Membrane Pervaporation for Wastewater Reuse in Microirrigation

A novel wastewater microirrigation technology for plants to extract reclaimed water from hydrophilic, homogenous dense membrane modules placed directly in the soil was evaluated. A series of tests were conducted in the laboratory to examine the effects of membrane configuration (hollow fiber (HF) and corrugated sheet (CS) membranes), soil texture (a loam and loamy sand soil), soil water content, feed pressure, and contaminant concentration on water permeate flux. The performance was evaluated in terms of soil water content, soil electroconductivity, water permeate flux and enrichment factor using borate, selenate, sodium chloride and glucose as model compounds. The results showed that the water permeate fluxes ranged from 0.21 to 1.04 L/m^2/d for CS modules and from 0.10 to 1.00 L/m^2/d for HF modules, respectively. Soil water content and feed pressure were identified as the main controlling factors for water flux. The enrichment factors were found to be less than 0.25 for all the tested contaminants. Thus, it was concluded that this membrane technology holds promise either to treat brackish ground water or to reuse wastewater for agricultural micro-irrigation.