Alumina Removes Water Contaminants

Water treatment technology based on activated alumina can provide long-term safe water supplies in highly contaminated areas.

 Is your tap water safe to drink? That was a difficult question to answer if you lived in the City of Andrews in West Texas. Alumina has made the city’s water supply safe to drink, but it took some time.

The story began in March, when the Environment Integrity Project, a Washington DC–based organization that lobbies for the enforcement of environmental regulation, posted an online article stating that 34 water supply systems in rural Texas exceed the arsenic limits stipulated by the federal authorities, and had been doing so over the past 10 years. The City of Andrews was one of the guilty parties.

It transpired that, like many places, City of Andrews fell foul of America’s tightening environmental regulations, which are far stricter than their equivalent regulations in Europe. In 2002, the Texas Commission on Environmental Quality, a state agency that collates data on environmental matters, reported that the City of Andrews’ water supply had approximately 30 parts per billion of arsenic content, a concentration regarded at the time as safe.

But in 2006 the federal standards changed with the introduction of the Federal Safe Drinking Water Act. This dropped the safe upper arsenic concentration limit to 10 from an earlier limit of 50 parts per billion.

State officials in Texas were left with the task of finding some kind of technology to improve water quality so that it complied with the new federal standards.

The result was a $5.5 million prototype water treatment project that involved injecting activated alumina into the ground around water wells at high speeds. The alumina acts as a filter and can remove any excesses of fluoride as well as arsenic from the ground. The result is a superior quality of drinking water that has no traces of arsenic.

The engineers involved on this project claim that the treatment will work over the coming 75 to 100 years and provide continuous safe drinking water.

Ceramics such as alumina have a high resistance to abrasion and corrosion and so make ideal conduits for filtering water supplies that contain aggressive chemicals. They are superior to metals in this case, as the metal could react with the contaminants and produce further toxicity in the water supply.

Feel free to contact julesblain@multi-lab.co.uk  if you have any questions.

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