Zapping water with electricity could save your life.
Not something you thought we’d ever say?
We’re shocked, too.
By introducing an electric current into lead pipes filled with a harmless phosphate solution
researchers at UC Berkeley were able to rapidly form a protective coating around corroded
lead pipes, reducing leaching of this toxic element by roughly 99%.
Lead exposure is a huge public health issue, according to The World Health Organization.
Paint and dust laced with lead are the most common sources of exposure, but contaminated
water is another big issue.
In the U.S. alone, over 5,000 water systems violate the EPA’s Safe Drinking Water Act,
placing an estimated 18 million people at risk.
And lead poisoning is no joke.
This chemical element (Pb) can accumulate in our body over time, leading to kidney damage,
reduced IQ, increased risk of cancer, stroke, and even death.
That’s all thanks to lead’s sneaky ability to mimic and inhibit calcium, break through
the blood-brain barrier, and result in the misfiring of neural signals, impairing our
ability to learn and develop.
Evidence suggests that ancient Romans knew their lead pipes were poisonous, but lead’s
dangers weren’t widely re-discovered until the period of industrialization in the 19th
century, when reports of lead poisoning began to pick up.
Decades of subsequent scientific investigation and their damming findings eventually prompted
many governments to distance themselves from sources of lead, like gasoline additives,
paint, and piping material, which was favored as a durable and long-lasting material well
into the 20th century.
But it takes time to redo the plumbing of entire cities, as was made painfully clear
when taps in Flint, Michigan began dispensing lead-contaminated water to residents in 2014.
One sample even had lead levels reaching 13,200 parts per billion!
So...we’re stuck with all this lead-laden water.
Now what?
Water doesn’t contain much lead on its own, but it can be corrosive.
Once in contact with lead pipes, it can breakdown the metal and cause leaching.
To prevent this, inorganic phosphates are commonly added to public water supplies, where
they react with positively charged lead ions to form a protective, insoluble mineral scale
on the inside of pipes.
. But without maintaining tight control of the chemistry, that coating is quickly eaten
away.
To fix a water supply that’s turned toxic, pipe replacement is by far the best solution,
but it’s extremely costly and slow.
Case in point: it took two years after Flint’s water crisis erupted for the city’s roughly
170 million dollar pipe replacement program to break ground.
And as of 2019, roughly 2,500 lines still need replacement.
So is there a better way to zap the situation?
ASHOK: In our work, we ask the question, "what can we do to rapidly stop a leaching lead
pipe so that the drinking water that passes through it will become safe all over again?"
The team specializes in drinking water treatment using electrochemistry, which is the science
of looking at how electricity interacts with materials.
It starts by introducing a threaded wire down the inside of a lead pipe into a tank of water
filled with phosphates, then switching on an electric circuit.
At first, the voltage causes lead ions to leach into the water, but as these ions react
with the phosphates, they begin to form insoluble lead phosphate.
Searching for somewhere to deposit, these minerals begin to settle on the lead pipe
itself.
ASHOK: As the lead phosphate lines the inside of the lead pipe for a given voltage, less
and less current can flow because the lead pipe becomes non-conducting...that's how we
know that our process is working.We can reduce the leaching of lead from those pipes by a
factor of about 150.
We have not tested it yet in the field, but we have a solution that works.
Their preliminary results found that once a charge is introduced, a mineral barrier
can accumulate on the pipe wall in less than 2 hours, effectively decreasing lead leaching
by ~99%.
Any part of the lead pipe that’s left uncoated, the current self-tunes to go where it needs
to go.
As for cost, it’s cheap.
There is also a sense of public responsibility in fixing the problem...replacing a pipe costs
about 100 dollars a foot if you fold in all the costs.
Our goal is to bring that cost down to, maybe, three dollars a foot.
Water chemistry varies by a lot.We haven't explored all that space of unknowns...to say
"oh yeah, we got the silver bullet.
We need to test it out, but we are ready to do that very soon we think.
If all goes well, the team plans to try their technique in nearby schools as early as this
year.
Once refined, this technology could act as a vital stopgap until communities are able
to replace lead pipes, as that ultimately remains the best solution.
And maybe a 5-star filter for your water tap.
Are you excited about this research to stop this toxin from polluting our tap?
Let us know in the comments below, and don’t forget to subscribe for more Seeker.
I’ll see you next time, thanks for watching.