凹凸棒添加堆肥过程中的重金属形态变化与生物毒性研究

发布时间：2018-01-08 01:08

  本文关键词：凹凸棒添加堆肥过程中的重金属形态变化与生物毒性研究　出处：《兰州交通大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 凹凸棒 堆肥 重金属 形态转化 生物毒性

【摘要】：随着我国规模化、专业化、集约化养殖业的迅速发展,含有大量重金属添加剂的饲料被广泛应用,这导致禽畜粪便中重金属元素严重超标。以此作为有机肥在农耕过程中长期施用,不仅会导致重金属在土壤和植物中的累积,处理不当会造成严重的环境问题,危及人类健康。因此,研究重金属形态在鸡粪堆肥发酵过程中的动态变化规律,探明凹凸棒的钝化机理,分析重金属形态的生物毒性对指导畜禽养殖业废弃物的资源化利用和凹凸棒在堆肥过程中的应用具有现实意义。本研究以采自甘肃省张掖市甘州区祥翔养殖农民专业合作社的鸡粪和由甘肃双泰凹土科技有限公司提供的凹凸棒为实验材料。设定6个处理,分别在鸡粪中添加不同比例的凹凸棒,进行好氧堆肥实验。通过测定在鸡粪堆肥发酵过程中,Cd、Cr、Cu、Ni和Zn五种重金属在不同处理中各个取样时间点(第1、4、12、20、25、32天)上的总量、BCR连续提取法的形态分布,以及分析各形态间不同重金属的相关性、不同重金属各形态与种子萌发特性的相关性,来研究凹凸棒添加堆肥发酵过程中的重金属形态变化和生物毒性。实验结果表明:(1)在凹凸棒添加的鸡粪堆肥发酵过程中,堆肥32天腐熟后,各个处理中Cd、Cr、Cu、Ni和Zn的浓度均大于堆肥前,且随着凹凸棒添加比例的增高,表现出更为显著的相对浓缩效应。(2)在凹凸棒添加的鸡粪堆肥发酵过程中,堆肥32天腐熟后,各个处理中重金属Cd、Cr、Ni和Zn的形态变化均表现出由不稳定形态向稳定形态转化的趋势。重金属Cu则表现出由不稳定形态酸溶态和稳定形态残渣态向其它形态转化的趋势。各处理不同的配比方案,对鸡粪堆肥发酵过程中重金属的钝化效果,因重金属元素的不同而各异,A3(凹凸棒:鸡粪为3:20)处理对重金属Cd和Cr的钝化效果最佳;A9(凹凸棒:鸡粪为9:20)处理对重金属Cu和Ni的钝化效果最佳;A6(凹凸棒:鸡粪为6:20)处理对重金属Zn的钝化效果最佳。(3)凹凸棒的添加对堆肥中重金属的形态具有显著影响。对酸溶态Cd、Cr、Cu、Ni和Zn而言,同一时间下,随凹凸棒添加比例的增加其浓度逐渐降低;同一凹凸棒添加比例的处理中,其浓度随时间的延长而降低。对还原态Cd、Cr、Cu、Ni和Zn而言,同一时间下,随凹凸棒添加比例的增加其浓度逐渐降低。同一凹凸棒添加比例的处理中,还原态Cr浓度随时间的延长而降低;还原态Cd、Cu、Ni和Zn浓度随时间的延长而升高。对氧化态Cr、Cu、Ni和Zn而言,同一时间下,随凹凸棒添加比例的增加其浓度逐渐降低;而氧化态Cd随凹凸棒添加比例的增加其浓度逐渐升高。同一凹凸棒添加比例的处理中,氧化态Cd、Cr、Cu和Ni浓度随时间的延长而升高;氧化态Zn浓度随时间的延长而降低。对残渣态Cd、Cr、Ni和Zn而言,同一时间下,随凹凸棒添加比例的增加其浓度逐渐降低;同一凹凸棒添加比例的处理中,其浓度随时间的延长而升高。对残渣态Cu而言,同一时间下,随凹凸棒添加比例的增加其浓度逐渐升高;同一凹凸棒添加比例的处理中,其浓度随时间的延长而降低。说明凹凸棒在鸡粪堆肥发酵过程中的添加,对重金属稳定形态浓度的升高和不稳定形态浓度的降低具有促进作用;对重金属稳定形态浓度的降低和不稳定形态浓度的升高具有抑制作用。(4)凹凸棒添加的鸡粪堆肥发酵过程中,综合六个处理,在不同的重金属形态中各重金属之间皆具有显著相关性。(5)对植物种子而言,与重金属形态变化的相关性排序依次为:白菜?小麦?豌豆?玉米;对种子的萌发指标而言,与重金属形态变化的相关性排序依次为:发芽指数?活力指数?发芽率?发芽势;对不同重金属而言,重金属在鸡粪堆肥发酵过程中其生物毒性的大小依次为Zn?Cd?Cu?Cr?Ni;对重金属不同形态而言,有效性较高的重金属形态对植物种子的萌发具有一定的抑制作用。
[Abstract]:With China's scale, specialization, the rapid development of intensive livestock farming, feed additives contain large quantities of heavy metals are widely used, which leads to heavy metals in livestock manure seriously exceed the standard. As the organic fertilizer in farming in the process of long-term application, will not only lead to the accumulation of heavy metals in soil and plant, improper handling will cause serious environmental problems that endanger human health. Therefore, study on heavy metal speciation in the composting of chicken manure in the process of dynamic changes, proved the passivation mechanism of attapulgite, analysis has practical significance in application of biological