Study on the qualitative assessment of in-vessel food waste compost by indexing method

Abstract

The consumption of different food-based goods produces a considerable amount of waste that needs to be conserved in an eco-friendly manner. A study was carried out on food waste compost made from the in-vessel compost process for use in agriculture and its marketability for its fertility and contamination potential. Food waste samples were collected from the canteen and hostels of GITAM University, Visakhapatnam (Andhra Pradesh), India and were transferred to a 125Kg in-vessel food waste composter (Molten Mind F125) and allowed to digest for 24 hrs followed by curing for seven days. After curing, the samples were characterized for nutrient content for fertility index (FI) and heavy metal contamination for clean index (CI). The compost quality index was derived from FI and CI to assess its suitability for agriculture. The pH of the food waste compost sample was reported as 8.4 and the C/N ratio was 28, which was higher than the standard ratio (15-20). The other physicochemical characteristics were analyzed using the standard methods and the concentration of metals was analyzed using Inductively Coupled Plasma Mass Spectrometry ( ICPMS). From the analysis, it was evident that heavy metal concentrations were well within the permissible limits. Further, the compost was characterized to know the fertility index (FI) and contamination index (CI) and its suitability to the soil. FI value was reported as more than 3.1 and CI value more than 4, which indicated that compost was best in quality, having high-value potential and low heavy-metal content, which will be suitable for high-value crops such as organic farming.