洛阳石化PTA废水生物处理系统污泥膨胀原因解析

ANALYSES ON SLUDGE BULKING OF PTA WASTEWATER BIOTREATMENT SYSTEM IN LUOYANG PETROCHEMICAL CORP

洛阳石化PTA废水生物处理系统中活性污泥长期处于膨胀状态,严重影响系统的正常运行。对洛阳石化PTA废水生物处理流程的进水水质、容积负荷、污泥负荷以及氮磷质量浓度、生物相进行调查与分析。结果表明,PTA进水COD在1 862～7 568 mg·L-1之间,波动幅度很大;一级生化池常超负荷运行,而二级生化池负荷过低,各流程负荷失衡。进水氮组成中主要为NO3--N,质量浓度为80～165 mg·L-1,经过一级生化处理后,硝酸盐几乎完全被反硝化,不能被微生物利用;而NH4+-N质量浓度仅25～42 mg·L-1,进水磷约0.1～0.3 mg·L-1。从C/N/P比来看,微生物生长所需氮磷浓度明显不足,这是引起污泥膨胀的主要原因。上游来水水质不稳定,特别是其中的有机胺类物质(环己胺),对下游生物处理系统造成冲击,并产生严重的跑泥现象。

Sludge bulking frequently takes place in PTA wastewater biotreatment system of Luoyang Pentrochemical Corp, which apparently has influence on normal operation of the system. Here, we investigate influent water quality, volume loading, sludge loading, biofacies and concentration of nitrogen and phosphorus in PTA treatment system. The results shows that COD concentration of the influent ranges from 1 862 mg·L^-1 to 7 568 mg·L^-1 with a larger fluctuation. Overload operation of the first biochemical pool and lowload operation of the second biochemical pool results into poor mic robial activity and imbanlance of loading in the biotreatment system. The major composition of nitrogen was nitrate-nitrogen （from 80 to 165 mg·L^-1） in the influent Most of nitrate was denitrified in the first biochemical pool so that these nitrogen can＇t be used by microbes The influent NH4^＋-N and phosphorus are 25 -42 mg ·L^-1 and 0.1 -0.3mg ·L^-1, respectively. Carbon-nitrogen-phosphorus （C/N/P）ratio shows insufficient nitrogen and phosphorus for microbial growth, which is main fator affecting sludge bulking. Moreover, Unstable water quality of the influent in the biotreatment system, especially organic amines （Cyclohexylamine）, also cause enormous impact to the system and sludge washout.