【作者】 张薇；

【导师】 吴劳生；

【作者基本信息】 浙江大学 ， 农业资源环境， 2017， 硕士

【摘要】 本文包含野外场地试验与室内盆栽试验两部分,野外场地试验主要研究赤子爱胜蚓与不同钝化剂联合堆肥对猪粪堆肥过程中重金属铜(Cu)和锌(Zn)形态转化及其生物可利用性的影响,室内盆栽试验主要研究堆肥产物的安全利用。在本研究中,试验组选取钙镁磷肥、膨润土、生物炭、酵素、EM菌、粉煤灰和沸石作为钝化剂与蚯蚓联合堆肥,对照组只使用蚯蚓进行堆肥,以研究钝化剂对蚯蚓猪粪堆肥组中重金属Cu、Zn的影响。取得如下结果:(1)不同钝化剂对蚯蚓堆肥中重金属Cu、Zn含量及其生物可利用性的影响研究结果表明:从重金属形态分析,部分钝化剂与蚯蚓联合堆肥对重金属Cu、Zn具有一定的钝化效果。通过加入生物炭、酵素、EM菌、粉煤灰和沸石作为钝化剂,使畜禽粪便中重金属Cu形态发生明显变化,可利用态Cu(可交换态和可还原态)转变成非可利用态Cu(可氧化态和残渣态),且与对照组比较呈现显著差异(p<0.05)。膨润土、生物炭和酵素组中可利用态Zn(可交换态和可还原态)转变成非可利用态Zn,且酵素和生物炭组可利用态Zn的分配率显著减少(p<0.05);从钝化效果分析,生物炭对生物可利用态Cu钝化效果最佳,试验前后可利用态Cu的分配率减少42.34%,可利用态Zn分配率减少2.70%;另外酵素对可利用态Zn钝化效果最佳,试验前后可利用态Zn分配率减少3.77%,可利用态Cu分配率减少33.25%。且均与对照组相比呈现显著差异(p<0.05)。(2)蚯蚓与不同钝化剂联合堆肥处理后重金属Cu、Zn的形态变化规律:对重金属Cu而言,堆肥处理后Cu呈现可氧化态Cu>残渣态Cu可还原态Cu>可交换态Cu,可氧化态Cu含量占主导地位,其分配率占50%以上;而Zn呈现与Cu不同的规律,主要表现为可交换态Zn>可还原态Zn>可氧化态Zn>残渣态Zn,堆肥处理后还原态Zn和可交换态Zn仍占主导,两者分配率之和超过80%。在堆肥产物中Cu主要以不可利用态Cu的形态存在,而Zn主要以可利用态形式存在,因此更应重视堆肥产物中Zn所带来的环境污染风险。(3)盆栽试验结果表明,以生物炭作为钝化剂的堆肥产物显著提高小白菜的生物量,堆肥产物添加量为土壤总量1/3(1/3M)的处理组效果最佳。从白菜中重金属Cu、Zn含量来看,小白菜根中重金属Cu、Zn含量均高于茎叶中Cu、Zn含量。就盆栽土壤中重金属Cu、Zn含量而言,盆栽试验后土壤中重金属含量均有所下降,其中1/3M组效果最佳,其Cu和Zn含量分别减少27.31%和20.93%。应用地累积指数法对土壤重金属进行污染风险评估,结果表明长期使用有机肥添加量为土壤总量1/3的施肥方式造成的重金属Cu、Zn污染风险小于其它施肥方式,但该施肥方式仍有可能造成Cu的轻度污染风险,Zn的重度污染风险。研究结果可为猪粪堆肥过程中重金属铜锌钝化提供一些理论依据和技术支持,对猪粪堆肥产物安全施用具有一定的指导意义。更多还原

【Abstract】 This research focused on the effects of passivator and vermicomposting on fractionation of heavy metals(Cu and Zn)and their bioavailability during swine manure vermicomposting and land application vermicompost swine manure.In our experiment treatments,calcium-magnesium phosphate,bentonite,biochar,enzymes,EM bacteria,fly ash and zeolite were added to the swine manure as heavy metal passivators,while vermicomposting treatment without passivator was set as control.Our results indicated that:(1)Biochar,enzymes,EM bacteria,fly ash and zeolite treatments had a passivation effect on Cu fractionation.Meanwhile the bioavailable Cu was converted into immobilized Cu,and there was a significant difference between the treatmented group and the control(p<0.05);Biochar,enzymes and bentonitead a passivation effect on Zn fractionation.In terms of the distribution rates of available Cu and Zn,biochar was considered as the best passivator with up to 42.34%reduction of the distribution rate of available Cu,and up to 2.7%reduction of the distribution rate of available Zn.Enzymes were considered as the best passivator for available Zn(p<0.05)with a maximum reduction(3.77%)of the distribution rate.(2)The concentrations of various Cu forms in each fraction for the vermicompost swine manure were in the order of oxidizable Cu>residual Cu>reducible Cu>exchangeable Cu,while the concentrations of various Zn forms followed the order of exchangeable Zn>reducible Zn>oxidizable Zn>residual Zn.Oxidizied Cu was the dominant specie for Cu with a fraction up to 50%,while exchangeable and reduced Zn were the dominant species for Zn(>80%)in the vermicompost swine manure.Based on the BCR sequential specie analysis,the bioavailability of Cu and Zn decreased after vermicomposting.Passivators differed in their effect on the bioavailability of Cu and Zn:Zn was mostly available while Cu was mostly unavailable to plants after vermicomposting.Therefore,more attention should be paid to the risk of environmental pollution caused by Zn in compost application.(3)Pot experiments showed that,the biomass of pakchoi significantly increased by the application of vermicompost swine manure and the optimal additional amount of vermicompost manure was 1/3 of the soil mass(1/3M).The concentrations of Cu and Zn in the roots of pakchoi were higher than those in the stems and leaves.The concentrations of Cu and Zn in the treated soil decreased by 27.31%and 20.93%,respectively,in the 1/3M treatment.Indexes and levels of geo-accumulation of heavy metals in soils revealed that excessive application of manure may pose slight risk of Cu polluation but severe risk of Zn pollution.This research provided theoretical and technical information on vermicomposting of swine manure,which is of great significance to pollution prevention and risk management for heavy metals in land application of swine manure.更多还原