Sparingly Soluble Constant Carbonate Releasing Inert Monolith for Enhancement of Antimicrobial Silver Action and Sustainable Utilization

Abstract

Silver, a metal with phenomenal commercial importance has been exploited in its ionic form in the field of water purification, with the objective of delivering microbially safe drinking water. Silver released at such concentrations is unrecoverable and has to be reduced to ensure sustainable utilization of the metal. We have shown that small concentrations of carbonate can effectively bring down the amount of silver ion used for microbial disinfection by half. Implementation of this finding requires constant carbonate releasing materials in natural water for extended period. In this work, we describe a hybrid material with intrinsically high stability in water, prepared using naturally abundant ingredients which releases carbonate constantly and in a controlled fashion. This composition in conjunction with reduced silver ion concentration delivers mircobially safe water, tested with E.coli and MS2 phage. Use of constant carbonate releasing material for antimicrobial applications can reduce the unrecoverable silver released into the environment by ~1,300 tons/year. We also show that the composition can be modified to release cations of choice without disturbing the CO32- release from the same. A sustained release of selective cations along with carbonate can supplement drinking water with the minerals of interest.