Silicate and silicone removal by pretreatment to prevent membrane fouling in garment washing wastewater treatment

Abstract

Membrane technology is being increasingly used in reclamation of textile wastewater. High concentration of silicate and silicone auxiliaries in garment washing wastewater can cause detrimental and unbearable fouling on membrane. Chemical pretreatment before membrane separation is feasible to prevent fouling. Experiments of coagulation were conducted to investigate the characteristics of silicate and silicone removal for reclamation of garment washing wastewater. Two precipitants were tested: iron salt TW-19 and calcium oxide. The optimum precipitant dose is 400 ppm TW-19 in combination with 75 ppm calcium oxide with pH = 9·8 for the garment washing wastewater. Polyacrylamide (PAM) as precipitant aid was also tested with optimum precipitant doses. 2 ppm of PAM is helpful to reduce the metal ions concentration to decrease membrane fouling potential.

Keywords:

• Silicate
• Silicone
• Coagulation
• Membrane fouling
• Wastewater treatment

Acknowledgements

Thanks are due to nnzhaoguan company for supplying the various precipitants and precipitant aids used in research.