量在不同施肥处理间没有显著差异;施肥增加了土壤有效态Cu、Zn和Fe含量,其中施用猪粪及秸秆还田的3个处理显著增加了土壤有效态Cu、Zn和Cd含量,而土壤有效态Pb含量在不同施肥处理间没有显著差异。不同处理糙米Cu、Zn、Fe、Mn和Pb含量变化较小或没有显著性差异,而在3个施猪粪和秸秆还田处理中,糙米Cd含量均超过国家食品卫生标准(>0.2 mg kg-1)。水稻地上部吸收积累Cu、Zn、Fe、Mn、Pb和Cd总量与其地上部生物量呈正相关,土壤Cu、Zn、Cd有效态与全量含量呈极显著相关关系,而糙米中的镉含量与土壤镉含量有较好的相关关系。长期施用畜粪导致土壤Cd污染问题应引起高度重视。     

市政污泥直接施用对玉米生长和品质的影响

[目的]研究市政污泥施用后对土壤和作物生长与品质的影响,为市政污泥的直接土地利用提供科学依据。[方法]以玉米为试验材料,利用田间试验研究了污泥不同的施用方式(沟施、撒施、表土下20 cm施用)和施用量(30,90,200 t/hm~2)对玉米生长和品质以及土壤重金属含量的影响。[结果]适量的污泥对玉米个体的生长有促进作用,施用量为30 t/hm~2时株高、单株生物量、叶片叶绿素含量、籽粒蛋白质含量均显著高于对照。表土下20 cm施用污泥在整体上较其他两种施用方式有更高的出苗率和籽粒产量,在施用量为30 t/hm~2时籽粒产量最高,为656.70 kg/667m~2,高出对照29.64%。3种施用方式下,土壤中的Cu,Zn,Pb含量及玉米籽粒中的Cu,Zn含量均随污泥施用量的增加而增加,而玉米籽粒中Pb含量与对照相比差异不显著,土壤和籽粒中重金属含量均未超过国家相关标准。以重金属浓度满足土壤环境质量标准为限制条件,推算出当地的市政污泥施用量为30 t/hm~2可以连续施用5 a。[结论]施用30 t/hm~2的污泥具有良好的效果和环境效应;为了降低污泥在土壤中的局部累积而导致的胁迫效应,表土下20 cm施用和地表撒施是相对较好的方式。     

污泥施用对土壤及小麦生理特性的影响

以兰州市安宁区污水处理厂污泥为研究对象,采用盆栽方法研究污泥施用后对土壤pH值的影响,对土壤中重金属Cu、Zn、Pb含量的影响以及对小麦叶片叶绿素含量和脯氨酸含量特性的影响。结果表明,污泥施用后土壤的pH值显著下降,并呈递减趋势。不同污泥施加量土壤中3种重金属元素的含量均远低于我国土壤环境质量二级标准（GB15618—1995）中碱性土壤的限制性标准值。3种小麦叶片的叶绿素总含量随污泥浓度的增加而增加,污泥在混配土壤中的干重比为15%时3种小麦均达到最大值,随着污泥施加量的进一步加大出现下降。污泥施用后3种小麦叶绿素a/b值与对照相比无显著变化,小麦叶片中脯氨酸含量比对照有大幅的增加。低污泥施加量时（5%、10%和15%）,3种小麦叶片中脯氨酸含量随施加量增加而增加,但高污泥施加量时（25%和35%）的脯氨酸含量无显著增加,污泥中污染物胁迫超过小麦耐受限值后,小麦生理代谢出现反常。土壤中3种重金属元素的含量与3种小麦体内脯氨酸含量均呈极显著正相关关系,土壤的pH值与3种小麦的叶绿素总含量和脯氨酸含量均呈负相关关系。综合考虑污泥施用对小麦生理特性的影响,对小麦的耕种土壤中一次性施用污泥时,污泥在混配土壤中的干重比应限量在15%以下。     

施用城镇生活污泥对小麦产量和品质及安全性的影响

针对城镇生活污泥施入农田的潜在污染风险问题，通过田间试验，开展了城镇生活污泥在小麦上的施用效果研究，探讨了施用城镇生活污泥对小麦产量和品质及安全性的影响，以期为城镇生活污泥农业上资源化利用提供依据。研究结果表明:施用城镇生活污泥有助于提高小麦产量。单施生活污泥(T2、T3)较空白不施肥(CK)处理小麦增产83.85%～139.04%，一定范围内，小麦产量随着生活污泥用量的增加而增大。在生活污泥2250 kg/hm²配合复合肥450 kg/hm²(T6)处理更有助于小麦产量增加，合理配施城镇生活污泥有助于有机养分替代及化肥减量。施用城镇生活污泥有利于提升小麦籽粒品质。与空白不施肥(CK)处理相比，施用生活污泥显著提高了小麦籽粒干面筋、湿面筋及淀粉含量，单施生活污泥6000 kg/hm²(T3)处理的小麦籽粒干面筋、湿面筋和淀粉含量分别提高了19.7%、15.2%和7.83%。部分化肥配施生活污泥(T4、T9)处理小麦籽粒中Cr含量超过国家限量标准(1 mg/kg)。随着生活污泥施用量的增加，小麦籽粒重金属富集的风险增高，但不同元素增幅存在差异。施用城镇生活污泥，小麦籽粒中多环芳烃类、酞酸酯类有机污染物含量符合食品安全国家标准。城镇生活污泥农用时，建议单独施用生活污泥用量6000 kg/hm²；生活污泥与化肥进行配施的情况下，用量为生活污泥2250     

