A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science of the Asian Institute of Technology, Bangkok, Thailand.

Thesis (M.Sc.) - Asian Institute of Technology, 1976

The major pollutional wastewaters of the Asia Fiber Co. (Ltd.) are the processing wastewaters from the polymerization and dyeing sections. From the wastewater characteristics analyses, the polymerization wastewater contributed about 2/5 of the total amount of the wastewaters in the factory, is much easier to subject to the biological treatment; whereas, for the dyeing wastewater, it is a kind of waste that is more difficult to undergo the biological degradation, as its BOD6 /COD is only 0.2. The stabilization pond provides a promising way to treat these kinds of wastewaters. The colour of the dyeing wastewater can be removed during the long detention time in the stabilization pond. The possible mechanisms involved in the colour removal might due to the sunlight bleaching action as well as the biological absorption and adsorption actions. In order to conform to the Standard laid by the authorized Ministry of Thailand as well as to make full use on the present treatment facilities, treatment modification have thus been subjected into 3 ways. The three alternatives are giving the most promising and economical way to treat the plant's effluents. The inorganic constituents of the wastewater from the water treatment plant can simply hold in a separate pond, so to equalize its various pH from the four different ion-exchanger systems. The domestic wastewater of the factory, in the future, can pipe-up and combine with the polymerizing wastewater before undergoing the biological treatment. This might upgrade the biological activities and save the cost of manual Phosphorus addition.