外源有机物对污水、土壤铜形态及土壤铜生物有效性的影响

发布时间：2018-05-19 20:06

本文选题：外源有机物 + 铜形态　；参考：《华北水利水电大学》2017年硕士论文

【摘要】：我国水资源总体匮乏,且随着经济社会的发展,工业用水和生活用水所占比重越来越大,严重挤压了农业用水,导致农业用水短缺的问题越来越突出。为缓解农业用水紧张的现状,一方面需要农业灌溉节约用水,另一方面需要开发利用可利用的水资源进行灌溉。污水作为可利用的宝贵水资源,且每年排放量还在急剧增加,在这样的背景下,污水亟待开发与利用,来进行农业灌溉。但是污水中含有大量的污染物,若处理不当,会造成土壤重金属富集,因此灌前对污水的预处理与灌后对土壤的修复,是利用污水进行农业灌溉的必要措施。本文以人民胜利渠灌区及附近农田作为研究区域,利用有机物进行污水处理及污染土壤的修复。利用有机物来降低污水中的重金属活性,可以缓解农业灌溉水资源短缺,为污水资源化奠定基础;利用有机物对重金属污染农田进行修复,可以降低土壤重金属生物有效性,有利于改善不合理污灌造成的土壤重金属污染。重金属的形态分布对重金属的活性起关键作用,外源有机物对重金属的形态分布与生物活性有重要影响。因此本研究首先探讨了外源有机物腐殖酸对不同污染水体中铜的形态的影响;采用土壤培养的方式研究了在模拟铜污染土壤中添加沼渣、猪粪、羊粪、鸡粪4种有机物料对土壤中酸溶态、可还原态、可氧化态和残渣态铜等4种土壤形态的影响。在此基础上,以对铜生物有效性有影响的有机组分腐殖酸为外源有机物,以生菜为指示作物,研究了不同腐殖酸添加量下土壤中铜形态分布规律及生菜中铜吸收量的分布,初步明确不同腐殖酸添加量对铜形态及其生物有效性的影响。最后,配置含有腐殖酸成分的4种有机无机复合物料,研究4种复合物料对土壤铜生物有效性的影响,为土壤修复工作的进一步研究提供了有价值的参考方法。主要结论如下:(1)在含铜量为5.77 mg/L的灌溉水中添加不同浓度的腐殖酸(从5 mg/L到35mg/L),颗粒态铜含量上升最多,溶解态铜下降最多,表明此时腐殖酸的加入最有利于污灌所带来的农田污染风险。在3≤pH≤7的污水中添加腐殖酸,污水中颗粒态铜能够急剧增加,减小铜在水中的迁移能力和生物可利用性,为污灌降低风险。(2)在污染土壤中添加4种不同有机物料的试验过程中,对照组与处理组均出现残渣态含量上升,可氧化态含量下降。在不添加铜的土壤中,添加羊粪处理时,此现象最明显,可氧化态含量下降了29%,残渣态含量上升了25%。(3)在不添加铜的土壤中,施用4种有机物料,增加了土壤中有效态铜含量。在铜浓度为50 mg/kg、250 mg/kg的土壤中,添加4种有机物料均降低了土壤中有效态铜含量。且当铜为250 mg/kg时,添加有机物料对有效态铜含量的降低作用最大,此时4种有机物料对有效态铜的降低作用可以总结为鸡粪羊粪沼渣猪粪。(4)在铜浓度500 mg/kg的土壤中,羊粪的添加降低了土壤中有效态铜含量,羊粪添加量越大,对有效态铜含量的降低作用越明显。(5)腐殖酸的加入对铜生物有效性的影响是负效应,可抑制生菜对重金属铜的吸收。随着腐殖酸添加量的增加,对各污染水平的土壤中生菜铜吸收量(根部+地上部)的降低作用越明显。当腐殖酸添加量为8 g/kg时,处理组比对照组平均降低33.4%。所有组合中,只有当铜浓度50 mg/kg、腐殖酸浓度为6 g/kg和8 g/kg时,对生菜铜(地上部+根部)吸收量的降低量较多,分别降低了46%和44%,此时生菜地上部铜含量10mg/kg,符合国家卫生标准。在铜为50 mg/kg的土壤中,加入腐殖酸后生菜铜吸收量比对照组降低的最多。(6)植物根际活动促进土壤中可还原态铜含量升高,促进可氧化态含量降低。根际土中不同形态含量从高到低依次为残渣态可还原态可氧化态酸溶态。非根际土中,4种形态含量从高到低依次为残渣态可氧化态可还原态酸溶态。(7)4种有机无机复合物料中,以腐殖酸含量为主的复合物料D对铜生物有效性的负效应影响最明显。土壤中添加复合物料D后,小白菜体内铜含量减少最多,比对照组减少了59%。
[Abstract]:With the development of economy and society, with the development of economy and society, the proportion of industrial water and domestic water is becoming more and more serious, and the agricultural water is squeezed seriously. The problem of agricultural water shortage is becoming more and more prominent. In order to alleviate the current situation of agricultural water use, it is necessary for agricultural irrigation to save water, on the other hand, it needs to be exploited and utilized. Water resources are used for irrigation. Sewage is used as a valuable water resource, and the annual discharge is still increasing rapidly. In this context, sewage is urgently developed and used for agricultural irrigation. But there are a lot of pollutants in the sewage. If the sewage is not treated properly, it will be enriched in heavy metals in the soil, so the pre irrigation of sewage is pre placed. The restoration of soil after irrigation and irrigation is a necessary measure for agricultural irrigation with sewage. This paper takes the people's Shengli canal irrigation area and the nearby farmland as the research area, and uses organic matter to treat the sewage and the remediation of contaminated soil. The use of organic matter to reduce the heavy metal activity in the sewage can alleviate the shortage of agricultural irrigation water resources. The utilization of organic matter to the remediation of heavy metal polluted farmland can reduce the bioavailability of heavy metals and improve the pollution of heavy metals caused by unreasonable irrigation. The distribution of heavy metals plays a key role in the activity of heavy metals, and the morphological distribution and biological activity of exogenous organic matter to heavy metals. In this study, the effect of exogenous organic humic acid on the morphology of copper in different polluted water bodies was investigated. The soil culture method was used to study the acid soluble, reducible, oxidizable and residue copper of 4 organic materials in the simulated copper contaminated soil, pig manure, sheep dung and chicken manure 4. On this basis, on this basis, the organic components of the organic compounds, which have influence on the bioavailability