Water Purification by a Micelle-Clay Composite Alone and its Collaboration with other Technologies

Removal of chemicals and pathogenic microorganisms by filtration may provide safe drinking water, and decrease the risk from harmful disinfection by products. Micelle-clay complexes produced have a relatively large surface area, large hydrophobic fractions, and are positively charged to about half of the cation exchange capacity of the clay. Their material characteristics differ from those of organo-clays of the same composition, which are formed by adsorption of cations as monomers. Granulated micelle-clay composites (0.4 to 2mm) formed by the organic cation ODTMA (Octadecyltrimethylammonium), removed efficiently from water by filtration chemicals, such as herbicides, and dissolved organic matter, pharmaceuticals, perchlorate, and microorganisms, such as bacteria, viruses and a parasite, such as crytosporidium. Bacteria removed included (a) Escherichia coli S-17; (b) total bacteria count (TBC); and (c) Cyanobacteria (Microcystis and Aphanizomenon). A model which considered convection, adsorption, and desorption simulated the filtration results and yielded predictions. The emphasis in this minireview is on collaboration of this technology with other procedures, which may enhance treated water quality and reduce the costs of treatment. Thus a new approach intends to utilize both filtration and biocidal/biostatic activity of free cations in removal of microorganisms from water. A two stage purification of greywater by a moving bed reactor followed by a micelle-clay filter yielded an order of magnitude increase in the capacity of the filter. Water purification by filtration followed by solar photocatalysis enabled removal of recalcitrant molecules and indicator bacteria from secondary treated wastewater, thus yielding high quality water for irrigation. Other examples are reduction of membrane fouling of UF membranes and a suggested reduction of fouling of RO membranes by a pretreatment by the micelle-clay filter, or its combination with granulated activated carbon filter.