The anaerobic fixed film reactors can be hydraulically charged to 94 kg COD m-3 day-1 over a period of 24 h and recover normal performance 12-48 h after overload. The COD conversion decreased with increasing overload and depended on the operating temperature and the type of waste. The quality and quantity of digester gas were also affected, but returned to normal stable values once the overload was stopped.
In India, there are several large-scale distilleries integrated with sugar mills (Pant Deepak and Adholeya Alok, 2007). The production of ethyl alcohol in distilleries based on sugarcane molasses constitutes an important industry in India (Nagaraj M. and Dr. Aravind Kumar, 2007). One of the most important environmental problems facing the world is waste management. Different industries create a variety of wastewater pollutants, which are difficult and costly to treat (Anupama S. et al, 2013). About 295 distilleries in India produce 2.7 billion liters of alcohol and annually generate 40 billion liters of wastewater (Pant Deepak and Adholeya Alok, 2007). The aqueous distillation effluent stream known as residual washing is a highly organic effluent of dark brown color and is about 12-15 times by volume of the alcohol of the product. Treatment, treatment and disposal of bulk washing are of great importance and need special attention (Pradeep NV et al, 2011) It is one of the most complex, problematic and strongest organic industrial effluents with extremely COD and BOD values high.