Membrane Fouling Mitigation in Water Filtration Using Piezoelectrics

Abstract The clogging of filtration membrane by particles otherwise known as fouling is a major concern in membrane filtration technology due to severe flux reduction associated with it, which results to the reduction of membrane lifespan, reduced system performance and increased process and operating costs in industries that utilize membrane in their production process. This is because the cleaning or replacement of the fouled membrane requires production to be interrupted for the cleaning process or the entire system to be shut down for the replacement process to take place, leading to great loses to the industries involved. Many approaches have been devised over the years through research to tackle this problem, some of which not only undermine the performance of the filtration membrane but also contribute to great loses to industries that apply them. Cheaper and more efficient means of fouling control remains the key to salvaging this problem. This work proposes a water filtration system in which piezoelectric crystals attached at strategic points on a tubular polyvinylidene fluoride (PVDF) membrane are used to increase flux and delay the clogging of the pores of the filtration membrane by particles during water filtration. Filtration tests with mud solution show that the membrane vibrated with piezoelectrics reduced the clogging of the pores and increased permeate flux of the filtration process as compared with the case where the membrane was not vibrated with piezoelectrics, suggesting that vibrating the system with piezoelectrics is a good fouling reduction method that can be used in fluid separation processes. To optimize the permeate flux production of the system and fouling reduction, the anti-fouling effects of the piezoelectric crystals on the membrane surface is investigated through experiments together with the effects of voltage application, positioning and placement distance of the piezoelectrics and some other variables involved in this work.