Influence of membrane morphology on humic acid removal behavior of adsorptive membrane by embedding modified montmorillonite

In this study the efficiency of two different morphologies of polysulfone adsorptive membranes was examined for the humic acid removal from contaminated water. Adsorptive membranes with finger-like and sponge-like pore structures were prepared using modified montmorillonite with amino acid. Structure of fabricated membranes was investigated by Field Emission-Scanning Electron Microscopy, pure water flux, porosity and contact angle measurement. The obtained results showed that the addition of modified montmorillonite (MMT) to the membrane with finger-like structure altered the morphology and improved pure water flux, porosity and hydrophilicity. These changes were negligible in PSf with sponge-like structure. In addition, the adsorption property of these membranes for the removal of humic acid (HA) was extensively studied. Adsorption capacity of cellular membrane was higher than the finger-like structure and Freundlich isotherm model was fitted for both of them. Nevertheless, the membrane with finger-like pores provides rapid adsorption of HA respect to cellular structure. It was also found that increasing the pH until pH=8 enhanced HA removal for adsorptive membranes, but increasing the pH above this point was not favorable. The obtained results from the dynamic adsorption revealed that sponge-like and finger-like membranes could generate 100 mL and 50 mL permeate of high quality (<1 ppm HA in water), respectively.

Keywords:

Adsorptive membrane , Pore structure , Humic acid , Montmorillonite , Amino acid