Liu Victor Lei, Nakhla G, Bassi A
Department of Chemical and Biochemical Engineering, The University of Western Ontario, London, Ont., Canada N6A 5B9.
J Hazard Mater. 2004 Aug 9;112(1-2):87-94. doi: 10.1016/j.jhazmat.2004.04.007.
In this work, batch activated sludge studies were investigated for the treatment of raw pet food wastewater characterized by oil and grease concentrations of 50,000-66,000 mg/L, COD and BOD concentrations of 100,000 and 80,000 mg/L, respectively, as well as effluent from an existing anaerobic digester treating the aforementioned wastewater. A pre-treatment process, dissolved air flotation (DAF) achieved 97-99% reduction in O&G to about 400-800 mg/L, which is still atypically high for AS. The batch studies were conducted using a 4-L bioreactor at room temperature (21 degrees C) under different conditions. The experimental results showed for the DAF pretreated effluent, 92% COD removal efficiency can be achieved by using conventional activated sludge system at a 5 days contact time and applied initial soluble COD to biomass ratio of 1.17 mg COD/mg VSS. Similarly for the digester effluent at average oil and grease concentrations of 13,500 mg/L, activated sludge affected 63.7-76.2% soluble COD removal at 5 days. The results also showed that all kinetic data best conformed to the zero order biodegradation model with a low biomass specific maximum substrate utilization rate of 0.168 mg COD/mg VSS day reflecting the slow biodegradability of the wastewater even after 99% removal of oil and grease.
在本研究中，对分批活性污泥法处理生宠物食品废水进行了研究。该废水的特点是油脂浓度为50,000 - 66,000 mg/L，化学需氧量（COD）和生化需氧量（BOD）浓度分别为100,000 mg/L和80,000 mg/L，以及来自处理上述废水的现有厌氧消化器的出水。预处理工艺——溶解气浮（DAF）使油脂去除率达到97 - 99%，降至约400 - 800 mg/L，这对活性污泥法来说仍然异常高。分批研究在室温（21摄氏度）下使用4升生物反应器在不同条件下进行。实验结果表明，对于经DAF预处理的出水，在接触时间为5天且初始可溶性COD与生物量之比为1.17 mg COD/mg挥发性悬浮固体（VSS）的情况下，采用传统活性污泥系统可实现92%的COD去除效率。同样，对于平均油脂浓度为13,500 mg/L的消化器出水，活性污泥在5天时对可溶性COD的去除率为63.7 - 76.2%。结果还表明，所有动力学数据最符合零级生物降解模型，生物量比最大底物利用率低至0.168 mg COD/mg VSS·天，这反映出即使在油脂去除率达到99%之后，废水的生物降解性仍然较慢。
