Compost Production from Household Solid Wastes by Earthworms

BACKGROUND AND OBJECTIVE: Increasing of world population and excessively consumption of the needed materials result to greatly household solid wastes generation that can threaten human health and environment. Thus, application of appropriate methods for solid waste disposal is effective on community health. This study was performed to identify the capability of native earthworms of Mazandaran province (Iran) for compost production from household solid wastes.METHODS: In this cross sectional study, the types of earthworms were separated based on appearance characteristics. Plastic bin, loam soil, sand and animal fertilizer were used for bedding. 50gr of vegetable (lettuce) was poured on the bed. Earthworms with a certain number and weight were located on soil bed. Sequential water was added to beds for moisture control. Seventeen and thirty-five days after loading, the soil of different beds were assessed for chemical and microbiological analysis. FINDINGS: The organic matter, organic carbon, nitrogen, phosphorous and electrical conductivity in initial substrate and vermicompost increased from 16.8% to 40.2 and 45.2%, from 1.95% to 3.9 and 5.85%, from 1.1% to 3.6 and 3.9%, from 1.8% to 2 and 2.6% and from 344 to 372 and 1068 microsiemens per centimeter, respectively. Ash percentage, C/N ratio and total coliforms in initial substrate and vermicompost decreased from 83.2% to 65% and 59.8%, from 1.75% to 1.63% and 1.49 %and from 4.5×106 to 3.3×103 and 1.3×103 MPN/100ml, respectively. CONCLUSION: The results of this study showed that earthworms can produce compost from household solid wastes during 17 days.