Featured Research

from universities, journals, and other organizations

Hot Microbes Cause Groundwater Cleanup Rethink

Date:
September 24, 2009
Source:
CSIRO Australia
Summary:
Australian researchers have discovered that micro-organisms that help break down contaminants under the soil can actually get too hot for their own good.

Schematic showing how biosparging enhances the microbial degradation of contaminants.
Credit: Willem van Aken / Courtesy of CSIRO Australia

CSIRO researchers have discovered that micro-organisms that help break down contaminants under the soil can actually get too hot for their own good.

While investigating ways of cleaning up groundwater contamination, scientists examined how microbes break down contaminants under the soil’s surface and found that subsurface temperatures associated with microbial degradation can become too hot for the microbes to grow and consume the groundwater contaminants.

This can slow down the clean up of the groundwater and even continue the spread of contamination.

The new findings mean that researchers now have to rethink the way groundwater remediation systems are designed.

CSIRO Water for a Healthy Country Flagship scientist Mr Colin Johnston, who is based in Perth, Western Australia, said the researchers were investigating how temperatures below the soil’s surface could be used as an indicator of the microbial degradation process associated with biosparging.

Biosparging is a technique that injects air into polluted groundwater to enhance the degradation of contaminants.

The contaminants are ‘food’ to the microbes and the oxygen in the air helps the microbes unlock the energy in the food so that they metabolise and grow, consuming more contaminants and stopping the spread of the contamination.

“Observations of diesel fuel contamination showed that, at 3.5 metres below the ground surface, temperatures reached as high as 47 C,” Mr Johnston said.

“This is close to the 52 C maximum temperature tolerated by the community of micro-organisms that naturally live in the soil at this depth and within the range where the growth of the community was suppressed.”

The growth of the soil’s micro-organism community can also be helped by adding nutrients.

However computer modelling confirmed that any attempts to further increase degradation of the contamination through the addition of nutrients had the potential to raise temperatures above the maximum for growth.

“Although increasing the flow of air would reduce temperatures and overcome these limitations a fine balance needs to be struck as the injected air can generate hazardous vapours that overwhelm the micro-organisms leading to unwanted atmospheric emissions at the ground surface,” Mr Johnston said.

“This would be particularly so for highly volatile compounds such as gasoline.

“It appears that prudent manipulation of operating conditions and appropriate timing of nutrient addition may help limit temperature increases.”

Mr Johnston said further research was required to better understand the thermal properties in the subsurface as well as the seasonal effects of rainfall infiltration and surface soil heating.


Story Source:

The above story is based on materials provided by CSIRO Australia. Note: Materials may be edited for content and length.


Cite This Page:

CSIRO Australia. "Hot Microbes Cause Groundwater Cleanup Rethink." ScienceDaily. ScienceDaily, 24 September 2009. <www.sciencedaily.com/releases/2009/09/090918100006.htm>.
CSIRO Australia. (2009, September 24). Hot Microbes Cause Groundwater Cleanup Rethink. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2009/09/090918100006.htm
CSIRO Australia. "Hot Microbes Cause Groundwater Cleanup Rethink." ScienceDaily. www.sciencedaily.com/releases/2009/09/090918100006.htm (accessed July 28, 2014).

Share This




More Plants & Animals News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com
Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Newsy (July 28, 2014) The asteroid that killed the dinosaurs struck at the worst time for them. A new study says that if it hit earlier or later, they might've survived. Video provided by Newsy
Powered by NewsLook.com
Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) Video provided by AP
Powered by NewsLook.com
Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Newsy (July 27, 2014) The satellite is back under ground control after a tense few days, but with a gecko sex experiment on board, the media just couldn't help themselves. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins