Thesis (M. Sc.) - Asian Institute of Technology, 1995

A thesis submitted in partial fulfillment of the requirments for the degree of Master of Science.

The study was under taken to assess the impact of zeolite, that composed in phosphate-free detergen, on environment. Site of study is the Chao Phraya river within one km. distance where JICA's plan to obstruct the water for water supply for Patum Thani province. Field survey and the laboratory experiment were performed to find out the water consumption, zeolite concentration both soluble and insoluble concentration in wash water and in the river From this study it was found that the water consumption used in this area is 55 L/c/d, the zeolite production is 1.4 g/c/d. The soluble and insoluble zeolite concentration ratios in wash water was found to be 1 :2. The zeolite concentration in the river water, which determined in form of aluminium concentration was 2 g/L. But it could not be said that the total aluminium concentrarion formed in the river water was caused by zeolite. Zeolite can substantially result in increase aluminium to the environment. As a result, obtained the concentration of aluminium in the river water raised up to the toxic range to plants, fish and man. This study suggested that the aluminium concentration in the river water is appoximately 0.2 mg/L. It can be said that the aluminium concentration that existing in the study area can be regarded as harmful if the water is in acid condition.