INFLUENCE OF VEGETAL WASTE/PIG SLURRY RATIO ON THE QUALITY OF COMPOST

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-14-8 / ISSN 1314-2704, June 19-25, 2014, Book 3, Vol. 2, 183-190 pp

ABSTRACT
Composting is a traditional and inexpensive method to convert organic waste into useful material (compost) that can be used as soil conditioner and organic fertilizer. The carbon/nitrogen ratio is an important quality parameter that is used to assess the rate of decomposition of compost mixture. Compost may be used as a soil amendment, when the values measured of C/N ratio varied between 5 and 17, depending on the type of raw material. During composting processes, the waste that contained the carbon and nitrogen are transformed through the activities of successive microbial populations into more stable complex organic forms namely humic substances and mineral compounds as salts of nitrogen (nitrate, nitrite, ammonia) and phosphorus (phosphates). Metabolic activity evolution is affected by the chemical composition of starting material, carbon/nitrogen ratio, moisture, temperature, pH, the turning frequency, the oxygen input and the particle size. In this paper the influence of vegetal waste/pig slurry weight ratio on the quality of compost has been studied. Like vegetal waste were used the marc from fermented fruits (plum, apples and peaches) and sawdust from fir and beech wood. Moisture, temperature, pH values, volatile organic carbon, total organic carbon, Kjeldalh nitrogen and ash content were monitored for 63 days for characterization of the compost quality. The weight increase of either pig slurry or sawdust in the composting system involves the decrease of C/N ratio and the increase in the quality of mature compost.

Keywords: aerobic process, biodegradation, composting, vegetable waste