【作者】 李荣华；

【导师】 张增强；

【作者基本信息】 西北农林科技大学 ， 环境科学， 2013， 博士

【摘要】 为了促进畜禽粪便资源化利用和缓解因畜禽粪便农田利用造成的潜在土壤重金属污染,本研究以规模化养殖场的猪粪为原材料,以玉米秸秆为调理剂,以工业废弃物粉煤灰、风化煤和膨润土为重金属钝化剂,通过自行设计的强制通风好氧高温堆肥反应器进行了为期90d的好氧堆肥制作。旨在研究(1)高Cu、Zn含量猪粪的农业可利用性和环境风险；(2)重金属钝化剂对堆肥进程中堆体一般物理化学性质(如温度、pH、EC等)的影响；(3)重金属钝化剂对堆肥进程中堆体红外光谱和堆肥质量的影响；(4)重金属钝化剂对堆肥进程中主要营养元素的动态变化影响；(5)重金属钝化剂对堆肥进程中Cu和Zn的总量、生物有效量和化学形态的影响；(6)堆肥施用量对盆栽小麦幼苗生长的影响和(7)堆肥的农田施用量估算和环境风险评价。获得了如下结论：1.经过90d的高温好氧堆制,获得了含氮磷钾丰富的堆肥产品,且堆肥中未检测出Ni、Cd、Cr、Pb、Hg和As等有害重金属,仅含Cu256.31mg/kg,Zn474.40mg/kg。盆栽试验表明,适量施用该堆肥能显著促进大豆的茎叶和根系生长,同时提高籽粒产量和籽粒中的Zn的含量。污染指数评价法和地积累指数评价法表明,当堆肥施用量不超过5%时不会构成上壤环境重金属污染。若堆肥连续施用20年,则堆肥施用量应控制在90.28t/(hm2.a)。研究表明该猪粪具有优良的农用价值。2.堆肥过程中,所有处理的堆体温度均能迅速升至70℃左右,并维持在55℃以上超过一周；各处理堆体的含水量随着堆肥时间的延长而逐渐降低,并在90d后达到30%左右；对照处理pH持续降低并最终稳定在pH7.88以下,添加粉煤灰的各处理pH在8.55～9.21的范围内波动,而添加膨润土的各处理pH呈现出先降低后升高然后又逐渐降低的趋势,并分别于90d堆制结束时稳定在pH7.20-7.88之间,添加风化煤的各处理pH呈现出先逐渐升高随后逐渐降低并最终稳定在pH7.82～7.90之间的趋势；添加粉煤灰和风化煤的各处理中水溶性盐分(EC)均呈现出先增加后降低的趋势,对照处理和添加膨润上的各处理中EC随着堆肥时间的延长而增加,且增加趋势随着膨润土添加比例的增加而增大,至90d堆制结束,EC分别达到3.74、4.74、6.12、7.10和7.74mS/cm；随着堆肥时间的延长,对照处理和添加风化煤的各处理中,雪里蕻种子的发芽率最终均达到90%以上,GI约1.0左右,而在添加膨润土合粉煤灰的各处理中,至90d堆肥结束,发芽率最高仅达80%,仅有2.5%和5.0%添加比例的处理中GI大于0.5,且GI的增加趋势随着膨润土和粉煤灰的添加比例增加而降低。3.红外光谱分析显示,堆肥过程有机质的降解持续至60d以后,添加粉煤灰、风化煤和膨润土对堆体有机物料的降解无明显影响。整体上,在堆肥过程中,波数1640cm-1处的羰基峰和1160cm-‘处多糖吸收峰强度呈下降趋势,而1460和1546cm-1处芳环结构振动峰,以及1030和875cm-1处的Si-O-Si不对称伸缩振动峰强度呈增大趋势。可以将2853cm-1附近的亚甲基C-H伸缩振动峰和醛、酮、羧酸类化合物在1740cm-1附近的C=O伸缩振动峰存在与否作为堆肥酵解腐熟是否完成的标志。红外光谱分析法有利于堆肥过程的实时检测,是进行堆肥降解分析的有用工具。研究中最终堆肥产品的基本理化指标均显著高于我国堆肥产品质量控制指标,可作为一种优质、稳定的有机生态肥和土壤改良剂。4.试验表明,随着粉煤灰含量的增加,添加粉煤灰处理中,各处理总氮含量有一定的降低,且降低趋势随着粉煤灰用量的增加愈加明显。添加风化煤和膨润土的各处理堆体中总氮的变化趋势则基本相同,基本呈现出随着堆肥时间延长总氮持续增加并趋于稳定的趋势,且总氮含量基本随着风化煤和膨润土用量的增加而有少许增加。添加粉煤灰、风化煤和膨润土的各处理中,有机质均呈现出逐渐降低最后趋于相对稳定的趋势。但添加风化煤的处理中,有机质的含量随着风化煤用量的增加有一定的增加,而添加粉煤灰和膨润上的处理中有机质则随着其添加比例的增加而减少。除了10%粉煤灰处理以外,其余所有处理中C/N比均随着堆肥时间的延长而降低并最终稳定在20左右。对照堆体和添加粉煤灰各处理堆体中,NH4-N含量先增加后降低,但添加粉煤灰对NH4-N的影响不大；而在添加风化煤和膨润上的各处理中,NH4-N先增加后降低的趋势有一定减弱,且基本随着风化煤和膨润上的添加比例的增加而降低。在堆肥初期,添加风化煤和膨润土的处理中,N03-N的产生受到一定的抑制,但随着堆肥时间的延长,这种抑制作用逐渐减弱。但添加粉煤灰却会抑制堆肥中N03-N的生成,且与粉煤灰用量呈正相关。添加风化煤、粉煤灰和膨润上均能提高堆肥的磷含量,所有处理的总磷含量均随着堆肥时间的延长呈迅速增加的趋势。5.不同用量钝化剂对猪粪堆肥过程中Cu、Zn总量、有效态含量和化学形态变化的影响研究表明：随着堆肥时间的延长,堆体Cu和Zn的总量逐渐增加,表现为明显的“相对浓缩效应”,但有效态Cu和Zn在总量中所占的比例则逐渐降低。其中添加5.0%的粉煤灰对DTPA-Zn的钝化效果较好,添加10%的风化煤对DTPA-Zn的钝化效果较好,添加10%的膨润土对DTPA-Zn的钝化效果较好；堆肥中,添加5.0%的粉煤灰对DTPA-Cu的钝化效果较好,添加2.5%的风化煤对DTPA-Cu的钝化效果较好,添加10%的膨润土对DTPA-Cu的钝化效果较好。进一步采用Sposito法进行的重金属形态分析表明,Zn各种形态比例为硫化物态>碳酸盐结合态>有机态>残渣态>交换态>水溶态,Cu的各种形态比例为有机态>硫化物态>碳酸盐结合态>残渣态>交换态>水溶态,Zn的各种形态比例为残渣态>碳酸盐结合态>有机结合态>硫化物态>交换态>水溶态。6.与对照相比,添加风化煤处理的堆肥对小麦成活率无显著影响；随着堆肥施加比例的增加和膨润上比例的增加,小麦幼苗成活率受较大影响；添加2.5%FA和5.0%FA的处理,对小麦幼苗成活率影响较小,而添加7.5%FA和10%FA的处理,当堆肥用量超过10%以后,随着堆肥施加比例的增加,小麦幼苗成活率迅速降低。添加粉煤灰、风化煤和膨润土能显著降低小麦生长初期对Cu和Zn的吸收,不同种类和用量钝化剂之间也存在一定差异。后期研究有望在延长作物种植时间,扩大作物种植种类上展开。7.进行有机肥农田施用量估算时,应以全年施氮量为标准进行估算较为科学,除了10%FA处理的堆肥外,其余堆肥的土壤年施用量在10.83～22.03t/(hm2.a),在该施用量下,连续多年施用,不会造成土壤重金属污染。如果考虑重金属的生物毒性,进行有机肥农田施用量估算,容易导致使用量过大,从而产生土壤次生盐渍化的风险。在实际堆肥的农用研究上,仍需进一步开展田间长期定位试验,以全面权衡其对农产品和环境质量的影响。更多还原

【Abstract】 In order to enhance the livestock manure agricultural application and to reduce the resulting potential soil environment heavy metal pollution risk, pig manure from a pig feeding plant was selected as raw material in the experiments, and mixed with corn stalk powder before composting in an aerobic reactor for90days. And the experiments were conducted to:(1) Study effects of pig manure compost agricultural application on the soybean planting and its environmental risk,(2) Evaluate the effect of different amounts (at0,2.5,5.0,7.5and10%in weight ratio) heavy metal passiving agent such as flyash, weathered coal and bentonite on the compost physicochemical properties during the swine manure composting,(3) Reveal the organic matter degradation during composting by using Fourier