超声波耦合好氧堆肥预处理结合蚯蚓处理剩余污泥研究

发布时间：2018-03-21 10:41

本文选题：剩余污泥　切入点：超声波破解　出处：《西南交通大学》2017年博士论文　论文类型：学位论文

【摘要】：随着城镇污水处理厂的大量建设和运行,污泥的产量大幅度增加。我国于2015年2月发布的《水污染防治行动计划》(“水十条”)明确指出:在2020年底前,地级及以上城市污泥无害化处理处置率应达到90%以上,由此可见,污泥的处理处置已迫在眉睫。大量研究表明,在污水处理过程中产生的剩余污泥,含有大量有机质和营养元素,是一种有一定价值的资源。因此,开发低碳环保的资源化污泥处理处置技术是目前国内外污水处理行业的研究热点。本文首先分析国内外关于污泥处理处置的主要方法及其优缺点,然后,以污泥处理处置的减量化、无害化和资源化为基本原则,并基于蚯蚓的生态处理功能,选择以污水厂剩余污泥为主要原料,并混合掺加一定量的秸秆和鸡粪,采用超声波破解技术耦合好氧堆肥预处理,结合蚯蚓处理工艺对其进行处置。该研究主要测试了污泥的基本性质、微生物数量、营养物质和重金属含量等指标,进而分析污泥在处理前后,性质的变化特征和影响因素。主要研究内容和研究成果有以下几个方面:好氧堆肥使污泥堆肥堆体温度上升,其产生的高温,能够满足污泥无害化的基本要求。在预处理过程中,含水率、EC (电导率)、有机质、TOC、TN、C/N、富里酸(FA)、病原体含量有不同程度降低,pH值、TP、TK、胡敏酸(HA)、HA/FA值则有不同程度的提高。污泥经过超声波破解耦合好氧堆肥预处理后,污泥的腐殖化和有机质稳定化程度得到初步提高,为下一步蚯蚓处理污泥创造了良好条件。采用蚯蚓对经预处理后的污泥进行处置,污泥的pH值、TOC、C/N、FA、污泥中病原体含量有所降低,而EC值、TN、TP、TK、HA值、碱解氮、速效磷、速效钾则有所升高,可见,蚯蚓处理能使有机质得到进一步分解。同时,有机氮的矿化程度加快,堆肥产品的肥效和腐熟程度均得到提高,从而能够进一步有效减少污泥处理后的病原体含量,使其能够满足土地利用的要求。而鸡粪的添加对污泥各项指标的影响较小。在构建超声波耦合好氧堆肥预处理结合蚯蚓处理剩余污泥系统时,通过基于时间的变化和TOC的减少速率,探讨建立该系统的动力学模型。在整个处理过程中,通过微生物和蚯蚓的协同作用,反应器中的有机质不断分解。随着水分和一些有毒有害气体的挥发,堆体存在质量损失,产生浓缩效应,使得重金属在处理后,Zn、Cu、Pb、Cd、Cr、Hg、As等8种元素的相对浓度均有所上升,但其总量变化幅度不大。通过采用修正BCR法对污泥中的重金属形态进行分级测定可知,其弱酸提取态和可还原态所占比例均有所降低,而稳定性更高的可氧化态和残渣态占比上升,因此经过处理后,污泥中的重金属稳定性得到提高。在蚯蚓对重金属的吸收方面,蚯蚓对Cd和Ni表现出生物富集作用,对其他的重金属则表现为生物吸收,说明蚯蚓处理可促进重金属钝化/固化,并能降低其生物毒性。经过超声波设备处理的污泥,其内部产生“空穴”作用,能够有效的破坏污泥絮体结构,击破污泥细胞壁结构并释放出细胞内的物质,为污泥好氧堆肥和蚯蚓处理,创造有利的条件。因此,使用超声波技术的组别,在有机质、TN、TP、TK、速效养分含量和病原体的灭活率等方面,在不同程度上优于对照组,可见,超声波处理技术能够提高污泥处理的深度。蚯蚓处理污泥后,其体重平均增长25.38%,通过方差分析表明,超声波破解技术的加入和蚯蚓放养密度对蚯蚓体重的增长,存在显著影响。并且蚯蚓的放养密度对于污泥的有机质降解、TP、TK和重金属的富集等方面有积极的作用。通过对污泥微观结构的观察,超声波破解耦合好氧堆肥预处理和蚯蚓生物处理均有助于破坏污泥原有的致密结构,提高空气的流通效率,降低堆肥粘度,促进土壤团聚体形成,并能够把污泥转化为结构疏松、团粒结构丰富并富含营养成分的蚯蚓粪,从而提高污泥的回收利用价值。综合试验的各项指标,确定使用超声波耦合好氧堆肥预处理结合蚯蚓处理剩余污泥系统的运行参数:超声处理时间10分钟,处理量为60%,蚯蚓放养密度为80 g/kg。
[Abstract]:With a large number of construction and operation of urban sewage treatment plant, sludge yield greatly increased. In February 2015 China issued "water pollution prevention action plan" (water ten) clearly pointed out that before the end of 2020, the prefecture level and above city sludge harmless disposal rate should reach 90% or more, thus, treatment sludge disposal is imminent. A large number of studies show that, the residual sludge in the sewage treatment process, contains a lot of organic matter and nutrients, is a valuable resource. Therefore, the resources of sludge treatment and disposal technology development of low carbon environmental protection at home and abroad is the sewage treatment industry. This paper first analyzes the research hotspot the main methods of sludge treatment and disposal at home and abroad and its advantages and disadvantages, and then, the sludge treatment and disposal of sludge reduction, harmless and resource as the basic principle, and based on the ecological treatment of earthworm Function, choose to excess sludge as the main raw material, and mixed with a certain amount of straw and chicken manure, by coupling ultrasonic crack technology of Aerobic Composting Pretreatment Combined with earthworm treatment process to dispose of them. The study mainly tested the basic properties of sludge, microbial quantity, index of nutrients and heavy metal content then, in the analysis of sludge before and after treatment, factors change characteristics and impact properties. The main research contents and results are as follows: aerobic composting of sludge compost pile temperature rise, the high temperature generated, can meet the basic requirements of sludge harmless. In the process of pretreatment, water content, electrical conductivity (EC), organic matter, TOC, TN, C/N, fulvic acid (FA), the pathogen content decreased to some extent, the value of pH, TP, TK, Hu Min acid (HA), the HA/FA value is improved to different degrees. The sludge after ultrasonic coupling good crack Aerobic composting after pretreatment