Identification of microbial groups in the aeration tanks of secondary wastewater treatment stage

Abstract

Microbes are prevalent in wastewater, degrading organic matter that impact the environment. In recent years, wastewater treatment plants have been used to process treated water for domestic purposes, sustaining groundwater resources for the future. The current study assessed the present microbial species in the aeration tanks for the secondary wastewater treatment stage in the Sulaibiya Wastewater Treatment and Reclamation Plant, Kuwait. Biweekly wastewater samples were collected for a period of three months from October 2022 to December 2022 from the aeration tanks. The collected wastewater samples were analyzed for microbiological parameters including total coliform, fecal coliform, Salmonella, and E. coli. Further, the microbial species were identified using the Biolog Omnilog Instrument. The results indicated that a total of 45 bacterial species isolates were identified with the most dominant genus being Bacillus with twenty-one isolates. Though Bacillus is common in aeration tanks, the presence of Bacillus thuringiens/cereus is rare and their existence could be due to the change in climatic conditions such as rainfall, dust and wind. Therefore, the study recommends that all microbial groups should be identified at all treatment stages including, primary, secondary, tertiary, and advanced treatment stages to ensure the complete removal of microbes.