畜粪蚯蚓堆肥中腐殖质形成及其结合态重金属变化规律和机理研究

发布时间：2018-01-31 23:07

本文关键词： 猪粪蚯蚓堆肥 DOM 腐殖物质重金属　出处：《杭州师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：本研究采用猪粪、13C标记水稻秸秆混合物为原材料进行蚯蚓处理,研究蚯蚓处理前后堆制物的基本特性及重金属变化规律、水溶性有机物(DOM)和腐殖质组分的表征及其重金属变化,进一步研究畜粪蚯蚓堆肥中胡敏酸(HA)对Cu的吸附及影响因素和蚯蚓活动对腐殖质组分及其结合态重金属转化的影响等,主要结论如下:(1)蚯蚓堆肥过程中,蚯蚓的存活率和蚓体生长量变化一致,均呈先减后增趋势。当蚯蚓适应环境后,可促进堆制物的降解;堆肥结束后,蚯蚓处理使堆制物的pH、EC、温度和CEC升高;TC、TN含量增加,但C/N减少;营养元素总P、总K含量增加,且有效态的N、P、K含量亦呈增加趋势;微生物量碳含量减少但过氧化氢酶含量较高。蚯蚓能富集重金属Cu、Zn,对Cu具有更高的富集能力;蚯蚓处理使堆制物中总Cu量增加而使其有效态Cu含量减少,但Zn含量则相反。根据δ13C值和重金属含量变化,发现13C标记水稻秸秆和重金属能在蚓体、蚓粪中迁移、转化;各物质的Cu和Zn含量相互间存在影响。(2)蚯蚓处理后,堆制物中DOM含量增加,但DOM溶液中重金属Cu、Zn含量减少。经蚯蚓处理后,堆制物DOM中C、H、N含量增加,O含量减少,与自然堆肥处理相比,蚯蚓处理堆制物的DOM中具有更少的脂肪族官能团和更多的含氧官能团,其分子量更大,多糖物质含量降低,含氮物质增加,并具有更多复杂和密集的芳香结构存在。DOM的δ13C值的变化与DOM浓度呈显著相关,但蚯蚓堆肥中稻草碳源不易转化为DOM。(3)蚯蚓堆肥过程中,堆制物腐殖物质组分HS、HA和FA含量均呈增长趋势。与自然堆肥相比,蚯蚓堆肥后,腐殖物质组分HA分子量变小,其含氮官能团、脂肪族官能团和含氧官能团均相对较少,所含脂肪族物质和多糖物质呈减少趋势;FA中含氮化合物、脂肪族官能团增加,含氧官能团减少,所含芳香族化合物或羧酸类物质和多糖物质增加,分子量增大。荧光光谱分析表明,相对于自然堆肥,蚯蚓处理后堆制物腐殖质组分HA和FA具有较少的芳香蛋白物质、类胡敏酸、类富里酸及类蛋白物质,但结构复杂化程度较高。蚯蚓堆肥过程中,HA和FA的δ13C值变化相反,δ13C值始终为FAHA,故HA可能被转化成为了FA。(4)HA对Cu的吸附能力受pH、温度和HA初始浓度变化影响。通过拟合Henry、Langmuir和Freundlich方程可知,随着pH的增大,HA对Cu的最大吸附量增加;当温度和HA起始浓度适中时,蚯蚓处理的HA对Cu的吸附量最大。HA与Cu配合后,发生荧光猝灭现象,猝灭程度受pH、温度和HA浓度影响。HA吸附Cu后的荧光特征峰强度:随pH及HA起始浓度增大,HA吸附Cu后的荧光峰强度减小;随温度增加,HA吸附Cu后的荧光峰强度呈先增后减趋势。此外,S1处理所得HA比S2处理更能与Cu发生荧光猝灭现象。(5)蚯蚓处理过程中,蚯蚓活动能增大腐殖物质的矿化速率而重金属Cu会抑制蚯蚓活动,影响微生物和蚯蚓对腐殖物质分解。蚯蚓活动造成HA含量减少,HS和FA含量增加,并使HA/FA值降低,促进HA向FA转化;添加Cu后腐殖物质及各组分含量更少,这可能与蚯蚓活动促进Cu与腐殖质结合形成难溶性物质有关。红外光谱分析和荧光光谱分析结果发现,蚯蚓活动对HA中多糖类物质的形成有一定促进作用,蚯蚓活动会造成FA中脂肪族物质相应减少;相对于自然堆肥,蚯蚓堆肥在一定程度上造成HA中类胡敏酸有机物和FA类富里酸有机物中增加缓慢,FA中芳香族蛋白质物质减少缓慢,而重金属Cu会影响它们的形成。此外,蚯蚓对重金属Cu具有富集作用,且腐殖物质中FA结合态Cu远大于HA结合态Cu。
[Abstract]:This study used 13C labeled pig manure, rice straw mixture as raw materials for earthworms, basic characteristics and heavy metal changes before and after treatment of earthworm composting material, water soluble organic matter (DOM) characterization and change of heavy metal and humus, further research on animal manure composting earthworm Hu Min acid (HA) adsorption on Cu and the influence factors of Earthworm on humus composition and associated heavy metals into impact, the main conclusions are as follows: (1) the process of vermicomposting, survival rate and earthworm earthworm growth variation, were decreased at first and then increased. When earthworms adapt to the environment, can promote the degradation of composting fabric; after composting, the composting earthworms. PH, EC, TC, CEC and temperature increased; the content of TN increased, but C/N decreased; total nutrient P, increase the content of total K, and available N, P, K content also increased; microbial biomass carbon Reduce the amount but higher content of catalase. Earthworms enrichment of heavy metals of Cu, Zn, has a higher enrichment ability of Cu; the total Cu of composting earthworms in increasing the available Cu content was decreased, but the content of Zn on the contrary. According to the change of 13C values and heavy metal content, found that 13C markers in rice straw and heavy metals in earthworm, migration, vermicompost; Cu and Zn content of each substance exists mutual influence. (2) the earthworm treatment, increase the content of DOM in the composting material, but the heavy metal Cu in DOM solution, the content of Zn decreased. After vermicomposting and composting of DOM C, H, N content increased, O content decreased, compared with natural composting, Vermicomposting of composting material has less DOM in aliphatic groups