一般常用的脫色處理方法有凝結法(Coagulation)，活性碳吸附法(Actjvated Carbon)，氧化怯，及逆滲透壓法(Reverser Osmosis)。然分散性染料係非離子性染料(Nonionicdye)，在水溶液中呈固態分散粒子，而且近年來開發耐日光堅牢度(Light fastncss)，和耐煙牢度(gas-fume fastness)極佳的高級分散性染料，因此活性碳吸附或氧化法等皆未能獲得理想的效果。因此，木文擬先採用凝結法進行脫色處理。
本文中採用三種凝結劑(Coagulants)，如PAC(Polyaluminum chloride)，硫酸鋁(Aluminum sulfate)，及硫酸鐵(Ferric sulfate)分別處理偶氮系，蔥醌系與一支黑色分散性染料染色廢水，並探討其最佳凝結效果的PH值範圍及有效用量。結果顯示：PH值是影響凝結劑脫色效果的重要因素。所用的三種凝結劑中以PAC脫色效果最佳，而其他二者以硫酸鋁較佳。凝結劑有效用量與廢水中的染料濃度成正比例關係。分散性染料分子結構對於凝結劑脫色效果無顯著的影響。分散劑用量會影響凝結劑的脫色效果。
Several ways have been applied to the deceleration of wast-water, such as coagulation, activated carbon, oxidation and reverse osmosis. In this work three coagulants used are polyaluminum chloride (PAC), aluminum sulfate and ferric sulfate. With them we respectively treated wastewater of azoid dyes, anthraquinoid dyes and a black dye.
It can be concluded that PH is one of the important factors of coagulation. Among the three coagulants used, PAC has the best results, ferric sulfate the worst. The effective dosage of coagulants is in proportion to the dye contents of the wastewater.
