生物沥浸污泥工程化好氧堆肥效果及其机理研究

发布时间：2018-04-08 10:08

本文选题：常规脱水污泥　切入点：生物沥浸污泥　出处：《南京农业大学》2015年博士论文

【摘要】：截至2014年,我国设市城市、县共建成城市污水处理厂3717座,污水处理能力达1.57亿M3/日,相应的含水率80%的城市污泥产生量达10×104吨/日。由于经济和技术方面的原因,我国城市污泥尚未得到妥善处置,污泥随意弃置或不合理的施用已对环境造成了潜在危害。污泥堆肥后土地利用是目前最经济有效的污泥资源化利用方式,污泥堆肥产品具有改良土壤、增产增收的效应。然而由于常规脱水污泥含水率达78%～85%,需要加入大量的调理剂或有机添加剂以降低含水率并增加孔隙率,导致堆肥占地面积大、操作不便、堆肥效率低、成本难以控制、堆肥质量不稳定。因此实现污泥高效脱水得到较低泥饼含水率(小于60%)是改善当前这些问题的关键。以复合硫杆菌为主体的微生物生物沥浸技术可以对城市污泥实现很好的调理,明显改善污泥脱水性能。工程实践表明,生物沥浸后的污泥可机械脱水至含水率低于60%,并且与化学调理不同,污泥生物沥浸后有机质、氮、磷等养分含量无明显降低,泥饼肥效没有损失。将含水率60%的生物沥浸污泥饼进行工程化堆肥,无需加入大量调理剂调节含水率,可节约运行成本并且堆肥操作更加简便。然而,目前生物沥浸污泥工程化堆肥处理的相关研究仍然缺失。本文针对生物沥浸污泥堆肥资源化过程中可能遇到的问题,重点开展了生物沥浸污泥工程化堆肥效果及生物沥浸污泥堆肥过程中氮素损失控制、生物沥浸污泥工程化堆肥条件优化、生物沥浸污泥堆肥腐熟度评价方法的研究。经过系列试验,主要研究结论如下:1、江苏省无锡市城市污水处理厂脱水污泥含水率平均值达80.8%,有机质、总氮、总磷以及总钾含量的均值为45.4%、3.49%、2.02%和0.24%,其中总氮和总磷含量均高于普通农家肥,全部满足污泥土壤改良及污泥农用处置养分要求。然而脱水污泥中的重金属含量均有不同程度的超标现象,污泥中的重金属是制约城市污泥土地利用的重要因素。2、利用污泥生物沥浸反应器对城市污泥进行生物沥浸处理。处理后的污泥经板框压滤机脱水,泥饼含水率下降至55.8%,同时污泥养分含量未发生明显减少。生物沥浸污泥饼中重金属Cu、Zn、Cr与Ni的含量相比原始污泥分别下降48.2%、11.4%、9.8%和12.3%,并且重金属的形态也发生较大变化,重金属的生物有效性明显降低,有利于污泥后续土地利用。3、对生物沥浸污泥工程化好氧堆肥效果及其降低堆肥氮素损失的机理进行研究。结果表明,生物沥浸污泥堆肥所需调理剂约为常规脱水污泥堆肥的10%,堆体pH值相比常规脱水污泥堆肥低0.2～0.3;生物沥浸污泥堆肥体系中的有机物更易被微生物降解,有机氮更容易发生矿化,NH4+-N含量明显升高,然而累计氨气挥发量仅为常规脱水污泥堆肥的51%。研究发现相对较低的堆体pH值、微生物氨同化作用以及生物沥浸污泥中存在的水溶性铁离子联合抑制生物沥浸污泥堆肥氨气挥发,减少了氮素损失,因而生物沥浸污泥堆肥产品肥力更高并且重金属含量低。4、使用不同有机调理剂进行生物沥浸污泥条垛式堆肥,发现麦糠的加入可以促进堆体升温,堆料有机物和粗纤维降解率最高,麦糠是生物沥浸污泥堆肥快速腐熟的高效有机调理剂;添加菇渣的堆肥氨气挥发速率最低,氨气挥发量仅为麦糠处理的31%,且堆肥产品的总氮含量最高,较堆肥前增加23.6%。通过分析得知,菇渣比表面积较高,结构疏松多孔,具有较强的氨气吸附能力。菇渣是减少生物沥浸污泥堆肥氮素损失的优良调理剂。5、采用硫酸亚铁、沸石和过磷酸钙作为减少氨气挥发的生物沥浸污泥堆肥保氮剂。结果表明,相比对照处理,过磷酸钙和硫酸亚铁的加入使得累计氨气挥发量分别减少了30%和94%,而沸石处理增加了38%。实验结果表明,硫酸亚铁固定了堆肥过程中产生的NH4+-N,堆肥氮素损失减少45.6%。硫酸亚铁可以作为生物沥浸堆肥工程中高效、廉价的氮素损失抑制剂。6、通过对不同堆肥时期生物沥浸污泥堆肥样品的理化性质和生物指标分析,建立了一种简单快捷的生物沥浸污泥工程化堆肥腐熟度评价方法并提出相应标准:以CO2释放速率≤5000 mg CO2/kg vs/d作为堆肥样品完全腐熟的标准;当CO2释放速率12000 mg CO2/kg vs/d时,可以认为堆肥样品接近腐熟,对作物没有毒害作用,可直接进行土地利用。选取不同原料堆肥样品进行腐熟度测定,结果表明,该方法对不同原料的堆肥具有一定的适用性。7、建立了生物沥浸脱水污泥饼高温堆肥工程并详细分析工程工艺流程、设备选型、运行参数、处理效果及经济性。二年多的工程实践结果表明,生物沥浸污泥堆肥系统解决了目前常规脱水污泥堆肥所遇到的诸多问题,堆肥产品用于园林绿化,具有良好的经济效益和社会效益。论文研究成果对于生物沥浸污泥工程化堆肥技术的应用及推广具有指导意义。
[Abstract]:As of 2014, China set up the city of city, county to build a city of 3717 sewage treatment plants, sewage treatment capacity of 157 million M3/, corresponding to the city sludge moisture content of 80% production capacity of 10 x 104 tons / day. Due to the economic and technical aspects of the city, our country has not been properly dispose of sludge, sludge discarded or unreasonable use has caused a potential hazard to the environment. The land utilization of sewage sludge compost is the most economical and effective sludge resource utilization, sludge composting products with improved soil, increase production effect. However, up to 78% ~ dehydrated sludge moisture content of 85%, need to add a lot of conditioner or organic additives to reduce the moisture content and porosity increased, resulting in composting of large area, inconvenient operation, composting efficiency is low, the cost is difficult to control, the compost quality is not stable. So the realization of efficient