Environmental Science: Processes & Impacts blog

With enteric viruses as emerging waterborne pathogens improved methods for detection and quantification in environmental samples are needed. Adelaide Almeida and colleagues employed ultracentrifugation with epifluorescence microscopy in this increasingly important area of analysis.

Check out the details and read the article – FREE to access for 4 weeks.

Ultracentrifugation as a direct method to concentrate viruses in environmental waters: virus-like particle enumeration as a new approach to determine the efficiency of recovery

Catarina Prata, Andreia Ribeiro, Ângela Cunha, Newton. C. M. Gomes and Adelaide Almeida
J. Environ. Monit., 2012, Advance Article
DOI: 10.1039/C1EM10603A, Paper

Choosing the right sorbent materials for passive air samplers is vital for monitoring persistent organic pollutants (POPs) over long time periods. Jasmin Schuster and Kevin Jones from the University of Lancaster joined forces with colleagues from the Meteorological Service of Canada and Environment Canada to test out passive samplers in a year-long field study.

Discover what they found out and read the article  – FREE to access for 4 weeks.

Assessment of sorbent impregnated PUF disks (SIPs) for long-term sampling of legacy POPs

Jasmin K. Schuster, Rosalinda Gioia, Tom Harner, Sum Chi Lee, Knut Breivik and Kevin C. Jones
J. Environ. Monit., 2012, Advance Article
DOI: 10.1039/C1EM10697J, Paper

A national picture for river aluminium levels in England and Wales has been revealed by researchers at Lancaster University and the Centre for Ecology and Hydrology in Wallingford, UK. Aluminium can have toxic effects in rivers particularly in the Al3+ form and 54 river sites in rural, agricultural and urban locations were involved in the study.

The work by Paul Scholefield and colleagues showed, for example, that for mid Wales there are limited declines in aluminium following acidification recovery, and unexpected variations for organic and colloidal aluminium. Among other findings the study has highlighted the need for further investigation of the hydrogeochemical ecotoxicological relevance of colloidal aluminium.

Read the full article here

Aluminium in UK rivers: a need for integrated research related to kinetic factors, colloidal transport, carbon and habitat
Colin Neal, Philip Rowland, Margaret Neal, Helen P. Jarvie, Alan Lawlor, Darren Sleep and Paul Scholefield
J. Environ. Monit., 2011, Advance Article
DOI: 10.1039/C1EM10362H, Paper

Lorena Rios and colleagues at the University of the Pacific in Stockton, California, USA, have
found that floating plastic debris in the ocean adsorbs pollutants found in the water. Pollutants including PCB’s(polychlorinated byphenyls) in marine environments normally tend to accumulate in sediments. This research, however, shows that plastic debris acts like a floating version of sediments – absorbing and concentrating pollutants from seawater.

Plastic debris from the Pacific Ocean

Plastic pollution is a big issue because plastic materials do not readily biodegrade. They remain a
source of toxins (including endocrine disruptors) to marine organisms over a long period. Considerable challenges lie ahead to address this problem: “The dangers of ingestion of contaminated plastic by marine creatures is an important but difficult message to convey to the general public” explains Rios.

Find out more from the full article

Zero-valent iron microparticles that include an organic component efficiently destroy carbon tetrachloride in soil, say US scientists.

Carbon tetrachloride was used in pesticides, degreasers, fire-extinguishers and for dry cleaning until it was banned in the US in the 1970’s due to concerns about its cancer causing properties and the effect on the environment. Continuous applications, such as protecting grain in storage, contaminated the surface soil and as it is a very persistent compound it can find its way into the local drinking water source so clean-up processes are very important.

Modified iron microparticles clear up soil

Nanoparticles of zero-valent iron (ZVI) have been considered for in situ remediation of carbon tetrachloride, but complex degradation mechanism means that often not all the carbon tetrachloride is reduced to harmless products and toxic compounds such as chloroform are produced.

Now Jorge Alvarado and colleagues at the Argonne National Laboratory have investigated the use of modified zero-valent iron microparticles that include a controlled release carbon component. The organic component of the microparticles is nutrient rich, hydrophilic has a high surface area capable of supporting the growth of bacteria in the groundwater environment, explains Alvarado. Processes induced by the bacteria growth, such as production of volatile fatty acids that can act as electron donors, support the degradation reaction, making it more efficient.

‘The main advantages of this method are the combination of microbiological and physical effects that create the conditions needed [to destroy the carbon tetrachloride],’ says Alvarado. ‘Concentrations of carbon tetrachloride in our laboratory studies decreased by more than 90%.’ Additionally, field studies carried out in a highly contaminated area in Kansas showed concentrations dropped to below regulatory levels after 16 months of observation.

Tom Mallouk, an expert in the use of nanoscale materials for environmental remediation, comments ‘this is an interesting study that shows the effectiveness of zero-valent iron for remediation of carbon tetrachloride, both in the laboratory and in a field test.’

Alvarado says there are still many challenges in this research area, including understanding the mechanism and how the different processes involved interact to create the conditions needed to destroy the carbon tetrachloride, understanding the effectiveness of the zero-valent iron product for long distances and improving application techniques in aquifer systems.

Read the full article.