Effect of Heavy Metals on Earthworm Activities During Vermicomposting of Municipal Solid Waste

Abstract

The effect of heavy metals on the activities of earthworm species Eudrillus eugineae was studied during vermicomposting of municipal solid waste (MSW) spiked with heavy metals. The activities of earthworms, in terms of growth and biomass production and number of cocoons produced, were monitored periodically, and the concentration of heavy metals in earthworms and substrates was determined at definite intervals. Laboratory-scale experiments were performed by mixing individual heavy metals in MSW. Copper, cadmium, chromium, lead, and zinc were selected for the study. The study concludes that heavy metals tend to accumulate in the body of earthworms; hence, the inherent concentration of heavy metals in the substrate before vermicomposting must be considered in view of composting of MSW and its application to soil. It was observed that copper and cadmium were toxic for the worms at 1.5 and 0.1 g/kg of the waste, respectively. The studies also suggest that earthworms are susceptible to the free form of heavy metals. Cadmium is the most toxic metal, followed by copper. Based on the investigation and observation, it was also found that earthworms should be separated from castings before the use of castings in soil amendments. Water Environ. Res., 80, 154 (2008).

Commercial African Catfish (Clarias gariepinus) Recirculating Aquaculture Systems: Assessment of Element and Energy Pathways with Special Focus on the Phosphorus Cycle

“…Vermifiltration: The treatment of organic wastes by Vermifiltration has gained much attention in recent years [61]. Evidence suggests high capacity to mineralize nutrients [62] and the remediation of pollutant elements [63]. The experimental use of worms to treat distillery waste water demonstrated removal of about 91% BOD, 89% COD, 90-92% TDS and 92% TSS [64].…”

Feasibility of nutrient recovery from industrial sludge by vermicomposting technology

“…Various industrial sludges tested for vermicomposting include solid paper mill sludge, textile mill sludge, winery waste, guar gum industrial waste, etc. [3][4][5][6][7][8][9].…”

Antioxidant Enzyme Activity and Lipid Peroxidation in Aporrectodea caliginosa Earthworms Exposed to Silver Nanoparticles and Silver Nitrate in Spiked Soil

“…And heavy metals, including Ag, accumulate in earthworms by soil ingestion, via ion exchange of dissolved heavy metals across the lipophilic outer membrane and/or adsorption on membrane surfaces. For example, divalent metals such as cadmium (Cd 2+ ), copper (Cu 2+ ), chromium (Cr 2+ ), lead (P 2+ ), and zinc (Zn 2+ ) accumulated in tissues of the earthworm Eudrilus euginiae exposed to 0.1 and 1.5 g of waste (vermicomposting municipal solid waste; Kumar et al 2008). These divalent heavy metals may also be present in brownfields and public parks (Jennings et al 2002).…”