Assessment Efficiency of Vermifiltration in Municipal Wastewater Treatment: A Pilot Study

Aim: 
Nowadays, most developing countries face the challenge of ever-increasing municipal sewage in rural areas. In this respect, many countries cannot afford the cost of establishing a wastewater treatment plant. Therefore, this study aims to obtain executive information and evaluate the efficiency of vermilter (VF) in domestic wastewater treatment.
Methods: 
This study investigates the performance of a pilot-scale vermifilter system containing Eisenia fetida earthworms for sanitary wastewater treatment. For this purpose, a pilot-scale vermifilter was installed to ascertain the variation of pH, biological oxygen demand (BOD₅), chemical oxygen demand (COD), total suspended solids (TSS), total dissolved solid (TDS), NO₃^—N, NH₃-N, TN, PO_4,³ − and total phosphorus (TP) in an incubation period of 120 days. In addition, a conventional geofilter without earthworm was used as the experimental control. The process includes using two small cylindrical plastic reactors with a depth of 62.5 cm and a capacity of 80 L.
Results: 
The vermifiltration (VF) caused a significant decrease in the levels of BOD₅ (92.5%), COD (77.1%), TSS (88.8%), TDS (70%), NH₃-N (95.11%), TN (52%), PO₄³⁻ (77.1%), and TP (69.86%). Meanwhile, the removal efficiencies for the above parameters in the control reactor were 54.94%, 67.5%, 70.4%, 53.37%, 42%, 77.3%, 72.65%, and 62.17%, respectively.
Conclusion: 
Vermifilter is one of the feasible methods for wastewater treatment. Therefore, VF technology can be considered an environmentally friendly method for wastewater treatment.