Standardization of the optimal ratio of distillery spent wash to the pressmud windrows for effective and ecofriendly compost

Abstract

Distillery effluent, a waste water of distillery industry is of purely plant origin and contains large quantities of soluble organic matter and plant nutrients, but not contains any toxic compounds. The spent wash obtained from distilleries being effectively utilized with sugar factory waste known as pressmud through compositing process. Compositing was utilized as a source for measuring C:N ratio and to produce stable organic soil manure. Nine pressmud windrows were formed by fixed weight ratios of pressmud and different ratio of spent wash (1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5 and 1:5). Compositing process parameters include temperature, pH, electrical conductivity, C:N ratio, phosphorus and biological property were measured periodically. Addition of effluent above in 1:3.5 ratio caused notable increase in pH and temperature in the windrows. Salt content, organic carbon, N, P and K percent in the compost were increased with increase in spent wash application. The treatment with 1:1.5, 1:2 and 1:2.5 of compost pressmud and spent wash were found good for microbial population. The various compost parameters were found optimum in the 1:3.5 ratio of compost press mud and spent wash application.