Air stripping pre-treatment process to enhance biogas production in anaerobic digestion of chicken manure wastewater

Abstract

Anaerobic digestion is typically applied for water and air pollution control and energy recovery from chicken manure wastewater. Unfortunately, high nitrogen content of the chicken manure could be prohibitive to efficient anaerobic digestion. In this study, air stripping was employed as a pre-treatment process for ammonia removal from a chicken manure wastewater. Laboratory-scale experiments of air striping were conducted at various temperatures, initial pH values, air flow rates, and stripping times. The experimental results showed that the high ammonia removal efficiencies of more than 80% could be achieved from the air stripping process operating at the initial pH, temperature, and air flow rate of 11, 80 °C, and 4.0 L/min, respectively. The ammonia removal kinetics were found to fit with the first-order reaction. Bio-methane potential tests suggested that air stripping pre-treatment of the chicken manure wastewater resulted in about 25% increase in biogas production.