In new research scientists at MIT have demonstrated the possibility of selective, continuous and cost-effective removal of lead from water, a long-standing and elusive goal in environmental engineering, due to the toxic nature of heavy metal contaminants in drinking water.
The use of lead pipes in plumbing has been phased out in most countries since the 1960’s, but lead piping has not been replaced everywhere, and in some countries lead contamination is a feature of drinking water supplies.
Recently controversies have arisen in the United States over water infrastructure that has reached or surpassed its lifespan. Most notably in Flint, Michigan, a water quality crisis emerged when it was identified that children had high levels of lead in their blood as a result of inadequate water sourcing and treatment.
US national water quality standards prescribe maximum levels of lead in drinking water to protect public health, which is often achieved through relatively costly techniques such as reverse osmosis. These techniques are effective but are not selective, also removing elements such as magnesium and sodium which are naturally present in healthy mineral water.
The new research has demonstrated the feasibility of selectively removing lead from contaminated water while only partly removing sodium. The results were achieved by producing an electric shockwave through porous material containing the water, and then separating the pure water from the brine. The process has been shown to remove 95 Percent of dissolved lead in the sample water, reducing concentrations to safe levels below 1 part per billion.
It is expected that further research will be needed to enable the scaling up of the technology from laboratory conditions to its application in water treatment facilities.