Daily Archives: August 27, 2012

Perchlorate removal from drinking water….a review

Ye, L., You, H., Yao, J., Su, H. Water treatment technologies for perchlorate: A review. Desalination, Volume 298, 16 July 2012, Pages 1–12

Perchlorate is not only a known health hazard for human but also one of the persistent inorganic pollutants. Some significant technologies have been carried out to remove or reduce perchlorate inwater. A comprehensive review about these technologies is presented, including adsorption, membrane filtration, ion-exchange (IX), biodegradation, chemical reduction, electrochemical reduction and bioelectrochemistry reduction. The mechanisms, influencing factors and practical applications of various technologies are discussed in detail. In particular, IX is the most effective technology for removing trace quantity perchlorate from drinking water, and biodegradation is suitable for large scalewastewater. Regrettably, there is no single technology that is perfect for complete perchlorate removal or reduction, although correlative studies are still in process. The integrated technologies, such as IX combined with biodegradation, may bring a glimmer of dawn and hope to the improvement of completely removing perchlorate from water.

Click here for the full paper (fee).

 

Aurora, Colorado wants 1-mile buffer around water reservoir

The City of Aurora Water Dept wants a 1-mile drilling buffer around Spinney Mountain Reservoir….to protect it from the perceived evils of oil and gas drilling…..

Colorado’s economy is essentially government union-controlled, with environmental activist groups opposing just about everything having to do with water resources development….so let the battles begin…..click here for more….  

Public support for seawater desalination rises in San Diego, California

“33 percent chose ocean water desalination as their main priority for diversification, up from 28 percent in 2011, and more than 80 percent said the process was important.”

Click here for the news report.

 

Plankton not at risk from ocean acidification

This study refutes the claims of the IPCC that plankton will not survive because of ocean acidification.

Nielsen, L.T., Hallegraeff, G.M., Wright, S.W., Hansen, P.J. Effects of experimental seawater acidification on an estuarine plankton community. Aquatic Microbial Ecology, 65:271-285 (2012) doi:10.3354/ame01554

The atmospheric CO2 concentration is rising, and models predict that by the end of the century it will have increased to twice the amount seen at any given time during the last 15 million yr. This will cause a decrease in average surface water pH of 0.4, and planktonic protists will be among the organisms to be affected first by this change. We tested whether reduced pH (and increased free CO2) would affect plankton communities over an incubation period of 14 d. In a laboratory microcosm setup using a natural plankton community from the Derwent River estuary, Australia, 2 treatments with reduced pH (8.0 and 7.7) were compared to an unaltered control of pH 8.3. An extreme pH 6.3 was included for comparison. Measured parameters included community photosynthesis, nutrient uptake and biomass build-up as well as enumeration of 25 protist taxa and quantitative HPLC of phytoplankton pigments. A major succession was seen during the 14 d, but no effects at all were found in pH treatments 8.0 and 7.7, whereas the extreme pH 6.3 clearly affected the community for all measured parameters. Thus, it is unlikely that the investigated plankton community would be significantly affected by a pH and CO2 change as predicted for the 21st century. This has previously been found for other coastal plankton assemblages as well, and we suggest that high pH resilience is a necessity for protist species living in coastal waters with relatively large pH fluctuations.

Click here for the full paper (fee).