Love that dirty water: Scientists find low-tech way to recycle H2O

May 24, 2010 By Tom Avril

Horticulturists at Pennsylvania State University have come up with a low-cost, green method for recycling so-called "gray" water -- the stuff from sinks, showers and washing machines that would otherwise go down the drain.

They filter the water through some and layers of crushed stone, peat moss and -- making it clean enough to reuse for growing vegetables or flushing toilets -- but not for drinking.

Using gray water is generally not allowed in the United States, but some states have explored the idea. The Penn State researchers hope their data -- which show such biofilters can remove almost all suspended solids, nitrogen compounds and other pollutants from gray water -- might lead to greater acceptance.

Meanwhile, such filters could be used in poor nations that lack adequate water for sanitation and irrigation, said Robert D. Berghage, associate professor of horticulture.

Robert Cameron, the doctoral student on the project, presented the research this month at a sustainable-farming meeting in Cuba.

The system consists of two plastic pipes filled with layers of porous rocks, soil, crumbs from discarded tires, composted cow manure and peat moss. Vegetables and other plants are planted in holes along the sides of the pipes.

The pipes stand in a basin with still more plants -- papyrus and horsetail reed -- whose roots support microbes that remove pollutants.

Each material in the pipes removes different contaminants, though the tire crumbs are there mainly as filler. Tire crumbs also contain contaminants, but tests showed they are not released into the water, Berghage says.

With enough treatment, you could even drink water that goes through such filters, Berghage says. He admits that this wouldn't gain wide acceptance, even though drinking-water plants already treat from rivers that receive treated waste.

"Most of us have this sort of aversion to drinking treated wastewater," he says, "even though much of the time we're doing it anyway."

Explore further: US delays decision on Keystone pipeline project

4.2 /5 (9 votes)
add to favorites email to friend print save as pdf

Related Stories

Roots meshed in waste materials could clean dirty water

May 05, 2010

Plant roots enmeshed in layers of discarded materials inside upright pipes can purify dirty water from a washing machine, making it fit for growing vegetables and flushing toilets, according to Penn State ...

Lead leaching and faucet corrosion in PVC home plumbing

Jun 02, 2008

Scientists in Virginia are reporting that home plumbing systems constructed with polyvinyl chloride (PVC) plastic pipes may be more susceptible to leaching of lead and copper into drinking water than other ...

What's in our water?

Nov 05, 2009

(PhysOrg.com) -- Although America's supply of drinking water is considered among the world's safest, there is an urgent need to develop more stringent regulations to guide how water is monitored for pollutants, ...

Human waste feeds rest stop greenhouse

Aug 31, 2005

A new Vermont highway rest stop has blue water in the toilets as part of a "green" system that uses tropical plants to cleanse and recycle sewage water.

Scrap tires can be used to filter wastewater

Nov 17, 2006

Every year, the United State produces millions of scrap tires that clog landfills and become breeding areas for pests. Finding adequate uses for castoff tires is a continuing challenge and illegal dumping has become a serious ...

Recommended for you

US delays decision on Keystone pipeline project

Apr 18, 2014

The United States announced Friday a fresh delay on a final decision regarding a controversial Canada to US oil pipeline, saying more time was needed to carry out a review.

New research on Earth's carbon budget

Apr 18, 2014

(Phys.org) —Results from a research project involving scientists from the Desert Research Institute have generated new findings surrounding some of the unknowns of changes in climate and the degree to which ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Shootist
1 / 5 (2) May 25, 2010
They filter the water through some plant roots and layers of crushed stone, peat moss and waste materials -- making it clean enough to reuse for growing vegetables or flushing toilets -- but not for drinking"


Oh, for heaven's sake. Septic tanks and drain fields have been doing this for centuries.

More news stories

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

UN weather agency warns of 'El Nino' this year

The UN weather agency Tuesday warned there was a good chance of an "El Nino" climate phenomenon in the Pacific Ocean this year, bringing droughts and heavy rainfall to the rest of the world.

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...