Alkaline hydrolysis of the sludge generated from a high-strength, nitrogenous-wastewater biological-treatment process

The production of acrylonitrile butadiene styrene (ABS, a petrochemical product) in Taiwan is one of the biggest manufactoring processes in the world. The large amount of ABS sludge generated in the wastewater treatment plant from the highly nitrogenous-wastewater contains significant amount of complex and biorefractory organic substances. Resource recovery is the optimal conception of the traditional sludge treatment for the purpose of organic matters removal. An alkaline pretreatment method is used to enhance the efficiency of biological hydrolysis of industrial wastewater sludge in the present study. The operating conditions for the alkaline pretreatment of the ABS sludge were maintained at room temperature (25 ± 3°C), reaction time of 24 h, total solids in the feed of 0.5–2%, and NaOH dosages of 10–50 mg l−1. Considering the increasing concentrations of soluble chemical oxygen demand and biochemical oxygen demand, the experimental results indicated that the alkaline pretreatment method was useful in biodegradability enhancement.