Top ten most accessed ES:P&I articles in Q1 2014

This month sees the following articles in Environmental Science: Processes & Impacts that are in the top ten most accessed January – March:-

Human exposure to aluminium 
Christopher Exley 
Environ. Sci.: Processes Impacts, 2013,15, 1807-1816
DOI: 10.1039/C3EM00374D  
  
A review with recent advancements on bioremediation-based abolition of heavy metals 
Nisha Gaur, Gagan Flora, Mahavir Yadav and Archana Tiwari    
Environ. Sci.: Processes Impacts, 2014,16, 180-193
DOI: 10.1039/C3EM00491K  
  
Iron nanoparticles for environmental clean-up: recent developments and future outlook 
Weile Yan, Hsing-Lung Lien, Bruce E. Koel and Wei-xian Zhang    
Environ. Sci.: Processes Impacts, 2013,15, 63-77
DOI: 10.1039/C2EM30691C  
  
The role of indirect photochemical degradation in the environmental fate of pesticides: a review 
Dr Christina Keenan Remucal 
Environ. Sci.: Processes Impacts, 2014,16, 628-653
DOI: 10.1039/C3EM00549F  
  
Temporal trend studies on polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in ringed seals from East Greenland 
Frank Rigét, Katrin Vorkamp, Rune Dietz and Suresh C. Rastogi    
J. Environ. Monit., 2006,8, 1000-1005
DOI: 10.1039/B609522D  
 
Identification of polymer types and additives in marine microplastic particles using pyrolysis-GC/MS and scanning electron microscopy 
Elke Fries, Jens H. Dekiff, Jana Willmeyer, Marie-Theres Nuelle, Martin Ebert and Dominique Remy    
Environ. Sci.: Processes Impacts, 2013,15, 1949-1956
DOI: 10.1039/C3EM00214D  
  
Quantitation of persistent organic pollutants adsorbed on plastic debris from the Northern Pacific Gyre’s “eastern garbage patch” 
Lorena M. Rios, Patrick R. Jones, Charles Moore and Urja V. Narayan    
J. Environ. Monit., 2010,12, 2226-2236
DOI: 10.1039/C0EM00239A  
 
Planning for sustainability in China’s urban development: Status and challenges for Dongtan eco-city project 
Hefa Cheng and Yuanan Hu    
J. Environ. Monit., 2010,12, 119-126
DOI: 10.1039/B911473D  
 
Impact of metallic and metal oxide nanoparticles on wastewater treatment and anaerobic digestion 
Yu Yang, Chiqian Zhang and Zhiqiang Hu    
Environ. Sci.: Processes Impacts, 2013,15, 39-48
DOI: 10.1039/C2EM30655G  
 
Silver nanoparticles in the environment 
Su-juan Yu, Yong-guang Yin and Jing-fu Liu    
Environ. Sci.: Processes Impacts, 2013,15, 78-92
DOI: 10.1039/C2EM30595J  

Why not take a look at the articles today and blog your thoughts and comments below.

Fancy submitting an article to Environmental Science: Processes & Impacts? Then why not submit to us today or alternatively email us your suggestions.

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Free access to HOT articles

These HOT articles were recommended by our referees and are free to access for 4 weeks*

Structural characterization of dissolved organic matter: a review of current techniques for isolation and analysis
Elizabeth C. Minor, Michael M. Swenson, Bruce M. Mattson and Alan R. Oyler  
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C4EM00062E, Critical Review

Graphical abstract: Structural characterization of dissolved organic matter: a review of current techniques for isolation and analysis

Energy positive domestic wastewater treatment: the roles of anaerobic and phototrophic technologies
B. D. Shoener, I. M. Bradley, R. D. Cusick and J. S. Guest  
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00711A, Critical Review

Graphical abstract: Energy positive domestic wastewater treatment: the roles of anaerobic and phototrophic technologies

Air quality concerns of unconventional oil and natural gas production
R. A. Field, J. Soltis and S. Murphy  
Environ. Sci.: Processes Impacts, 2014,16, 954-969
DOI: 10.1039/C4EM00081A, Perspective

