(168g) Designing Clay-Polyelectrolyte Hybrid Membranes for Effluent Treatment

Authors: 
Sanyal, O., Michigan State University
Liu, Z., Michigan State University
Meharg, B., Michigan State University
Liao, W., Michigan State University
Hong, J. S., Soongsil University
Lee, I., Michigan State University

In this study, clay-polyelectrolyte composite membranes were employed for reducing the COD level of an electrocoagulation—treated high strength effluent. A few recent studies have shown the incorporation of Montmorrillonite (MMT) clay nanoplatelets within polyelectrolyte multilayers for developing desalination membranes with high permeability. However, most of these studies involved lab-based synthetic solutions constituting mainly the target ion, for testing these membranes. These solutions fail to emulate the complexities involved in actual wastewater solutions. In our research we showed, for the first time, the application of these composite membranes to treating real effluents. This involved the selection of the appropriate substrate as well as the appropriate polyelectrolyte combination. The number of bilayers deposited and the pH of the polyelectrolytes used were also tweaked in order to get the best combination of high permeability as well as high COD removal. This complex effluent system also presented an opportunity to test the fouling propensity of these hybrid systems in presence of the various types of natural organic matters present in the solution. The performance of these membranes were compared with commercial nanofiltration and reverse osmosis membranes as well as pure polyelectrolyte-based membranes in terms of permeability, removal and anti-fouling property. Our results show that these hybrid membranes show lower flux decline over a given period of time than the remaining membranes, rendering them highly permeable as well as fouling resistant.