Carbon and phosphorus Recovery and Removal during High Rate Activated Sludge (HRAS) Process treating Domestic Wastewater

Abstract: With the on-going paradigm shift in wastewater management from energy negative to energy positive services, high-rate activated sludge (HRAS) process is attracting attention due to its high efficiency in carbon recovery. While carbon is recovered at short SRTs, phosphorus removal is also desired to be integrated into the process. This study aims to optimise a HRAS pilot plant by changing operating parameters, including solids retention time (SRT), dissolved oxygen (DO), hydraulic retention time (HRT), to achieve good contaminants removal and energy recovery. It will also analyse and evaluate the optimal conditions of HRAS to achieve phosphorus removal at short SRTs. Further optimisation of the biogas production will be attempted using FNA pre-treatment of the HRAS sludge.