论文标题:污泥堆肥施用对土壤与作物的影响研究
Study on Effect of Soil and Crop with Sludge Compost Application
论文作者 殷宪强
论文导师 王国栋,论文学位 硕士,论文专业 环境工程
论文单位 西北农林科技大学,点击次数 97,论文页数 71页File Size619k
2004-06-01论文网 http://www.lw23.com/lunwen_314545432/ 污泥堆肥;土壤;作物;氮;磷;有机质;重金属;重金属形态
sludge compost; soil; crop; N; P; organic matter; heavy metal; heavy metal form
污泥中含有大量的有机物、重金属以及病原菌等，不加处理任意排放，会对环境造成严重的污染。近年来，我国城市污泥中的有害重金属含量已经明显下降，将污泥堆肥化处理后施用于园林绿地是较理想的土地利用方式，为了寻求污泥土地利用更广阔的途径，将污泥堆肥化处理后施用于蔬菜、作物是一个重要的研究内容。本试验在借鉴前人利用污泥的经验基础上，通过田间微区实验探讨污泥堆肥对作物的生物效应和土壤环境效应，寻求污泥堆肥作为肥料的最佳施入量，对污泥堆肥施用后土壤、植物中的重金属总量及土壤中重金属形态的分布情况进行研究，进一步说明重金属在土壤植物系统中的分布情况，结果如下：1．污泥堆肥施用后与化肥处理相比较油菜增产14.9%～28.3%，生菜增产5.5%～9.9%，小麦在污泥堆肥施用量为60t/hm2时增产12.54%，对于塿土来说，60t/hm2施用量增产效果比较明显，是较佳的施用量。2．施用污泥堆肥后促进了油菜、生菜及小麦体内氮、磷含量的增加，增加了表层土壤中全氮、全磷、碱解氮、速效磷及有机质的含量。3．污泥堆肥施用后引起了生菜、油菜、小麦植株中重金属在不同部位不同程度的累积，重金属进入植物体内主要分布在根系，其次才是茎叶，籽粒内含量往往最低，在利用污泥堆肥时，最好避开利用根部的植物。污泥堆肥施用未引起生菜和油菜叶内重金属超标，对于小麦，污泥堆肥施用量大于118t/hm2后超出国家卫生标准，叶中Cr，籽粒中Ni的含量和污泥堆肥的施用量间呈极显著正相关，在污泥堆肥的施用中存在的潜在隐患主要为Cr和Ni的累积污染。4．施用污泥堆肥后，土壤中的Cu、Zn、Pb、Cd、Cr的含量显著提高，其中Cu、Zn、Cd和Cr和污泥堆肥施用量的相关关系达到显著水平，Ni的含量增加较少，这与污泥堆肥中的重金属含量紧密相关。小麦收获后重金属的迁移现象表明，土壤中Cu、Zn、Pb和Cd迁移较小仅至20cm，这说明重金属在土壤中的淋溶相当缓慢，污泥堆肥的施用在短期内不会有大量的淋溶。5．污泥堆肥施用后重金属分配在不同的形态中，导致了各形态重金属含量的增加，主要增加了土壤中残留态重金属的含量。其余各形态中铁锰结合态居首，其次为有机结合态和碳酸盐结合态，可交换态的增加量最少，不同的重金属有所差异：Cd主要以铁锰氧化结合态和碳酸盐结合态存在，Zn和Pb以铁锰氧化结合态为主，碳酸盐结合态和有机结合态次之，Ni、Cu、Cr以铁锰氧化物结合态和有机结合态为主。6．从潜在有效态（可交换态、碳酸盐结合态、铁锰氧化结合态、有机结合态）重金属占总量的比例来看，重金属的活性大小为Cd>Zn>Ni>Cu>Cr>Pb。从污泥堆肥施用后对土壤中重金属的活性影响看：Zn和Cr的活性提高分别为13%和1%，Pb和Cd的活性降低分别为9%和13%，Cu和Ni的活性基本无变化。 7．污泥堆肥施用后土壤中的重金属有效态含量与污泥堆肥施用量的关系呈显著正相关，有效态的含量：Zn>Cu>Pb>Ni>Cd，这与污泥堆肥和土壤中的重金属含量密切相关。8．土壤重金属的可交换态、碳酸盐结合态、铁锰结合态、有机结合态、残留态和全量均能不同程度影响到土壤中重金属的有效性。各形态对有效态的作用大小，不同的重金属有所差异，Cu：有机结合态>铁锰结合态>残留态>可交换态；Zn：铁锰结合态>有机结合态；Pb：碳酸盐结合态>有机结合态；Cd：铁锰结合态>残留态>碳酸盐结合态；Ni：铁锰结合态>有机结合态>碳酸盐结合态，其余各形态对有效态的贡献相对较小。
There are lots organisms, heavy metal, pathogen and pathogenic bacterium in sludge, so it would pullout environment badly if it was discharged arbitrarily. In recent years, heavy metal content in sludge had decreased distinctly. It is reasonable and important of applying sludge compost on vegetable and crop for seeking wider approach of sludge using.The study on the base of precursor"s experience, through field experimental plot to discuss the biologic effect on crop and soil of sludge compost, seek the optimal application rate of sludge compost, research the content and form of heavy metal in soil and plant, furthermore explain the heavy metal distribution in soil-plant continuum. The results show:1. Compared with inorganic fertilizer, the yield of rape and lettuce raised 14.9%～28.3% and 5.5%～9.9% respectively under application of sludge compost. Wheat yield increased 12.54% when the application rate was 60t/hm2, for Lou soil it was better.2. The