Problem statement: Pollutions of water bodies by dye wastes from textile industries and other sources have become critical consideration. A photocatalytic technique using semiconductor materials such as Titanium Dioxide (TiO 2 ) activated by lights has been considered as one economical method to solve this problem. Approach: We attached titanium dioxide on the surface of polymer grains as photocatalyc agents using a cylinder milling method. Photodegradation processes were observed in decomposition of Methylene Blue (MB) solutions, as waste model, under solar illumination. Several parameters were optimized such as the milling temperature, the milling period, number of coated grain layers on the surface of the waste. The repeatability of using the coated grains was also sipected. Results: Two layers of TiO 2 coated grains resulted the optimum decomposition rate of the MB solution. The milling temperature of 100°C and the milling period of 90 min produced the optimal decomposition rate. After five times repetition, the TiO 2 coated grains still function well by decomposition up to 97% MB compound. Conclusion: These materials have the potential in large scale wastewater treatment in the tropical regions and nearly do not require a complicated late handling in the process of separating the catalyst for treated water as well as requires very small energy, expect the sunlight energy.