Older filters, fresher water

Nov 26, 2007

Scientists in Australia have discovered that the older the water filter the better when it comes to reducing the off-putting earthy taste of some tap water. Writing in the Inderscience publication International Journal of Environment and Waste Management, the team explains how bacteria that grow on particles in a sand filter effectively extract the compounds that produce the taste.

Natural earthy and musty smells in our drinking water are not usually a health risk, but many consumers prefer a fresher taste. This represents an ongoing challenge to the water companies.

"Although adverse odors do not present a risk to human health, their presence often leads to a misconception that the water is unsafe for drinking," explains Gayle Newcombe, Research Leader at the Applied Chemistry Unit of the Australian Water Quality Centre in Salisbury, South Australia.

She and her colleagues have investigated the effect of sand filters in extracting the most common earthy molecules, geosmin and methylisoborneol, from the water supply. These two compounds occur naturally in water and are non-toxic.

Newcombe and her colleagues at the Australian Water Quality Centre and Bridget McDowall in the School of Chemical Engineering at The University of Adelaide have now demonstrated that they can remove geosmin and MIB using biologically active sand filters. In such filters, the particles of sand are allowed to accumulate a biological film of beneficial bacteria that absorb and break down the biodegradable odor molecules.

The team tested sand filter material taken from working water treatment plants. They found that sand taken from a 26-year old filter had a well-established biofilm and was able to remove any detectable traces of geosmin and MIB in less than two weeks. Fresh filter sand with no biofilm, in contrast, was essentially ineffective, removing less than two-thirds of the geosmin and MIB even after several months of operation.

The team is now investigating how to accelerate the development of active biofilms for water purification.

Source: Inderscience Publishers

Explore further: Rising anger as Nicaragua canal to break ground

add to favorites email to friend print save as pdf

Related Stories

Scientists study stormwater, deadly to salmon

Nov 17, 2014

A team of researchers is running experiments this fall to understand what happens when salmon are exposed to rain runoff collected from one of Seattle's busiest highways.

Water purification at the molecular level

Oct 30, 2014

(Phys.org) —Fracking for oil and gas is a dirty business. The process uses millions of gallons of water laced with chemicals and sand. Most of the contaminated water is trucked to treatment plants to be ...

Better water supply in Karst areas

Oct 13, 2014

Drinking water is scarce in the Indonesian region of Gunung Kidul. In this karst area, rainwater quickly drains away into the ground. It accumulates in an underground cave system and flows into the ocean ...

Environmental bridge over troubled waters

May 08, 2013

A breakthrough innovation designed to purify water through the rapid removal of oily pollutants, could have major environmental benefits in agriculture and manufacturing industries.

Recommended for you

Rising anger as Nicaragua canal to break ground

8 hours ago

As a conscripted soldier during the Contra War of the 1980s, Esteban Ruiz used to flee from battles because he didn't want to have to kill anyone. But now, as the 47-year-old farmer prepares to fight for ...

Hopes, fears, doubts surround Cuba's oil future

Dec 20, 2014

One of the most prolific oil and gas basins on the planet sits just off Cuba's northwest coast, and the thaw in relations with the United States is giving rise to hopes that Cuba can now get in on the action.

New challenges for ocean acidification research

Dec 19, 2014

Over the past decade, ocean acidification has received growing recognition not only in the scientific area. Decision-makers, stakeholders, and the general public are becoming increasingly aware of "the other carbon dioxide ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.