【作者】 姜萍；

【导师】 吕家珑； 周东美；

【作者基本信息】 西北农林科技大学 ， 环境科学， 2010， 硕士

【摘要】 目前集约化规模化养殖产生的猪粪包含高浓度的Cu、Zn、Pb、Cd等重金属,而这些粪肥常大量使用在蔬菜种植中。伴随猪粪带入土壤的重金属元素在土壤-水体-植物系统中的积累和转化,必然对植物的生长发育、植物体内重金属含量以及地下水水质等产生影响。本文在对江西省余江县大型养猪场的饲料、粪便、菜地土壤和蔬菜重金属污染状况调查基础上,以含高浓度Cu、Zn猪粪为有机肥料,通过一系列盆栽试验和土柱试验,系统研究了含Cu、Zn畜禽粪施用于土壤后,Cu、Zn在土壤-水-植物系统中的迁移过程,讨论了不同猪粪添加量及不同改良剂对青菜生长和吸收重金属的影响,并且研究了改良剂石灰对重金属在土壤中迁移特性的影响。本研究结果为红壤地区合理利用猪粪有机肥和保证蔬菜质量安全等提供了宝贵科学依据。主要研究结论如下:(1)本文调查分析了江西省余江县39个大型养猪场的饲料、猪粪、以及长期施用这些猪粪的菜地土壤及蔬菜的Cu、Zn、Pb、Cd含量,并对饲料、猪粪、土壤和蔬菜重金属含量进行了相关分析。结果表明,大猪和小猪饲料Cu含量超标率分别达81.6%和30.8%,Zn含量超标率分别达89.5%和94.9%, Pb、Cd未超标。猪粪Cu、Zn含量亦严重超标,且饲料和猪粪中Cu、Zn、Pb、Cd含量呈显著正相关关系。土壤总Zn和总Cd含量分别有7.8%和5.2%的样品超过三级标准,污染较为严重。所有蔬菜样品Cu、Zn、Pb含量均未超过我国食品卫生质量标准,空心菜和芋头Cd含量超标。土壤总Cu、Zn、Cd含量与提取态呈显著正相关。(2)通过盆栽试验,研究了0、2%、4%猪粪添加量对青菜吸收重金属Cu、Zn的影响,并选择凹凸棒土、石灰、钙镁磷肥三种土壤改良剂对猪粪污染土壤进行改良。发现猪粪添加能够显著提高土壤pH值,增加土壤电导率,促进植物生长。青菜吸收Cu、Zn的量与猪粪添加量成正比。改良剂能够抑制土壤中重金属的生物有效性,其中石灰的抑制作用最强,同时石灰还有固定红壤磷素的作用。(3)土柱淋溶试验研究了淋溶过程中4%猪粪及1.5%改良剂对红壤pH、盐分、有机质、有效磷及Cu、Zn有效态的动态变化规律。研究表明,菜地土壤中施用猪粪有机肥能够通过提高土壤pH值、EC及土壤有机质含量,显著提高了土壤生产力,但猪粪的施用同时也带入了Cu、Zn等重金属污染。溶解态的Cu、Zn离子能够通过淋溶作用进入地下水,进而危害人类健康。改良剂熟石灰能够较好地解决有机肥提高土壤肥力及猪粪导致重金属污染这一矛盾。我们的研究表明,熟石灰能够更好地改善酸性土壤pH,并能限制Cu、Zn等重金属离子的活度,从而有效地降低重金属随水流迁移的风险。更多还原

【Abstract】 The poultry manures from intensive farming often contain high contents of heavy metals just as copper, zinc, lead, cadmium and so on, and these manures are widely used to vegetable field at a high rate. After a long-term application of such these manures, it will cause accumulation of Cu, Zn, Pb and Cd in soil and crops, which affects the growth of crop, heavy metal uptake and groundwater quality. This study surveyed animal feed, poultry manures, soils and vegetables sampled at 39 different sites in the Yujiang city in Jiangsu province, China, where manures are applied for many years. A series of experiments and pot trials were designed to investigate the transferring processes of Cu and Zn from manures to water and plants.The main results were as follows.Firstly, this study investigated the concentrations of Cu, Zn, Pb and Cd in feeds, pig manures, soils and vegetables sampled from 39 intensive farming plants in Yujiang County, Jiangxi Province. The results showed that the rate of exceeding allowable limit of Cu in big pig feed and piglet feed were 81.6% and 30.8%, respectively. Meanwhile, the rate of exceeding allowable limit of Zn in big pig feed and piglet feed were 89.5% and 94.9%, respectively. In addition, Cu and Zn concentrations in some pig manures were also above the Pollutant Emission Standard for Livestock and Breeding Industry (In China). Furthermore, there were significant positive correlations between the heavy metal concentrations in feeds and pig manures. Total Zn concentration in 7.8% of soil samples and total Cd concentration in 5.2% of soil samples exceeded the Chinese Soil Environmental Quality Standard III, which means they have been heavily polluted. The survey also showed that the concentrations of Cu, Zn, and Pb in all vegetable samples were lower than the National Food Hygiene Standard, while Cd concentrations in Ipomoea Aquatica and Colocasia Esculenta exceeded the standard. The significant positive correlations were found between the total Cu, Zn, Cd concentrations and the extractable heavy metal concentrations in soils.Secondly, a pot experiment was designed to study the effect of 0, 2%, 4% of pig manure addition on heavy metal uptake by vegetables Cu and Zn. We chose three kinds of soil amendment (attapulgite, limestone, fertilizer of calcium magnesium phosphates) on manure contaminated soil improvement .The results showed that significant improvement of soil pH was been found in pig manure additive treatment. Pig manures obviously increased soil electrical conductivity, and promoted plant’s growth. Vegetables absorb Cu, Zn addition of the quantity and proportion of pig manure. Modifier can inhibit the bioavailability of heavy metals in soil, in which the strongest inhibitory effect of lime, and lime have a fixed role of red phosphorus.Thirdly, soil column leaching experiments had studied the dynamic changes of soil pH, contents of EC, DOC, available phosphorous and heavy metals during the leaching process. The results showed that applications of pig manures can increase soil pH, EC and organic mater contents, meanwhile, pig manures brought some heavy metals just as Cu and Zn into soils. These dissolved Cu and Zn may be leached into groundwater, thereby endangering human health. Modifier hydrated lime can improve soil fertilizer while not lead to heavy metal pollutions. Our research shows that hydrated lime can better improve the acid soil pH, and to limit the activity of Cu, Zn and other heavy metal ions, it can effectively reducing the risk of migration of heavy metals in groundwater.更多还原