Monday, May 5, 2014

Australia - Sewer Corrosion - Bringing science to the sewers, a collaborative research work of five research and 11 industry partners coordinated by Advanced Water Management Centre, University of Queensland

It is a smelly problem with serious financial and environmental consequences. But a University of Queensland-led research project could spell the end for stinky sewers. And by dispelling the smell, researchers have cut down on the major cause of sewer corrosion, saving councils and utility companies hundreds of millions of dollars.

Led over five years by Professor Zhiguo Yuan from UQ's Advanced Water Management Centre and involving five research and 11 industry partners, including engineers, microbiologists, material scientists, analytical chemists and mathematical modellers, the team have won the 2014 International Water Association Asia Pacific Regional Project Innovation Award for applied research. While the generation of hydrogen sulphide was known to be a major cause of odour and corrosion, dealing with it was another matter. Which is why engagement and business development manager for the UQ Advanced Water Management Centre, Sandra Hall, said it was necessary to bring “science to the sewers”.

“It was about knowledge generation in the beginning, and understanding the problem,” Dr Hall said. “Once they understood the problem, it was about applying logic and reason and coming up with a solution.“What UQ has also done is develop tools and computer models so that utilities and asset owners can monitor what is happening in their sewers and be able to apply those chemicals that they used to reduce bio films and odour corrosion problems in the right place at the right time, so that it makes the process more efficient, more effective for the asset owner.

Article Source:
Publication Date: 27April2014

Thursday, May 1, 2014

India - Water Contamination - Schoolkids on Guwahati fringes drink acidic water

GUWAHATI: In an alarming find, the state public health and engineering department (PHED) and an NGO said schoolchildren in the tribal belt along the outskirts of the city have been consuming water, which is highly acidic in nature and unfit for drinking. The source of the water for these children is a well.

A little over five per cent of the samples were found to contain iron above the permissible limit of 0.3 mg/l. The survey pointed out that long time consumption of water with a high concentration of iron could lead to liver diseases. The test was conducted to ascertain the availability of pure drinking water to the students in the Rani-Deepor Beel-Gorchuk belt bordering Meghalaya by NGO Eco Concept in collaboration with PHED.

Apart from the high pH value, the survey also found the levels of hardness, turbidity, residual chlorine, iron and bacteria high in the water. Of the 1,052 water samples tested across 129 villages, 202 or 19.20% were found to have pH above 7 while 33 samples or 3.13% had pH above 8.5 limits, which is considered unsuitable for drinking. "The pH value is a measure of the intensity of alkali or acid in water. A high value of pH hastens scale formation in water-heating apparatus and reduces the germicidal potential of chlorine. A pH level below 6.5 leads to corrosion in pipes thereby releasing toxic metals," the report said. Only 549 samples or 52.18% of the total samples were found to have pH levels within permissible limits of 6.5 to 8.5 pH. Absolutely pure water has a pH value of 7.0.

Four different schools were selected for the tests on different days. The samples were taken to the school by students from their homes. Free chlorine concentration (0.1-0.4 ppm) is usually maintained in municipal water. Only 222 samples tested had free chlorine concentration. Use of proper chemicals in the water source can improve the quantity of free chlorine concentration in water, which is essential for good health.

On the other hand, 90 samples had a turbidity range of 10 Nephelometric Turbidity Unit and 56 samples had turbidity of 25 NTU. The report said samples above 10 NTU should be filtered before consumption. Samples in 96 containers tested positive for bacterial contamination. Gorchuk had the highest number of samples testing positive for bacterial contamination followed by Pamohi.

Article Source:
Publication Date: 30 April 2014