Catalytic Partial Desalination of Saline Water

Abstract

More than 1 billion ha of land is adversely affected by salinization, including about 54 million ha of irrigated cropland. This study trials a batch flow, bubble column, static bed, catalytic, pressure swing adsorption−desorption, zero valent iron, and diffusion reactor train, which is designed to partially desalinate water, for use as either livestock feed water or partially desalinated irrigation water. ZVI desalination produces a partially desalinated water product, without producing a waste brine product. The trial demonstrates sequential batch processing of 50 (0.86 m3) batches of saline water (43 m3 total), using a single ZVI charge, without loss of activity. The trialed feed water contained between 1 and 9 g NaCl L−1. The average desalination was 41.84% (standard deviation was 15.61%). The optimum batch processing time is determined as being between 12 and 24 h. For each batch, the first-order forward rate constants, for both Cl− and Na+ ion removal, decline with time. The study considers the irrigation application of the product water on crop yield for 70 crop varieties; the application of the technology to desalinate a saline aquifer; applications of the technology to improve the environmental efficiency of conventional desalination plants.