Boron Treatment Alternatives for CCR Porewater, Leachate and Groundwater

摘要

This paper summarizes water treatment technologies available for boron and the benefits and limitations of each. Boron is a naturally-occurring element found at variable concentrations in ambient soil and groundwater, as well as in coal, coal combustion residuals (CCR), and ash leachate. Additionally, it is a common constituent in agricultural drainage in some areas of the west. Its predominant form at neutral pH in groundwater is as the uncharged complex [B(OH)_3~0], which is mobile in groundwater, but complexation with metal or organic cations can result in sorption or precipitation. Reverse osmosis, ion exchange, sorption (with or without complexation), precipitation, and electrocoagulation are widely utilized methods to remove boron from groundwater and industrial wastewaters. Electrodeionization is an emerging technology that is currently in development. Our paper discusses recent advances in boron removal technologies, including treatment strategies that result in the generation of a usable boron product that is not classified as a waste and can be reused as a plant fertilizer. Based on a review of Guan et al. (2016) and other more current papers cited herein, we conclude that ion exchange systems utilizing boron-selective resins represent the most promising technology available for boron removal from groundwater.