Juntima Chungsiriporn

Utilization of Waste from Para Rubber Industry to Produce Compost

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 NH3 from 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.

Removal of NH3 in Air Released from Rubber Latex Process Using Skim Serum Absorbent

The treatment of NH3 releasing concentrated rubber latex to air was studied using skim serum in laboratory scale of bubble absorption reactor. The skim serum (pH 2.5 to 3) is a liquid waste from concentrated rubber latex. The concentration of NH3 in air (300 to 1500 ppmv) and air flow rate (0.5 to 1.5 l/min) feeding into the reactor were measured for the effect of the treatment efficiency. At lower NH3 concentration and air flow rate have resulted to higher NH3 removal efficiency. Bubble absorption reactor can be effectively used and applied to remove NH3 releasing from the concentrated rubber latex process to the air without any plugging of the skim rubber in the system. Skim serum waste liquid has the result in higher efficiency in NH3 removal comparing to pure water usage. This study would be practically used as a guidance for the further design and operate to minimize waste and emission control in rubber industrial-scale system.

Synthesis and Characterization of SnO2/N-Doped TiO2 Nanoparticles

SnO2/N – doped TiO2 photocatalysts were prepared by the modified sol-gel method. Tin tetrachloride pentahydrate, urea and polyethylene glycol were used as precursors and calcined at a temperature of 500 °C for 2 h for making powders. Different interstitial amount of nitrogen additives were in range of 0 to 40 mol%N. The XRD patterns show the TiO2 nanocomposites are anatase phase. It was also apparent that doped nitrogen has an effect on crystallite size and band gap energy on absorbed light wavelength leading of enhancement of photocatalytic activity of TiO2 composite nanoparticles. The result showed 20 mol%N of TiO2 nanocomposites exhibited high photocatalytic activity, redshift in adsorption edge and a small crystallite size.