of sludge and organic matter humification degree has been improved steadily, creating favorable conditions for the next step. The use of earthworm earthworm treatment sludge disposal of the pretreated sludge, sludge pH, TOC, C/N, FA, pathogen content in sludge decreased, while EC the value of TN, TP, TK, HA value, available nitrogen, available phosphorus, available potassium increased, visible, earthworms can make further decomposition of organic matter. At the same time, the degree of mineralization of organic nitrogen to accelerate, the fertilizer efficiency of compost and maturity are improved, which can further reduce the pathogen content of sludge after the treatment, which can meet the requirements of land use. The chicken is added on the indicators of the sludge is smaller. In the construction of ultrasonic coupling Aerobic Composting Pretreatment sludge treatment system combined with earthworm, through the change of time and based on TOC The reduction rate of dynamic model of the system. In the whole process, through the synergy of microorganisms and earthworms, organic matter in the reactor of continuous decomposition. With water and some toxic and harmful gas volatilization, pile quality loss, condensation effect, the heavy metal in the after treatment, Zn, Cu Pb, Cd, Cr, Hg, and the relative concentration of 8 kinds of elements such as As increased, but the total change slightly. By using the modified BCR method for speciation of heavy metals in sludge classification determination shows that the acid extractable state and reducible proportion decreased, and higher stability oxidizable and residual ratio increased, so after the treatment, the stability of heavy metals in the sludge can be improved. In the absorption of heavy metals on earthworms, earthworm Cd and Ni exhibit bioaccumulation of heavy metals showed the other For the biological absorption, indicating earthworm treatment can promote the passivation / curing, and can reduce the biological toxicity. After ultrasonic treatment equipment of sludge, the internally generated "hole" effect, can effectively destroy the sludge floc structure, break the sludge cell wall structure and release of intracellular substances for aerobic composting and earthworms, and create favorable conditions. Therefore, the use of ultrasonic technology in groups, organic matter, TN, TP, TK, available nutrient content and pathogen inactivation rate, in varying degrees than the control group, the ultrasonic treatment technology can improve the sludge treatment. The depth of earthworm treatment sludge, the the average weight increase of 25.38%, through the analysis of variance showed that the growth of the technology of ultrasonic crack and adding earthworm stocking density on earthworm weight, has a significant impact. And earthworm stocking density for organic sludge Quality degradation, TP, and TK have a positive effect on the heavy metals accumulation and so on. Through the observation of microstructure of sludge, ultrasonic disintegration coupled Aerobic Composting Pretreatment and earthworm biological treatment are helpful to destroy the dense original sludge, improve air circulation efficiency, reduce the viscosity of compost, and can promote the formation of soil aggregates. The sludge into loose structure, aggregate structure and rich in nutrient rich vermicompost, thereby improving sludge recycling value. The indexes test, operating parameters are determined using ultrasonic coupling Aerobic Composting Pretreatment sludge treatment system combined with earthworm: ultrasonic treatment time of 10 minutes, the processing capacity of 60%, earthworm stocking the density is 80 g/kg.

【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S141.4;X703

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