【作者】 李灵香玉；

【导师】 田光明；

【作者基本信息】 浙江大学 ， 环境工程， 2010， 硕士

【摘要】 近年来,畜牧业的规模化、集约化和机械化发展,使产生的大量畜禽粪便面临集中处理和处置;同时,由于饲料添加剂的广泛、大量使用,致使猪粪中重金属元素如Cu和Zn等的含量升高,从而给粪便的安全处理处置以及资源化利用的二次污染风险控制带来隐患。用猪粪饲养蚯蚓（简称猪粪-蚯蚓系统）用作动物饲料的方法是在畜禽废弃物资源化利用技术研究中开发的一种很有前景的循环途径,已经取得了显著的环境、经济和社会效益,并得到广泛的推广应用。但对蚯蚓养殖过程中重金属Cu和Zn的累积情况以及它对下游生物的潜在风险并没有相应的研究报道。为了进一步明确猪粪-蚯蚓系统的应用前景,本文在室外抽样调查的基础上,利用温室开展了猪粪饲养蚯蚓过程中重金属Cu、Zn的迁移积累规律,并考查了草炭、磷矿粉和粉煤灰等几种重金属调理剂对降低蚯蚓蚓体中Cu和Zn、蚓粪中Cu和Zn含量及其生物有效性等的效果,主要取得了如下结果:1.室外抽样调查研究,主要针对蚯蚓吸收积累猪粪中Cu、Zn进行了抽样调查研究。选取余杭区四个正利用猪粪饲养蚯蚓的室外大棚进行抽样调查,以此了解蚯蚓对猪粪中Cu、Zn的吸收积累程度及积累量与猪粪中Cu、Zn生物有效性的关系。结果表明:猪粪饲养的蚯蚓体内含有较高的Cu,浓度为24.22-81.44 mgkg^-1;Zn浓度更高,达到177.85-481.79 mg kg^-1,是Cu浓度的5.92-7.34倍。显然,蚯蚓对猪粪中Cu、Zn存在明显的吸收积累作用,但对Cu和Zn的积累程度或能力存在显著差异,蚯蚓对Cu的吸收积累能力远小于Zn。基于生物富集因子计算显示,蚯蚓体内Cu、Zn的生物富集因子分别为0.030-0.099和0.318-0.738。蚯蚓体内Cu含量与猪粪中可交换态和铁锰氧化物结合态铜的浓度存在显著的正相关关系;蚯蚓体内Zn含量则与猪粪中可交换态、碳酸盐结合态和铁锰氧化物结合态锌的浓度存在明显的线性关系。猪粪中Cu、Zn可交换态浓度分别与蚯蚓体内Cu、Zn含量存在极显著的正相关性(Cu（r=0.973,p＜0.01）、Zn（r=0.702,p＜0.01）,表明猪粪中Cu、Zn可交换态浓度越高,则蚯蚓体内Cu、Zn含量越高。2.重金属Cu、Zn在猪粪-蚯蚓系统中形态转化研究。利用温室开展了猪粪饲养蚯蚓试验,比较了猪粪和蚓粪中Cu、Zn的形态分布、总量及部分理化性质（pH、有机质浓度、总磷浓度）,研究了蚯蚓对其影响,并探讨了蚓粪中Cu、Zn形态分布与蚓粪理化性质的关系。结果表明:蚯蚓将猪粪中Cu、Zn形态进行了重新分配,使有机结合态铜的含量从60%提高到75%,显著降低了Cu的生物有效性,有助于降低蚓粪中Cu向周边环境扩散的风险;有机结合态锌的含量从50%降低到25%,同时碳酸盐结合态锌的含量从15%提高到30%,两者累加明显提高了Zn的生物有效性,增加了蚓粪中Zn向周边环境扩散的风险。蚯蚓对猪粪的理化性质（pH、有机质浓度、总磷浓度）和Cu、Zn总量也存在明显的影响效果。猪粪经蚯蚓肠道作用后,pH和有机质浓度均显著下降,但总磷与Cu、Zn浓度却明显上升。多元回归分析显示,蚓粪中Cu的形态分布受蚓粪有机质、总磷和Cu浓度的影响;Zn形态分布却只受Zn浓度的影响。3.重金属调理剂对蚯蚓体内Cu、Zn吸收积累量、蚓粪中Cu、Zn浓度和生物有效性影响的试验研究。选用草炭、磷矿粉和粉煤灰作为重金属调理剂,分别使用单一调理剂按0%、5%、10%和15%（质量比）添加到猪粪中,在温室利用猪粪混合物进行了蚯蚓的饲养试验,结果表明:猪粪中分别添加草炭、磷矿粉和粉煤灰都明显降低蚯蚓体内Cu、Zn随时间积累的浓度。当蚯蚓体内Cu、Zn浓度维持稳定后,与空白组（调理剂添加量为0%）相比,草炭处理单元中蚯蚓体内Cu浓度下降1.82-9.72 mg kg^-1,最大降幅为29.16%,Zn浓度下降4.56-67.58 mgkg^-1,最大降幅为42.09%;磷矿粉处理单元中蚯蚓体内Cu浓度下降1.25-8.26 mgkg^-1,最大降幅为24.41%,Zn浓度下降3.85-45.63 mg kg^-1,最大降幅为28.42%;粉煤灰处理单元中蚯蚓体内Cu浓度下降1.76-10.83 mg kg^-1,最大降幅为32.02%,Zn浓度下降5.67-59.52 mg kg^-1,最大降幅为32.82%。显然,粉煤灰对降低蚯蚓体内Cu浓度的效果最佳;而草炭则对降低蚯蚓体内Zn浓度的效果最佳。但三种调理剂均没有明显降低蚓粪中Cu、Zn浓度和生物有效性,而且在部分处理单元中三种调理剂反而提高蚓粪中Cu、Zn浓度和生物有效性。更多还原

【Abstract】 The intensive pig farming has developed rapidly in recent two decades.As a consequence,the amount of pig manure increases significantly and its component varies a lot compared with that before.Pig manure is moderately to heaily polluted with heavy metals（e.g.Cu and Zn）.This is caused by feed additives overuse（largely exceeds physiological requirement levels for waine disease control and weight improvement）.The growth of the swine industry has caused a surplus of manure to be disposed of in comparison to the areas available for it to be spread.As a result,there are a lot of environmental problems such as water,air and soil pollution as well as safety of agricultural food.Additionally,the great deal of pig manure restricts the sustainable development for pig production.A