An Efficiency-Centred Hierarchical Method to Assess Performance of Wastewater Treatment Plants

An efficiency-centred hierarchical model is developed to assess the performance of wastewater treatment plants (WWTPs). Specifically, a new treatment performance index (TPI) has been proposed to determine the overall treatment performance of WWTP by analysing the TPI values and the weights of individual treatment phase for overall treatment performance. Three modules have been developed to examine the performance of the primary, secondary, and tertiary treatment units of a WWTP. The model is applied to three WWTPs with different scale, loading rate, capacity, and process phases. The case study results indicate that the developed tool is useful in assessing the WWTP system in terms of treatment efficiency, operating conditions, and cost-effectiveness of its management schemes. The model can be also combined with an infrastructure condition rating index model to form a condition rating model for a WWTP, and used as a cost-effective tool to evaluate current and future needs in operation and management.