高铁酸钾应用于城市污泥厌氧发酵产酸及脱水性研究

发布时间：2017-12-28 19:02

本文关键词：高铁酸钾应用于城市污泥厌氧发酵产酸及脱水性研究　出处：《苏州科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着城镇化进程的加快,居民对用水量的需求越来越大,必然会产生大量的污水,而活性污泥法作为污水生物处理的常用工艺,处理效果好、稳定性高,但存在大量污泥生成、污泥膨胀等现象,截止2015年已突破4000万吨。剩余污泥含水量高、难降解、污染难以控制等缺点越来越引起人们重视。目前污泥的处理处置工艺有填埋、焚烧、堆肥、污泥消化等,然而污泥消化是一种环境友好、资源利用的常用措施。污泥消化主要有好氧和厌氧两种,其中污泥厌氧技术作为减排、环保的关键技术,一直受到人们的青睐。在厌氧发酵阶段实现有机物的分解,达到了污泥减量化的目的。然而厌氧水解技术的瓶颈在于污泥破壁、反应效率等问题。高铁酸钾作为一种绿色多功能水处理剂,集氧化、絮凝、吸附、杀菌、除臭为一体,表现出了良好的应用前景。本文通过对国内外污泥厌氧发酵技术以及化学法预处理污泥的机理进行了分析与综合,并结合高铁酸钾的特性,提出了经高铁酸钾预处理后的城市剩余污泥的氧化减量、发酵产酸资源化的技术方法,并对该方法进行了试验研究。通过静态实验的设计,获得最佳的高铁酸钾投加量,研究了不同量的高铁酸钾投加量对污泥混合液中SCOD、污泥浓度、污泥粒径、固相与液相中TS、VS及蛋白质含量的变化规律;并分析了最佳投加量的条件下p H值对混合液中氨氮、正磷酸盐、SCOD的影响。本实验中,最佳高铁酸钾投加量为0.8 mg/g SS,且用于污泥破壁预处理的高铁酸钾p H适用范围在8~13。设计多个单因素实验,研究高铁酸钾、PAM以及复合调理剂对城市剩余污泥脱水性的影响,获得最佳调理剂投加量;研究了单一的两种调理剂对污泥含水率、滤液浊度、EPS中蛋白质与多糖含量、比阻的变化情况;本实验中,最佳高铁酸钾投加量为0.6 mg/g SS,使污泥比阻下降了71.82%,PAM600最佳投加量为90ppm,污泥比阻下降了78.19%;在高铁酸钾投加量为0.6 mg/g SS基础上,使用PAM600加强了污泥的脱水效果,当PAM600投加至为90ppm时,污泥比阻下降了99.36%,表明复合调理剂(高铁酸钾与PAM600)组合优于单一调理剂对城市剩余污泥的脱水效果。设计发酵实验,研究了经高铁酸钾的预处理对城市剩余污泥厌氧发酵的影响,研究了其对混合发酵液中SCOD、氮磷、挥发性有机酸等的影响;并在基于前文的基础上选择最佳高铁酸钾投加量0.8 mg/g SS,对产酸的来源进行了分析,p H的改变对产酸含量及发酵前期混合液中可溶性蛋白质与可溶性碳水化合物浓度的影响研究;最后推导出了高铁酸钾预处理的产酸动力学。结果表明:当经过0.8mg/g SS的K2Fe O4预处理后,VFAs产量最大,p H=10时产总酸浓度最高,混合液中可溶性蛋白质是污泥厌氧发酵的主要底物,而碳水化合物在发酵初期就被消耗;当K2Fe O4投加范围在0.6~1.0mg/g SS、温度为35±1℃、连续发酵十二天,污泥中VFAs转化率、底物降解率均明显得到提高;当K2Fe O4投加量从0增加至0.8mg/g SS时,乙酸积累量明显增加,产生速率显著加快,且由产酸动力学可知,发酵前十二天的发酸效果优于之后继续发酵产酸的效果。
[Abstract]:With the acceleration of urbanization, the residents of greater water demand, will produce large amounts of sewage and activated sludge as the common process of sewage treatment, good effect, high stability, but there are a lot of sludge and sludge bulking phenomenon, by the end of 2015 has exceeded 40 million tons. More and more attention has been paid to the disadvantages of high water content, difficult degradation and uncontrollable pollution of residual sludge. At present, sludge treatment and disposal processes include landfill, incineration, composting, sludge digestion and so on. However, sludge digestion is a commonly used measure of environmental friendliness and resource utilization. Sludge digestion is mainly composed of two kinds of aerobic and anaerobic, of which sludge anaerobic technology is the key technology of emission reduction and environmental protection, which has always been favored by people. At the stage of anaerobic fermentation, the decomposition of organic matter is realized, and the purpose of sludge reduction is achieved. However, the bottleneck of anaerobic hydrolysis technology is sludge wall breaking, reaction efficiency and so on. As a kind of green multi-function water treatment agent, potassium ferrate combines oxidation, flocculation, adsorption, sterilization and deodorization, showing a good prospect of application. This paper analyzed and synthesized by sludge anaerobic fermentation technology at home and abroad as well as chemical sludge pretreatment mechanism, combined with potassium ferrate's characteristics, puts forward the technology of