Treatment performance of Tlogomas communal wastewater treatment plant Available to Purchase

Communal wastewater treatment plant (CWWTP) most located at the riverbank for convenience to discharge. The effluent has not monitored regularly so the treatment performance is unknown. Tlogomas CWWTP located at Tlogomas gang 8 Malang city East Java that operated since 2011. The operating capacity exceed the design capacity of 350 peoples. This research was aimed to know the quality of effluent and their treatment performance. We followed the Minister of Environment and Forestry regulations No. 68/2016 parameters for wastewater quality standard such as Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD). In addition, also tested the concentration of Nitrate (NO₃) and Phosphate (PO₄). Sampling method was based on Standard Nasional Indonesia (SNI) 6989.59:2008. The laboratory analysis based on SNI 6989.2.2019 for COD, APHA 5210 B.2017 for BOD, Q1/LKA/65 for NO₃ and SNI 6989-31:2021 for PO₄. The evaluation result of Tlogomas CWWTP’s effluent quality showed that effluent still contain high organic and nutrient. The concentration of COD consecutively 584.5 mg/L; 120.5 mg/L; 285.9 mg/L; 194.6 mg/L. The concentration of BOD are 28.85 mg/L, 206.6 mg/L; 91.44 mg/L and 62.73 mg/L. The value of NO₃ concentration respectively 5.323 mg/L; 10.63 mg/L; 11.65 mg/L; 8.919 mg/L. PO₄ concentration are 13.23 mg/L; 13.7 mg/L; 21.45 mg/L; 9.115 mg/L. The high organic contains caused by hydraulic loading (38.22 m³/m².day) which exceed the design (27.87 m³/m².day). So, the organic loading also exceeding the design (2.2 kg/m².day; 0.31 kg/m².day; 0,97 kg/m².day; 0.67 kg/m².day). Furthermore, low treatment performance also caused by poor maintenance that caused sludge accumulation.