Effect of Eisenia Foetida Population Density on the Efficiency of a Pilot-Scale Tohá Vermifiltration System for Non-Domestic Wastewater Treatment

Vasquez S.R.; Guerra-Saldaña M.; Reátegui R.D.; Ojanama J.R.; Trigozo L.C.; López-Rojas J.J. · Chemical Engineering Transactions (2026) · DOI: 10.3303/cet26127056

Resumen

Non-domestic wastewater generated by municipal markets often presents high pollutant loads that exceed regulatory standards, causing severe damage to sewage infrastructure and aquatic ecosystems. Decentralized and ecological treatment alternatives, such as vermifiltration, are required to address this issue. This study evaluated the effect of Eisenia foetida population density on the efficiency of a pilot-scale Tohá system for the treatment of commercial wastewater from a central municipal market. Two parallel reactors were operated with identical local substrates (coarse gravel, sand, coconut fiber, sawdust, and compost) but different earthworm biomasses: 350 g (System 1) and 750 g (System 2). A baseline characterization revealed that the influent's initial concentrations for Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD5), Total Suspended Solids (TSS), and Oils and Greases (O&G) exceeded the Maximum Allowable Values. Wilcoxon and T-tests were employed to evaluate the systems' performance. Results demonstrated that the higher population density in System 2 yielded superior removal efficiencies of 96.4 ± 3.7 % for O&G, 74.6 ± 6.4 % for COD, 77.2 ± 6.7 % for BOD5, and 78.5 ± 5.9 % for TSS, successfully bringing the effluent within regulatory limits. It is concluded that increasing E. foetida density in the Tohá system enhances the degradation of physicochemical pollutants, providing a sustainable solution for non-domestic wastewater management. Copyright

Instituciones: Universidad Nacional de San Martín; Universidad César Vallejo