Graphical abstract: Air quality concerns of unconventional oil and natural gas production

Radiocesium derived from the Fukushima Daiichi Nuclear Power Plant accident in seabed sediments: initial deposition and inventories
Shigeyoshi Otosaka and Yoshihisa Kato  
Environ. Sci.: Processes Impacts, 2014,16, 978-990
DOI: 10.1039/C4EM00016A, Paper

Graphical abstract: Radiocesium derived from the Fukushima Daiichi Nuclear Power Plant accident in seabed sediments: initial deposition and inventories

*Free access to individuals is provided through an RSC Publishing personal account. It’s quick, easy and more importantly – free – to register!

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Shedding light on the degradation of black carbon in surface waters

By Ian Keyte, Doctoral Researcher at University of Birmingham and web writer for the Royal Society of Chemistry Environmental Team

Degradation by sunlight is an important sink for black carbon in surface waters. This study by researchers at University of Michigan and Old Dominion University in Norfolk, Virginia demonstrates how partial degradation of condensed aromatic compounds is the primary mechanism for this process.


The predicted frequency of wildfire activity during the 21st century will lead to increased production of black carbon (BC) in the environment. The recalcitrant nature of BC means it displays a relatively long residence time in soils, thus constituting a key sink for atmospheric CO2.

Abiotic and microbial degradation of condensed aromatics of BC in soils can lead to transfer of water-soluble BC components to surface waters, as well as particulate BC. This will expose both particulate and dissolved BC components to degradation by sunlight.  The condensed aromatic component of BC in surface waters can be photo-oxidized either completely, forming CO2 or partially, forming compounds no longer be detected as BC.

Identifying the contribution of complete and partial BC photodegradation is key to understanding the extent and speed to which CO2 is returned to the carbon cycle. To date no study has investigated the relative importance of these two competing reaction pathways in surface waters. This study by Collin Ward and co-workers represents the first quantitative assessment of partial vs. complete photoxidation of BC in dissolved and particulate phases.

Previously, degradation of condensed aromatics has investigated using FT-ICR-MS or detection of molecular markers such as benzene polycarboxylic acids (BPCAs). However this approach cannot distinguish between complete and partial oxidation.

In this study, aqueous suspensions of particulate BC (BC-p) and solutions of dissolved BC (BC-d) were prepared from charring of arctic biomass, mimicking BC produced from wildfires. These were exposed to natural sunlight in a 17 hour exposure experiment. Complete and partial oxidation were quantified by monitoring CO2 production and O2 consumption using a dissolved inorganic carbon (DIC) analyser and membrane inlet mass spectrometer (MIMS) respectively.

Complementing this approach, the study also investigated the shift in chemical/optical properties of BC during exposure using UV-Vis absorbance, fluorescence spectroscopy and FT-ICR-MS. Results were assessed relative to dark control tests.

Results indicate BC-d in surface waters was disproportionately more susceptible to photooxidation than BCp, based on O2 consumption and CO2 production during exposure. It was shown that 8-13% of the C in BC-d was photo-mineralized to CO2 while 68-91% was partially oxidized to compounds that remained in solution.

Following exposure to sunlight the majority of identified molecules in the mass spectra were aliphatics (85%) with smaller amounts of condensed aromatics (10%) and aromatics (5%), while in dark controls, most identified compounds were condensed aromatics, suggesting these compounds are being partially oxidised primarily. Indeed, 89% of the condensed aromatics identified in dark controls were absent from the mass spectrum following exposure.

Furthermore, the average O/C of aromatics was shown to decrease for aromatics and aliphatics but increase for condensed aromatics remaining after photooxidation, suggesting condensed aromatics are more susceptible to oxidation.

These results strongly suggest sunlight is a key sink for BC in surface waters and that condensed aromatics are the class of compound primarily involved in these photo-reactions. However, the primary reaction pathway involved partial oxidation to less aromatic photoproducts with unknown susceptibility to further degradation. The authors highlight that there is a need to further investigate the reactivity of BC photoproducts to understand the role of sunlight as a sink for BC in the wider geochemical system.