new approach of pig manure treatment,pig manure-earthworm system（i.e., breeding earthworms with pig manure）,has been developed in recent years.By this way,the pig maure is reclaimed and disposed,and protein-rich earthworm biomass, the perfect feed for livestock,is obtained.The earthworms play an important role in the pig manure-earthworm system.Based on the spot check,we investigate the migration and accumulation of Cu and Zn in pig manure-earthworm system in the greenhouse,and the possibility of reducing the risk of heavy metals accumulated in earthworms and earthworm cast by adding additives such as peat,phosphate rock and fly ash.The study was done as follow:1.Study on the accumulaltion of Cu and Zn in earthworm（Eisenia fetida） by spot check.Pig manure samples and earthworms were collected from four different greenhouses located in Yuhang country,Zhejiang Province,China.The four greenhouses selected were Site 1（S1）,Site 2（S2）,Site 3（S3） and Site 4（S4）, respectively.The study was investigated whether and to what extent E.fetida accumulated Cu and Zn in the pig manure-earthworm system,and the relationship between bioavailability of Cu and Zn in pig manure and their bioaccumulation in E. fetida.It was found that E.fetida did accumulate Cu and Zn although the concentrations of Zn in earthworm were between 5.92 and 7.34 times higher than those of Cu;the concentrations of Cu in E.fetida were between 24.22 and 81.44 mg kg^-1,and the concentrations of Zn in E.fetida were between 177.85 and 481.79 kg mg^-1.Based on the bioaccumulation factor（BAF） in earthworm E.fetida,the BAFs of Cu were between 0.030 and 0.099,whereas those of Zn were between 0.318 and 0.738.Significant relationships were found between bioavailability of heavy metals in pig manure and their bioaccumulation in E.fetida.The variation in the Cu concentration of E.fetida was best explained by the concentration of exchangeable and Fe-Me oxides-bound fractions,while that of Zn was best explained by the concentrations of exchangeable,carbonates-bound and Fe-Me oxides-bound fractions. Furthermore,there were strong positive correlations between the concentrations of the exchangeable fraction in the pig manure and the concentrations of corresponding metal accumulated in E.fetida,e.g.,Cu（R=0.973,p＜0.01） and Zn（R=0.702,p＜0.01）.It confirmed that the higher the concentration of exchangeable fraction in pig manure was,the higher the corresponding metal concentration of earthworm was.2.Study on the effect of the transit through the gut of earthworm（E.fetida） on fractionation of Cu and Zn in pig manure.The study was investigated the fractionation of Cu and Zn in the earthworm（E.fetida） casts from pig manure,the effect of the gut transit on the factors affecting