Comparative assessment of domestic wastewater treatment via Vermifiltration through various filter bed material

Vermifilter (VF) is considered sustainable for rural areas; however, filter media is the most important but has been explored less. This study evaluated the performance of vermifilters in treating domestic wastewater (DWW) using various filter media, including areca nutshell (AS), rice straw (RS), dry leaves (DL), and chicken eggshells (ES). We compared the results with four different reactors: R1 (AS), R2 (RS), R3 (DL), and R4 (ES). DWW was applied with a hydraulic loading rate (HLR) of 1 m³/m²/d with Eisenia fetida earthworm species. The results showed the removal of biochemical oxygen demand (BOD) by 82%, 76%, 73%, and 87%; chemical oxygen demand (COD) by 75%, 73%, 72%, and 88%; phosphate by 36%, 25%, 27%, and 50%; sulfate by 56%, 54%, 53%, and 71% in R1, R2, R3, and R4, respectively. Simultaneously, R4 experienced a fivefold reduction in total bacteria and a sixfold reduction in total coliform. Moreover, the most exceptional filter media for vermifiltration is eggshells for the earthworm's growth and treatment efficacy.