To downloads the full article for free* click the link below:

Insights into the complete and partial photooxidation of black carbon in surface waters

Collin P. Ward, Rachel L. Sleighter, Patrick G. Hatcher, and Rose M. Cory
DOI: 10.1039/c3em00597f

*Access is free untill 23.04.14 through a registered RSC account – click here to register

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Free access to HOT articles

These HOT articles were recommended by our referees and are free to access for 4 weeks*

Bayesian uncertainty assessment of a semi-distributed integrated catchment model of phosphorus transport
Jostein Starrfelt and Øyvind Kaste
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00619K, Paper

Graphical abstract: Bayesian uncertainty assessment of a semi-distributed integrated catchment model of phosphorus transport

Blending remote sensing data products to estimate photochemical production of hydrogen peroxide and superoxide in the surface ocean
Leanne C. Powers and William L. Miller
Environ. Sci.: Processes Impacts, 2014,16, 792-806
DOI: 10.1039/C3EM00617D, Paper

Graphical abstract: Blending remote sensing data products to estimate photochemical production of hydrogen peroxide and superoxide in the surface ocean

Wavelength and temperature-dependent apparent quantum yields for photochemical formation of hydrogen peroxide in seawater
David J. Kieber, Gary W. Miller, Patrick J. Neale and Kenneth Mopper
Environ. Sci.: Processes Impacts, 2014,16, 777-791
DOI: 10.1039/C4EM00036F, Paper

Graphical abstract: Wavelength and temperature-dependent apparent quantum yields for photochemical formation of hydrogen peroxide in seawater

Modelling phosphorus loading and algal blooms in a Nordic agricultural catchment-lake system under changing land-use and climate
Raoul-Marie Couture, Koji Tominaga, Jostein Starrfelt, S. Jannicke Moe, Øyvind Kaste and Richard F. Wright
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00630A, Paper

Graphical abstract: Modelling phosphorus loading and algal blooms in a Nordic agricultural catchment-lake system under changing land-use and climate

Association of nuisance filamentous algae Cladophora spp. with E. coli and Salmonella in public beach waters: impacts of UV protection on bacterial survival
Aubrey Beckinghausen, Alexia Martinez, David Blersch and Berat Z. Haznedaroglu
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00659J, Paper

Graphical abstract: Association of nuisance filamentous algae Cladophora spp. with E. coli and Salmonella in public beach waters: impacts of UV protection on bacterial survival

Degradation of organic pollutants in/on snow and ice by singlet molecular oxygen (1O*2) and an organic triplet excited state
Jonathan P. Bower and Cort Anastasio
Environ. Sci.: Processes Impacts, 2014,16, 748-756
DOI: 10.1039/C3EM00565H, Paper

Graphical abstract: Degradation of organic pollutants in/on snow and ice by singlet molecular oxygen (1O*2) and an organic triplet excited state

Estimating hydroxyl radical photochemical formation rates in natural waters during long-term laboratory irradiation experiments
Luni Sun, Hongmei Chen, Hussain A. Abdulla and Kenneth Mopper
Environ. Sci.: Processes Impacts, 2014,16, 757-763
DOI: 10.1039/C3EM00587A, Paper

Graphical abstract: Estimating hydroxyl radical photochemical formation rates in natural waters during long-term laboratory irradiation experiments

The importance of charge-transfer interactions in determining chromophoric dissolved organic matter (CDOM) optical and photochemical properties
Charles M. Sharpless and Neil V. Blough
Environ. Sci.: Processes Impacts, 2014,16, 654-671
DOI: 10.1039/C3EM00573A, Critical Review

Graphical abstract: The importance of charge-transfer interactions in determining chromophoric dissolved organic matter (CDOM) optical and photochemical properties

A critical assessment of the photodegradation of pharmaceuticals in aquatic environments: defining our current understanding and identifying knowledge gaps
Jonathan K. Challis, Mark L. Hanson, Ken J. Friesen and Charles S. Wong
Environ. Sci.: Processes Impacts, 2014,16, 672-696
DOI: 10.1039/C3EM00615H, Critical Review

Graphical abstract: A critical assessment of the photodegradation of pharmaceuticals in aquatic environments: defining our current understanding and identifying knowledge gaps

*Free access to individuals is provided through an RSC Publishing personal account. It’s quick, easy and more importantly – free – to register!