the metal fractionation,like pH, organic matter（OM）,total phosphorous（TP） and the amount of Cu and Zn,and the relationship between fractionation of metal in the earthworm cast and factors.It showed that the content of Cu bound to organic matter in pig manure increased from 60%to 75%after transit through the gut of earthworm,whereas that of Zn decreased from 50%to 25%.Based on these changes,Cu was less bioavailable,whereas Zn was more bioavailable.The factors affecting metal fractionation,like pH,organic matter（OM） and total phosphorous（TP） contents,and total metal concentration,were also affected significantly by the transit through the gut of earthworm.The pH value was significantly lower（p＜0.05） in the earthworm casts compared with the pig manure.As well as the pH,OM content decreased significantly（p＜0.05）.On the contray,the contents of TP and total Cu and Zn increased significantly.Stepwise multiple regression analysis revealed that the fractionation of Cu in the earthworm casts was influenced by OM,TP and the amount of Cu in the earthworm casts.The total Zn concentration in the earthworm casts was the primary factor that explained most of the variation in Zn fractionation.3.Study on the control of Cu and Zn in the pig manure-earthworm system.The peat was added to the pig manure at the level of 0%,5%,10%and 15%（mass ratio）, respectively,so were phosphate rock and fly ash.Earthworms were reared with the mixture in the greenhouse.The study was investigated the effect of additives on the accumulation of Cu and Zn in earthworms（E.fetida）,the concentrations of Cu and Zn in earthworm cast and,the bioavailability of Cu and Zn in earthworm cast.It showed that the amount of Cu and Zn accumulated in E.fetida was reduced by adding additives;the concentrations of Cu in E.fetida were reduced between 1.82 and 9.72 mg kg^-1 by adding peat to pig manure,with the maximal extent to 29.16%,and those of Zn were reduced between 4.56 and 67.58 mg kg^-1,with the maximal extent to 42.09%.As for phosphate rock,the concentrations of Cu in E.fetida were reduced between 1.25 and 8.26 mg kg^-1,with the maximal extent to 24.41%,and those of Zn were reduced between 3.85 and 45.63 mg kg^-1,with the maximal extent to 28.42%. The concentrations of Cu in E.fetida were reduced between 1.76 and 10.83 mg kg^-1 by adding fly ash to pig manure,with the maximal extent to 32.02%,and those of Zn were reduced between 5.67 and 59.52 mg kg^-1,with the maximal extent to 32.82%. Obviously,the fly ash played the most significant role in the reducing the amount of Cu accumulated in E.fetida,whereas the peat was the optimal additive for that of Zn. The additives did not reduce but increase the concentrations and bioavailability of Cu and Zn in earthworm cast.更多还原