ViroMineTM Technology - Background
The problem of surface water pollution from run-off at abandoned mines and spoil heaps has been well documented. Acidic and alkaline, metal-contaminated waters arise from inundation of mine workings and percolation of oxygenated rainwater through spoil heaps.
Extensive research has been conducted over the last 20 years into the most sustainable and cost-effective means of treating these wastewaters such that their discharge poses no detrimental impact upon the receiving environment. Both active and passive treatment methods have been developed, with the primary focus based on the removal of soluble iron, whereby treated waters can be discharged without impacting upon the pH of the water body or depositing insoluble iron oxyhydroxides as unsightly red deposits which have a smothering effect on the natural flora and fauna.
A number of approaches have been adopted for the treatment of these ferruginous waters. Passive treatment technologies have favoured the use of anoxic or oxic drains and wetlands. Active techniques have involved raising the pH of the target minewater, combined with an oxidation step to precipitate the soluble iron species. Although both techniques have shown successes, they also have disadvantages. The land requirement for most passive technologies can be prohibitively large. In addition, wetlands and reed beds have finite life spans of around 10 - 15 years, at which point the build-up of toxic sludge can prevent biological growth requiring bed replacement and disposal of sludge. Active treatment technologies involve the use of chemicals that are costly and hazardous. These processes also produce large volumes of caustic, hazardous sludge, which require off-site disposal.
Due to the inflexible characteristics of some of these technologies, and the unpredictable nature of groundwaters, legislative problems can develop. This will usually result in site discharge consents being breached at regular intervals, thereby preventing long term environmental sustainability.
Application of Virotec’s ViroMine™ Technology can reduce or even remove many of the problems associated with these conventional approaches.