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Grazing the surface of agricultural effects on water quality – impacts of in-stream cattle activity

By Ian Keyte, Doctoral Researcher at University of Birmingham and web writer for the Royal Society of Chemistry Environmental Team

The presence of cattle in close proximity to water courses can influence pollution levels in both direct and in-direct means. This study by researchers at Lancaster University reveals how these impacts can be best understood using simultaneous monitoring of both physical movement of cattle and water quality parameters.

Livestock farming in close proximity to streams can influence water quality in numerous ways. For example enhanced bank-side erosion and removal of vegetation can result in mobilization of sediments into water courses and increase turbidity. However, uncertainty exists regarding the extent to which the physical movement of cattle into and within the stream bed influences sediment resuspension and contribute to water quality degradation.

Previous studies assessing in-stream cattle impacts have focussed on short-term controlled events and often do not differentiate between bank-side and in-stream activity. The irregular behaviour of cattle means there is a need for high–frequency and simultaneous monitoring of cattle in-stream movement and water quality parameters over  sufficiently long periods.  This investigation by Julie Terry and co-workers at the Lancaster Environment Centre, UK attempts to assess the temporal relationship between physical in-stream activity of cattle and the level water quality.

This study investigated the physical movement of cattle in a stream and the impacts on suspended solid concentration (SSC) and observing a ‘signal response’ in an unfenced stretch of river in Cumbria, north-west England over a 4 month period. This involved the use of high resolution monitoring data derived using motion capture camera surveillance, taking over 31,000 images. At the same time, high resolution water quality data including turbidity (converted to SSC), water level and flow rate were also monitored.

It was shown that for the days when cattle were grazing nearby, of the instances that SSC exceeded 25 mg/l (the Freshwater Fish Directive guidance threshold), 58% could be attributed to the presence of cattle. However, only 3.6% of total sediment load in the stream was directly caused by cattle in-stream activity. Flow is still the main factor influencing total sediment transported, with cattle contributing a much smaller proportion. No relationship was noted between SSC response and absolute number of cattle feet in the water, attributed to the episodic nature of cattle-related sediment disturbances and the variability in stream flow.

Hysteresis analysis (modelling the relationship between concentration levels and discharge) demonstrated a lag time between the presence of cows in the stream and a critical amount of their contribution to SSC  with a reoccurring ‘first-flush’ of sediment created from non-cattle activity.  It was indicted, however that cattle can also provide considerable contribution indirectly e.g. due to erosion of stream banks.

Don’t let this work go in one ear and out the udder. It demonstrates the impact cattle can have on water quality in unprotected and unmonitored stretches of river and indicates the need for best practice measures for livestock management need to be adhered to closely in order to reduce maintain the ecological status of water courses. The authors have demonstrated the need for high-resolution monitoring data is to best understand and mitigate against these dangers and also outline directions for further work to compliment these results.

To access the full HOT Article for free*, click the link below:

Temporal dynamics between cattle in-stream presence and suspended solids in a headwater catchment
Julie A. Terry, Clare McW.H. Benskin, Emma F. Eastoe and Philip M. Haygarth
Environ. Sci.: Processes Impacts, 2014,
DOI: 10.1039/C3EM00686G

*Access is free for the next 4 weeks through a registered RSC account – click here to register

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Free access to HOT articles

These HOT articles were recommended by our referees and are free to access for 4 weeks*

Assessing the effect of phosphate and silicate on Cd bioavailability in soil using an Escherichia coli cadAp::luc-based whole-cell sensor
Qi-Hui Hou, An-Zhou Ma, Ye Li, Xu-Liang Zhuang, Zhi-Hui Bai, Xin-Ke Zhang and Guo-Qiang Zhuang  
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00598D, Paper

