Environmental Science: Processes & Impacts blog

This HOT article from Orsolya Klebercz and co-workers from Hungary and the UK discusses the ecotoxicity of fluvial sediments that resulted from the spillage of bauxite processing residue (red mud) in Ajka, Hungary.

The team carried out physico-chemical analyses on a number of samples taken from sites downstream of the spill. Biological characterisation and ecotoxicity testing was also carried out on a number of test species, including the Vibrio fischeri luminescence inhibition test, the Sinapis alba root and shoot growth inhibition test and the Heterocypris incongruens mortality test.

Adverse effects were recorded across a range of trophic levels at the different sample sites, although the microbial activity was shown to have increased. Lemna minor was shown to be a useful test species when assessing the impact of red mud contamination.

Read more about the study here – the paper is free to access for 4 weeks:

Ecotoxicity of fluvial sediments downstream of the Ajka red mud spill, Hungary
Orsolya Klebercz, William M. Mayes, Áron Dániel Anton, Viktória Feigl, Adam P. Jarvis and Katalin Gruiz
DOI: 10.1039/C2EM30155E

Researchers at the University of Toronto, Canada, have evaluated the Ambient Ion Monitor-Ion Chromatograph (AIM-IC) system’s performance and accuracy for the measurement of the water-soluble chemical composition of atmospheric fine particulate matter (PM_2.5).

The team, led by Jennifer Murphy, determined the system’s detection limits for gas phase NH_3(g), SO_2(g), and HNO_3(g) and particle phase NH₄⁺, SO₄²⁻, and NO₃⁻. The group also evaluated the system for response time to changing compound concentrations, with a variety of different membranes.

Read more about the study here – the paper is free to access for 4 weeks:

Characterization and optimization of an online system for the simultaneous measurement of atmospheric water-soluble constituents in the gas and particle phases
Milos Z. Markovic, Trevor C. VandenBoer and Jennifer G. Murphy
DOI: 10.1039/C2EM00004K

This critical review, written by Michael Dodd from the University of Washington, focuses on the role that wastewater treatment plants play in the removal of antibiotic resistance genes from the wastewater to stop the spread of antibiotic resistant bacteria to non-resistant communities.

Although most treatments inactivate antibiotic resistant bacteria, stopping horizontal gene transfer processes, antibiotic resistance genes can be left in cell debris in the water, allowing natural transformation and/or transduction of the DNA into non-resistant bacteria. The review introduces these topics and processes fully (along with their environmental implications), and describes five common wastewater treatments, along with their effects on antibiotic resistant bacteria and antibiotic resistance genes.

Potential impacts of disinfection processes on elimination and deactivation of antibiotic resistance genes during water and wastewater treatment
Michael C. Dodd
DOI: 10.1039/C2EM00006G

This HOT article is free to access for the next four weeks following a simple registration for individual users.

Scientists at Colorado State University, USA, have performed statistical analysis on publicly available data relating to in situ recovery uranium mining at a Wyoming mine to evaluate the efficacy of groundwater sweep remediation with reverse osmosis and H₂S (chemical reductant) treatment, and also to evaluate the time needed for site stabilization and the immobilization of target contaminants.

The team concluded that groundwater sweep remediation, combined with reverse osmosis treatment, provided a very good level of remediation. Additional chemical reductant treatment did not appear to improve the contaminant levels. With regards to the immobilization of target contaminants, the team believe that natural attenuation is likely to be the major factor in immobilizing residual concentrations, stopping them from moving outside the mined area. Additional studies are needed to collect more data to improve the understanding of the environmental impacts of the different remediation techniques.

Determination of contaminant levels and remediation efficacy in groundwater at a former in situ recovery uranium mine
Thomas Borch, Nicholas Roche and Thomas E. Johnson
DOI: 10.1039/C2EM30077J

This HOT article is free to access for the next four weeks following a simple registration for individual users.

The first HOT paper this week comes from Yuefeng Xie and colleagues at The Pennsylvania State University. They investigated the effect that treatment at watewater treatment plants (WWTPs) had on disinfection by-product (DBP) precursors. Eight different WWTPs were studied, and an additional plant that carries out two biological treatment processes was also investigated as a comparative study. The level of DBP precursors was established in the wastewater of each WWTP, and this was then compared to the levels after the processing had occurred. Amongst other results, they found that WWTPs that removed the most organic matter and accomplished better nitrification resulted in lower disinfection by-product formation potentials in the effluent. They state the study can be used by water and wastewater professionals to ‘better control wastewater-derived DBPs in downstream potable water supplies’.

Disinfection by-product formation potentials in wastewater effluents and their reductions in a wastewater treatment plant
Hao L. Tang, Yen-Chih Chen, John M. Regan and Yuefeng F. Xie
DOI: 10.1039/C2EM00015F

The second HOT paper comes from Tomei Gianfranco and co-workers at the University of Rome. They measured blood benzene and two urinary acid levels in traffic policemen, police drivers and roadmen. Benzene exposure was higher for urban workers than the general population and comparable in non-smoker traffic policemen and police drivers, and was increased in (non-smoker) urban workers when compared to rural workers. There was significant correlation in the levels of airborne benzene and blood benzene in non-smoker urban workers.

Environmental and biological monitoring of benzene in traffic policemen, police drivers and rural outdoor male workers
Ciarrocca Manuela, Tomei Francesco, Caciari Tiziana, Capozzella Assunta, Scimitto Lara, Nardone Nadia, Andreozzi Giorgia, Scala Barbara, Fiaschetti Maria, Cetica Carlotta, Di Giorgio Valeria, Schifano Maria Pia, Tomei Gianfranco and Sancini Angela
DOI: 10.1039/C2EM30120B

Both these papers are free to access for 4 weeks following a simple registration for individual users.