Applicability of Vermifiltration for Wastewater Treatment and Recycling

Abstract

With the rapid population growth and wastewater generation due to anthropogenic activities, availability of freshwater is decreasing annually. Untreated wastewater discharged from the municipal and industrial sectors reaches to the local surface water bodies and degrades water quality. Conventional wastewater treatment systems possessing high carbon footprint require mechanistic operations and need to be made affordable with ease of operation. To overcome the impediments associated with the conventional treatment systems, vermifiltration technique employing earthworms in a filter bed has emerged as an alternative for wastewater treatment and recycling. Further, the potential of macrophyte has also been explored by integrating with the vermifiltration system for wastewater treatment. This chapter presents the applicability of vermifiltration technique with various filter design configurations and mechanisms involved for the treatment and recycling of both sewage and industrial effluents. Further, the influence of different operational parameters like hydraulic retention time (HRT), organic loading rate (OLR), hydraulic loading rate (HLR), filter media bed design, earthworm density and flow mode on organic, nutrient and pathogen removals from domestic and industrial wastewater is discussed concisely. Moreover, future perspectives have been provided towards the improvement of the efficacy of the vermifiltration system for wastewater treatment and recycling.