Graphical abstract: Assessing the effect of phosphate and silicate on Cd bioavailability in soil using an Escherichia coli cadAp::luc-based whole-cell sensor
Insights into the complete and partial photooxidation of black carbon in surface waters
Collin P. Ward, Rachel L. Sleighter, Patrick G. Hatcher and Rose M. Cory  
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00597F, Paper

Graphical abstract: Insights into the complete and partial photooxidation of black carbon in surface waters
Temporal dynamics between cattle in-stream presence and suspended solids in a headwater catchment
Julie A. Terry, Clare McW.H. Benskin, Emma F. Eastoe and Philip M. Haygarth  
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00686G, Paper

Graphical abstract: Temporal dynamics between cattle in-stream presence and suspended solids in a headwater catchment
Outdoor passive air monitoring of semi volatile organic compounds (SVOCs): a critical evaluation of performance and limitations of polyurethane foam (PUF) disks
P. Bohlin, O. Audy, L. Škrdlíková, P. Kukučka, P. Přibylová, R. Prokeš, Š. Vojta and J. Klánová  
Environ. Sci.: Processes Impacts, 2014,16, 433-444
DOI: 10.1039/C3EM00644A, Paper

Graphical abstract: Outdoor passive air monitoring of semi volatile organic compounds (SVOCs): a critical evaluation of performance and limitations of polyurethane foam (PUF) disks
Photometric hydroxyl radical scavenging analysis of standard natural organic matter isolates
J. E. Donham, E. J. Rosenfeldt and K. R. Wigginton  
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00663H, Paper

Graphical abstract: Photometric hydroxyl radical scavenging analysis of standard natural organic matter isolates

Remedy performance monitoring at contaminated sediment sites using profiling solid phase microextraction (SPME) polydimethylsiloxane (PDMS) fibers
Courtney Thomas, David Lampert and Danny Reible  
Environ. Sci.: Processes Impacts, 2014,16, 445-452
DOI: 10.1039/C3EM00695F, Paper

Graphical abstract: Remedy performance monitoring at contaminated sediment sites using profiling solid phase microextraction (SPME) polydimethylsiloxane (PDMS) fibers
Cluster analysis of passive air sampling data based on the relative composition of persistent organic pollutants
Xiande Liu and Frank Wania  
Environ. Sci.: Processes Impacts, 2014,16, 453-463
DOI: 10.1039/C3EM00605K, Paper

Graphical abstract: Cluster analysis of passive air sampling data based on the relative composition of persistent organic pollutants

Critical review of electrochemical advanced oxidation processes for water treatment applications
Brian P. Chaplin  
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00679D, Critical Review

Graphical abstract: Critical review of electrochemical advanced oxidation processes for water treatment applications
 
Kinetics of heterogeneous reactions of ozone with representative PAHs and an alkene at the air–ice interface at 258 and 188
K D. Ray, H. Lišková and P. Klán  
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00665D, Paper

Graphical abstract: Kinetics of heterogeneous reactions of ozone with representative PAHs and an alkene at the air–ice interface at 258 and 188 K

*Free access to individuals is provided through an RSC Publishing personal account. It’s quick, easy and more importantly – free – to register!

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Free access to HOT articles!

These HOT articles were recommended by our referees and are free to access for 4 weeks*

The role of indirect photochemical degradation in the environmental fate of pesticides: a review
Christina K. Remucal
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00549F, Critical Review 

Automated method for determining the flow of surface functionalized nanoparticles through a hydraulically fractured mineral formation using plasmonic silver nanoparticles
Samuel J. Maguire-Boyle, David J. Garner, Jessica E. Heimann, Lucy Gao, Alvin W. Orbaek and Andrew R. Barron
Environ. Sci.: Processes Impacts, 2014,16, 220-231
DOI: 10.1039/C3EM00718A, Paper 

