【作者】 荆肇乾；

【导师】 吕锡武；

【作者基本信息】 东南大学 ， 环境工程， 2006， 博士

【摘要】 五箱一体化活性污泥工艺是在UNITANK、三沟式氧化沟等工艺基础上研制开发的具有除磷脱氮功能的新型污水处理工艺,该工艺由五个矩形反应池组成,五池间水力连通,通过五个池子随时间和空间控制状态变化,实现厌氧、缺氧、好氧和沉淀过程交替,通过进出水位置转换实现污泥和混合液的循环流动和自动回流,不需要外加污泥和混合液回流措施,恒水位运行,达到高效除磷脱氮。该工艺中每个池子为一个完全混合反应器,五个池子共同构成一组阶式反应器,因而整体具有推流反应器的特征,反应效率高,能适应一定的冲击负荷。与UNITANK等工艺相比,该工艺在时间和空间转换中更容易实现理想的厌氧、缺氧和好氧交替,创造了更适宜于聚磷菌的生长环境,从而显著提高除磷脱氮效率。池体方形,五个池子间共用池壁和底板,布置紧凑,结构稳定性好,土建投资省,占地面积小。其中有两个边池交替出水,不需要单独设置沉淀池,省却了污泥和混合液回流设备,恒水位运行,水头损失小,装机负荷低,可以大大节省动力消耗。系统通过PLC可编程序控制器控制自动运转,运行方式和控制状态可以灵活调整,维护管理方便。通过该工艺小试试验装置在南京江宁开发区污水处理厂应用,研究工艺运行的适宜参数及对不同水质的适应性,通过跟踪试验对工艺除磷脱氮的过程和机理进行探讨,并在连续流运转状态下对ORP和pH变化的特征点与反硝化、释磷和硝化过程的关系及反馈控制除磷脱氮过程的可行性进行了分析。研究了该工艺中的反硝化除磷现象,对反应器污泥的反硝化除磷能力及聚磷菌组成进行了细致研究,并对反应器污泥的微生物相和除磷脱氮的相关性进行了分析。建立了交替运行工艺的污泥分布推流模型,对该工艺中污泥分布规律进行理论化推导,并与三池交替活性污泥工艺(UNITANK等工艺)进行对比。在五箱一体化活性污泥工艺中,厌氧、缺氧和好氧状态在同一池子的不同阶段以及同一阶段不同池子之间交替出现,厌氧释磷、吸磷、硝化、反硝化随之发生,利用多种微生物和电子受体完成除磷脱氮过程,整体除磷脱氮效率高。在水力停留时间为13h,周期设置按主体段、过渡段和沉淀段分别为90min、120min和30min,泥龄为12d～15d,边池污泥浓度为4000mg/L～6500mg/L的工艺条件下,进水COD浓度在421mg/L、TP浓度在4.82mg/L、TN浓度在49.6mg/L、NH4+-N浓度在45.2mg/L以下时出水能满足《城镇污水处理厂污染物排放标准》(GB18918-2002)一级A标准要求。对该工艺运行中ORP、pH、DO变化进行研究表明:边池在进水搅拌过程中ORP、pH出现特征点,与反硝化结束和厌氧磷释放具有同步性,在曝气过程中ORP、pH、DO同时出现特征点,与硝化结束时间对应。ORP和pH监测信号可以用于控制脱氮和除磷过程。该工艺在运行过程中出现一定的反硝化除磷现象,利用有机物在脱氮的同时完成除磷过程。反应器中污泥能利用硝酸盐氮和亚硝酸盐氮作为电子受体反硝化除磷,具有较高的反硝化除磷能力。以往的研究一般根据厌氧释磷后在开始阶段缺氧吸磷速度和好氧吸磷速度的比值确定反硝化聚磷菌的比例,本研究发现在开始阶段缺氧吸磷速度大于好氧吸磷速度,提出根据厌氧释磷后缺氧吸磷量和好氧吸磷量的比值确定反硝化聚磷菌比例的新方法。该反应器污泥中反硝化聚磷菌比例为99.25%,能以氧气、硝酸盐氮和亚硝酸盐氮三种物质作为电子受体的聚磷菌占全部聚磷菌的97.75%。更多还原

【Abstract】 Five-tank integrated activated sludge system, a new wastewater treatment process with the function of phosphorus and nitrogen removal was developed on the basis of such process as UNITANK and triple oxidation ditch. This process is composed of five hydraulicly connected rectangle tanks. The alternation of anaerobic, anoxic, aerobic and settling state was realized by timely and spatial control change to these five tanks. Mixed liquid and sludge are recirculated automatically by location transition of inlet and outlet without additional sludge or mixed liquid recirculation. This process runs with constant water level and high phosphorus and nitrogen removal rate.Every tank in this process is a CSTR(completely stirred tank reactor). All the five tanks constitute a group of CSTR cascade. On the whole, this process has the characteristic of puff flow reacter. So this process has high removal efficiency and can endure some shock load. Compared with UNITANK, the alternation of anaerobic, anoxic and aerobic state is more incident with timely and spatial change.Thereby, this process creates more suitable growth environment for polyphosphate accumulating organisms(PAOs) and enhances phosphorus and nitrogen removal.These five rectangular tanks have wall and motherboard in common with close collocation and stable structure. The construction investment and location space are spared. There are two side tanks for alternating outlet. Additional settling tank, sludge and mixed liquor recirculation equipment are omitted. This process runs at constant water level with small water head loss. Power consumption is greatly saved because of low power load. This system is automatically operated under the control of PLC (Programmable Logic Controller). Running mode and controlling state can be adjusted conveniently.A pilot scale test was applied in Nanjing Jiangning Development Zone Wastewater Treatment Plant. The preferable parameters of this system and its adaptability to different wastewater quality were studied. The process and mechanism of phosphorus and nitrogen removal were explored by tracking test. The relation of the characteristic points of ORP and pH with denitrification, phosphorus release and nitrification under continuous flow operation was analyzed. The feasilility to use these characteristic points as feedback for phosphorus and nitrogen removal was also discussed. The phenomenon of denitrifying phosphorus removal in this system was studied. The denitrifying phosphorus removal ability and polyphosphate accumulating organisms composition of the sludge in this reactor was detailedly investigated. The relativity of the biofacies to phosphorus and nitrogen removal in this reactor was also analyzed. The plug flow model of sludge in this system was founded to theoretically predict sludge distribution during operation, which was also contrasted to that in three-tank alternating activated sludge system such as UNITANK.Anaerobic, anoxic and aerobic state appeared alternately in one tank on different phases and on one phase in different tanks. Accordingly, phosphorus uptake, nitrification and denitrification arose. Diverse microorganism and electron acceptors were utilized for phosphorus and nitrogen removal resulting with更多还原