Scientific Contributions

The effect of different coagulants on the performance of UF membranes to treat seawater containing algal blooms was investigated. The results highlight that using advanced coagulant ferrate (Fe(VI)) in the process prior to the UF process enhanced the membrane permeability and substantially reduced biofouling. Removal of UF process was enhanced with the use of ferrate and removal efficiency of 99 %, 71 %, 98 %, 99 %, and 100 % for turbidity, TOC, ATP, bacteria, and TEP, respectively was achieved. In addition, the treated feed with ferrate led to a thinner fouling layer on the UF membrane surface compared to the layer that was formed with the use of ferric chloride which was thicker and denser. High water flux with a value of 831.0 ± 27 L.m−2.h−1.bar−1 was obtained when algal-laden seawater was treated with the advanced coagulant before the UF process, compared to the value of 602 ± 11 L.m−2.h−1.bar−1when a traditional coagulant was used. Indeed, use of the advanced coagulant ferrate in a hybrid coagulation/UF process could be a promising system to substantially enhance seawater quality, decrease operational cost, and increase the membrane life-expectancy.