Fouling Mitigation in Membrane Distillation Using Pulsation Flow Technique

Abstract

The main obstacles to scaling up membrane distillation (MD) on a commercial level are membrane fouling and temperature polarization. Therefore, in this study, the significance of the pulsation feed flow phenomenon was used for membrane distillation (DCMD) polarization, and comparisons were made using steady-state feed flow. Two different Hertz and amplitudes of pulsation feed flow trends were used in DCMD using different sources of water, including distilled water, seawater, and wastewater. Compared to steady-state feed flow, the results revealed that flux was enhanced for seawater once the operating flow became turbulent, and it enhanced even more once the flow rate was increased and the turbulence flow was moved. For wastewater, pulsation in the feed flow had an impact on delaying the beginning of the flux decline point and enhancing the overall freshwater recovery. In both pulsation feed flows (1 and 2 Hertz), the results also revealed a deficiency in fouling and an improvement in the temperature distribution in the feed channel for seawater desalination and wastewater running under typical operational conditions. Taking this value into consideration, an enhancement in mass flux (~5–10%) was observed compared to steady-state feed flow. Moreover, the pulsation feed channels were found to reduce CPC by about 10–15%, proving the role of turbulence in mixing the flow and mitigating the reduction in concentration polarization.