UV photoelectrocatalytic degradation of m- cresol pollutant using TiO2 dip -coated stainless steel electrode system

In the present study, the removal of m- cresol in an aqueous medium was studied by the photoelectrocatalytic (PEC) degradation by the TiO2 suspension on dip-coated stainless steel electrode under UV lamp of the wavelength of 352nm. The performance of the PEC method on the degradation of m- cresol was studied by made the comparison with the photocatalytic oxidation (PCO) method in terms of COD removal and kinetic study. In the PEC study on the degradation of m- cresol pollutant was studied by the various parameters such as initial concentration, pH, and the bias potential. The result found that the optimum degradation efficiency of m- cresol in the PEC and PCO methods were 79.6% and 39.8% at pH 5.0. The result showed that the kinetic constants (k) in the PEC and PCO methods were -0.0116 and -0.0058 under optimum conditions. The result found that the PEC method using TiO2 coated on stainless steel electrode is two times higher than the PCO method on the degradation of m- cresol.

STRUCTURAL AND ELECTROCHEMICAL PROPERTIES OF CHEMICALLY DEPOSITED COPPER DOPED NICKEL HYDROXIDE

Present work reported, copper doped Ni(OH) deposited successfully by chemical bath deposition method on 2 economical stainless steel electrode. The XRD analysis represent hexagonal crystal structure and presence of Ni and Cu confirm by FT-IR study. The surface morphology studied by SEM indicates nanopetals linked marigold like microflowers. -1 -1 The 0.2% Cu doped Ni(OH)2 shows specific capacitance 715 Fg at scan rate 10 mV s . EIS study interprets that electrode N-0.2% have least charge transfer resistance which improve value of specific capacitance. All results revels cupper is good dopant for improve the specific capacitance.

Structured Thin Films Based on Synergistic Effects of MnTa2O6 Oxide and bis-Carboxy-phenyl-substituted Porphyrins, Capable to Inhibit Steel Corrosion

Covering steel surfaces with suitable materials with the capacity to protect against corrosion represents a challenge for both research and industry, as steel, due to its paramount utility, is the most recycled material. This study presents the realization of new sandwich type materials based on 5,10-(4-carboxy-phenyl)-15,20-(4-phenoxy-phenyl)-porphyrin or 5,15-(4-carboxy-phenyl)-10,20-diphenylporphyrin and MnTa2O6 designed to improve corrosion inhibition of steel in aggressive media. The thin films, designed as single- or sandwich-type structures were obtained on carbon steel through the drop-casting technique. Morphological investigations of thin films were carried out by field emission-scanning electron microscopy (SEM) and atomic force microscopy (AFM). The inhibition of a steel corrosion process was evaluated in an aggressive environment of 0.1 M HCl by performing electrochemical investigations such as open circuit potential (OCP) and the potentiodynamic polarization technique. The influence of variations in the cathodic Tafel slopes βc and anodic Tafel slopes βa over the corrosion rates was discussed. The best corrosion inhibition efficiency of 91.76% was realized by the steel electrode covered with sandwich-type layers of 5,15-(4-carboxy-phenyl)-10,20-diphenylporphyrin on the bottom layer and MnTa2O6 on the top. The effect of location of the COOH groups in the cis or trans position on the tetrapyrrolic ring was also discussed to understand the corrosion inhibition mechanism.

Electrodeposition of Calcium Carbonate and Magnesium Carbonate from Hard Water on Stainless-Steel Electrode to Prevent Natural Scaling Phenomenon

This study focuses on preventing scale formation in hard waters by controlled electrode-position of Ca2+ and Mg2+ on a stainless-steel cathode at constant applied current intensity. The influence of the anode material, BDD or Ti/Pt/PbO2, cathode active area, stirring speed, and applied anodic current intensity on the inorganic carbon (IC), Ca2+, and Mg2+ removal was investigated. Assays were performed with model hard water solutions, simulating Bounouara (Algeria) water. The scaling inhibiting properties of the treated water were followed by measuring IC, calcium, and magnesium concentrations and chronoamperometric characterization of the treated solutions. The influence of the Ca/Mg molar ratio on the inorganic carbon removal by electrolysis was also evaluated, utilizing model solutions with different compositions. It was found that an increase in stirring speed or cathode geometric area favors IC and Ca2+ and Mg2+ removal rates. The applied current intensity was varied from 0.025 to 0.5 A, and the best results were obtained for 0.1 A, either in IC and Ca2+ and Mg2+ removals or by the accelerated scaling tests. However, energy costs increase with applied current. The deposit formed over the cathode does not seem to influence posterior deposition rate, and after eight consecutive assays, the solid deposition rate was kept constant. Ca/Mg ratio influences IC removal rate that increases with it. The results showed that hard-water scaling phenomena can be prevented by solid electrodeposition on the cathode at applied constant current.

Characteristics and corrosion protection of polypyrrole doped with salicylate anions on CT3 steel passivated by molydate

In recent years, the conducting polymers have attracted much attention in research and development because of their applications in medical and civil engineering. Here, the salicylate doped polypyrrole films were prepared on the carbon steel surface and their corrosion protection in 3 % NaCl solution were studied. Polypyrrole (Ppy) film was electrochemically synthesised with constant current techniques in a sodium salicylate solution (0.05M, 0.1M, 0.15M) and 0.1M pyrrole monomer on mild CT3 steel electrode passivated by molybdate. The morphological, structural, composition and thermal properties of salicylate doped Ppy films were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA) techniques. The anti-corrosion ability of these films was assessed by electrochemical measurements in 3 % NaCl solution. The obtained results suggested that salicylate anions contributed in corrosion protection ability of Ppy films for mild steel electrode. The concentration of sodium salicylate of 0.1M and pyrrole of 0.1M is most suitable for preparation of good protection coating. The self-healing mechanism has been also mentioned for salicylate doped Ppy films on CT3 steel substrate.

Improving the Treatment Efficiency and Lowering the Operating Costs of Electrochemical Advanced Oxidation Processes

Electrochemical advanced oxidation processes (EAOP®) are promising technologies for the decentralized treatment of water and will be important elements in achieving a circular economy. To overcome the drawback of the high operational expenses of EAOP® systems, two novel reactors based on a next-generation boron-doped diamond (BDD) anode and a stainless steel cathode or a hydrogen-peroxide-generating gas diffusion electrode (GDE) are presented. This reactor design ensures the long-term stability of BDD anodes. The application potential of the novel reactors is evaluated with artificial wastewater containing phenol (COD of 2000 mg L−1); the reactors are compared to each other and to ozone and peroxone systems. The investigations show that the BDD anode can be optimized for a service life of up to 18 years, reducing the costs for EAOP® significantly. The process comparison shows a degradation efficiency for the BDD–GDE system of up to 135% in comparison to the BDD–stainless steel electrode combination, showing only 75%, 14%, and 8% of the energy consumption of the BDD–stainless steel, ozonation, and peroxonation systems, respectively. Treatment efficiencies of nearly 100% are achieved with both novel electrolysis reactors. Due to the current density adaptation and the GDE integration, which result in energy savings as well as the improvements that significantly extend the lifetime of the BDD electrode, less resources and raw materials are consumed for the power generation and electrode manufacturing processes.