Corrosion and scale studies of copper used in Moroccan industrial cooling water systems

Abstract

The corrosion and scale behavior of copper in industrial cooling water system were investigated via electrochemical measurements, ionic chromatography, SEM/EDAX, and X-ray diffraction analyses. It was found that the studied water has a corrosion and scale character. The EDAX and XRD analyses indicated that the major corrosion and scale products were the CuO 2 and CaCO 3 , respectively. In addition, the middle Mueller-Hinton test was also employed to evaluate the development of microorganisms for copper in make-up water solution. It is noted that bacterial colonies appeared after immersion of samples in make-up water, indicating that this water develops bacterial colonization. Finally, the influence of some operating parameters on the corrosion and scale rate was studied. It was shown that the scale rate increases with pH, temperature, and the addition of chloride and sulfide ions. It was also found that the corrosion rate increases with temperature and chloride ions and decreases with pH and immersion time.

Nicotinic acid as green inhibitor for copper corrosion in 3.5 wt % NaCl solution: experimental and quantum chemical calculations

“…The polarization resistance and the inhibitory efficiency of NAC increase with the concentration of inhibitor and reach maximum values of 4046 Ω and 88% respectively for an inhibitor concentration of 10 mM and decrease thereafter. A similar behavior have been reported on copper corrosion inhibition in the cooling liquids of industrial systems in the presence of CetyltrimethylAmmonium Bromide (CTAB) (Elhousni et al, 2017). These authors have justified the decrease of the efficiency in the case of high inhibitor concentrations by the formation of an oxide and / or hydroxide layer on the surface of the material.…”

“…The diameter of the capacitive loops increases with the concentration of NAC indicating that the inhibition efficiency is a function of the inhibitor concentration (Elhousni et al, 2017). and a larger |Z| represents a better protection performance.…”

Sodium nitrite as a corrosion inhibitor of copper in simulated cooling water

“…Although considered a resistant metal, copper may still suffer from corrosion in aqueous conditions by harsh ions like halides, sulfates, etc. Another hindrance to its application is fouling, which is caused by colonies of microorganisms thriving over a long time in the neutral or basic cooling water systems 24 . Efficiency and longevity of cooling coils/pipelines depend on the protection of copper surface which should be devoid of pits and accumulated toxic wastes after degradation.…”

Green Biocide from Boerhaavia diffusa Leaf Extract Inhibits Biocorrosion of Mild Steel (MS1010) in Cooling Towers: Bactericidal and Electrochemical Studies

“…Indeed such electrochemical changes in metallic surfaces of industrial circuits are induced by the array of microbial cells (chemoautotrophs and/or heterotrophs) and extracellular polymeric substances (EPS). EPS assists in anchorage of microbial cells and other inorganic precipitates (derived from endogenous metal substratum) to the metallic surfaces of industrial circuits, like cooling towers (Elhousni et al, 2017;MacDonald and Brozel, 2000). Microbial metabolites like sulphides, organic acids, inorganic acids, ammonia and presence of bacterial cells reducing sulfides, acid producing bacteria, ferrotrophic bacterial cells (oxidizing and reducing) and fungi collectively induces biocorrosion in industrial settings.…”