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VIROTEC 06 November 2009 VIROTEC GLOBAL SOLUTIONS
Treating Contaminated Stormwater
Virotec Global Solutions today released a new Technical Data Sheet summarising its recent work in treating stormwater. The Technical Data Sheet, which is available for download from Virotec’s web site (http://www.virotec.com/viroflow.shtml), highlights the work the company has conducted in Australia.
Dr Lee Fergusson, Virotec’s Chief Executive Officer and principal author of the Technical Data Sheet, noted that “stormwater is a significantly under-estimated source of urban and rural contamination. This Technical Data Sheet introduces the enormous impact stormwater has on our environment, and also summarises the work Virotec has conducted in a number of industries to address it.”
As Dr Fergusson pointed out, stormwater is often contaminated with heavy metals, such as lead, and almost always with phosphorus. The heavy metals in stormwater originate on highways or industrial sites, and the phosphorus comes from farm runoff. Both contribute significantly to the pollution of surface and ground water. The widespread dispersal of phosphorus from sewage effluent, industrial wastewater, detergents, and stormwater run-off from urban and agricultural land has played a major part in the eutrophication of freshwater and marine ecosystems in many parts of the world.
An example of the problems associated with polluted stormwater can be seen in a March 2008 issue of the Los Angeles Times and the Santa Monica Daily Press which both carried articles on lawsuits that have been filed by the National Resources Defense Council and other environmental groups against Los Angeles County and the City of Malibu. According to reports, concentrations of fecal bacteria, heavy metals, and other pollutants associated with stormwater runoff from Los Angeles and Santa Monica exceed water quality guidelines. It appears that the lawsuit is designed to compel Los Angeles County and the city of Malibu to better manage and treat urban stormwater runoff to prevent violations of water quality standards in coastal waters that receive the runoff.
The Technical Data Sheet presents results which indicate that ViroFlow™ Technology can have a profoundly beneficial affect on stormwater quality. One example is at a large lead smelter in London. This large lead smelter represents a “classic” example of why stormwater attenuation and treatment is a potential problem in industrial, urban areas. The site is covered with large processing plants and factories, and the outer areas of the site were covered with vast open areas of impermeable roadways and concrete pads. Even regular rainfall, not to mention heavy storm events, can cause a problem at the site, because the atmosphere and surfaces of the site can be laden with lead dust particles. Lead, being a potentially dangerous element to human health, is constantly monitored by the Environment Agency at the perimeter of the site.
Rainwater that accumulates on the site must be captured and adequately treated to stringent limits before being discharged into the neighbouring River Thames. Rainwater (and stormwater runoff), and any collected debris and lead particulate matter, are directed via a series of gutters and channels to two large holding bays, where it is pumped to a dam. Stormwater that was collected in the dam is then pumped through a gravity-fed ViroFlow™Technology filtration system to remove heavy metals and adjust pH downward. Water is pumped to the head of the filter and allowed to feed slowly through the pelletised filter matrix. Water is dispersed evenly across the head of the filter via a rotating distribution arm and is discharged at the bottom of the filter system.
Results from the application indicate that ViroFlow™ Technology is effective in treating acidity and heavy metals, such as arsenic, lead, cadium and zinc, in the stormwater prior to discharge into the River Thames. For example, arsenic was reduced from 9.3 parts per million before ViroFlow™ Technology to 0.49 parts per million after treatment. Similarly, lead was 4.5 parts per million before treatment and only 0.06 parts per million after treatment.
These results mean that any number of large-scale industries now has a viable and cost-effective solution for treating their contaminated stormwater, and thereby operate within their approved discharge limits.
For further information please contact: Daniel Blair +61 7 5573 3373
VIROTEC GLOBAL SOLUTIONS www.virotec.com |
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