【作者】 王成；

【导师】 李建政；

【作者基本信息】 哈尔滨工业大学 ， 环境工程， 2016， 硕士

【摘要】 干清粪养猪废水具有高氨氮(NH4+-N)、低C/N比的特性,处理难度大,尤其是生物脱氮更加困难。如何更加经济有效地去除NH4+-N和总氮(TN),是干清粪养猪废水处理面临的主要问题。为解决传统生物脱氮工艺存在的工艺流程长、占地面积大、脱氮效率不理想且处理成本高的问题,课题组在前期研究中,研发出了可以同步高效去除碳氮的升流式微氧处理工艺和装置。为优化控制参数以进一步提升系统的处理效能,利用悬浮污泥和生物膜两种生物处理系统,对干清粪养猪废水C/N比的调控方法,以及温度和出水回流比对升流式微氧反应器处理效能的影响进行了研究。利用序批式活性污泥反应器(SBR)对养猪废水的预处理研究表明,SBR对因生产周期而产生的水质波动有着较好的承受能力。通过曝气时间的调控,可将不同水质的废水的COD/TN比控制1以下。对于NH4+-N为400 mg·L-1左右,COD/TN比在1.2-2.0之间的养猪废水,建议的曝气时间为30分钟;对于NH4+-N为200-250mg·L-1,COD/TN比为3.0-4.5的废水,建议曝气时间为50-65分钟。升流式微氧污泥床反应器(UMSR),在HRT 8 h、回流比45:1的条件下,温度在20-27℃之间变化,都能保证出水污染物浓度满足《畜禽养殖业污染物排放标准》(GB18696-2001)的要求。研究发现,温度为23℃时,UMSR对NH4+-N,TN和COD的去除负荷平均可达0.71,0.64和0.55 kg·m-3·d-1。当温度降低至20℃时,anammox菌群和反硝化菌群活性受到了较显著的影响,尽管UMSR对NH4+-N的去除率仍保持较高水平,NO2--N积累现象明显,系统的TN去除率下降到了78.0%左右,COD去除率也降低到了53.4%左右。出水回流比在25:1-45:1之间变化时,升流式微氧生物膜反应器(UMBR)出水也都能满足GB18696-2001的要求。在较高的回流比45:1条件下,系统的溶解氧(DO)可以达到0.70 mg·L-1的水平,会抑制厌氧氨氧化作用,降低系统的TN去除效能。在HRT 8 h、27℃和回流比为35:1的条件下,UMBR内的DO为0.40 mg·L-1,对NH4+-N和TN的去除负荷平均可达0.94和0.91 kg·m-3·d-1,COD去除负荷也能达到0.60 kg·m-3·d-1左右。分析认为,填料的布设及生物膜的着生,不仅保证了UMBR的微生物持有量,而且可为化能自养菌群、氨氮氧化菌群、自养反硝化菌群和异养反硝化菌群等微生物类群创造各自适宜的微环境,是系统保持污染物高效去除的生物学基础。更多还原

【Abstract】 Manure-free piggery wastewater was identified as high ammonium(NH4+-N) and low chemical oxygen demand/total nitrogen(C/N) ratio. Open discharge or disposal of piggery wastewater without treatment has a potential health effect and significant adverse effect on the environment and human health. The nitrogen removal is a common problem and has been considered a major challenge in piggery wastewater treatment. The novel microaerobic biological treatment technology including upflow microaerobic sludge reactor and upflow microaerobic biofilm reactor were constructed in the present study. And the effect of wastewater characteristic and reflux ratio on the performance of UMBR and the effect of temperature decrease on the performance of UMSR was investigated. According to the quality of the wastewater fluctuated following the breeding seasonality, sequencing batch reactor(SBR) was introduced as a pretreatment for a feasible influent C/N ratio for the subsequent microaerobic treatment.The SBR used in the present study had a good bearing capacity to the piggery wastewater quality fluctuation with seasonal change. The manure-free piggery wastewater with different influent NH4+-N concentration and C/N ratio treated by the SBR could maintain a feasible C/N for subsequent microaerobic treatment by adjusting aeration time. In the early stage of aeration time, the dissolved oxygen(DO) in the SBR was used to oxidizing organic matter, resulting in a rapid decrease of chemical oxygen demand(COD). And after COD decreased to a certain degree, the residual DO was used to NH4+-N oxidation, and a nitrite(NO2--N) accumulation was observed. According to the previous study about the effect of C/N ratio on the UMSR, the aeration time of the SBR was set to satisfy effluent C/N ratio as low as possible. When influent NH4+-N was lower than 400 mg·L-1 and C/N ratio averaged at 1.2-2.0, the aeration time was suggested 30 minutes. When influent NH4+-N was about 200-250 mg·L-1 and C/N ratio averaged at 3.0-4.5, the aeration time was suggested at 3.0-4.5 minutes.The UMSR had a better pollutant removal including COD, NH4+-N, TN and TP treating manure-free piggery wastewater with low C/N ratio at HRT 8 h, reflux ratio 45:1 and 27℃, and the pollutant in effluent could met the standard required by the Ministry Environmental Protection of China. When the temperature was 23℃, the removal load of NH4+-N, TN and COD averaged 0.71, 0.64 and 0.55 kg·m-3·d-1. But when the temperature further decreased to 20℃, although the NH4+-N removal in the UMSR could maintain at a better performance, the anammox bacteria was inhibited due to the low temperature. The TN removal was only 78.0% in the UMSR with an obvious NO2--N accumulation. Meanwhile, the COD removal was decreased to 53.4% with the temperature decreasing.The DO range in the UMBR was 0.20-0.70 mg·L-1 controlled by refluxing aerated effluent with the reflux ratio decreased from 45:1 to 25:1 by stages. No negative impact on COD removal had been found with a well NH4+-N oxidation. But the anaerobic ammonium oxidation would be inhibited by a DO above 0.70 mg·L-1 and resulted in a decrease in TN removal when reflux ratio was 45:1. The average COD, NH4+-N and TN removal load reached 0.60, 0.94 and 0.91 kg·m-3·d-1, respectively, with the HRT 8 h, DO 0.40 mg·L-1 and the reflux ratio 35:1 at 27℃. Obviously, the filler allowed more activated sludge to grow as biofilm in the UMBR and could construct suitable microenvironments for chemoheterotrophic bacteria, ammonia oxidizing bacteria, autotrophic and heterotrophic denitrifiers, separately. And the diversity of physiological groups of bacteria laid the foundation for the excellent pollutant removal in the microaerabic process.更多还原