A novel bio-film wastewater treatment system using encapsulated microbes

Abstract

The untreated or incomplete disposal of nitrogen pollutants in the wastewater can cause great harm to the environment. A large amount of ammonia-nitrogen (NH3-N) will consume dissolved oxygen and cause eutrophication. The conventional wastewater treatment process in Malaysia is not efficient enough to remove the NH3-N. Most of the sewage treatment plants (STPs) in Malaysia are open structures which occupy a large area and emit stench. The existing STPs are not suitable for construction in the compact urban areas and some of these STPs operation are costly. This study designs a novel biological water purification system using a biofilm reactor with encapsulated microbes that is known as Mass Bio System (MBS). The MBS had been used in the east of Asia to treat high concentration of NH3-N in the industrial wastewater with high efficiency. MBS has not been reported to treat domestic wastewater. This paper reports the adaptability and verification of the new sewage treatment system based on MBS to treat domestic wastewater in Malaysia. The study will dynamically monitor the key parameters and compared with the conventional extended aeration (EA) process that is the most common STP applied in Malaysia using the same influent conditions. The aim is to verify that the MBS can treat the wastewater to meet the local emission standard where the water discharge shows the characteristics well below the discharge limits. The study showed that the average effluent and removal efficiency of NH3-N was approximately 2 mg/L and 88.6 % (with maximum 99.7 % removal). All evaluated parameters in the MBS showed stability of effluent characteristics and met the requirements of Malaysian sewerage industry guidelines. MBS also offers the co-benefits of energy, and space saving than the conventional process. The process is recommended as an efficient sewage treatment system in Malaysia and other countries with similar climatic conditions.