Water and solute transport in pervaporation hydrophilic membranes to reclaim contaminated water for micro-irrigation

The suitability of a homogeneous hydrophilic dense membrane for reusing brackish and/or contaminated waters was investigated. Its performance was evaluated in terms of water permeate flux and membrane enrichment factors using borate, selenate, sodium chloride and glucose as model contaminants. A series of experiments were conducted using a sweeping air pervaporation unit to examine the effects of membrane configuration (hollow fiber membranes (HFM) and corrugated sheet membranes (CSM)), sweeping air velocity, feed temperature, pressure and contaminant concentration. The collected data were then modelled to determine the individual mass transfer coefficients. The results showed that water fluxes ranged from 2.9 to 4.4 and 2.0 to 3.7 kg/(m2 day) for HFM and CSM, respectively. Air velocity and feed pressure were identified as the controlling factors for water flux. In all the cases, the average enrichment factors for glucose, selenate, borate and sodium chloride were 0.18, 0.08, 0.20 and 0.23, respectively. Thus, it was concluded that this membrane has the promise to provide an innovative treatment alternative for reusing brackish groundwater and residential wastewater in agriculture micro-irrigation.