Description:
Objective:
The main objective of this research is focussed
at meeting the need for the rapid on-site quantification of mercury emissions
from coal-fired power plants in order to facilitate cost-effective control strategies
for these emissions. Boron Doped Diamond (BDD) electrodes are novel electrodes
utilized for the mercury analysis by electroanalytical method. It is expected
that mercury concentrations in the range of ppb-ppt can be determined. Though,
the spectroscopic techniques such as cold-vapor atomic fluorescence spectrometry
(CV-AFS), cold vapor atomic absorption spectrometry (CV-ASS) and inductively
coupled plasma spectrometry (ICP-MS) have been used successfully to detect mercury,
they require large sample volumes and not suitable for on-line monitoring. Our
present method using BDD electrode using electroanalytical technique is a simple
and novel approach for mercury detection.
Approach:
Differential pulse anodic stripping (DPAS) technique will
be used for the present electroanalysis of mercury. Here the species of Hg2+
in solution are first deposited (reduced) electroanalytically onto an inert
electrode at constant applied potential. A dc voltage ramp (mV/sec) is then
applied in a direction that will cause the deposited material to be stripped
(oxidized) from the electrode at a characteristic potential. This allows the
separation of the charging current from the Faradaic current component, which
is proportional to the concentration of the analyte. The peak position of the
current at a specific potential due to metal stripping is indicative of the
particular element and the amount of current represents the quantity of the
element present. The use of ultrasound during mercury deposition on the BDD
electrode will also be examined.
Expected Results:
Preliminary results have demonstrated the high sensitivity
and capacity of the BDD electrodes for mercury determination. Other electrodes
such as glassy carbon have specific disadvantages on tedious preparation, pretreatment
and high background currents. The present technique using BDD has the advantage
to overcome such problems for the detection and quantification of mercury in
the ppb-ppt range. Moreover, BDD can be used in harsh environments due to its
inertness. Rapid on site detection and quantification of mercury will make a
very important contribution to the solution of mercury problem in the environment.
Supplemental Keywords:
water, innovative technology, monitoring, analytical.
, Air, RFA, Waste, Engineering, Chemistry, & Physics, Incineration/Combustion, air pollution, air quality, air sampling, boron doped diamoond electrodes, combustion flue gases, combustion gases, combustion kinetics, electrochemical technology, mercury, mercury , mercury abatement technology, mercury absorbtion, mercury emissions
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