【作者】 任健；

【导师】 李军；

【作者基本信息】 北京工业大学 ， 市政工程， 2009， 硕士

【摘要】 全国约三分之一的城市污水存在碳源不足的问题,某些污水处理厂采用化学除磷工艺也难以实现氮磷指标的达标排放。本论文以初沉污泥为底物,采用两级完全混合水解酸化工艺进行碳源开发。采用恒温水浴控制水解酸化池的温度为35℃,研究了HRT、SRT和污泥回流比对初沉污泥水解酸化的影响。研究结果表明,固定SRT为3天,污泥回流比为1的条件下,HRT为32~36小时,工艺具有较好的溶解性有机物累积效果,工艺出水的SCOD稳定在1090~1180mg/L范围内;固定HRT为32小时,污泥回流比为1的条件下,SRT为4~7天时,可以较好地实现水解酸化菌和产甲烷菌的分离,工艺具有较好的水解酸化效果,出水SCOD保持在980~1180 mg/L范围内;污泥回流比对初沉污泥的水解酸化也有较重要的影响,控制HRT为32小时,SRT为4天的条件下,污泥回流比为0.75~1的范围时,工艺具有较好的水解酸化效果。开发碳源的目的是为了提高城市污水生物脱氮除磷工艺的生物脱氮除磷效率与效果。采用序批式试验的方式研究了投加酸化液(富含VFAs的工艺出水)对反硝化菌反硝化速率以及聚磷菌厌氧释磷好氧吸磷速率的影响。研究结果表明,投加酸化液能够显著提高微生物的脱氮除磷效率。测定反硝化速率的序批式试验中,随着碳源浓度的降低,反硝化菌的反硝化速率不断减小,当酸化液的投加量为30mg/L(以TOC计)时,反硝化菌在第一阶段的平均反硝化速率为0.367mgNO3-N/mgVSS.d,对应的耗碳速率为0.713mgTOC/mgVSS.d;不同工况中活性污泥中聚磷菌的释磷潜力相近,污水中的碳源越多越能激发它的释磷潜能,因此,酸化液的投加量越大,聚磷菌的释磷速率也越快。当酸化液投加量为30mg/L(以TOC计)时,聚磷菌的平均释磷速率达到0.137mgP/mgVSS.d。碳源充足与否,对聚磷菌的平均好氧吸磷速率影响不大,而对聚磷菌吸磷持续的时间有重要影响。碳源充足的工况聚磷菌吸磷持续的时间长,而碳源不足时聚磷菌吸磷持续的时间短。采用序批式试验研究的各工况中,聚磷菌的平均吸磷速率在0.129~0.160mgP/mgVSS.d范围内,因此,碳源充足时,聚磷菌具有更强的吸磷能力。反硝化菌和聚磷菌能利用的有机物有一定的差别,以酸化液投加量为30mg/L(以TOC计)为例,可被反硝化菌利用的有机碳百分含量为75.7%,而可被聚磷菌利用有机碳的百分含量为57.4%。将酸化液投加到连续运行的A/A/O工艺中,投加点位于厌氧段起端,酸化液的投加量为36mg/L(以TOC计),工艺出水营养物指标分别为TN=14.18 mg/L、TP=0.4mg/L,达到《城镇污水处理厂污染物排放标准(GB18918-2002)》的一级A标准。更多还原

【Abstract】 About one third wastewater treatment plants had the crisis of carbon source shortage in our nation. Although chemical phosphorus removal process was used in some plants, nitrgon and phosphorus could not meet the discharge standard simultaneously. For the problem of shortage of carbon resource in the sewage, primary sludge would be used as substrate to develop carbon resource with two-stage complete mixing hydrolysis and acidification process. The temperature of hydrolysis and acidification reactor was controlled by thermostatic waterbath and the temperature was 35℃. Effects of HRT、SRT and sludge recycle ratio on hydrolysis and acidification of primary sludge were studied. The results of research showed that when the HRT is in the scope of 32 to 36 hours, the process had a good VFAs cumulative effect and the soluable COD (SCOD) of effluents is 1090~1180mg/L, in the codition of SRT was 3 days and sludge recycle ratio was 1; when the SRT is between 4 to 7days, acidogenic bacteria and methanogenic bacteria could be separated and the process had a good hydrolysis and acidification effect, The SCOD of the effluents was in the scope of 980~1180 mg/L, when the codition of HRT is 32 hours and sludge recycle ratio is 1; recycle ratio also had an improtant effect on hydrolysis and acidification of primary sludge, when HRT and SRT were controlled to 32 hours and 4 day, the process had a good hydrolysis and acidification effect when sludge recycle ratio was between 0.75 to 1.The aim of developing carbon resource was improving the nitrogen and phosphrous removal effect of biological nutrient removal (BNR) process. Effects of dosing hydrolysate (process’effluents is rich in VFAs) on denitrification rate of denitridiers and phosphorus release and phosphorus uptake rate of PAOs (phosphorus accumulating organisms) were be studied by sequencing bath reactor. The studied results showed that dosing hydrolysate to the BNR process could improve nitrogen and phosphorus removal rate remarkablely, in the sequencing bath reactor of denitrification, as the concentration of carbon resource reducing, the denitrification rate was changing by stages. When the hydrolysed dosage was 30 mg/L (measured by TOC), the average dentrification rate of the denitrifier was 0.367mgNO3-N/mgVSS.d while carbon consumption rate was 0.713mgTOC/mgVSS.d at the first stage; phosphorus accumulating organisms have the same phosphorus release potential in the active sludge, the more carbon resource in the sewage, the stronger phosphorus release potential would be stimulated. The more hydrolysate addition in the sewage, the quicker phosphorus release rate PAOs have. When hydrolysate dosage was 30mg/L (measured by TOC), the average phosphorus release rate of PAOs is 0.137mgP/mgVSS.d. Carbon resource rich in the sewage or not had a less impact on the average aerobic phosphorus uptake rate, but a strong effect on the sustained time of phosphorus uptake process. When the sewage was rich in carbon resource, phosphorus uptake process of PAOs sustained a long time, and vice versa. The average phosphorus uptake rate of PAOs was between 0.129 to 0.160mgP/mgVSS.d in the sequecing bath reactor, therefore PAOs had strong phosphorus uptake capacity. Organic matters uptaked by denitrifier and PAOs were different, such as the conditions that dosage of hydrolysate was 30mg/L(measured by TOC), the percentage of organic carbon that could be used by denitrifier was 75.7%, and uptaked by PAOs was 57.4%. When dosing hydrolysate to the anaerobic origin of A/A/O (anaerobic-anoxic-oxic) process and the dosage is 36mg/L (measured by TOC) , the nutrient parameter of the effluents were as follows, TN is 14.18 mg/L and TP is 0.4mg/L, which meet the first level A criteria specified in the Discharge standard of pollutants for municipal wastewater treatment plant (GB18918-2002).更多还原