Out of the millions of tons of Municipal Solid Waste (MSW) generated annually in India, only about 75-80% of the waste gets collected and out of this, only 22- 28% is processed and treated, and the remaining is deposited indiscriminately at dump yards. Hyderabad city generates around 5500MT of waste every day. And only 20% of the waste is used for composting using the windrow composting process. MSW composting is a rapidly growing method of solid waste management in Hyderabad and In-Vessel composting is the recent initiative by the Govt. of India to reduce the organic solid waste generated at the source. The present study was aimed to assess the degree of accumulation and contamination of the heavy metals in composts from Centralised Windrow Composter (CWC) and Source Segregated Accelerated Vessel Composter (AVC). Compost Samples from CWC and AVC were analysed for metals concentration using Energy Dispersive X-ray Fluorescence Spectrometers (ED-XRF). CWC samples were found with slightly high concentrations of heavy metals like Zinc (0.51 – 0.66%), Copper (0.36 – 0.45%), Nickel 0.03 – 0.05%), Iron (11.46 – 13.27%), and chromium (0.06 – 0.14%) compared to AVC. AVC samples contained high concentrations of Calcium (14.99 – 64.19%), Potassium (9.13 – 29.59%) and Phosphorous (1.55 – 3.43%) when compared to CWC. The current study does a comparative analysis on the process and nutrients available to assess the quality of the compost from both sources. Considering the above findings source segregated AVC seems to be a better composter than centralised CWC, as the concentrations of Ca, K, and P required by the plant were abundant in AVC. Also, considering the process aspect, there is always scope for cross-contamination if the waste is separated after treatment which is the case in CWC.
Quality assessment of compost from Centralized windrow composter (CWC) and Source segregate automatic vessel composter (AVC) at Hyderabad city in India
