Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cleansing toxic waste -- with vinegar

04.03.2009
Engineers and environmental scientists at the University of Leeds are developing methods of helping contaminated water to clean itself by adding simple organic chemicals such as vinegar.

The harmful chromium compounds found in the groundwater at sites receiving waste from former textiles factories, smelters, and tanneries have been linked to cancer, and excessive exposure can lead to problems with the kidneys, liver, lungs and skin.

The research team, led by Dr Doug Stewart from the School of Civil Engineering and Dr Ian Burke from the School of Earth and Environment, has discovered that adding dilute acetic acid (vinegar) to the affected site stimulates the growth of naturally-occurring bacteria by providing an attractive food source. In turn, these bacteria then cleanse the affected area by altering the chemical make-up of the chromium compounds to make them harmless.

"The original industrial processes changed these chemicals to become soluble, which means they can easily leach into the groundwater and make it unsafe, says Dr Burke. "Our treatment method reconverts the oxidised chromate to a non-soluble state, which means it can be left safely in the ground without risk to the environment. As it is no longer 'bio-available' it doesn't present any risk to the surrounding ecosystem."

Chromate chemicals have previously been successfully treated in situ in neutral Ph conditions, but this study is unique in that it concentrates on extremely alkaline conditions, which are potentially much more difficult to treat.

The current favoured method of dealing with such groundwater contaminants is to remove the soil to landfill, which can be costly, both financially and in terms of energy usage. The Leeds methods being developed will allow treatment to take place on site, which is safer, more energy efficient and much cheaper.

Dr Stewart says: "Highly alkaline chromium-related contaminants were placed in inadequate landfill sites in the UK right up until production stopped in the 1970's – and in some countries production of large quantities of these chemicals still continues today. The soluble and toxic by-products from this waste can spread into groundwater, and ultimately into local rivers, and therefore will remain a risk to the environment as long as they are untreated."

Current environmental regulations mean that before the team can test out its research findings in the field, they need water-tight proof that their methods can work, as it is illegal to introduce any substance into groundwater - even where it is contaminated - unless it has been shown to be beneficial.

"From the results we have so far I am certain that we can develop a viable treatment for former industrial sites where chromate compounds are a problem," says Dr Stewart. "Our next step is to further our understanding of the range of alkalinity over which our system can operate. As society becomes more environmentally-aware, new regulations demand that past mistakes are rectified and carbon footprints are reduced. By designing a clean-up method that promotes the growth of naturally occurring bacteria without introducing or engineering new bacteria, we are effectively hitting every environmental target possible."

The research, part funded by The Royal Society, is published online in the Journal of Ecological Engineering doi:10.1016/j.ecoleng.2008.12.028.

Jo Kelly | EurekAlert!
Further information:
http://www.leeds.ac.uk

More articles from Ecology, The Environment and Conservation:

nachricht Joint research project on wastewater for reuse examines pond system in Namibia
19.12.2016 | Technische Universität Darmstadt

nachricht Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>