好氧-沉淀-厌氧工艺处理效能及抗冲击负荷研究

Performance of Treating Wastewater and Anti-shockloading in Oxic-Settling-Anaerobic(OSA) Process for Minimization of Excess Sludge

以传统活性污泥法（CAS）为参照,系统研究了好氧-沉淀-厌氧（OSA）污泥减量工艺连续运行240 d,污水处理效果、污泥性能、温度波动和难降解有毒物质的冲击对系统稳定性的影响.结果表明,OSA工艺废水处理效率整体上优于CAS工艺,COD去除效率略高于CAS,总氮、总磷去除率分别比CAS高出42.58%和53.84%.OSA和CAS工艺每100 g好氧污泥中生物结合的磷分别是2.69 g和1.11 g,进一步证实了OSA工艺有生物除磷功能.由于厌氧-好氧耦合,OSA污泥沉降性能和污泥活性都得到改善,SVI稳定在97左右,SOUR和脱氢酶活性均高于CAS污泥.OSA污泥胞外多聚物中蛋白质浓度比CAS高出1.69 mg·g^-1,多糖浓度要比CAS低6.7 mg·g^-1,解释了OSA污泥沉降性能改善的原因,也证实了污泥厌氧池的插入对污泥性能、微生物种群结构的影响.OSA工艺对温度波动的影响滞后于CAS工艺3～4 d,出水COD、NH4^＋ -N、SS均升高,污泥产率Y（MLSS/COD）降低至0.403 mg·mg^-1和0.227 mg·mg^-1.OSA受对-硝基苯酚（PNP）的冲击比CAS更敏感,PNP浓度为10 mg.L-1,系统完全失去脱氮除磷功能.OSA系统受温度和PNP冲击后,比CAS更难修复.

Efficiency of pollution degradation, performance of activated sludge, effect of temperature fluctuation and recalcitrant organic compounds on system stability were investigated in OSA process for minimization of excess sludge. CAS process and OSA process were run with synthetic wastewater for 240 d. The results indicate that the OSA process excels the CAS process as a whole. COD removal efficiency in OSA process was slightly more than that in CAS. Removal efficiency of nitrogen and phosphorus could be enhanced to 42.58% and 53.84% respectively. Biological phosphorus accumulation in aerobic sludge from OSA and CAS were 2.69g and 1.11 g per 100 g dry sludge, which further approved biological phosphorus removal in OSA process. Because of alternative aerobic and anaerobic environment in OSA process, sludge settleabillty and activity are improved. SVI in OSA process was 97 averagely. SOUR and dehydrngenase activity of sludge in OSA were higher appreciably than those in CAS. Protein concentration was higher above 1.69 mg·g^-1 and polysaccharide concentration was lower 6.7 mg·g^-1 in OSA sludge than those in CAS, which confirms the effect of anaerobic tank on sludge performance and microorganism diversity. Lower polysaccharide concentration in OSA sludge improves the settleability. Contrasting to CAS process, OSA process is more sensitive to impact of p-nitrophenol（PNP） and more inactive to temperature fluctuation. Temperature fluctuation led to an increase of the concentration of COD, NH4^＋ -N, SS in effluent while sludge production Y（MLSS/COD） was reduced to 0.403 mg·mg^-1 and 0.227mg·mg^-1 in CAS and OSA. When concentration of PNP was increased abruptly to 10 mg·mg^-1 , biological nutrient removal was ceased in OSA process. Once OSA system is impacted, it is difficult to restore.