The 12th International Conference on Environmental ... - Events

Session 62 Abstracts
SESSION 62 - RECENT DEVELOPMENTS IN ER TECHNOLOGIES
1) THE DEVELOPMENT OF METALLISED MEMBRANES FOR ANALYTICAL SEPARATION PROCESSES - 16069
Michael A Bromley, John Tyndall Institute for Nuclear Research (UK); Colin Boxall, University of Lancaster (UK);
Sarah Galea, John Tyndall Institute for Nuclear Research (UK);
Jonathan Francis, University of Central Lancashire (UK)
Fast, controllable and selective separation of metal ions from complex solutions plays a key role in a wide range of activities
including; chemical analysis, environmental monitoring, environmental remediation, metal recycling, desalination and process control,
to name but a few. <strong>The</strong>se activities are in turn encountered in a wide range of industries including; the nuclear, pharmaceutical,
mining, foodstuffs, power generation and wastewater processing industries.
Novel, surface-metallised, ion-selective membranes are being developed for use in the separation and preparation of pure isolates
of a range of metal ions prior to their analysis. Passage of ions through the membranes will be controlled by the application
of an electric field across the membrane. <strong>The</strong>se metallised membranes will to be used as the principle component of a suite of novel
methods for premeasurement separation and preconcentration of analytes of interest to the Nuclear Industry.
<strong>The</strong> membranes are metallised utilising semiconductor photocatalysis to initiate electroless deposition. <strong>The</strong> technique uses light
in place of a chemical catalyst. During absorption of light at or above the band-gap energy at the semiconductor, electrons are excited
from the valence band to the conduction band, creating electron/hole pairs. <strong>The</strong> photogenerated electrons are used to drive the
initial metal ion reduction reaction, resulting in the deposition of principle metal particles onto the semi-conductor surface, which
in turn, catalyse electroless deposition onto the surface.
2) CHARACTERIZATION OF CADMIUM-RESISTANT BACTERIA AND THEIR
APPLICATION FOR CADMIUM BIOREMEDIATION - 16072
Surasak Siripornadulsil, Wilailak Siripornadulsil, Khon Kaen University (Thailand)
On a global basis, trace-metal pollution is one of the most pervasive environmental problems. It is particularly difficult to prevent
or clean up because the metals are toxic in their elemental form and cannot be decomposed. Bioremediation has been shown
to be a powerful system for heavy metal pollution clean up and prevention. In this work, we characterized the cadmium (Cd)-resistant
bacteria isolated from rice field soil downstream from zinc (Zn) mineralized area which the owners were contaminated at high
level of cadmium content in their blood (>10 μgCd/g creatinine). We found that all 24 isolated bacteria tolerated toxic Cd concentrations
(2,500 μM). In order to determine whether the Cd toxicity affected the growth of isolated bacteria, we grew the isolated
bacterial cells in the absence and presence of toxic concentrations of CdCl2 (500 μM). In the absence of Cd, all isolated bacterial
cells grew slightly better than in the presence of toxic concentrations of Cd. In addition, the Cd binding capacity of all isolated bacteria
were very high, ranging from 6.38 to 9.38 log[Cd(atom)]/cell when grown in the presence of 500 μM CdCl2. Furthermore,
the stability of Cd-bacteria complex of all isolated bacteria was affected by 1mM EDTA.
When grown in the presence of 500 μM CdCl2, Cd-resistant isolates S2500-6, -8, -9, -15, -17, -18, -19, and -22
increasingly produced proteins containing cysteine (SH-group) (from 1.3 to 2.2 times) as well as 11 isolates of Cd-resistant
bacteria, including S2500-1, -2, -3, -5, -6, -8, -9, -11, -16, -20, and -21, increasingly produced inorganic sulfide (1.5 to 4.7 times).
Furthermore, the Sulfur K-edge X-ray absorption nearedge structure (XANES) spectroscopy studies indicated that Cd-resistant isolated
S2500-3 precipitated amounts of cadmium sulfide (CdS), when grown in the presence of 500 μM CdCl2. <strong>The</strong> results suggested
that these Cd-resistant bacteria have potential ability to precipitate a toxic soluble CdCl2 as nontoxic insoluble CdS. Interestingly,
Cd-resistant bacteria isolated S2500-3, -8, -9,and -20 increased cadmium tolerance of Thai jasmine rice (Kao Hom Mali 105)
when grown in the presence of 200 μM CdCl2. <strong>The</strong>se 4 isolates also decreased cadmium concentration accumulation in Kao Hom
Mali 105 plant at 61, 9, 6, and 17%, respectively when grown in the presence of 200 μM CdCl2. <strong>The</strong>y were identified by 16S rDNA
sequence analysis and classified as Cupriavidus taiwanensis (isolate S2500-3) and Pseudomonas aeruginosa (isolates S2500-8, -
9, and -20).
3) ENHANCED BIOREMEDIATION AS A COST EFFECTIVE APPROACH FOLLOWING
THERMALLY ENHANCED SOIL EXTRACTION FOR SITES REQUIRING REMEDIATION
OF CHLORINATED SOLVENTS - 16296
Anna-Maria Kozlowska, AIG Engineering Group Limited (UK);
Steve R. Langford, AIG Engineering Group Limited (UK); Dr H.G. Williams, EnviroGene Ltd (UK)
<strong>The</strong>rmally enhanced bioremediation can be a more cost-effective alternative to full-scale in-situ thermal treatment especially
for sites contaminated with chlorinated solvents, where reductive dechlorination is or might be a dominant biological step.
<strong>The</strong> effect of <strong>The</strong>rmally Enhanced Soil Vapour Extraction (TESVE) on indigenous microbial communities and the potential
for subsequent biological polishing of chlorinated solvents was investigated in field trials at the Western Storage Area (WSA) —
UKAEA — Oxfordshire, UK.
<strong>The</strong> WSA site had been contaminated with various chemicals including mineral oil, chloroform, trichloroethane (TCA), carbon
tetrachloride and tetrachloroethene (PCE). <strong>The</strong> contamination had affected the unsaturated zone, groundwater in the chalk
aquifer and was a continuing source of groundwater contamination below WSA.
During TESVE the target treatment zone was heated up above the boiling point of water increasing the volatalization degree
of contaminants of concern (CoC), which were mobilised and extracted in the vapour phase. A significant reduction of chlorinated
solvent in the unsaturated zone was achieved by a full-scale application of TESVE In Situ <strong>The</strong>rmal Desorption (ISTD) technology.
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