【作者】 刘芳；

【导师】 邱凌；

【作者基本信息】 西北农林科技大学 ， 植物资源学， 2014， 硕士

【摘要】 目前我国污泥年产生量高达3000万t（以含水率80%计），其中约80%的污泥未能妥善进行处理，污泥中丰富的有机质含量（约50%～70%）、较高的含水率和不稳定性，并含有致病微生物、重金属等有害物质，如不加处理直接施用或抛弃，必然会对环境造成污染。污泥是一种复杂的非均匀质体，含有多种细菌以及丰富的氮、磷营养和微量元素，能有效改善土壤的理化性质，并且支持植物生长，但绝大部分元素以稳定的有机结合态形式存在，不易溶解释放和加以利用。特别是污泥中的有害物质去除与转化问题解决不彻底，增加了污泥利用的风险性。污泥处理技术是应用理化或先进科技方法将污泥中大分子有机物质氧化分解，破坏其絮体结构将胞内物质加以释放。目前污泥处理方法涉及物理、化学、机械、生物水解等领域，焚烧、填埋、超声波、热处理等方式均在一定程度上具有相对局限性，且可行性差，操作难度大等特点，在实际中应用效果不理想。本文以污水处理厂活性污泥为样品，主要研究酸碱化学处理、臭氧氧化处理和酸碱耦合臭氧处理对污泥中营养成分的影响，以及重金属和卫生学指标等进行综合评价。本研究主要内容及结论如下：（1）酸碱耦合臭氧处理对污泥养分变化的影响。试验结果显示，酸碱单独处理相对臭氧处理污泥，COD的释放效果需要更长的处理时间，酸碱耦合臭氧缩短了处理时间，在处理30min后，效果更好。酸碱耦合臭氧处理污泥中TN表现出下降趋势；硝态氮的含量变化基本表现一致，均处于上升态势，但耦合处理显然硝态氮转化率更快更高。耦合处理后可溶性磷酸盐结果显示：强酸耦合处理＞弱酸碱耦合处理＞强碱耦合处理＞未调酸碱处理。（2）酸碱耦合臭氧处理污泥安全评价指标研究。试验结果表明，在酸碱处理初期，各处理大肠杆菌含量均超过国家安全农用标准，7天后，强酸、强碱处理组均达到安全标准；臭氧处理60min后大肠杆菌含量达标，但7天后，大肠杆菌复活数量达到1300个/100ml，超出安全标准；酸碱耦合臭氧处理污泥，可以缩短大肠杆菌含量达标的时间，且7天后复活率大大降低。酸碱耦合臭氧处理污泥，残渣态重金属所占百分比较大，碱耦合处理组重金属总量高于酸耦合处理组。（3）酸碱耦合臭氧处理污泥工艺参数的优化。通过污泥pH值为4、7、10，臭氧处理时间为10min、35min、60min，污泥浓度为1%、3%、5%的三因素三水平正交试验，得到对SCOD、NH+4-N和PO3-4-P影响效应顺序为：臭氧处理时间＞pH值＞污泥浓度。将3%浓度的污泥pH调节为10，臭氧处理60min，其SCOD释放量最大；将5%浓度的污泥pH调节为4，臭氧处理60min，其NH+4-N释放量最大；将3%浓度的污泥pH调节为4，臭氧处理60min，其PO3-4-P释放量最大。酸性耦合臭氧处理时间60min，对浓度为3%的污泥处理，其营养物质释放量最大。更多还原

【Abstract】 At present, the sludge discharge up to30million t (in moisture content80%), of whichabout80%is not properly handled.The content of organic matter in the sludge is rich(about50%~70%), applying directly without disposing or abandoned will cause serious pollutionto the environment.Sludge is consist of bacteria,organic, inorganic particles,while lowchemical stability. Sludge is rich in nitrogen and phosphorus nutrition and some traceelements, which can effectively improve the soil physical and chemical properties, and meetthe need of plant growth, but most of these elements exist with stabilize sulfide,residual stateand the organic combination state form.Sludge treatment technology applies physical andchemical or advanced technology method to decompose macromolecular organic matter ofthe sludge oxidatively, destroy the floc structure and intracellular material would be released,transfer the insoluble or refractory nutrient substances in the sludge into soluble or solublestate. The present study, the disposal method of sludge involved in physics, chemistry,machinery,biological hydrolysis.But incineration and landfill, ultrasonic wave, heat treatmenthave relative limitations to some extent, and the feasibility is poor and operation is difficulteither, the actual application effect is not ideal.This test apply sewage treatment plant activated sludge as the research sample, the mainresearch includes acid and alkali chemical treatment, ozone oxidation treatment and acid-basecoupling ozone treatment on sludge, then evaluates comprehensive indicators such as theeffect of nutrition and hygiene and the safety of heavy metals.In this paper, the main research contents and conclusions are as follows:(1) The nutrient changes with acid-base coupling ozone treatment on sludge. Test resultsshowed that the release of the COD required longer time with acid and alkali separatetreatment compared with ozone treatment on sludge, effect of acid and alkali.Acid-basecoupling ozone treatment on sludge,TN showed a downward trend; The variation in contentof nitrate nitrogen is consistent, both rising, but the coupling treatment obviously ownedhigher nitrate conversion rate. Soluble phosphate coupling after processing results showedthat the strong coupling treatment> weak alkali coupling coupling treatment>> strong alkaliacid and alkali treatment. (2) The evaluation on safety index of sludge with acid-base coupling ozone treatment onsludge. Test result showed that at the beginning of acid and alkali treatment, all conducts of e.coli content exceeded the national security of agricultural standard;strong acid, strong alkalitreatment group met safety standard after7days;content of e. coli with ozone treatment after60min was eligible,but after7days the number of e. coli resurrected up to1300a/100mlwhich exceeded safety standards; acid-base coupling ozone treatment sludge can shorten theeligible time of the content of e. coli, and after7days the resurrection rate is reduced greatly.Acid-base coupling ozone treatment sludge residue state of heavy metals accounted for abigger percentage,alkali coupling treatment groups is higher than acid coupling treatmentgroups in total heavy metals,each branch detection of heavy metals content met the nationalsafety standards in different treating conditions.(3)The optimization model of acid-base coupling ozone treatment on sludge. Adjustingsludge pH value of4,7,10, ozone treatment for10min,35min,60min and sludgeconcentration into1%,3%,5%,doing three factors and three levels orthogonal experiment fora week.The poor analysis of test data concluded that the effects of three factors in primaryand secondary order such as SCOD, NH4+-N and PO43--P is ozone treatment time> pH>sludge concentration.Also concluded that,adjust pH of3%sludge to10, ozone treatment60min,gained the largest release quantity of SCOD;adjust pH of5%sludge to4, ozonetreatment60min,gained the largest release quantity of NH4+-N;adjust pH of3%sludge to4,ozone treatment60min,gained the largest release quantity of PO43--P.In total,acid-basecoupling ozone treatment3%sludge,the optimal treating time is60min,would release thelargest quantity.更多还原