摘要

In this research, a facile process combined chitosan adsorption and UV-Fenton advanced oxidation process (CAAOP) has been developed for the treatment and reuse of spent acid dyebaths. The acid dyes in the spent dyebaths are completely removed through the adsorption column filled with chitosan, while most of sodium sulphate and Peregal O-25 (nonionic organic surfactant) can pass through the adsorption column with the water. Although the resulting recycled spent acid dyebaths are reused over ten times as new dyebaths for dyeing with C.I. Acid Red 1, the changes of the color differences and the relative unlevelness properties on dyed fabrics are still remained within the acceptable levels. That is also true for the other shade dye, namely C.I. Acid Yellow 11, in the 11th recycling cycle. As a result, an average saving of 87.4%, 91.7% and 50.1% for water, sodium sulphate and Peregal O-25, respectively, is achieved with the reuse process for the total eleven dyebaths. The exhausted chitosan can be easily recovered by dilute alkali as a desorbing agent, and the emissions from the two eluted concentrates treated with UV-Fenton are found to meet the most stringent emission standards for both COD and color in China. Results reveal that CAAOP is a promising process for the treatment and reuse of textile dyeing wastewaters, which can benefit the environment and reduce the operating cost.

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