Utilization of Waste from Para Rubber Industry to Produce Compost

Abstract

A survey of cooperative concentrated rubber latex industry in southern Thailand showed that most of them do not have adequate treatments for their wastes. Especially, skim latex serum (SS) with high source of ammonia is a main wastewater generated from their industries and concentrated latex sludge (CS) with high source of phosphorus is a main solid waste obtained from their industries. It was noted that both of the wastes cause environment problems. Water pollution and bad smell of NH3from these waste systems have also been generated and affected to human health. One low investment possibility is the elaboration of these wastes by composting because these wastes contain some nutrients (N, P, K) in available forms resulting in high potential to add value for fertilizer production. However, both of the wastes have a small amount of organic matter content that need to be mixed with other materials with high organic matter such as sawdust (SD). Thus, the aim of this research was to investigate the utilization of these wastes to produce compost. In this work, the SS, CS and SD were composted in specially designed composting vessel (6L) with various mixing ratios of the SS, CS and SD in order to examine the optimized mixing condition and physical properties of the compost. Each treatment was composted with 60 days of composting duration. The performance of composting process was analyzed in term of the following: temperature, pH, electric conductivity, total organic carbon, total nitrogen, total phosphorus and C/N ratio. The analysis of temperature, pH, and electric conductivity was measured every day while the analysis of total organic carbon, total nitrogen, total phosphorus and C/N ratio was investigated every 10 days. According to the results, the optimized mixing ratio of SS, CS and SD for composting was 1:1:1. The final resultant compost was feasible for agricultural use. From the view point of compost qualities, it was in the range of the Thai compost standard with 7.91 of pH, 15.06 (%w/w) of total organic carbon, 1.24 (%w/w) of total nitrogen, 0.69 (%w/w) of total phosphorus and 21.6 of C/N ratio.