Study of influence of carbon/nitrogen ration on compost of cellulosic waste

Abstract

Composting is an old and inexpensive method to converts organic waste into useful material (compost) that can be used as soil conditioner and organic fertilizer. Composting is a self-heating, aerobic, solid-phase biological accelerated natural process of biodegradation and mineralization of organic matter. Industrial composting is a controlled process. The main objectives of this process are to maximize the hygienization and biodegradation/mineralization. The C/N ratio is an important quality parameter when using compost as a soil amendment, because materials with a high C/N ratio can immobilize soil nitrogen by the on going decomposition of the carbonaceous substances once the compost has been applied to soil. The ratio decreases as composting progresses because of the conversion of organic C to CO2. At the same time, part of the nitrogen can be lost in form of NH3. C/N ratio can either be measured in the compost or in an aqueous extract. Normally, a C/N ratio of less than 20 in mature compost is thought to be desirable. However, C/N values measured in sufficiently stabilized composts varied between 5 and 20, depending on the type of raw material. In this paper was studied the influence of vegetal waste/pig slurry weight ration on the quality of compost. Moisture, temperature, pH values, volatile organic carbon, total organic carbon, Kjeldahl nitrogen and ash content were monitored for 63 days.