【作者】 王丽平；

【导师】 张立秋；

【作者基本信息】 北京林业大学 ， 环境科学， 2011， 硕士

【摘要】 城市污水中的氮、磷未经有效处理即排放,会造成水体富营养化,从而带来巨大的经济损失。膜生物反应器因其具有良好的除污染性能和优良的出水水质而逐渐应用于污水处理,然而,它却存在着除磷效率低等问题。本文提出一种新型的复合式MBR组合工艺,通过添加填料强化MBR脱氮,同时进行污泥外循环厌氧释磷,提高工艺除磷性能并进行磷回收。在小试试验研究中,以系统对TN的去除率为评价指标,确定HRT和DO的最佳值为：HRT在4.0h左右,DO在0.8～1.5mg/L左右。通过厌氧释磷静态试验确定：厌氧释磷适宜的时间为2.0h,乙酸钠最佳投加量为至溶液中COD浓度为356mg/L。污泥外循环复合膜生物反应器(ASR-HSMBR)工艺由于增加污泥外循环厌氧释磷,系统对TP的去除效果明显高于HSMBR工艺。出水中磷浓度稳定在1mg/L左右,磷的去除率基本在80%以上,解决了MBR除磷效果不好的弊端。采用人工配置的富磷污水,分别考察了pH值、初始磷浓度、物料比、钙离子浓度等因素对磷回收过程的影响。得出结论：pH在8.5～9.0之间；Mg:N:P摩尔比为2：2：1有利于生成MgNH4PO4沉淀；同时试验发现初始磷浓度越高越有利于回收；钙离子浓度越高越不利于鸟粪石的生成。在中试试验研究中,HSMBR对COD和NH4+-N的平均去除率分别高达95.3%和90.1%。试验启动初期,系统对TN的平均去除率仅有20%左右。通过增加填料的投加量可强化系统脱氮效能,后期系统出水TN浓度在10mg/L左右,TN去除率达80%以上。在HSMBR系统运行初期,出水中TP浓度基本在1.0～2.0mg/L之间,系统对TP的去除率在80%左右。但随着试验的进行,系统对TP的去除率不断下降至65%左右。厌氧释磷过程选取厌氧搅拌为3h左右,厌氧释磷周期为3d。增加外循环释磷后,系统对TP的平均去除率高达90.2%。与单独HSMBR工艺对TP的去除效果对比表明,ASR-HSMBR工艺通过污泥外循环,解决了HSMBR工艺存在的除磷效果不理想的问题。同时污泥外循环厌氧释磷过程不会影响HSMBR对有机物以及氮的去除效果。在厌氧释磷充分后,采用化学沉淀法回收磷,富磷污水来自厌氧释磷环节,因此磷回收效果直接受厌氧释磷过程的影响。更多还原

【Abstract】 The nitrogen and phosphorus in wastewater without effective treatment causes water eutrophication, then it brings huge economic losses. Membrane Bioreactor is gradually used in wastewater treatment for its good performance and excellent effluent, however it exists in the low efficiency of phosphorus removal. This paper proposes a new kind of HMBR, by adding bio-filler to improved nitrogen removal, meanwhile through the processes of activated sludge recycle and anaerobic release phosphorus, it can improve the process phosphorus performance and phosphorus recycling.In the laboratory, the optimal HRT is 4h and optimal DO value ranges from 0.8 to 1.5mg/L, for the aim of the removal of TN. Through the static test, the optimal time of anaerobic release phosphorus is 2.0 h and the optimal dosing quantity of acetic acid sodium to solution is 356mg/L of COD concentration. Because of the recycle of activated sludge, the removal efficiency of TP by ASR-HSMBR significantly higher than HSMBR process. In the effluent, TP concentration is about lmg/L, and the removal efficiency is above 80%, it can solve the disadvantages of MBR. Using artificial phosphorus wastewater, the study focuses on the influence of the pH value, material ratio, initial phosphorus concentration and calcium ion concentration to phosphorus recycling. In the conclusion:the optimal pH is 8.5～9.0 between 9.0; Mg:N:P ratio is 2:2:1; Meanwhile the study find that the higher the concentration of initial phosphorus, the more conducive to recovery. The high concentration of calcium ion goes against the generatation of struvite.In the pilot test, the average removal efficiencies of COD and NH4+-N are 95.3% and 90.1%,respectively. At the beginning, the average of TN removal is only 20%. the efficiency of denitrification increase through the increase of bio-filler, during later stage the TN concentrations in effluent is about 10mg/L, TN removal efficiencies up to 80%.And the TP removal efficiency is about 80% in the initial, but it drop to 65%.The optimal time of anaerobic release phosphorus is 3.0 h, and the optimal cycle is 3d.After the recycle of activated sludge processes, the removal efficiency is up to 90.2%.Meanwhile it does not affect the organic and nitrogen removal, on the contrary, the removing efficiency of TN increases in HSMBR. After anaerobic phosphorus release, using chemical precipitation method to phosphorus recovery, in the supernatant the phosphate concentration is 1.29 mg/L, the average removal efficiency is 89.79%.更多还原