预处理技术强化剩余污泥厌氧发酵产挥发酸及释磷影响研究

发布时间：2018-02-01 10:51

本文关键词： 剩余污泥预处理挥发酸磷　出处：《辽宁大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来由于城镇化发展进程加快,使得越来越多的污水进入城镇污水处理厂,导致大量剩余污泥产生。目前,污泥处理处置运行成本已占污水处理厂50%以上,这正成为一个亟待解决的问题。剩余污泥中含有大量的无毒有机物和磷,这些都是重要的回收资源。然而,由于污泥水解发酵阶段需要较长时间,并且效率低下,这正成为污泥厌氧发酵的限速步骤。本课题的研究以污泥资源化为切入点,通过研究两种污泥预处理技术对剩余污泥破解效果和厌氧发酵过程中产挥发酸和磷释放的影响,获得了相对能较高回收剩余污泥中碳源和磷源的处理方法。第一种方法研究了单独超声(US)、单独Fenton和超声/Fenton(US/Fenton)联合预处理对剩余污泥水解酸化效果的影响。结果表明,超声/Fenton联合预处理后的溶解性碳水化合物浓度为441 mg COD/L,分别是单独Fenton、单独超声和未经预处理污泥的2.36倍、2.17倍和17.11倍。相对应的联合预处理后的溶解性蛋白质浓度为2059 mg COD/L,分别是单独Fenton、单独超声和未经预处理污泥的2.43倍、1.47倍和13.37倍。联合预处理后的污泥破解率DDSCOD为15.4%,而超声和Fenton预处理分别只有9.97%和3.18%。此外,未处理污泥的颗粒粒径d50在44.01μm,与Fenton预处理后相近(41.53μm),但是高于超声(24.52μm)和联合预处理(22.63μm)。联合预处理后的污泥最大挥发酸积累量为4594 mg COD/L,而单独超声处理为3485 mg COD/L,单独Fenton处理为2700 mg COD/L。实验得出联合预处理法对提高污泥水解和后续厌氧发酵产挥发酸有协同作用。第二种方法对高压脉冲预处理强化剩余污泥水解和释磷效果进行了研究。经过高压脉冲处理后的溶解性化学需氧量(SCOD)浓度为1405 mg/L,是未处理污泥的6.4倍,有利于后续厌氧发酵过程。高压脉冲预处理后的溶解性正磷酸盐浓度为109 mg/L,是未处理污泥的1.5倍。然而,在厌氧发酵过程中,也会有较高浓度的金属离子释放。所以,最好在厌氧发酵的前3-4天,也就是大量磷酸盐沉淀形成前对发酵液进行磷回收。通过SMT方法(Standards,Measurements and Testing)分析,得出在厌氧发酵过程中,污泥固相中的磷灰石无机磷(AP)和有机磷(OP)保持相对稳定。所以,厌氧发酵液中的正磷酸盐释放主要来自非磷灰石无机磷(NAIP)的溶解。实验结果表明,在污泥厌氧发酵前进行高压脉冲预处理是一种提高污泥水解和释磷的有效方法。
[Abstract]:In recent years, due to the rapid development of urbanization, more and more sewage into urban sewage treatment plants, resulting in a large number of excess sludge. The operating cost of sludge treatment and disposal has accounted for more than 50% of the sewage treatment plant, which is becoming an urgent problem to be solved. The excess sludge contains a large amount of non-toxic organic matter and phosphorus, which are important resources for recovery. Sludge hydrolysis and fermentation stage takes a long time and low efficiency, which is becoming the speed limit step of anaerobic sludge fermentation. The effects of two sludge pretreatment techniques on the cracking effect of excess sludge and the release of volatile acid and phosphorus during anaerobic fermentation were studied. A relatively high recovery method for carbon and phosphorus sources in excess sludge was obtained. The effect of Fenton alone and ultrasonic / Fenton / US / Fenton pretreatment on the hydrolysis and acidification of excess sludge was studied. The concentration of soluble carbohydrate after ultrasonic / Fenton pretreatment was 441mg / L, respectively, which was Fenton alone. The concentration of soluble protein of ultrasonic alone and untreated sludge was 2.36 times 2.17 times and 17.11 times as much as that of untreated sludge. The corresponding concentration of soluble protein was 2059 mg COD/L. Fenton alone, ultrasound alone and untreated sludge were 2.43 times, 1.47 times and 13.37 times as much as those of untreated sludge, respectively. The sludge cracking rate (DDSCOD) after combined pretreatment was 15.4%. However, ultrasonic and Fenton pretreatment were only 9.97% and 3.18, respectively. In addition, the particle size of untreated sludge was 44.01 渭 m. It was close to 41.53 渭 m after pretreatment with Fenton. But it was higher than that of ultrasonic treatment (24.52 渭 m) and combined pretreatment (22.63 渭 m). The maximum accumulation of volatile acid in sludge after combined pretreatment was 4594 mg / COD/L. The ultrasound alone was 3485 mg COD/L. 2700mg treated with Fenton alone. The experiment shows that the combined pretreatment method has synergistic effect on sludge hydrolysis and subsequent anaerobic fermentation to produce volatile acid. The second method is to study the effect of high pressure pulse pretreatment on the enhancement of hydrolysis and phosphorus release of excess sludge. Dissolved chemical oxygen demand after high pressure pulse treatment. The concentration of SCO was 1405 mg/L. The concentration of dissolved orthophosphate after high pressure pulse pretreatment was 109 mg / L, 1.5 times as much as that of untreated sludge. Higher concentrations of metal ions are also released during anaerobic fermentation. Therefore, it is best to do so 3-4 days before anaerobic fermentation. In other words, phosphorus was recovered from the fermentation broth before the formation of a large amount of phosphate precipitation. The SMT method was used to analyze the phosphorus content of the fermentation broth by Standard measures and testing. The results showed that the apatite inorganic phosphorus (APP) and organic phosphorus (OPP) in the solid phase of sludge remained relatively stable during anaerobic fermentation. The release of orthophosphate from anaerobic fermentation broth mainly comes from the dissolution of non-apatite inorganic phosphorus (NAIPP). High pressure pulse pretreatment before anaerobic fermentation is an effective method to improve sludge hydrolysis and phosphorus release.
【学位授予单位】：辽宁大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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