Preparation of Polysulfone Capillary Ultrafiltration Membranes for Pre-treatment of Sea Water Reverse Osmosis and Studies on its Fouling behavior after Turbidity Removal from Sea Water

By : V. S. Mamtani, A. K. Ghosh, R. C. Bindal

Page No: 137-149

Abstract
In this study, polysulfone based capillary ultrafiltration membranes with desired characteristics were indigenously developed and their performance was evaluated with respect to turbidity removal from raw sea water. Capillary membranes were spun with in-house fabricated spinneret using polymer casting solution (dope solution) of different compositions having different viscosity using polyvinyl pyrrolidone (PVP) as pore-forming agent. Different experimental conditions namely dope pressure, bore fluid flow rate and air gap distance are optimized to get membranes of desired properties. Test results of individual capillaries in terms of pure water permeability (PWP), separation of single uncharged solutes like polyethylene glycol (PEG) and mechanical strength were discussed. Increase in dope pressure and air gap decreases PWP but increases the strength of the capillary membranes whereas addition of PVP in dope solution and increase in bore fluid flow rate has opposite effect on PWP and strength of the membrane. The optimum range of dope feed pressure was found 1-1.25 kg/cm2 with bore fluid flow rate of 25-30 ml/min and air gap of 12-15 cm. Selected membranes were tested for removal of turbidity from raw sea water with turbidity upto 120 NTU and the extent of turbidity removal was studied as a function of turbidity loading of sea water. The membranes were able to remove turbidity by more than 97.5%. After sea water filtration, the pure water flux recovery was evaluated on cleaning by backwashing using DI water.

Authors :
V. S. Mamtani
Membrane Development Section, Chemical Engineering Group, Bhabha Atomic Research Centre, Trombay, Mumbai, India.

A. K. Ghosh
Membrane Development Section, Chemical Engineering Group, Bhabha Atomic Research Centre, Trombay, Mumbai, India.

R. C. Bindal
Membrane Development Section, Chemical Engineering Group, Bhabha Atomic Research Centre, Trombay, Mumbai, India.
 

DOI: https://doi.org/10.32381/JPM.2022.39.1-2.9