Fabrication of glassy ceramic membrane filters for filtration of spring water with clogging phenomena

Ceramic membrane filters consisting of a filtration layer of varying thickness coated on a tubular porous support made of quartz-based materials and with a pore size of about 10 μm were fabricated. The filtration performance for spring water clarity was examined. The coatings were prepared by a filtration process with a dilute particle suspension of quartz-natural zeolite–lead borosilicate glass mixture. The filter matrix was of quartz type and the additives (frit glass and zeolite) made the filters with glassy pore walls as the sintering temperature applied was above their fusion temperature. The pores of the filtration layer have a relatively coarse size distribution and thus lead to clogging phenomena within the glassy pores during filtration operation. The pore clogging is a benefit for producing clear filtrate and the glassy pore walls favour the filter cleaning and recovery. It was observed that a sufficiently thick coating (>62 μm) was required for good enough filtrate clarity (0.2 NTU turbidity) and cleaning of the filter was possible by filtrate backflushing and air blowing.