Potential of Gamma Irradiated Sewage Sludge as Fertilizer in Radish: Evaluating Heavy-Metal Accumulation in Sandy Loam Soil

Soil application of sewage sludge as an amendment in crop plants has became a popular method of municipal sewage-sludge disposal in many countries. However, the presence of heavy metals in untreated sewage sludge has raised concerns of adverse effects on crop growth, quality of product, and environmental health. Gamma irradiation is one of the treatments for hygienization of sewage sludge before use as fertilizer. To evaluate the potential of gamma-irradiated sewage sludge as fertilizer in vegetable crops, the field investigation was conducted in a root crop, radish (Raphanus sativus L.), during the 2005–06 and 2006–07 growing seasons in a sandy loam soil. Treatments consisted of three source of fertilizers [farmyard manure (FYM), gamma-irradiated sewage sludge (GISS), and nonirradiated sewage sludge (NISS)]; each were compared at six application levels (1, 3, 6, 7, 9, and 11 t ha^?1). The physicochemical properties of all the three fertilizers used in this study were compared. Growth parameters and yields of radish were not significantly influenced by source of fertilizers or their application levels, except plant stand, which was influenced by type of fertilizers used. There was no significant difference observed between source of fertilizer treatments with respect to any of the measured soil properties, including major nutrients [nitrogen (N), phosphorus (P), and potassium (K)], metallic micronutrients [copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn)], and heavy metals [nickel (Ni), lead (Pb), cadmium (Cd), and cobalt (Co)]. Soil P and Zn were influenced by the various level of fertilizers. However, the interaction effect of source and level of fertilizer was absent for all the measured parameters. The maximum pollutant limits in sewage sludge and soil for agricultural use in different countries were compared. The concentration of metallic micronutrients and heavy metals in soil were less than the prescribed limit of the United States Environmental Protection Agency (USEPA), and no significant accumulation was noted after 2 years of application of GISS and NISS even at higher application rates.     

Assessment of Heavy Metals in Spinach (Spinacia oleracea L.) Grown in Sewage Sludge–Amended Soil

The assessment of heavy metals in spinach (Spinacia oleracea) grown in sewage sludge–amended soil was investigated. The results revealed that sewage sludge significantly (P < 0.01) increased the nutrients and heavy metals such as cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), and zinc (Zn) in the soil. The contents of metals were found to be below the maximum levels permitted for soils in India. The most agronomic performance and biochemical components of S. oleracea were found at 50% concentrations of sewage sludge in both seasons. The contents of Cd, Cr, Cu, Mn, and Zn in S. oleracea were increased from 5% to 100% concentrations of sewage sludge in both seasons. The order of contamination factor (Cf) of different heavy metals was Mn > Cd > Cr > Zn > Cu for soil and Cr > Cd > Mn > Zn > Cu for S. oleracea plants after application of sewage sludge. Therefore, use of sewage sludge increased concentrations of heavy metals in soil and S. oleracea.     

Application of composted sewage sludges contaminated with heavy metals to an agricultural soil

To elucidate the mechanism of transfer of heavy metals into the food chain, an experiment was carried out with a calcareous soil, to which two different doses of a sewage sludge compost contaminated with either Cd or Zn, Cd, Cu, and Ni were applied. A crop of lettuce was then grown in the amended soils. The application of sewage sludge composts to a calcareous soil lowered the soil's pH, although the value was always around 8 at the end of the experiment. Electric conductivity rose with organic amendment. As anticipated, such an amendment improved the nutritional level of the soils, particularly Nand P, both total and available. Plant yields were negatively affected by organic amendments contaminated with heavy metals, the most dangerous in our experiment being Cd and Zn since this metals easily taken up by plants. As Ni and Cu form insoluble complexes with the organic matter of the sewage sludge composts they are not readily absorbed. Of the metals studied, Cd and Zn showed the highest bioavailability index.     

