Permeate flux decline in the presence of HCO3− ions due to dense fouling cake. Higher permeate flux in case of SO42− due to repulsion of TiO2 by the membrane. Severe flux decline in the presence of humic acids and ions due to bridging effect. The highest loss of membrane separation properties in the absence of humic acids. Decrease of efficiency of humic acids removal in the presence of inorganic salts.