content of N and P in rape, lettuce and wheat, and total N, total P, available N, available P and organic matter in surface layer soil increased under application of sludge compost.3. The application of sludge compost caused heavy metal accumulation in different part of rape, lettuce and wheat. Heavy metal content was more in plant root than stem and seed, so sludge compost should be applied on the plant that not using root. Heavy metal content in rape and lettuce were not over proofed, but when the application rate exceeded 118t/hm2, the content in wheat may exceed GB. It was remarkable correlation between sludge application and the content of Cr in leaf and Ni in seed. The accumulative pollution of Cr and Ni was the hidden trouble in sludge compost application.4. The content of Cu, Zn, Pb, Cd, and Cr in soil applied sludge compost rose remarkably, and the correlation between sludge application and Cu, Zn, Cd and Cr was significance level. The addition of Ni was small, and it was closely correlative with the content of heavy metal in sludge. Heavy metal eluviations after reaping was only 20cm, so we can say that it was little at short-term after sludge compost application.5. Sludge compost application induced the increasing of content of various forms heavy metal; the rudimental form (R-) is the most. Amount the rest, the iron-manganese associative form (Fe-Mn) is the most, organic associative form (O-) is secondary and exchangeable form (Ex-) is the smallest. But various heavy metal were different, for example, iron-manganese oxidation associative form (Fe-Mn-Ox) and carbonate associative form (C-) is primary of Cd; Fe-Mn-Ox is primary and C- is secondary of Zn and Pb; Fe-Mn-Ox and O- is primary of Ni, Cu and Cr.6. From the content rate of potential effective form (Fe-Mn-Ox, O-, C- and Ex-) with total heavy metal, heavy metal activity order was Cd>Zn>Ni>Cu>Cr>Pb. The activity of Zn and Cr rose 13% and 1% respectively, but Pb and Cd reduced 9% and 13% respectively, and Cu and Ni had no change under application sludge compost.7. It was positive correlation between the application rate of sludge compost and the content of effective form heavy metal. The order of effective form content was Zn>Cu>Pb>Ni>Cd, and it was closely correlative with heavy metal content in sludge compost.8. Fe-Mn-Ox, Om-, Cr- and Ex- heavy metal and total Zn affected heavy metal availability. Various metal and its form had different influence degree on availability. For example, the order of Cu is O-> Fe-Mn-Ox >R-> Ex-, Zn is Fe-Mn-Ox > O-, Pb is C->O-, Cd is Fe-Mn-Ox >R-> C- and Ni is Fe-Mn-Ox > O-> C-. The role of else form was indirect and smaller.
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