Maknakorn W, Jutaporn P, Khongnakorn W
Center of Excellence in Membrane Science and Technology, Department of Civil Engineering, Faculty of Engineering, Prince of Songkla University, Songkhla, 90112, Thailand and Department of Civil Engineering, Faculty of Engineering, Prince of Songkla University, Songkhla, 90112, Thailand E-mail:
Department of Environmental Engineering, Faculty of Engineering, and Research Center for Environmental and Hazardous Substance Management, Khon Kaen University, Khon Kaen, Thailand and Research Program on Development of Appropriate Technologies for Coloring Agent Removal from Textile Dyeing, Pulp & Paper, Sugar Industries for Sustainable Management, Center of Excellence on Hazardous Substance Management (HSM), Chulalongkorn University, Bangkok, Thailand.
Water Sci Technol. 2019 Mar;79(5):877-887. doi: 10.2166/wst.2019.100.
This study investigated the performance of coagulation with ferric chloride (FeCl.6HO) and adsorption with activated carbon used as pretreatments prior to thin-film composite-forward osmosis (TFC-FO) filtration of ink printing wastewater. Wastewater samples were collected from a printing factory located in Chao Phraya river basin where zero liquid-discharge standards are regulated. The FO filtration unit was operated in co-current mode with the cross-flow velocity of 600 mL/min using 2 M NaCl as draw solution. The FO membrane achieved 83.9-91.0% chemical oxygen demand and 91.2-99.9% color rejections. FO filtration of raw wastewater, coagulation-treated wastewater, and coagulation and adsorption-treated wastewater resulted in 56.3%, 49.0% and 46.1% of flux decline in 150 min. Scanning electron microscopy and Fourier transform infrared spectrometry results revealed that cake formation caused by colloidal particles and pore blocking from precipitation were the major fouling mechanisms. Cake-enhanced concentration polarization also promoted adsorption of color and pigments at the membrane surface. Both fouling mechanisms were successfully mitigated by adsorption following coagulation pretreatment. Overall, the combined pretreatments and FO have potential for the effective treatment and reuse of ink printing wastewater.