Elevated risk from estrogens in the Yodo River basin (Japan) in winter and ozonation as a management option
Vimal Kumar, Seiya Hanamoto, Andrew C. Johnson, Naoyuki Yamashita, Norihide Nakada and Hiroaki Tanaka
Environ. Sci.: Processes Impacts, 2014,16, 232-238
DOI: 10.1039/C3EM00219E, Paper 

Evaluation of DGT as a long-term water quality monitoring tool in natural waters; uranium as a case study
Geraldine S. C. Turner, Graham A. Mills, Michael J. Bowes, Jonathan L. Burnett, Sean Amos and Gary R. Fones
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00574G, Paper 

Nanoscale zero-valent iron (nZVI) for the treatment of concentrated Cu(II) wastewater: a field demonstration
Shaolin Li, Wei Wang, Weile Yan and Wei-xian Zhang
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00578J, Paper

*Free access to individuals is provided through an RSC Publishing personal account. It’s quick, easy and more importantly – free – to register!

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Fireworks and the spread of particulate matter

A detailed study on the spatiotemporal distribution of atmospheric pollutants arising from the wide scale use of fireworks has been carried out by scientists in China, with a view to highlighting related environmental and health concerns.

Fireworks and firecrackers are used extensively across the globe in all manner of celebrations, though few match the sheer scale of Chinese New Year. They generate a variety of contaminants, including gasses such as carbon monoxide, sulphur dioxide and nitrogen oxide, in addition to aerosols of microparticles known as particulate matter.

Read the full article for free!

Study on spatial and temporal distributions of contaminants emitted by Chinese New Year’ Eve celebrations in Wuhan
Ge Han, Wei Gong, Jihong Quan, Jun Li and Miao Zhang  
Environ. Sci.: Processes Impacts, 2014, Accepted Manuscript
DOI: 10.1039/C3EM00588G, Paper

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Bio-cathodes : powering towards clean water, energy and biomass production

Published on behalf of Ian Keyte, Doctoral Researcher, University of Birmingham, and web writer for Environmental Science: Processes & Impacts

The use of passive biocathodes could potentially hold the key to producing an environmentally sustainable approach for achieving combined waste water treatment and water desalinization, researchers at Mississippi State University have indicated.

Current world population now exceeds 7 billion. As this number continues to grow, so does the demand for fresh water resources. Ensuring access to clean water supplies is now a major priority across the planet. A key factor governing this is the approach taken to achieve effective wastewater treatment and water desalination.

Wastewater treatment is commonly achieved through activated sludge treatment utilising biochemical reaction and physical separation, while desalination can be achieved through thermal evaporation or membrane separation. However, both of these approaches are intensive in terms of cost and energy usage and also emit CO2. There is a need to develop methods where external energy consumption is minimized and energy recovery can be optimized.

Microbial desalination cells (MDCs) are a recent technological innovation where simultaneous wastewater treatment and desalination are achieved. In such bioelectrochemical cells, chemical catholytes such as ferricyanide are commonly used. However, these are not suitable for large-scale usage due to the prohibitive cost, large energy demands and environmental toxicity issues.

Another option is to use air-cathodes, which utilize oxygen as a thermal electron acceptor. However, these can suffer from slower redox kinetics, requiring the use of expensive catalysts, and large energy requirements to maintain aeration levels. A more sustainable and financially viable approach could therefore be to use biological cathodes, which utilise microorganisms as biocatalysts.


In this study by Bahareh Kokabian and Veera Gnaneswar Gude, which featured as the cover article for Issue 12, Vol 15 of ESPI, the performance of an MDC with a conventional air-cathode and a photosynthetic microbial desalination cell (PMDC) utilising the microalgae Chlorella vulgaris were evaluated for their performance in terms of COD removal, desalination and energy generation from sewage sludge. This represents the first study of its kind to be attempted.

Fig 1. Schematic of the photosynthetic microbial desalination cell system with algal biocathode

The results indicate that PMDCs can perform better than air-cathodes and as well as other conventional MDCs. COD removal of 66% and 57% were measured for the PMDC and air-cathode MDC respectively. Desalination rates were also enhanced, with levels of 40% measured for the PMDC and 24% for the air-cathode MDC.