Transform Infrared Spectroscopy analysis method,(4) Investigate the Influence of passiving agent variety and proportion on the nutrient transformations during aerobic composting process,(5) explore the effects of flyash, weathered coal and bentonite on Cu and Zn chemical speciation and fractionation changing during aerobic composting,(6) detect the composts potential agricultural application on wheat cultivatation, and (7) to estimate the compost crop land application rate and the potential environment risk. The results showed that:1. After90days composting, the compost product was a potential organic fertilizer with plenty of NPK, and contained256.31mg Cu/kg and474.40mg Zn/kg but no other heavy metals such as Ni, Cd, Cr, Pb, Hg and As. The futher research conducted by the soybean planting pot experiments indicated that the application of the organic fertilizers had significant effect on the growth and yield of soybean within10%compost application rate, and increased the Zn content in the seeds of soybean. Rational application rate of swine compost in Yongshou zinc lack soil was90.28t/(hm2.a) and can be used for20years. The further pollution index and geoaccumulation index evaluation indicated that it would not cause soil environmental risk with the rational application rate of the compost in5%. The study implicated that the high Znic contaminated swine manure exhibit a potential agricultural application valve.2. The results showed that the pile temperature of all the treatments could rise to nearly70℃quickly and maintained above55℃more than a week. The moisture content gradually reduced with the composting time extension and was around30%after90days composting for all the treatments. Adding fly ash would present a strong alkaline composting environment, while adding the bentonite could significantly increase the compost water soluble salinities and the increasing were significant correlated with the amount of bentonite. The Potherb mustard seeds germination rate reached90%after90days composting in the control and weathered coal adding treatment, and the germination index were above1.0finally. While for the bentonite and flyash added treatments, after90days composting the germination index were lower than0.5except2.5%and5.0%treatments. The results implicated that add passive agents had no notable effect on compost temperature and moisture content. pH, EC and Potherb mustard roots growth were strongly influenced by the variety and adding proportion of the passive agents, although the Cu and Zn could be stabilized by adding the passive agents during the composting. The passive agent selection and dosage control should be considered in the pig manure aerobic composting process.3. The Fourier Transform Infrared Spectroscopy analysis showed that the organic matter decomposition would be continued for more than60days during the composting process. Addtion of flyash, weathered coal and bentonite had no effect on the compost raw material decomposition. During the composting, the peaks of polysaccharides at1640cm-1and1160cm-1declined, and the peaks of aromatic cylces at1460and1546cm-1, and the asymmetric stretching vibration peaks of Si-O-Si were increased. The peak of C-H vibration in methylene at2853cm-1and C=O stretching in aldehyde, acetone and carboxylic acid at1740cm-1, could be used to evaluate the decomposition of organic matter of compost. The final compost products were better than the compost product quality control standards in China, and these compost products could be used as organic fertilizer or soil amendments.4. Addition of fly ash, weathered coal and bentonite, lead the C/N ratio decrease according to composting time, whereas total N