Application of the SBR System to Improve the Efficiency of Existing Aerated Lagoons: A Case Study of Prince of Songkla University, Hat Yai campus

Abstract

This research aims to study the efficiency and operating costs of the Sequencing Batch Reactor (SBR) wastewater treatment system at Prince of Songkla University, Hat Yai Campus. The system was upgraded from the original Aerated Lagoon system, which consisted of two ponds: 1) an aeration pond and 2) a maturation pond. The original system could handle a maximum wastewater volume of 500 cubic meters per day and had been in operation for over 40 years. The upgrade transformed it into an SBR system capable of treating up to 1,000 cubic meters per day within the same treatment area of 2,244 square meters. The upgrade process included 1) sludge removal, 2) concrete wall reinforcement, 3) installation of aeration pumps, 4) installation of paddle aerators in the maturation pond, and 5) installation of water quality monitoring equipment before discharge into public waterways. The results of wastewater analysis revealed that the average BOD and TKN concentrations during the academic semester were 64.06 and 52.40 mg/L, respectively, while during the semester break, the concentrations averaged 50.47 and 41.53 mg/L, respectively. After the upgrade, the system demonstrated average reduction efficiencies of 72% for BOD and 37.01% for TKN. The operating cost of the upgraded wastewater treatment system was calculated at 1.65 THB per cubic meter, comprising 1) electricity costs of 0.98 THB per cubic meter, 2) water quality analysis costs of 0.40 THB per cubic meter, and 3) chemical costs for water quality improvement at 0.27 THB per cubic meter.