Process Design and Physicochemical Characterization of Extended Aeration Activated Sludge Treatment Plant: A Case Study

The discharge of untreated wastewater to the environment causes adverse environmental problems. In this regard, feasible wastewater treatment system must be designed and operated to reduce the pollutant load and to safeguard the public health. The efficiency of a sewage treatment plant located in a residential college in UiTM Sarawak Branch, Samarahan Campus was examined in terms of process design and physiochemical parameters. Physiochemical parameters included pH, temperature, turbidity, chemical oxygen demand (COD) and suspended solids (SS) from raw influent and treated effluent were investigated using the Standard Methods. Removal efficiency of these parameters was also determined to evaluate the performance of the plant. The findings revealed that overall performance of the plant was satisfactory. All physiochemical parameters of the treated effluent complied with the requirements of Standard B, Environmental Quality (Sewage) Regulations 2009 except SS. The lowest concentration of turbidity and COD in the effluent was reported in the second week of the sampling period. The findings obtained were due to the low influent loading during the semester break where the number of students resided in the college was very minimal. The removal efficiencies of turbidity and COD were found to be 65% and 83%, respectively. A non-compliance SS requires special attention to enhance the efficiency and to maintain the good operation of the system to meet the stipulated standards.