混凝沉淀—水解酸化—两级SBR处理养牛废水

发布时间：2018-01-10 23:25

本文关键词：混凝沉淀—水解酸化—两级SBR处理养牛废水　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：哈尔滨市某养牛场废水具有COD浓度高、固体悬浮物量大等特点,属典型的高浓度有机废水,本课题以养牛场废水作为研究对象,旨在确定高效低能的处理工艺及其相关参数。针对养牛场废水的处理方法多为厌氧+好氧处理而未加水解酸化,虽然养牛废水可生化性很好,但是由于COD浓度过高导致出水效果不是很好,而水解酸化可以有效的提高废水的可生化性,使出水COD降低。通过大量阅读中外文献,本课题采用混凝沉淀-水解酸化-两级SBR工艺处理养牛场废水。该工艺具有启动周期短,运行灵活,其水解酸化单元可以有效提高废水的可生化性,SBR工艺能适宜废水水量和水质的变化,使得该处理系统具有较强的抗冲击负荷能力。本研究通过对Fe Cl3、PAC、Al2(SO4)3三种混凝剂处理养牛废水进行了实验,结果发现Fe Cl3对该废水的处理效果最好。投加量为4ml/L,沉淀时间20min,慢速搅拌时间10min时,COD的平均去除率为53.95%,SS的去除率平均值为62.74%。水解酸化反应器经过30天左右的启动驯化后处理效果稳定。通过对各指标随HRT的变化,发现COD和SS的去除率随着HRT的延长逐渐上升,到HRT=16h时,趋于稳定。系统出水的COD去除率为32.14%,SS在12h去除率为75.2%。HRT为16h时反应器出水的酸化率达到了最高值为19.1%,出水的VFA为20.3mmol/L。经过水解酸化处理后,B/C提升到0.63左右,确定本实验处理养牛场废水的水解酸化反应器的水力停留时间为16小时。对水解酸化反应器进行了动力学分析,根据其稳定运行的数据求得了动力学常数K,发现K值与HRT、污泥浓度、进水有机物浓度有关。经过30天左右的时间两级SBR反应器启动成功,后对曝气时间、曝气量以及沉淀时间等运行参数进行试验,结果显示一级SBR周期时间为9.5h(进水10min,曝气8h,沉淀1h,排水20min),二级SBR周期时间为7.5h(进水10min,曝气6h,沉淀1h,排水20min)。稳定运行后两级SBR系统对COD和SS的去除率比较稳定,COD的去除率可达97%左右,出水COD浓度降为150mg/L左右,SS的去除率为93%左右,出水的SS浓度为130mg/L需进一步混凝试验去除多余的悬浮物。两级SBR系统氨氮的去除率在85%左右,TN的去除率在35%左右。系统内硝化作用较大,将废水中的氨氮大部分转化为利于植物根部吸收的硝态氮。考察了水解酸化和两级SBR组合系统的抗冲击负荷性能。结果发现,组合系统对养牛废水的处理效果比较稳定,水解酸化段的稳定性略差。两级SBR动力学分析结果显示两级SBR中污泥有机物降解反应符合一级反应,实验结果与理论相吻合,一级SBR反应器处理养牛场废水,进水为5121.34mg/L时的反应降解速率常数'1K为0.206h-1,二级SBR在进水780.15mg/L时的反应降解速率常数'1K为0.08h-1。
[Abstract]:The wastewater from a cattle farm in Harbin has the characteristics of high concentration of COD and large amount of solid suspended solids. It is a typical high concentration organic wastewater. This paper takes the wastewater of cattle farm as the research object. In order to determine the high efficiency and low energy treatment process and its related parameters. For cattle farm wastewater treatment methods are mostly anaerobic aerobic treatment without hydrolysis acidification although cattle wastewater biodegradability is very good. However, because of the high concentration of COD, the effluent effect is not very good, and hydrolytic acidification can effectively improve the biodegradability of wastewater and reduce the COD of effluent. In this paper, coagulation-precipitation-hydrolytic acidification-two-stage SBR process was used to treat cattle farm wastewater. This process has short start-up period and flexible operation, and its hydrolytic acidification unit can effectively improve the biodegradability of wastewater. The SBR process can adapt to the change of wastewater quantity and water quality, which makes the treatment system have strong anti-shock load ability. In this study, FeCl _ 3Pac has been studied. Three coagulants of Al2(SO4)3 were used to treat cattle wastewater. The results showed that Fe Cl3 had the best effect on the treatment of the wastewater. The dosage of Fe Cl3 was 4ml / L and the precipitation time was 20min. The average removal rate of COD was 53.95% when the stirring time was 10 minutes. The average removal rate of SS was 62.74 and the treatment effect of hydrolytic acidification reactor was stable after 30 days of start-up and acclimation. It was found that the removal rates of COD and SS increased gradually with the prolongation of HRT, and tended to be stable at HRT=16h. The COD removal rate of effluent was 32.14%. When the removal rate of SS was 75.2 and HRT was 16 hours, the acidification rate of effluent reached the highest value of 19.1%. The VFA of effluent was 20.3 mmol / L. After hydrolyzing and acidizing treatment, the content of B / C increased to about 0.63. The hydraulic retention time of the hydrolytic acidification reactor for cattle farm wastewater treatment was determined to be 16 hours. The kinetic analysis of the hydrolytic acidification reactor was carried out and the kinetic constant K was obtained according to its stable operation data. It was found that K value was related to HRT, sludge concentration and influent organic concentration. After 30 days, the two-stage SBR reactor was successfully started, and the aeration time was analyzed. The operation parameters such as aeration rate and sedimentation time were tested. The results showed that the first stage SBR cycle time was 9.5 h (10 min for influent, 8 h for aeration, 1 h for sedimentation and 20 min for drainage). The cycle time of two-stage SBR is 7.5 h (10 min of influent, 6 h of aeration, 1 hour of sedimentation and 20 min of drainage). The removal rate of COD and SS by two-stage SBR system is stable after stable operation. The removal rate of COD can reach about 97%, and the removal rate of SS is about 93% when the concentration of COD in effluent drops to 150 mg / L or so. The SS concentration of effluent is 130 mg / L and the removal rate of ammonia nitrogen in two-stage SBR system is about 85%. The removal rate of TN is about 35%. Most of the ammonia nitrogen in wastewater was converted into nitrate nitrogen which is beneficial to plant root absorption. The impact load resistance of hydrolytic acidification and two-stage SBR combination system was investigated. The results of two-stage SBR kinetic analysis showed that the degradation of sludge organic matter in two-stage SBR was in accordance with first-order reaction. The experimental results were in good agreement with the theory. The degradation rate constant of the first-order SBR reactor was 0.206 h ~ (-1) when the influent was 5121.34 mg 路L ~ (-1) 路L ~ (-1). The degradation rate constant of secondary SBR was 0.08h-1 when the influent was 780.15mg / L.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X713

【引证文献】