钝化剂对蚯蚓猪粪堆肥中铜和锌的钝化效果及堆肥产物安全利用的研究

发布时间：2018-11-25 15:04

【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(p0.05)。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(p0.05);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(p0.05)。(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。
[Abstract]:This paper includes two parts: field test and indoor pot experiment. Field experiments were conducted to study the effects of composting with different passivating agents on the transformation and bioavailability of heavy metals Cu (Cu) and Zn (Zn) in pig manure composting. The safe utilization of compost products was studied in pot experiment. In this study, calcium magnesia phosphate fertilizer, bentonite, biochar, enzyme, EM bacteria, fly ash and zeolite were selected as passivating agent and earthworm compost, while the control group only used earthworm to compost. The effect of passivating agent on heavy metal Cu,Zn in earthworm pig manure compost was studied. The results are as follows: (1) the effects of different passivating agents on the Cu,Zn content and bioavailability of heavy metals in earthworm compost were studied. The results showed that: from the speciation analysis of heavy metals, some passivating agents combined with earthworm compost on heavy metal Cu, Zn has a certain passivation effect. By adding biochar, enzyme, EM bacteria, fly ash and zeolite as passivating agents, the speciation of heavy metal Cu in animal manure was changed obviously. The usable state Cu (exchangeable state and reducible state) was transformed into non-usable state Cu (oxidizable state and residue state), and there was a significant difference compared with the control group (p0.05). In bentonite, biochar and enzyme groups, the usable Zn (exchangeable and reductible) was transformed into non-usable Zn, and the partition rate of available Zn in enzyme and biochar groups was significantly reduced (p0.05). From the analysis of passivation effect, biochar has the best passivation effect on bioavailable Cu. The available Cu distribution rate is reduced by 42.34% and the usable state Zn distribution rate is reduced by 2.70% before and after the experiment. In addition, the enzyme had the best passivation effect on available state Zn. The available state Zn partition rate decreased 3.77% and the usable state Cu distribution rate decreased 33.25% before and after the experiment. Compared with the control group, there were significant differences (p0. 05). (2) in the morphological changes of heavy metal Cu,Zn in the composting of earthworm and different passivating agent: for heavy metal Cu, there was no significant difference between the two groups (p0. 05). (2). After composting, Cu showed oxidizable Cu residuals Cu reducible Cu exchangeable Cu, oxidizable Cu content and its partition rate was more than 50%. However, Zn is different from Cu in that exchangeable Zn, reducible Zn, oxidable Zn residuals and exchangeable Zn still dominate after composting, and the sum of the two distribution rates is more than 80%. In compost products, Cu mainly exists in the form of unusable Cu, while Zn in the form of usable state. Therefore, the risk of environmental pollution caused by Zn in compost products should be paid more attention to. (3) the results of pot experiments show that, The biomass of pakchoi was significantly increased by the composting product of biochar as passivating agent, and the best effect was in the treatment group with soil total amount 1 / 3 (1 / 3M). According to the Cu,Zn content of heavy metal in Chinese cabbage, the content of Cu,Zn in the root of pakchoi was higher than that in the stem and leaf. As far as the Cu,Zn content in pot soil was concerned, the content of heavy metal in pot soil decreased after pot experiment, among which 1 / 3 M group had the best effect, its Cu and Zn contents decreased 27.31% and 20.93%, respectively. The pollution risk of heavy metals in soil was assessed by using the method of ground accumulation index. The results showed that the risk of Cu,Zn pollution caused by the long-term application of organic fertilizer was less than that of other fertilization methods when the amount of organic fertilizer was 1 / 3 of the total amount of soil. However, the application of fertilizer may cause the risk of Cu pollution and Zn pollution. The results can provide some theoretical basis and technical support for the passivation of heavy metal copper and zinc in the process of pig manure composting, and have certain guiding significance for the safe application of pig manure compost products.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S141.4

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