Maximum voltage produced was higher for the PMDC (0.236 V) than for the air-cathode MDC (0.219 V). Moreover, the PMDC produces longer, more stable voltage, unlike conventional cathodes where potential reduction occurs after a time. Furthermore, it was shown that only 55% of the cathode volume was utilised, indicating that power production and desalination rates could be further improved if the MDC reactor design and electrode/material configuration are optimized.


Algae biocathodes in PMDCs provide the advantage of a continuous supply of electron acceptors and omit the need for additional chemical transport, storage, dosing, and post-treatment. The biochemical nature of the process also means the wastewater is essentially treated as a growth medium, producing valuable algal biomass, which could be used to obtain constructive products such as biogas, biohydrogen and biofuels.

This study therefore demonstrates that the use of PMDCs can provide an environmentally benign approach to wastewater treatment in which algae act as an in situ generator of oxygen. This has the potential to be beneficial in enhancing environmental and economic sustainability of water treatment whilst helping to improve COD removal, desalination and energy recovery in the same process.


This HOT paper is available to download through the following link:
Photosynthetic microbial desalination cells (PMDCs) for clean energy, water and biomass production, Bahareh Kokabian and Veera Gnaneswar Gude. DOI: 10.1039/c3em00415e

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Free to access HOT articles!

These HOT articles were recommended by our referees and are free to access for 4 weeks*

Priority organic compounds in wastewater effluents from the Mediterranean and Atlantic basins of Andalusia (Spain)
Nieves Barco-Bonilla, Roberto Romero-González, Patricia Plaza-Bolaños, José Luis Martínez Vidal, Antonio J. Castro, Isabel Martín, Juan José Salas and Antonia Garrido Frenich  
Environ. Sci.: Processes Impacts, 2013,15, 2194-2203
DOI: 10.1039/C3EM00329A, Paper

Graphical abstract: Priority organic compounds in wastewater effluents from the Mediterranean and Atlantic basins of Andalusia (Spain)
Photosynthetic microbial desalination cells (PMDCs) for clean energy, water and biomass production
Bahareh Kokabian and Veera Gnaneswar Gude  
Environ. Sci.: Processes Impacts, 2013,15, 2178-2185
DOI: 10.1039/C3EM00415E, Paper

Graphical abstract: Photosynthetic microbial desalination cells (PMDCs) for clean energy, water and biomass production

Environmental specimen banks as a resource for mercury and mercury isotope research in marine ecosystems
Rusty D. Day, Paul R. Becker, Olivier F. X. Donard, Rebecca S. Pugh and Stephen A. Wise  
Environ. Sci.: Processes Impacts, 2014,16, 10-27
DOI: 10.1039/C3EM00261F, Perspective

Graphical abstract: Environmental specimen banks as a resource for mercury and mercury isotope research in marine ecosystems

Effects of pretreatment on the denaturation and fragmentation of genomic DNA for DNA hybridization
Xiaofang Wang and Ahjeong Son  
Environ. Sci.: Processes Impacts, 2013,15, 2204-2212
DOI: 10.1039/C3EM00457K, Paper

Graphical abstract: Effects of pretreatment on the denaturation and fragmentation of genomic DNA for DNA hybridization

Neutral polyfluoroalkyl substances in the global Atmosphere
A. Gawor, C. Shunthirasingham, S. J. Hayward, Y. D. Lei, T. Gouin, B. T. Mmereki, W. Masamba, C. Ruepert, L. E. Castillo, M. Shoeib, S. C. Lee, T. Harner and F. Wania  
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00499F, Paper

Graphical abstract: Neutral polyfluoroalkyl substances in the global Atmosphere
Assessment of environmentally persistent free radicals in soils and sediments from three Superfund sites
Albert Leo N. dela Cruz, Robert L. Cook, Barry Dellinger, Slawomir M. Lomnicki, Kirby C. Donnelly, Matthew A. Kelley and David Cosgriff  
Environ. Sci.: Processes Impacts, 2014,16, 44-52
DOI: 10.1039/C3EM00428G, Paper

