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一体式SBBR能量解偶联OSA工艺污泥产率的对比研究
Comparative Study on Sludge Production in SBBR System under OSA Operational Process
【作者】 姚萌;
【导师】 李晔;
【作者基本信息】 武汉理工大学 , 环境工程, 2007, 硕士
【摘要】 剩余污泥的处理与处置是传统活性污泥工艺(Conventional activated sludge process, CAS)亟待解决的问题之一。20世纪90年代提出的污泥减量化工艺依靠降低微生物产率以及利用微生物自身内源呼吸使污水生物处理系统所产生的生物固体量达到最少,是剩余污泥处理与处置的新方法,也是目前污泥减量技术的研究热点之一。现有的污泥末端减量技术不能从根本上实现经济高效的污泥削减,并且污泥减量化过程与污水的处理过程密切相关,因此,从源头上控制污泥的产生,在保证污水处理效果的同时实现较低污泥产率,即污泥源头减量新技术是污泥减量化工艺最新发展方向。本研究对比研究了序批式生物膜反应器在全泥龄好氧-沉淀-厌氧(OSA)运行模式下进行城市生活污水处理的同时实现能量解偶联,在污水处理过程中实现污泥源头减量效果。分别考察了低温条件下组合填料SBBR、投加球形填料SBR、和CAS工艺在OSA运行条件下污泥产率与污泥性质以及工艺污水处理效果以及常温条件下SBBR微生物附着生长体系内污泥源头减量程度及其水质处理效果。在低温条件下,组合填料SBBR、投加球形填料SBR以及CAS工艺中平均污泥表观产率分别为-0.292kg/kg、0.058kg/kg和0.302kg/kg,SBBR工艺污泥减量效果明显,对NH4+-N的平均去除率分别达到85.36%、64.15%和73.19%,COD平均去除率分别达到60.73%、61.58%和56.30%。试验表明,SBBR工艺在全泥龄低温条件实现高效水质处理效果的同时其OSA运行模式下能量解偶联的实现能有限降低剩余污泥产量。在全泥龄常温条件下,SBBR工艺与CAS工艺在OSA运行模式下其平均污泥表观产率分别为0.0932kg/kg和0.248kg/kg,SBBR工艺最大污泥负增长率达到了-0.244kgCOD/kgMLSS。剩余污泥量与系统内原生动物与后生动物生长状况密切相关,原生动物的滋生代谢会加速细菌的絮凝作用,明显改善污泥沉降性能;SBBR工艺与CAS工艺对COD和NH4+-N的平均去除效率达到了64.04%、86.50%与66.22%、81.57%。两种工艺运行过程中大型后生动物的出现不会影响工艺的硝化过程。由于反硝化过程碳源缺乏,能量解偶联的实现与后生动物的共同作用导致系统内总磷的明显释放。在SBBR系统中原生动物的捕食作用改变水中C:N:P的比值,导致细菌由悬浮生长型向附着生长型转变,加速SBBR系统内碳和营养物的矿化,加速了总呼吸作用,从而降低污泥产率。对于SBBR工艺与CAS工艺动力学研究表明,一体式SBBR和CAS能量解偶联OSA工艺有机物去除速率常数K2平均分别为0.00127L/(mg·d)和0.00108L/(mg·d),νmax分别为0.208d-1和0.534d-1,ks分别为14.602mg·L-1和101.94mg·L-1。
【Abstract】 The disposition of excess sludge is a big problem of CAS (Conventional activated sludge process). The excess sludge reduction is a new concept and a new method of excess sludge treatment, which denpends on reducing microbe production and ultilizing endogenesis breathe to make the minimum biomass. This method has been one of focuses for escess sludge reduction researches. The existing teminal disposal of excess sludge can not achieve economic and effective sludge reduction, and the sludge reduction process should be closely correlative with the sewage treatment process. Therefore, it’s necessary to adjust sewage treatment processes, control sludge production from source, realize low sludge production and insure sewage treatment effects synchronously. So the sludge reduction from source is the direction of development up to date.In this paper, sequencing batch bioflim reactor was used for urban sewage treatment under OSA (Oxic-Settling-Anaerobic) mode to achieve metabolic uncoupling effect and sludge reduction during wastewater treatment process. The production rate and characteristics of sludge and sewage treatment effects were analyzed in three bioreactors, SBBR (sequencing batch biofilm reactor), sequencing batch bioreactor with carriers and CAS (conventional activated sludge reactor). They were adopted to run under OAS operational process in low temperature. Furthermore, at nomal temperature condition, the sludge reduction degree from source and water treatment effects were reviewed in inserted growth system of SBBR.At low temperature condition (10.6℃), the sludge observed yield coefficient (Yobs) in SBBR, sequencing batch bioreactor with carriers and CAS were -0.092kg/kg, 0.058kg/kg and 0.302kg/kg respectively. The sludge reduced in SBBR apparently. The removal rate of NH4+-N in the three bioreactors were 85.36%, 64.15% and 73.19%, and the removal rate of COD were 60.37%, 61.58% and 56130% respectively. The experiment showed that SBBR system could achieve effective water treatment effect and reduce excess sludge production under OSA mode with metabolic uncoupling realization.At normal temperature condition, Yobs in SBBR and CAS systems were 0.0932kg/kg and 0.248kg/kg respectively. The maximal minus sludge production reached -0.244kg/kg of SBBR. The excess sludge yield was correlated with the metazoan growth status, and the breeding of metazoa would accelerate flocculation capability of bacteial and improve the performance of the sludge sedimentation apparently. The removal rate of COD and NH4+-N in SBBR and CAS were 66.84%, 86.50 and 67.22%, 81.57% respectively, while the metabolization of metazoan would not influence the nitrification processes of wastewater treatment and the TN of effluent wouldn’t increase. Due to carban source shortage of nitration, the reaction of metabolic uncoupling and the grazing of metazoan deduced the releasing of phosphate apparently. The C:N:P ratio was changed by the grazing effect of protozoan, which induced the filtration of bacteria population, accelerated carban and nutriment mineralization at the same time. The grazing effect accelerated the overall respiration, and reduced sludge production. In this paper, the kinetics of contamination biodegradation in SBBR and CAS systems under OSA energy uncoupling mode indicated that. the organic substance removal rate constant k2 were 0.00127L/(mg·d) and 0.00108L/(mg·d), vmax were 0.208d-1 and 0.534d-1, ks were 14.602mg·L-1 and 101.94mg·L-1 respectively.
- 【网络出版投稿人】 武汉理工大学 【网络出版年期】2008年 05期
- 【分类号】X703
- 【被引频次】2
- 【下载频次】240