“…As can be observed in the plot, the impedance of inhibitors derived from Tulsi extract is significantly greater than that of extracts derived from green tea leaves or of no inhibitors at all. Frequency dispersion describes this type of behavior, which may be linked back to the variations and hardness of solid substrates [ 42 , 54 , 55 ]. Fig.…”
Section: Resultsmentioning
confidence: 99%
“…This is because tulsi acted as a good corrosion inhibitor in the solution. The formation of a protective bio-film on the outer layer of the Al alloy contributed to the decreased rate of corrosion, which was connected to the fact that this mechanism was responsible for the reduction in corrosion [ 42 , 53 , 54 ]. The surface of the Al alloy will degrade more rapidly in the absence of these inhibitors.…”
“…As can be observed in the plot, the impedance of inhibitors derived from Tulsi extract is significantly greater than that of extracts derived from green tea leaves or of no inhibitors at all. Frequency dispersion describes this type of behavior, which may be linked back to the variations and hardness of solid substrates [ 42 , 54 , 55 ]. Fig.…”
Section: Resultsmentioning
confidence: 99%
“…This is because tulsi acted as a good corrosion inhibitor in the solution. The formation of a protective bio-film on the outer layer of the Al alloy contributed to the decreased rate of corrosion, which was connected to the fact that this mechanism was responsible for the reduction in corrosion [ 42 , 53 , 54 ]. The surface of the Al alloy will degrade more rapidly in the absence of these inhibitors.…”
“…On the other hand, when electrocoagulation is used as a pre-treatment for PC, there are no benefits for either treatment performance or costs. Overall, the achieved efficiencies might not be significant Additionally, NaOH, used as a neutralizer, can react directly with aluminum oxide, damaging the aluminum surface and hampering particle distribution throughout the surfaces [56]. These aspects are linked to reducing electrode wear time, especially at higher concentrations and reaction times.…”
Section: Discussionmentioning
confidence: 99%
“…Cl − ions are readily adsorbed to the surface of a film, resulting in the destruction of the passivation layer formed on the aluminum plate, leading to a greater rate of aluminum dissolution and resulting in increased pitting [55]. Additionally, NaOH, used as a neutralizer, can react directly with aluminum oxide, damaging the aluminum surface and hampering particle distribution throughout the surfaces [56]. These aspects are linked to reducing electrode wear time, especially at higher concentrations and reaction times.…”
Cork boiling wastewater (CBW) is a highly polluted and difficult to treat effluent resultant from the cork manufacturing industry. This study aims to evaluate a new, reliable, efficient, and sustainable process to treat this effluent. This paper tested electrocoagulation as a pre- and post-treatment to improve the already existing physicochemical treatment in a cork production facility in Portugal. In the physicochemical procedures (PC), the addition of different volumes of coagulant (ferric chloride (III) 40% w/w), neutralizer (sodium hydroxide, 32% w/w), and flocculant (polyacrylamide, 0.2 g/L) were evaluated. Electrocoagulation (EC) was performed in a bench-scale reactor, using aluminum and stainless-steel electrodes. For EC, different initial pH, current density, and current tension values were tested. When electrocoagulation was used as a post-treatment, better performances were achieved. However, treatment costs were increased significantly. Coagulation/flocculation offers a viable and cheap treatment, achieving removal efficiencies of 88.2%, 81.0%, 76.9%, and 94.2% for total chemical oxygen demand (tCOD), total carbon (TC), total nitrogen (TN), and soluble chemical oxygen demand (sCOD), respectively. With a PC-EC combination, it is possible to achieve removal efficiencies of 92.4%, 88.0%, 91.4%, and 91.4% for tCOD, TC, TN, and sCOD, respectively. The increased TN removal efficiency can translate into great benefits for certain discharge conditions and should be taken into consideration for improving the sustainability of cork industry. On the other hand, when EC is used as a pre-treatment, there are no benefits either in terms of treatment performance or operating costs.
“…In addition, they have good mechanical properties, such as static and dynamic strength, good electrical and thermal conductivity, and good resistance to atmospheric corrosion, as well as good technological properties, such as machinability, weldability, and castability [4,5]. All these properties allow designers to adopt a lightweight design approach when 2 of 17 manufacturing mechanical parts with a high strength-to-weight ratio, thus reducing the global weight of the machinery [6][7][8].…”
Aluminum alloys are extensively used to manufacture mechanical components. However, when exposed to alkaline environments, like lubricants, refrigerants, or detergents, they can be corroded, reducing their durability. For this reason, the aim of this study is to investigate the influence of aggressive alkaline solutions (i.e., pH and presence of chlorides) on the corrosion resistance of three aluminum alloys (AA 5083-H111, AA 6082-T6, and AA 7075-T6) with and without anodizing treatments. Open circuit potential (EOCP) and anodic polarization measurements were carried out and typical corrosion parameters such as corrosion current density (icor) and corrosion rate (CR) were determined. Morphology of the corrosion attack and samples microstructure were investigated by scanning electron microscope. Results show that corrosion behavior of the three investigated alloys is influenced by (i) the aggressiveness of the testing environments; (ii) the thickness of the anodizing treatment; (iii) the alloy chemical composition; (iv) the distribution of intermetallic phases in the aluminum matrix. Moreover, three galvanic series have been built also testing other metallic alloys commonly used in mechanical applications, i.e., carbon steel (C40), stainless-steel (AISI 304), and Cu-based alloys (Cu-Ni alloy and CW 617 N, respectively). Results clearly indicate that galvanic series play a fundamental role when it is necessary to select an alloy for a specific environment, highlighting the thermodynamic conditions for corrosion occurrence. On the other hand, kinetic measurements and microstructural studies carried out on the three aluminum alloys stress the importance of the surface treatments and relevant thickness as well as the effect of metal exposure. Future work will involve the study of other surface treatments on aluminum alloys and the evaluation of their corrosion behavior in acidic environments.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
