Correct Answer - Option 3 : 50 - 55%
Concept:
In Composting with a combination of proper environmental conditions and adequate time, microorganisms turn raw putrescible organic matter into a stabilized product.
Through composting, readily available nutrient and energy sources are transformed into carbon dioxide, water, and a complex form of organic matter compost. Process management can be optimized for a number of criteria, including the rate of decomposition (to reduce residence time in reactors and thus minimize facility size requirements), pathogen control, and odour management.
The key parameters are the available carbon to nitrogen (C: N) ratio, moisture, oxygen, and temperature.
Decomposition slows dramatically in mixtures under 40 to 45 percent moisture, which can lead facility operators to prematurely assume compost is stabilized and ready to sell.
A minimum moisture content of 50 to 55 percent is usually recommended for high rate composting of MSW.
During the active composting phase, additional water usually needs to be added to prevent premature drying and incomplete stabilization. MSW compost mixtures usually start at about 52 percent moisture and dry to about 37 percent moisture prior to final screening and marketing.