and more oxygen-containing functional groups, the molecular weight is bigger, reducing sugars content, nitrogen increased, and has more complex and dense aromatic structure the presence of.D 13C was significantly related to the change of OM value and DOM concentration, but the earthworm compost straw carbon source is not easily converted to DOM. (3) in the process of vermicomposting, composting material component of humic substances HS, HA and FA content showed an increasing trend. Compared with natural composting, vermicomposting, humic substances group HA molecular weight is small, the nitrogen containing functional groups, aliphatic groups and oxygen-containing functional groups are relatively small, containing aliphatic substances and polysaccharide substances decreased; compounds containing FA, aliphatic groups increased, reducing the oxygen containing functional groups, containing aromatic compounds or carboxylic acids and sugars increased molecular weight increased. The fluorescence spectra show that compared with natural compost, aromatic substances after composting earthworm protein matter humus fractions HA and FA have less, Hu Min acid, fulvic acid and protein like substances, but the structure is complex. A higher degree of vermicomposting In the process of HA, Delta 13C and FA values decreased, 13C values are always FAHA, so HA could be transformed into the FA. (4) adsorption capacity of HA Cu by pH. The change of temperature and the initial concentration of HA. By fitting the Henry, Langmuir and Freundlich equation, with the increase of pH, the largest the adsorption capacity of HA Cu increase; when the temperature and the initial concentration of HA is moderate, the maximum adsorption capacity of Cu.HA and HA Cu on earthworms after the match, the fluorescence quenching occurs, the quenching degree by pH, effects of temperature and concentration of HA fluorescence intensity of.HA after the adsorption of Cu: with the initial pH and HA concentration the increase of fluorescence intensity, decrease the adsorption of HA after Cu; with the increase of temperature, the fluorescence intensity of HA adsorption after Cu first increased and then decreased. In addition, the HA S1 treatment than S2 treatment to the fluorescence quenching occurs with Cu. (5) earthworm treatment process, earthworms can increase humic substances the mineralization rate and heavy Cu can inhibit the effect of microorganisms and earthworms, earthworm on decomposition of humic substances. Earthworm activity caused by reduced HA content and increased HS and FA content, and the decrease of HA/FA value, promote the HA to FA conversion; after adding Cu humic substances and components content less, which may Cu and humus combine to form insoluble substances related to earthworm activity promotion. Infrared spectroscopy and fluorescence spectroscopy analysis showed that earthworm activity has a role in promoting the formation of HA polysaccharide, earthworm activity will cause FA aliphatic substances decreased; compared with natural composting, vermicomposting resulted in a certain extent in HA Hu Min and FA rich organic acid in acid organic matter increased slowly, aromatic protein FA decreased slowly, and the heavy metal Cu will affect their formation. In addition, earthworms have accumulation of heavy metals and humic substances in FA Cu, bound Cu Far greater than HA bound Cu.

【学位授予单位】：杭州师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S141.4

【引证文献】