A university research project has demonstrated how protective phosphate scaling of lead pipes can be accelerated by running an electric charge through the pipe.
An environmental engineer and a graduate student at the University of California, Berkeley, designed a project to run a negative wire inside a lead pipe and send a positive charge through the pipe itself while pumping phosphate-treated water. The reaction saw lead ions shed from the pipe into the water where they attached to positively charged phosphate ions to form lead-phosphate scale.
The scale then accumulated on the pipe wall and in a matter of hours, reduced the amount of lead leaching into the water by 99 percent, the researchers said. Typical phosphate scaling can take months to effectively coat a pipe.
Although the process applied to new pipes would not result in water that meets the federal limit for acceptable lead levels of 15 ppb, it is intended to treat existing lead water lines that already have phosphate scaling, they said.
Presenting the results of his research at this year’s American Chemical Society annual meeting, UC-B grad student, Gabriel Lobo, said the process would help restore in-place water systems such as in Flint, MI, without having to excavate domestic water lines.
Following the Flint drinking water crisis in 2016, a study by the National Resource Defense Council estimated 17 million Americans are at a similar risk of drinking leadcontaminated water.