Removal of dissolved H2S from wastewater using hollow fiber membrane contactor: Experimental and mathematical analysis

The present study demonstrates the applicability of hollow fiber membrane contactors (HFMC) containing the hydrophobic polypropylene- (PP-) microporous hollow fibers for the removal of dissolved hydrogen sulfide (H2S) from wastewater. The tests were conducted on a fabricated and assembled laboratory-scale experimental set-up equipped with an HFMC module operated under liquid–liquid extraction (LLE) mode. The synthetic wastewater feed contained different H2S concentrations in the range between 300 and 1600ppm and aqueous monoethanolamine (MEA) was used as the extract phase. The HFMC system was shown to be effective in the treatment of H2S-laden wastewater, having more than 98% removal efficiency. Mathematical analysis was carried out explaining the experimental results. The model analysis was based on pore diffusion in the membrane, and also, the adsorption/desorption rate of H2S at the pore walls. The slope of the adsorption isotherm for H2S on the PP-surface was utilized as the model adjustable parameter. The model predictions and the data were found to be in reasonably good agreement, with the slope of the isotherm found within the same order of magnitude as described in the literature for different common water-dissolved gases on the various polymeric surfaces. [Display omitted] ► Dissolved H2S removal from waste water using hollow fiber membrane contactor ► 98% removal of H2S from wastewater was achieved. ► Mathematical analysis to explain the mechanism of separation ► Transport of gas molecules by adsorption/desorption on the walls of membrane pores ► Membrane contactors as effective tools to separate H2S, CO2 and NH3 from wastewater