Effectiveness of active control of surface charge of filter media on separation of microparticles from contaminated wastewater

Abstract

Abstract Depth filtration is a conventional concept for the solid–liquid separation process through granular media, and this technique is very useful in removal of large-sized particle. However, in the case of microparticles smaller than the pore space it does not function well. Accordingly, an effective small particle removal technique is desired. In this research, a carbon fiber felt was introduced as filter media and ± 1.0 V terminal voltage was applied for activating the media to enhance in adsorbing as well as desorbing the fine particles in the filtration and back-washing. Kaolin particles in the range of 0.1–4.0 µm were used as a model of microparticles. The complete kaolin particle removal was observed in pure water, and it decreased to around 50% in the anionic surfactant-contaminated wastewater at the hydraulic loading of 283 L/m2/min. On the contrary, at the back-washing hydraulic loading of 1274 L/m2/min, the kaolin particle washout removal efficiency was found to be around 73% in pure water and it dramatically decreased and found within the range of 5–50% when the kaolin was in contact with anionic surfactant and wastewater. Although the kaolin particle washout removal rate was observed very low in wastewater, this technique would be very useful in enhancing the refreshment of the filter media for extending the production time of the filter.

Keywords

• Carbon fiber felt
• Depth filtration
• Kaolin
• Microparticle
• Terminal voltage