showed an opposite trend for all treatments except10%flyash was amended. NH4-N concentration increased during the first several weeks and later rapidly decreased as composting progressed. At the end of composting, only small amounts of NH4-N were detected. There was no significant loss of NH4-N during the thermophilic phase by ash amendment. While, addition of fly ash also inhibited the nitrification process as indicated by the lower soluble NO3-N contents in ash-amended swine manure composts but had no effect on TP increasing. While, the NO3-N concentration in the weathered coal and bentonite addition treatments, remained very low for the first several weeks, and followed by a steady increase. For the bentonite-adding treatment, the final NO3-N contents were1.09,1.04,1.01,0.94,0.87g/kg, respectively. Compared with the control, no significant loss of nitrogen was found with bentonite-added treatments.With the prolonging of composting time, fly ash and bentonite-adding could accelerate organic matter reduction slightly. For example, from the control to10%bentonite treatment, the organic matter decreased by21.33%,21.97%,23.52%,26.56%, and28.19%, respectively for the bentonite-adding treatments. Total P content showed an increasing trend with extended composting time for all the treatments.5. The total Cu and Zn concentration in compost piles were concentrated during the composting process, while the percentages of DTPA extractable Zn and Cu in compost piles were decreased. Adding5%fly ash,10%weathered coal, and10%bentonite in the compost raw material would reduce DTPA-Cu significantly, while the addition of5%fly ash,2.5%weathered coal, and10%bentonite10%weathered coal would reduce DTPA-Zn remarkably. The Sposito’s chemical speciation analysis showed that the fractionation were in the order of residue＞sulfide＞organic bound＞organic complexed or carbonate＞exchangeable and soluble form for Cu, and residue＞organic complexed or carbonate＞organic bound＞exchangeable and soluble form for Zn, respectively.6. Compared with control, adding of weathered coal treatments had no significant effect on the wheat seedling survival rate, while the wheat seedling survival rate was remarkably affected wiht the bentonite addition amount increase. Addtion of2.5%and5.9%fly ash had lower effect on wheat seedling growth but the fly ash addion above7.5%and10%influenced the wheat seedling growth significantly. The Cu and Zn accumulation were reduced in the wheat sedling growth periods with the fly ash, weathered coal or bentonite addition, but the effects were different among the heavy metal paasiving reagent types. Later research was expected to extend the crop planting time and expand the planting species of the crops.7. The compost application rate could be estimated by using the nitrogen amount demaonded during the crop growth periods. In this study, except the compost of10%fly ash treatment, other compost sould be application in rate of10.83～22.03t/(hm2.a). And it would no heavy metal environmental risk occurr in the application rate recommended in many years’ applications in crop cultivation. If the organic fertilizer farmland application rate was estimated by considering the biological toxicity of heavy metals, the application amount would be excessive according to the nitrogen and phorphrous plant needed in growth, and it would be easy to cause the risk of soil secondary salinization. In the actual compost agricultural application experience, the further research should be carried out in the long-term field location test, and the balance of the increasing agricultural products and the influence on the quality of soil environment shoule be comprehensive investigated.更多还原