of copper, were taken as the exogenous organic matter. The distribution of copper in the soil and the distribution of copper absorption in the lettuce were studied under the addition of different humic acids. In the end, 4 kinds of organic and inorganic compound materials containing humic acid are arranged to study the effect of 4 kinds of compound materials on the bioavailability of soil copper, and provide valuable reference methods for further research on soil remediation. The main conclusions are as follows: (1) adding different concentrations in the irrigation water with copper content of 5.77 mg/L. With humic acid (from 5 mg/L to 35mg/L), the content of granular copper increases most and the dissolved copper decreases most. It shows that the addition of humic acid is most beneficial to the pollution risk of farmland caused by sewage irrigation. Adding humic acid to 3 less than pH < 7 of sewage, the granular copper in sewage can increase rapidly, and reduces the migration ability and bioavailability of copper in water. (2) to reduce the risk of sewage irrigation. (2) in the test process of adding 4 different organic materials in the contaminated soil, the residue state content of the control group and the treatment group increased and the oxidizable content decreased. In the soil without copper, this phenomenon was the most obvious, the oxidizing state decreased by 29%, and the residue content increased by 2. 5%. (3) added 4 kinds of organic materials in the soil without copper, which increased the content of effective copper in the soil. Adding 4 organic materials in the soil of 50 mg/kg and 250 mg/kg decreased the content of effective copper in the soil. And when copper was 250 mg/kg, the effect of adding organic materials to the effective copper content was the greatest, and 4 kinds of organic materials were found at this time. The effect of organic materials on the reduction of effective copper can be summed up as chicken manure pig dung. (4) in the soil of 500 mg/kg copper concentration, the addition of sheep dung reduced the content of effective copper in the soil. The greater the amount of sheep dung added, the more obvious the effect of the effective copper content. (5) the effect of humic acid addition on the bioavailability of copper was negative. It can inhibit the absorption of heavy metal copper in the lettuce. With the increase of humic acid addition, the reduced effect of the soil Nakamo Na absorption (root + top) at each level of pollution is more obvious. When the addition of humic acid is 8 g/kg, the treatment group is less 33.4%. than the control group, only when the concentration of copper is 50 mg/kg, the humic acid is strong. When the degree is 6 g/kg and 8 g/kg, the reduction in the absorption of copper (top + root) in lettuce is more than 46% and 44%, respectively. The copper content in the upper part of the lettuce is 10mg/kg, which conforms to the national hygienic standard. In the soil of 50 mg/kg, the absorption of copper by adding humic acid is most lower than that of the control group. (6) the plant rhizosphere activity promotes the soil. The content of the reducible copper is increased and the content of the oxidizable state is reduced. The content of different forms in the rhizosphere soil is from the high to the low to the oxidizable acid soluble state of the redox state of the residue. In the non rhizosphere soil, the 4 kinds of morphological content from high to low are in the residue state oxidizable state acid soluble state. (7) 4 kinds of organic and inorganic compound materials, humic acid The negative effect of D on the bioavailability of copper was most obvious. After adding compound material D in the soil, the content of copper in Chinese cabbage decreased by 59%., which was less than that of the control group.
【学位授予单位】：华北水利水电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S153.6;S273.5

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