Browsing by Author "Herath, A.M.C."

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    Electrocoagulation for the Abatement of Cr(VI) from Simulated Water Using Al Electrodes
    (Uva Wellassa University of Sri Lanka, 2021) Chandima, D.S.; Herath, A.M.C.
    Potentially toxic metal/metalloid contamination of water is inevitable mainly due to anthropogenic activities and pose highly adverse health effects on humans. Therefore, development of cost effective promising green technology is of immediate priority concern worldwide. Electrocoagulation holds great promise for the remediation of water and wastewater contaminated by toxic metal ions and organic pollutants. This study evaluates the electrocoagulation performance for the removal of 5 ppm Cr(VI) in simulated water composed of 0.003 mol dm-3 Na2SO4 which imparts a conductivity of 600 s cm-1. The electrocoagulation process, in terms of pH, conductivity, dissolution rate of both anode and cathode, current density was monitored at fixed direct current potentials in a range 1V to 5V at initial pH of 6.5 in a batch mode reactor. In the first 10 min, pH was found to increase from 6.5 to 9.0 and remained constant until the end of the electrocoagulation process after 60 min. Higher rate of dissolution of both anode and cathode was noticed due to electro oxidation and chemical dissolution of the anode and cathode respectively. The removal of Cr(VI) was monitored by UV-Visible spectroscopy at 370 nm and Inductively-Coupled Mass Spectroscopy (ICP-MS).The maximum removal of 97% achieved after two hours of electrocoagulation. The X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) studies performed on dried electrochemically generated sludge in the electrocoagulation reactor revealed the presence of Al and Cr. Keywords: Electrocoagulation; Batch-mode reactor; Pollution abatement; Cr(VI); Al electrodes
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    A Novel Polyaniline Modified Fluorine Doped Tin Oxide Anode for Microbial Fuel Cells
    (Uva Wellassa University of Sri Lanka, 2021) Heenatigala, H.M.S.U.; Wanduragala, P.S.B.; Herath, A.M.C.
    Microbial fuel cells are increasingly interest in the scientific community as a potential solution towards worldwide energy related problems and waste water purification. Microbial fuel cells harness the metabolism of microorganisms and utilize the organic matter to generate electric energy. The research method used in the study is cheap, easily manufactured and environmentally friendly compared to the other microbial fuel cells. A dual chamber microbial fuel cell, divided by a ceramic septum was used to separate anodic and cathodic compartments in the cell. Synthetic waste water was used as a fuel with Saccharomyces cerevisea as a biocatalyst and methylene blue as a mediator in anaerobic anodic chamber. Distilled water was used for aerobic cathodic chamber with platinum electrode as a cathode. Five different electrodes (i) Expanded graphite coated titanium plate (ii) Activated charcoal coated titanium plate (iii) Bare fluorine doped tin oxide glass (iv) Polyaniline deposited fluorine doped tin oxideglass (v) Polyaniline – activated charcoal composite coated fluorine doped tin oxide glass were used as the anode material at constant operating conditions. FT- IR spectrum was used to characterize the polyaniline-activated charcoal composite. Open circuit voltage, short circuit current and voltage through series of external resistances were measured. Electrical performance of microbial fuel cells were characterized using open circuit voltage-time curves, polarization curves, power curves, current-time curves and maximum power densities of each microbial fuel cell. The highest maximum open circuit voltage of 967 mV was shown by Polyaniline- activated charcoal composite coated fluorine doped tin oxide glass electrode. The highest maximum power densities were recorded in both expanded graphite coated titanium plate and polyaniline – activated charcoal composite coated fluorine doped tin oxide glass electrode which were 2.6810-3 mWm-3 and 2.6610-3 mWm-3 respectively. It is suggested that, polyaniline-activated charcoal composite coated fluorine doped tin oxide glass is a promising anode material for microbial fuel cells. Keywords: Microbial Fuel Cell; polyaniline; Saccharomyces cerevisea; Fluorine doped tin oxide glass