Powdered Activated Carbon Coated Hollow Fiber Membrane: Preliminary Studies on its Ability to Limit Membrane Fouling and to Remove Organic Materials

A new approach to a membrane hybrid system by pre-coating the hollow fiber membrane with powdered activated carbons (PAC) was evaluated for its ability to minimize the fouling of the membrane and to remove organic material from wastewater. This preliminary study evaluates the performance of a microfiltration membrane coated with three kinds of PACs: wood based (WB), charcoal based (CB) and coconut based (HA). Broadly, two scenarios were evaluated: one with low amounts of PAC coated on the membrane and another at higher amounts of PAC coating. The results indicate that the pre-coated membrane can effectively arrest the fouling agents in the wastewater in reaching the membrane pores and thereby limit membrane fouling. Interestingly, it was also found that, without any pre-treatment or addition of PAC in the tank, the pre-coated membrane also had the ability to retain organic materials. For the hollow fiber microfilter membrane used in the study having surface area of 2.58${\times}$$10^{-0.3}$ $m^2$ surface area, pre-coating the membrane individually with 458 mg of HA-PAC, 497 mg of WB-PAC and 906 mg CB-PAC, the reduction in permeate flux was as little as 14-20% after 8 hours of each operation and the maximum organic removals was about 76%, for all the three kinds of PAC coatings. The type of PAC coated on the membrane and the amount coated could be the key factors in deciding the performance of the system. Although further studies are required, it is evident that the PAC pre-coated membrane system has great potential in successfully reducing membrane fouling, which could improve membrane life, enhance process performance and reduce membrane cleaning time.