Development and characteristics of aerobic granular sludge at 40°C

Abstract

This study is conducted to develop aerobic granular sludge (AGS) for domestic wastewater treatment application in a hot climate and low humidity condition such as for Middle East countries e.g. Saudi Arabia and to investigate the performance of the granular sludge in organic matter and nutrient removal by using sequencing batch reactor (SBR). The operation of the reactor was based on the SBR system with a complete cycle time of 3 hours (5 min of feeding, 140 min of aeration, 15 to 30 min of settling, 5 min of discharging and 3 min idling) and operated at 1.6 g COD / L.d organic loading rate. Granular sludge was developed at temperature 40ºC in 30 days operation by using synthetic wastewater as the influent. Result showed that developed granular sludge had good settling ability with average size of the granules was found to be 1.03 to 2.42 mm. Meanwhile, the removal efficiencies of chemical oxygen demand (COD), ammonia nitrogen (NH3-N) and total phosphorus (TP) are 87.31%, 91.93% and 61.25%. The study shows AGS can be developed at high temperature and capable to treat organics and nutrients present in domestic wastewater at hot climates and low humidity condition.