Properties of Compost
The compost prepared from MSW should be black brown or at least black in colour. It should be crumbly in nature with an earthy odour. The pH should be neutral though slightly acidic or alkaline pH within the range of 6.5 to 7.5 can be tolerated.
The compost should neither be completely dry nor it be lumpy and water should not come out of the mass when squeezed.
The Nitrogen, Phosphorous and Potassium (NPK) contents should be more than one percent each. The Nitrogen should be in the form of Nitrates for proper utilisation by the plants. The C/N ratio should be between 15 to 20.
In order to ensure safe application of compost, the standards laid down in the Draft on Municipal Waste (Management & Handling) Rules, 1999, notified on 27th September, 1999 by the Ministry of Environment & Forests, Government of India, for production of compost given as per table 14.3 must be adhered to:-
Table 14.3 Standards for Compost
Parameter - Maximum acceptable concentration parts per million (ppm)
Arsenic - 20
Cadmium - 20
Chromium - 300
Copper - 500
Lead - 500
Mercury - 10
Nickel - 100
Zinc - 2500