dewatering of sludge to low mud cake Water content (less than 60%) is the key to improve these current problems. Microbial bioleaching by composite Thiobacillus as the main body of city sludge leaching technology can achieve good conditioning, improve sludge dewatering performance. The engineering practice shows that after bioleaching sludge mechanical dewatering can to below 60% moisture content, and chemical conditioning of sludge bioleaching after organic matter, nitrogen, phosphorus and other nutrient content did not significantly reduce the fertilizer loss. No cake, the moisture content of 60% bioleaching sludge composting project, without adding a lot of conditioner regulating water content, can save running costs and composting operation more convenient. However, the bioleaching research project of sludge compost treatment still missing. This paper may encounter bioleaching sludge composting process, focusing on the sludge bioleaching engineering pile The effect of fertilizer and bioleaching of controlling nitrogen loss during composting of sewage sludge, bioleaching sludge composting project optimization, research on Bioleaching evaluation method of sludge compost maturity. After a series of experiments, the main conclusions are as follows: 1, Jiangsu Province, Wuxi city sewage treatment plant sludge water content reached 80.8% on average organic matter, total nitrogen, total phosphorus and total potassium content, the average was 45.4%, 3.49%, 2.02% and 0.24%, the content of total nitrogen and total phosphorus were higher than the ordinary farmyard manure, all meet the sludge soil improvement and sludge nutrient requirements. However, the content of heavy metals in sludge dewatering have different degrees of exceed the standard phenomenon of heavy metals in sewage sludge. Is an important factor restricting the land use of city sludge.2, leaching reactor of city sludge bioleaching treatment by bioleaching sludge. The sludge dewatering by filter press mud. Cake moisture dropped to 55.8%, while the sludge nutrient content did not significantly decrease. Bioleaching of heavy metals of Cu, Zn in the sludge cake, compared the content of Cr and Ni of the original sludge were decreased by 48.2%, 11.4%, 9.8% and 12.3%, and the speciation of heavy metals are also changed, the bioavailability of heavy metals decreased significantly in favor of sludge land use.3, to study the mechanism of bioleaching sludge aerobic composting engineering effect and reduce nitrogen loss during composting. The results showed that the bioleaching sludge compost amendment required about dehydrated sludge compost pile 10%, pH value compared with the conventional dehydration of sludge compost low 0.2 ~ 0.3; bioleaching sludge composting system is more susceptible to microbial degradation, organic nitrogen mineralization occurs more easily, the content of NH4+-N was significantly increased, but 51%. of total amount of ammonia volatilization was dehydrated sludge compost hair The pile is relatively low pH value, microbial ammonium