Appropriate Ratio of Organic Waste and Grease Waste for Soil Amendments

Abstract

The purpose of this study was to examine the occurrence rate of solid waste and grease residues of Rong Kham Subdistrict Municipality. To begin the research, the samples were collected 7 days/week continuously for 3 months and the study of appropriate ratio of organic waste and grease waste in the production of soil amendments was commenced by mixing organic waste and grease waste at the ratio of 0:100, 100:0, 50:50, 20:80, 80:20, 40:60 and 60:40 by weight, respectively. The mixed material enters the fermentation tank and the fermentation process, which was done without aeration was finished in 90 days. The results showed that the average solid waste generated 4,120 kg/day and the solid waste generated rate was 0.68 kg/person/day. The weight of municipal solid waste in Rong Kham Subdistrict was 4,120 kg/day with a solid waste volume of 618 liters/day and an average density of 0.15 kg/liter. Most of the solid waste components were plastic and foam, which were 30.04%, followed by fabric 19.15% and food waste, which consists of vegetable and fruit at 16.63%. The rate of grease waste was 0.0012 kg/person-day or equal to 0.0015 kg/household-day. The results of the study on the optimum ratio of organic waste and grease waste for soil amendment production found that all ratios of organic waste and fat residue of soil amendment have pH in the range of 5.8 - 11.3 and the electrical conductivity in the range of 10.45 - 13.03 dS/m. The organic waste to grease waste ratio of 20:80 has the most total nitrogen percentage equal to 0.00051 (5.14 mg/kg). The detection of available phosphorus was found the most in organic waste to grease waste ratio of 60:40 at 0.03394% (339.37 mg/kg). Available potassium was found the most at the ratio of organic waste to grease waste of 0:100, 60:40 and 80:20 which have the percentage at 0.02059, 0.01975 and 0.01804, or 205.93, 197.51 and 180.36 mg/kg, respectively and the difference was statistically significant at the 0.05 level. The ratio of organic waste to grease waste of 40:60 has the most of organic matter equal to 2.139%. The ratio of organic waste to grease waste of 40:60 also had the most of organic carbon percentage at 1.241.