oxidation reduction, city sludge potassium ferrate after pretreatment of fermentation acid recycling method, and the method is studied. Through the design of static experiments, the best dosage of potassium ferrate, potassium ferrate different amount of dosage on the variation of sludge mixture SCOD, sludge concentration, sludge particle size, solid phase and liquid phase TS, VS and protein content; and analysis of the best dosage under the condition of P H effect of ammonia nitrogen, orthophosphate mixture, SCOD. In this experiment, the best dosage of potassium ferrate was 0.8 mg/g SS, and the application range of potassium ferrate P H for sludge wall pretreatment was 8~13. Design a single factor experiment of potassium ferrate, PAM and composite conditioner on sludge dewatering of city, get the best conditioner dosage; two kinds of single conditioner on the moisture content of sludge filtrate turbidity, EPS, protein and polysaccharide content, ratio of resistance; in this experiment, the best potassium ferrate dosage was 0.6 mg/g SS, the sludge is 71.82% lower than the resistance, the best dosage of PAM600 was 90ppm, the sludge resistance was 78.19% lower than in potassium ferrate; the dosage of 0.6 mg/g based on SS, using PAM600 to strengthen the sludge dewatering effect, when the PAM600 dosage is 99.36% 90ppm, sludge lower than the resistance, showed that the composite conditioner (potassium ferrate and PAM600) the dehydration effect is better than a single combination of residual sludge conditioner on city. The design of fermentation experiment was studied the effect of pretreatment on potassium ferrate city sludge anaerobic fermentation, studied its effect on mixed fermentation of SCOD, nitrogen and phosphorus, volatile organic acid; and on the basis of the above potassium ferrate to choose the best dosage of 0.8 mg/g SS based on the source of acid production study on P H analysis, the effect of change of soluble acid content and fermentation mixture of protein and soluble carbohydrate concentration; finally deduced potassium ferrate pretreatment of acid production kinetics. The results show that when the K2Fe O4 after pretreatment of 0.8mg/g SS, VFAs P H=10 is the largest output, the highest concentration of total acid, soluble protein in the mixed solution is the main substrate sludge anaerobic fermentation, and carbohydrates in the initial fermentation was consumed; when K2Fe O4 added in the range of 0.6~1.0mg/g SS and a temperature of 35 + 1 C, twelve days of continuous fermentation, sludge VFAs conversion rate and substrate degradation rate were significantly improved; when the K2Fe dosage of O4 increased from 0 to 0.8mg/g SS, acetic acid accumulation increased significantly, the production rate is accelerated significantly, and the acid production kinetics can be known before fermentation after twelve days of continued effect is better than that of acetify the effect of acid fermentation.
【学位授予单位】：苏州科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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