toxicity of heavy metals resources to guide livestock waste and attapulgite in composting process in this study. Collected from Zhangye province Gansu city Ganzhou District Xiangxiang aquaculture farmers professional cooperatives chicken manure and concave convex is provided by the Gansu science and Technology Co., Ltd. Thailand attapulgite double stick for Experimental materials. Set 6 treatments were added in different proportions in chicken manure attapulgite, aerobic composting experiment. Through the determination of chicken manure compost fermentation process, Cd, Cr, Cu, Ni and Zn five kinds of heavy metals in different treatments in each sampling time (1,4,12,20,25,32 days) on the amount, morphology the distribution of BCR sequential extraction method, and correlation analysis of different heavy metals, different forms of different heavy metals, correlation and seed germination characteristics of different forms of attapulgite, add composting process of heavy metals in morphology and biological toxicity. The experimental results show that: (1) in chicken manure composting process of attapulgite added in compost 32 days after maturity, Cd, Cu, Cr in each treatment, the concentration of Ni and Zn were higher than that of compost before and with the increase of attapulgite addition ratio, showed more significant enrichment effect. (2) in attapulgite added chicken manure In the fermentation process of compost fertilizer, 32 days after maturity, the treatment of heavy metals in Cd, Cr, Ni and Zn morphological changes showed by unstable form transformation to stable state trend. Heavy metal Cu exhibited by unstable form of acid soluble and stable form of residue to other forms of trend. The proportion of different processing, the effect of passivation of heavy metals during composting of chicken manure, because of heavy metals vary, A3 (attapulgite: chicken manure 3:20) treatment passivation effect on heavy metal Cd and Cr A9 (best; attapulgite: chicken manure 9:20) treatment passivation effect on heavy metals Cu and Ni the best; A6 (attapulgite: Chicken manure 6:20) treatment passivation effect on heavy metal Zn. (3) the addition of attapulgite has significant influence on the speciation of heavy metals in compost. The acid soluble Cd, Cr, Cu, Ni and Zn, at the same time, with the increasing proportion of Attapulgite 鍔犲叾娴撳害閫愭笎闄嶄綆;鍚屼竴鍑瑰嚫妫掓坊鍔犳瘮渚嬬殑澶勭悊涓，

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