Integration of nanofiltration, UV photolysis, and advanced oxidation processes for the removal of hormones from surface water sources

Abstract

This study evaluates the integration of nanofiltration with direct and indirect UV photolysis for drinking water treatment in order to guarantee effective removal of different hormones with endocrine disruption capabilities – mestranol, octylphenol, nonylphenol, progesterone, estrone, estriol, 17α-ethynylestradiol, and β-estradiol – from real surface water matrices.The integration of nanofiltration previously to low pressure ultraviolet direct or indirect photolysis reduces the level of turbidity as well as the micropollutant contamination levels in drinking water supplies, due to rejection based on size exclusion and molecular interactions with the nanofiltration membrane surface. The use of nanofiltration in the treatment of surface waters spiked with different hormones allowed their rejection at levels higher than 71% for all target hormones except estriol. Low pressure indirect photolysis with 100mg/L of hydrogen peroxide was also efficient to degrade the selected hormones with percent degradations higher than 74% achieved for all the hormones, except nonylphenol (55%).The integrated process (nanofiltration followed by direct photolysis or indirect photolysis) is extremely efficient to remove all the target hormones from a real surface water matrix and guarantees the production of water with extremely high chemical quality.