Virus Inactivation During Phosphate Precipitation

Phosphate removal from aqueous solutions by precipitation with calcium and aluminum results in large poliovirus Type I and bacteriophage T2 removals. Tests conducted in distilled water-phosphate solutions and filtered domestic wastewater effluent are described. The Freundlich isotherm is used to predict the removal of the two viruses from distilled water solutions. The pH during precipitation affects poliovirus removals. The mechanism of removal is believed to be mostly by chemical adsorption with some physical sorption occurring simultaneously. This is concluded from the inability to recover all viruses from the sludge. The sludge represents a potential health hazard and must be carefully handled. Virus removals are greater in distilled water-phosphate solutions than in wastewater treatment plant effluent. Results are extended to full scale treatment plants indicating that virus removals in excess of 98% and 92% may be expected from precipitation processes using aluminum or calcium, respectively.