Graphical abstract: Assessment of environmentally persistent free radicals in soils and sediments from three Superfund sites

Internal transcribed spacer rRNA gene sequencing analysis of fungal diversity in Kansas City indoor environments
William R. Rittenour, Christina E. Ciaccio, Charles S. Barnes, Michael L. Kashon, Angela R. Lemons, Donald H. Beezhold and Brett J. Green  
Environ. Sci.: Processes Impacts, 2014,16, 33-43
DOI: 10.1039/C3EM00441D, Paper

Graphical abstract: Internal transcribed spacer rRNA gene sequencing analysis of fungal diversity in Kansas City indoor environments

Field calibration of low density polyethylene passive samplers for gaseous POPs
Mohammed A. Khairy and Rainer Lohmann  
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00493G, Paper

Graphical abstract: Field calibration of low density polyethylene passive samplers for gaseous POPs

Bubble bursting as an aerosol generation mechanism during an oil spill in the deep-sea environment: laboratory experimental demonstration of the transport pathway
Franz S. Ehrenhauser, Paria Avij, Xin Shu, Victoria Dugas, Isaiah Woodson, Thilanga Liyana-Arachchi, Zenghui Zhang, Francisco R. Hung and Kalliat T. Valsaraj  
Environ. Sci.: Processes Impacts, 2014,16, 65-73
DOI: 10.1039/C3EM00390F, Paper

Graphical abstract: Bubble bursting as an aerosol generation mechanism during an oil spill in the deep-sea environment: laboratory experimental demonstration of the transport pathway

Bubble bursting as an aerosol generation mechanism during an oil spill in the deep-sea environment: molecular dynamics simulations of oil alkanes and dispersants in atmospheric air/salt water interfaces
Thilanga P. Liyana-Arachchi, Zenghui Zhang, Franz S. Ehrenhauser, Paria Avij, Kalliat T. Valsaraj and Francisco R. Hung  
Environ. Sci.: Processes Impacts, 2014,16, 53-64
DOI: 10.1039/C3EM00391D, Paper

Graphical abstract: Bubble bursting as an aerosol generation mechanism during an oil spill in the deep-sea environment: molecular dynamics simulations of oil alkanes and dispersants in atmospheric air/salt water interfaces

Evaluation of a novel personal nanoparticle sampler
Yue Zhou, Hammad Irshad, Chuen-Jinn Tsai, Shao-Ming Hung and Yung-Sung Cheng  
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00497J, Paper

Graphical abstract: Evaluation of a novel personal nanoparticle sampler

APEX (Aqueous Photochemistry of Environmentally occurring Xenobiotics): a free software tool to predict the kinetics of photochemical processes in surface waters
Marco Bodrato and Davide Vione  
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00541K, Paper

Graphical abstract: APEX (Aqueous Photochemistry of Environmentally occurring Xenobiotics): a free software tool to predict the kinetics of photochemical processes in surface waters

A review with recent advancements on bioremediation-based abolition of heavy metals
Nisha Gaur, Gagan Flora, Mahavir Yadav and Archana Tiwari  
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00491K, Critical Review

Graphical abstract: A review with recent advancements on bioremediation-based abolition of heavy metals

Leaching potential of metallic elements from contaminated soils under anoxia
Ramona Balint, Gheorghe Nechifor and Franco Ajmone-Marsan  
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00546A, Paper

Graphical abstract: Leaching potential of metallic elements from contaminated soils under anoxia

Testing flow-through air samplers for use in near-field vapour drift studies by measuring pyrimethanil in air after spraying
Trudyanne S. Geoghegan, Kimberly J. Hageman and Andrew J. Hewitt  
Environ. Sci.: Processes Impacts, 2014, Advance Article
DOI: 10.1039/C3EM00498H, Paper

Graphical abstract: Testing flow-through air samplers for use in near-field vapour drift studies by measuring pyrimethanil in air after spraying
*Free access to individuals is provided through an RSC Publishing personal account. It’s quick, easy and more importantly – free – to register!

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)