The aim of this research study is to evaluate an integrated wastewater treatment system for textile wastewater. The proposed integrated treatment starts with a membrane nanofiltration system (MNF), whose permeate with low concentration of pollutants is treated by advanced oxidation process (AOP) while the concentrate undergoes wet air oxidation (WAO) to partially degrade the bio-resistant pollutants prior to an "intensified" biological treatment (IBT). If the treated effluents from AOP and IBT satisfy the reuse standards, they will be recycled for use in the textile processes....[ Read more ]

The aim of this research study is to evaluate an integrated wastewater treatment system for textile wastewater. The proposed integrated treatment starts with a membrane nanofiltration system (MNF), whose permeate with low concentration of pollutants is treated by advanced oxidation process (AOP) while the concentrate undergoes wet air oxidation (WAO) to partially degrade the bio-resistant pollutants prior to an "intensified" biological treatment (IBT). If the treated effluents from AOP and IBT satisfy the reuse standards, they will be recycled for use in the textile processes.

As there are reported results available on the treatment of the textile wastewater by MNF, WAO and IBT, the experimental investigation for the present study focuses on the AOP. It was carried out in two stages, one is AOP on synthetic wastewater and the other is on real wastewater.

The textile wastewater is high in COD and bio-resistant, with a considerable amount of salinity. In order to recycle such effluent totally, the contaminants identified above should be mineralized and/or removed according to the reusable textile water quality standard.

From the experimental results on a synthetic textile wastewater (PVA solution) and on real textile wastewater, it is demonstrated that all MNF, AOP and WAO are effective in achieving the treatment goals.

Apart from achieving the treatment goal, the costing of this treatment scheme is also discussed. It is demonstrated that the process favors large textile plants over small ones, with payback periods in several years.

With this approach, the problem of increasing discharge rate of textile effluent in the HKSAR and Mainland China could be avoided. Similar integrated treatment schemes can be applied to other water-consuming industries as well.