Abstract
The removal of humic acids (HA) using ceramic tubular microfiltration membrane operated under various conditions including trans-membrane pressures, cross flow velocities, humic acids concentrations in the presence of different heavy metals, and high NaCl content (10000-35000 mg/L) has been investigated. It was found that HA retention increases sharply in the presence of heavy metals ions and at high salinity levels, while trans-membrane pressure has little effect on HA retention. It was also found that the effect of solution environmental on HA retention should reflect alterations in solute charge and in an extent of aggregation HA macromolecules. The fouling by HA was found to be a critical factor in microfiltration with ceramic membrane. Fouling was more severe at high concentrations of NaCl and heavy metals in the feed due to the tighter packing of the HA aggregates in the fouling layer formed on the membrane surface. These results provide an important insight into ceramic membrane fouling with HA at high salinity conditions relevant to the treatment of brackish and seawater.