某污水处理厂活性污泥法工艺对比和改造中试研究

发布时间：2019-04-17 15:59

【摘要】：某污水处理厂是一个综合型的污水处理厂,处理的废水主要以印染废水和生活污水为主。该污水厂的建造进程分为三期,一期和二期处理水量皆为30万吨/日,三期处理规模为40万吨/日。随着工业园区的发展扩大,污水水量不断增加,水质越来越差,而处理工艺的落后和处理设施的老化,使得处理厂的运行状况逐渐低于预期效果,为达到最新的排放标准,该污水厂必须进行升级改造。本文以该污水处理厂为研究对象,拟对污水处理工艺进行合理改造,结合以往处理厂的实际运行数据,对一期和三期生化段处理效果进行对比分析,提出一期现有工艺流程存在的问题。在进行工艺综合比较后,选择两段活性污泥法来替代原有传统活性污泥法,并通过中试试验验证。中试试验结果与原工艺出水状况进行对比,预处理+两段曝气(AB)组合工艺出水CODcr比一期好氧出水要低15-30%,高负荷段(A段)剩余污泥的产量远小于预期水平,工艺技术的优势明显。该项技术处理效果好,实施难度小、投资及运行成本都比较低。拟将之前的“厌氧池+沉淀池+好氧池+二沉池”改为“A段曝气池+A段沉淀池+B段曝气池+B段沉淀池”,实现一期工艺的升级。同时本文根据二期出水的水质情况制定了工艺参数的优化方案,调节生化处理段重要参数(溶解氧、污泥浓度、回流比)的范围来改进处理效果。通过正交实验得到溶解氧、污泥浓度、回流比的最佳组合为:3.5 g/L、2.5 mg/L~3.5 mg/L和65%,并且将工艺参数应用于实际处理系统中,实现二期工艺的升级。本次污水处理厂的改造升级工程具有重要的实际意义,将为已建成或者在建的大中型污水处理厂的改造优化提供理论与实践参考,而且在整个污水治理行业起到示范作用,同时对于当地的水体保护和城市发展具有长远意义。
[Abstract]:A sewage treatment plant is a comprehensive wastewater treatment plant, the main wastewater treatment is printing and dyeing wastewater and domestic sewage. The construction process of the sewage treatment plant is divided into three phases, the first and second phases are treated with three hundred thousand tons per day, and the third phase is four hundred thousand tons per day. With the development of industrial park, the quantity of sewage is increasing and the quality of wastewater is getting worse. With the backward treatment technology and the aging of treatment facilities, the operation of the treatment plant is gradually lower than the expected effect, in order to meet the latest discharge standards. The sewage plant must be upgraded. This article takes this sewage treatment plant as the research object, plans to carry on the reasonable transformation to the sewage treatment process, combined with the former treatment plant actual operation data, carries on the contrast analysis to the first stage and the third stage biochemical stage treatment effect, The problems existing in the first phase of the existing process are put forward. Two-stage activated sludge method was selected to replace the traditional activated sludge process after the comprehensive comparison of the process, and was verified by pilot-scale test. Compared with the effluent condition of the original process, the effluent CODcr of the pre-treatment two-stage aerated (AB) combination process is 15% lower than that of the first stage aerobic effluent, and the output of surplus sludge in the high load stage (A stage) is much lower than the expected level. The advantages of technology are obvious. The technical treatment effect is good, the implementation difficulty is small, the investment and the operation cost are relatively low. It is proposed to change the former "anaerobic tank sedimentation tank second sedimentation tank" to "A stage aeration tank A stage sedimentation tank B stage aeration tank B stage sedimentation tank" to realize the upgrading of the first stage process. At the same time, according to the water quality of the second stage effluent, the optimization scheme of the process parameters was made, and the range of the important parameters (dissolved oxygen, sludge concentration, reflux ratio) in the biochemical treatment stage was adjusted to improve the treatment effect. Through orthogonal experiment, the optimum combination of dissolved oxygen, sludge concentration and reflux ratio is 3.5 g / L, 2.5 mg/L~3.5 mg/L and 65%, and the process parameters are applied to the actual treatment system to realize the upgrading of the secondary process. The renovation and upgrading project of this sewage treatment plant has important practical significance. It will provide theoretical and practical references for the transformation and optimization of large and medium-sized sewage treatment plants that have been completed or are under construction, and will play an exemplary role in the whole sewage treatment industry. At the same time, it has long-term significance for local water body protection and urban development.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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