The Environmentalist

, Volume 28, Issue 4, pp 409-420

First online:

Sewage treatment by vermifiltration with synchronous treatment of sludge by earthworms: a low-cost sustainable technology over conventional systems with potential for decentralization

  • Rajiv K. SinhaAffiliated withSchool of Engineering (Environment), Griffith University Email author 
  • , Gokul BharambeAffiliated withSchool of Engineering (Environment), Griffith University
  • , Uday ChaudhariAffiliated withSchool of Engineering (Environment), Griffith University

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


Earthworms’ body works as a ‘biofilter’ and they have been found to remove the 5 days’ BOD (BOD5) by over 90%, COD by 80–90%, total dissolved solids (TDS) by 90–92%, and the total suspended solids (TSS) by 90–95% from wastewater by the general mechanism of ‘ingestion’ and biodegradation of organic wastes, heavy metals, and solids from wastewater and also by their ‘absorption’ through body walls. Earthworms increase the hydraulic conductivity and natural aeration by granulating the clay particles. They also grind the silt and sand particles, increasing the total specific surface area, which enhances the ability to ‘adsorb’ the organics and inorganic from the wastewater. Intensification of soil processes and aeration by the earthworms enable the soil stabilization and filtration system to become effective and smaller in size. Suspended solids are trapped on top of the vermifilter and processed by earthworms and fed to the soil microbes immobilized in the vermifilter. There is no sludge formation in the process which requires additional expenditure on landfill disposal. This is also an odor-free process and the resulting vermifiltered water is clean and disinfected enough to be reused for farm irrigation and in parks and gardens


Vermifiltration Vermifilter bed Biofilter Stimulate microbial degradation Odor-free process Synchronous sludge treatment Hydraulic retention time Hydraulic loading rate Biological oxygen demand Chemical oxygen demand Total dissolved and suspended solids