Energy utilization in sewage treatment - a review with comparisons

In recent years, the operating cost of sewage treatment plants (STPs) in some parts of the world has been rising due to increases in the cost of energy. STPs have focused on energy reduction and recovery from treatment processes in order to lower energy consumption. The development involves the improvement of capital set-up for treatment plants in terms of equipment upgrading/plant sizing as well as exploration of novel technologies for sewage, excess sludge treatment and biogas recovery. This review compares the current technologies applied in STPs around the world and discusses these technologies and facilities which may enhance energy reduction and recovery in sewage treatment.