Potential of Earthworm Lampito mauritii in Vermiremediation of Heavy Metals (Co, Ni and Cd) from Different Combinations of Animal Dung with Kitchen Wastes

Heavy metals are toxic and can cause a variety of health problems in humans and animals. They affect the natural environment in addition to the wide range of soil fauna. Effective management of heavy metal concentrations can be achieved through the inoculation of earthworms in their habitats. Lampito mauritii, an anecic species of earthworm, is known for its ability to accumulate heavy metals in its body yellow tissues. In the present research, we examined the concentrations of heavy metals in various combinations of animal dung with kitchen waste (KW) in the feed mixture that was initially prepared, in the final vermicompost, and in the earthworm’s body tissues. During the earthworm, Lampito mauritii vermicomposting process, a significant decrease in the levels of heavy metals, including cobalt (Co), nickel (Ni), and cadmium (Cd), was observed in all combinations of animal dung mixed with kitchen waste (KW). The concentration of Co and Ni was significantly increased (2.71% and 12.40%) in earthworm Lampito mauritii body (6.915 ± 0.004 and 7.120 ± 0.005 mg/kg) when treated in the combination of BD+KW (1:3) and BD+KW in 1:1 ratio respectively. Whereas, the concentration of Cd was maximum accumulated in the body tissue of earthworms from the combination of goat dung (0.42%, 61.899 ± 0.005 mg/kg). The results show that Lampito mauritii functions as a biological indicator and significantly decreases the number of heavy metals in the final vermicompost during vermicomposting processes. This method not only facilitates the effective management of kitchen waste but also mitigates the risk of heavy metal contamination in the human diet.