REVIEW OF AEROBIC GRANULAR SLUDGE TECHNOLOGY AND APPLICATION IN WASTEWATER TREATMENT

Abstract

This paper focuses on introducing an overview of aerobic granular sludge technology, granulation, removal efficiency and application of aerobic granules in wastewater treatment. Aerobic granular sludge has a bacterial layered structure including anaerobic, anoxic and aerobic bacteria in order from inside to outside layer, so it is capable of simultaneous chemical oxygen demand, nitrogen and phosphorus removal. Granular sludge also has capacity to remove persistent organic substances and adsorb heavy metals. As a result, aerobic granular sludge technology can be effectively applied for municipal and industrial wastewater treatment. Many wastewater treatment plants applying aerobic granular sludge technology have been deployed, most commonly in Europe and especially in the Netherlands, which is the first place to apply this technology in practical wastewater treatment with Nereda® trademark. However, aerobic granular sludge is stable on batch reactors and takes months to form stable granular sludge. Therefore, it is necessary to have further researches on the granulation mechanism and affective factors to shorten the time of aerobic granular sludge formation as well as maintain the long-term stability of the granular sludge and develop continuous reactors to maintain the stability of the aerobic granular sludge to meet the requirement of wastewater treatment plants in practice.