Determination of Heavy-Metal Concentration with Chlorophyll Contents of Wheat (Triticum aestivum) Exposed to Municipal Sewage Sludge Doses

The present study was conducted to assess the suitability of sewage-sludge amendment in soil for Triticum aestivum (wheat) by evaluating the heavy-metal accumulation and physiological responses of plants grown at 10, 25, and 50% sewage sludge amendment rate. Sewage sludge amendment modified the physicochemical properties of soil, thus increasing the availability of heavy metals in soil and consequently greater accumulation in plant parts. The chlorophyll contents generally increased after the sewage sludge treatments. Heavy-metal accumulation in the soil after the treatments did not exceed the limits for land application of sewage sludge recommended by the U.S. Environmental Protection Agency. Recycling sewage sludge as fertilizer will generate economical profits. However, the use of sewage sludge amendment in the soil for growing wheat may not be a good option due to risk of contamination of some heavy metals.     

Zinc and copper availability in herbage and soil of a Pinus radiata silvopastoral system in Northwest Spain after sewage‐sludge and lime application

Silvopastoral systems are ancient farming systems in the world, consisting of the combination of a woody component (trees or shrubs) and crops and/or animals within the same land‐management unit. In various European Union (EU) countries, the possibility of using sewage sludge as a fertilizer is under consideration as a viable method of disposal, considering the increase in sewage‐sludge production in recent years and the restrictions imposed by European policy on the usual methods of disposal. The concern is the concentration of heavy metals, which can reach humans through the food chain. In Spain, R.D. 1310/1990, as well as European Directive 86/278, limit the total in‐soil heavy‐metal concentration, but not the solubility changes, which directly affect plant absorption and leaching of heavy metals throughout the soil profile. The objective of this experiment was to compare, in a silvopastoral system over a period of 3 years, the effect of applying three doses of sewage sludge combined with and without liming, on total and available soil Zn and Cu and their concentration in plants. Liming did not affectct Zn and Cu availability; however, sewage sludge increased Zn and Cu availability, though total in‐soil Zn was increased only in November 2000. In‐plant Zn concentration was increased by sewage sludge in the last 2 years of the study. In all cases, the quality of forage obtained and measured with regard to the concentrations of Zn and Cu was adequate for animal consumption. With respect to sewage‐sludge application as a fertilizer, the management of heavy‐metal availability must be included in the policy, because environmental risk could then be adequately evaluated.     

Behavior of heavy metals from sewage sludge in a Chernozem of the dry belt in Saxony‐Anhalt/Germany

In a small‐plot trial different doses of sewage sludge (equivalent 82‐330 tons of dry matter per hectare) were incorporated in 0—25 cm depth (1982—1985). The aim of the investigations was to study the fate of the heavy metals Zn, Cd, Cu, Ni, Pb, and Cr, to determine their concentration in different soil fractions using a sequential extraction method and to ascertain their uptake by Zea mays L. plants. Eleven years after the last application the metals supplied with the sludge had moved as far as 50 cm in depth. The concentrations of Zn, Cd, Cu, Ni, and Cr in the saturation extract of the sampled soil layers were closely correlated with the concentrations of dissolved organic carbon (DOC). This result suggests that the heavy metal displacement was partly connected with the DOC movement in the soil. Considerable amounts of Zn and Cd coming from sewage sludge were found in the mobile fractions of the soil. Cu, Ni, and Pb were located especially in organic particles, and Cr was obviously bound by Fe‐oxides. Nine years after the last application the binding species of heavy metals were still different compared with those in the untreated soil. The whole withdrawal of heavy metals by plants yielded <1 % of the applied amounts. In the case of Zn the uptake from the sludge amended soil decreased during the experimental period. No similar tendency was observed for the other elements. In any case their annual variations of uptake exceeded the effect of sludge application.     

Transport of zinc,copper, and lead in a sewage sludge amended calcareous soil

The application of sewage sludge on farmland is practised in many countries since sludge is rich in macro- and micro- nutrients. However, increasing use of sewage sludge on farmland has raised concerns about the potential transport of heavy metals into food chains and groundwater. This study determined for a calcareous soil the effects of sludge application on soil physical properties and transport of zinc (Zn), copper (Cu), and lead (Pb). Secondary anaerobic digested sewage sludge was applied at rates of 0, 25, 50, and 100 t/ha (on a dried weight basis) for four consecutive years and mixed in the top 20-cm of soil. Corn (Zea mays L.) was planted as a spring crop, followed by wheat (Triticum aestivum) as a winter crop. Sludge application increased the dissolved organic matter content and modified the soil structure, increased the soil infiltration rate, saturated hydraulic conductivity, and aggregate stability, and decreased the bulk density. Sludge application greatly increased DTPA (diethylenetriamine pentaacetic acid)-extractable soil metal concentrations to 50 cm depth and significantly to 1 m. In the plots that received four application of 100 t/ha sewage sludge, the mean concentrations of Zn, Cu, and Pb in subsoil increased by 1600, 7, and 4.5 times, respectively, compared with the control. The results indicate that a combination of enhanced soil physical properties, heavy and inefficient irrigation and high organic matter content with heavy metals cause significant metal mobility. High sludge applications pose risks of groundwater and food chain contamination and rates are best restricted to those reflecting the nutrient demand of crops (20 t/ha every 4 to 5 yr or an average of 4 to 5 t/ha/yr).