Household bleach products as high-performance and cost-effective cleaning agents for membrane fouling

Abstract

It has been widely known that polymeric membrane such as polyvinylidene fluoride (PVDF) is very prone to fouling that occurs during the filtration process. In the same light, membrane cleaning has also been popularly used as a mean to remove foulants which accumulated on or inside the membrane. In this paper, the utilization of domestic bleach, which is affordable and easily found in the nearest markets, as the membrane cleaning agent is discussed. The performance evaluation is conducted on three kinds of commercial domestic bleaches, namely Bayclin, Proclin, and Soclin. In order to study deeper about those product potentials, the performance is compared with the pure sodium hypochloride (NaOCl) which has been known as a common chemical cleaning agent, and distillate water. The results show that the bleach products work excellence in cleaning the fouled membrane which confirmed by the scanning electron microscopy (SEM) analysis results, in which membranes cleaned with the bleaches have cleaner surface compared to that cleaned with distillate water. Interestingly, the positive outcome can also be seen in the flux recovery ratio (FRR) of the membranes after cleaning which managed to recover up to 95% of the lost flux. Overall, all three bleach products showed closely similar performance as the original NaOCl, and showed far better performance than distillate water. This result emphasizes that the domestic bleaches are highly promising to be membrane chemical cleaning agents, replacing the common chemicals. This work makes a significant contribution toward giving reasonably priced options for alternative methods of cleaning membranes.