The purpose of this study is to produce the soil improvement materials from food waste and water hyacinth by using a dehydration process. The experiments were divided into two parts : 1) the study of the optimum temperature and time for converting food waste and water hyacinths to soil improvement materials by determining the temperatures of 100 °C 150 °C and 200°C in the periods of 1 hour 2 hours and 3 hours respectively 2) the study of nutrient content in the materials before and after mixing into the soil for 5 days. The soil used in the experiment was sampled from Sai Ma Subdistrict Nonthaburi Province. The parameters used to evaluate the ability to improve the soil quality were soil moisture pH electro conductivity total nitrogen total phosphorus total potassium and organic matter. The results showed that the optimum temperature for drying the food waste was 150°C for 2 hours and the optimum temperature for drying the water hyacinth was 200°C for 3 hours. When the materials were mixed into soil it found that the soil drainage was improved. Mixing the materials into soil could increase the pH value from 5.2 to 5.4 and increase the electrical conductivity from 0.72 mS/cm to 14.78 mS/cm. Besides the plant nutrients including Nitrogen phosphorus and potassium also increased after adding soil improvement materials.

The purposes of this research were to investigate anaerobic digestion of concentrated food waste in biogas production system at mesophilic temperature (37 C). The effect of grinding and pH controlled at 6.20 and 7.00 on methane production were also studied. It was found that the ability of mix bacteria which had initial concentration of 2100 mg/l for digesting concentrated food waste with grinding was higher than that without grinding because of the increase in surface area (about 1.37 time). In this system the optimum condition for bacteria growth was found at pH 7.00. Under optimal condition the digestion efficiency in term of chemical oxygen demand (COD) removal was 18.81% higher corresponding to an increase in methane production rate (19.10%) than other conditions

The aim of this research was to develop a process for making an inoculum from cow dung. Consequently the inoculum together with food waste was employed to produce hydrogen gas. A total of four different inoculums were experimented including 1). Fresh inoculum 2). Autoclaved inoculum 3). Natural dried inoculum and 4). Hot air dried inoculum. The experimental results revealed that the autoclaved inoculum is the most effective in terms of producing a volatile fatty acid in a maximum value of 9.55 g/l. In addition a maximum hydrogen gas of 136.46 ml/g (of sugar) and also having an average pH of 4.85 and the sugar concentration of 0.33 g/l could be obtained. Furthermore it was found that creating an inoculum by using the autoclaved inoculum produces an inoculum powder having a concentration of 20%. This suggests that the autoclaved inoculum is the best in terms of producing the hydrogen gas from using food waste is 35 litre/litre (of food waste).