assimilation and bioleaching sludge in the presence of water soluble iron combined inhibition of bioleaching sludge compost ammonia volatilization, reduce nitrogen loss, and bioleaching sludge compost products fertility higher and low heavy metal content of.4, the use of different biological organic coagulant bioleaching sludge windrow composting, found that wheat bran addition could promote the stack temperature, feed organic matter and crude fiber degradation rate is highest, the high efficiency organic conditioner bioleaching sludge compost manure composting; adding mushroom residue compost ammonia volatilization rate was the lowest, the amount of ammonia volatilization was only 31% of the total wheat bran processing. The nitrogen content of compost and compost is the highest, the increase of 23.6%. through the analysis of that mushroom residue high specific surface area, porous structure, ammonia has strong adsorption capacity. The mushroom residue is reduced bioleaching Leaching sludge compost nitrogen loss excellent conditioner.5, using ferrous sulfate, zeolite and superphosphate decreased ammonia volatilization as biological leaching sludge compost nitrogen protecting agent. The results show that, compared with the control treatment, adding superphosphate and ferrous sulfate makes the total amount of ammonia volatilization was reduced by 30% and 94% respectively, while zeolite treatment increased 38%. experiment the results show that the fixed ferrous sulfate produced during composting composting NH4+-N, nitrogen loss reduced 45.6%. ferrous sulfate can be used as compost in bioleaching engineering efficiency, nitrogen loss inhibitor.6 cheap, through the analysis of different composting periods bioleaching sludge compost samples the physicochemical properties and biological indicators, establish a simple efficient bioleaching sludge composting project maturity evaluation method and put forward the corresponding standard: with the CO2 release rate of less than 5000 mg CO2/kg vs/d as compost samples Full maturity standard; when the CO2 release rate of 12000 mg CO2/kg vs/d, can be considered as compost samples close to maturity, no toxicity to crops, can be directly used for land use. Different raw compost samples were maturity determination results show that the.7 method has certain applicability to different raw material compost, set up bioleaching of dewatered sludge cake composting engineering and a detailed analysis of process flow, equipment selection, operation parameters, treatment effect and economy. The engineering practice for more than two years. The results showed that the bioleaching sludge composting system to solve the many problems currently encountered in conventional dehydration of sludge compost, compost for landscaping, with good the economic and social benefits. The research results have guiding significance for the application and promotion of bioleaching of sludge composting project.

【学位授予单位】：南京农业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：X703;S141.4

【参考文献】