Service life and stability of electrodes applied in electrochemical advanced oxidation processes: A comprehensive review

Masoud Moradi,Yasser Vasseghian,Alireza Khataee,Mehmet Kobya,Hossein Arabzade,Elena-Niculina Dragoi 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.87 No.-

In recent years, novel advanced oxidation processes (AOPs) based on electrochemical technology knownas electrochemical advanced oxidation processes (EAOPs) have been applied to the degradation of a widerange of persistent organic pollutants (POPs). EAOPs produce in situ hydroxyl radicals ( OH) capable ofdegrading POPs and their mineralization by producing stable electrode materials (e.g., boron-dopeddiamond (BDD), doped-SnO2, PbO2, and substoichiometric- and doped-TiO2). Moreover, ozone andsulfate radicals could be produced, based on electrolyte type, which cause the degradation of POPs. Although EAOPs are promising novel technologies, various parameters related to the types of electrodesin the POPs oxidation have not been fully addressed. In order to provide a full and comprehensive pictureof the current state of the art, and improve the treatment efficiency and motivate new researches in theseareas, this study analyzed the research covering EAOPs aspects, with a focus on the comparison ofstability, lifetime and service life of electrodes. Electro-chemical stability and longer life are the majorconcerns in the EAOPs. Since electrodes must be highly efficient for long periods of time, thedetermination of their lifetime is essential. On the other hand, in real-life situations, lifetimedetermination is difficult. The oxidation ability and durability of electrodes during the reactionsdepended on the structural properties of them. Electrodes composed of intermediate compounds had ahigher lifetime than binary oxides. Another factor affecting the stability of the electrodes was thestructure of the expanded mesh style anodes to better control the bubble growth through a polygonizedstructure. Anodes with irregular shapes at the surface were more likely to discharge the bubbles andreduce the negative effects of the high pressure on the surface of the electrode. The electrodes havinghigh oxidation strength and stability, had a shorter service life value. Furthermore, the calcinationtemperature and the amount of applied current directly affected the lifetime of the electrodes. On theother hand, the electrical resistance of the synthesized electrode was effective in the lifetime. Coating ofelectrodes with noble metals such as tantalum, titanium, niobium, zirconium, hafnium, vanadium,molybdate and tungsten improved the electrode stability.

A laboratory and numerical study on the effect of geogrid-box method on bearing capacity of rock-soil slopes

Moradi, Gholam,Abdolmaleki, Arvin,Soltani, Parham,Ahmadvand, Masoud Techno-Press 2018 Geomechanics & engineering Vol.14 No.4

Currently, layered geogrid method (LGM) is the commonly practiced technique for reinforcement of slopes. In this paper the geogrid-box method (GBM) is introduced as a new approach for reinforcement of rock-soil slopes. To achieve the objectives of this study, a laboratory setup was designed and the slopes without reinforcements and reinforced with LGM and GBM were tested under the loading of a circular footing. The effect of vertical spacing between geogrid layers and box thickness on normalized bearing capacity and failure mechanism of slopes was investigated. A series of 3D finite element analysis were also performed using ABAQUS software to supplement the results of the model tests. The results indicated that the load-settlement behavior and the ultimate bearing capacity of footing can be significantly improved by the inclusion of reinforcing geogrid in the soil. It was found that for the slopes reinforced with GBM, the displacement contours are widely distributed in the rock-soil mass underneath the footing in greater width and depth than that in the reinforced slope with LGM, which in turn results in higher bearing capacity. It was also established that by reducing the thickness of geogrid-boxes, the distribution and depth of displacement contours increases and a longer failure surface is developed, which suggests the enhanced bearing capacity of the slope. Based on the studied designs, the ultimate bearing capacity of the GBM-reinforced slope was found to be 11.16% higher than that of the slope reinforced with LGM. The results also indicated that, reinforcement of rock-soil slopes using GBM causes an improvement in the ultimate bearing capacity as high as 24.8 times more than that of the unreinforced slope.

Chitosan-furosemide/pectin surface functionalized thin film nanofiltration membrane with improved antifouling behavior for pharmaceutical wastewater treatment

Golshan Moradi,Rouhollah Heydari,Sirus Zinadini,Masoud Rahimi 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.124 No.-

A high-performance thin film composite (TFC) nanofiltration (NF) membrane was prepared by thefurosemide-modified chitosan (CS@FS) composite assisted pectin (PC) functionalization of the polyethersulfone(PES) NF membrane for antibiotic removal and pharmaceutical wastewater treatment. Analysesby Fourier transform infrared (FTIR) confirmed successful modification of CS. The effect of CS@FS-co-PCon physicochemical characteristics and separation performance of the prepared membrane was studied. The CS@FS-co-PC TFC membranes indicated a smoother surface with decreased water contact angle. Upon introduction of CS@FS-co-PC with 0.5 wt.% CS@FS on the membrane surface, the resultant TFCmembrane (TFC-0.5) achieved pure water flux (PWF) of 47.8 L/m2h, high flux recovery ratio (FRR) of94.2%, and irreversible fouling ratio (DRir) of 5.8%. All prepared TFC membranes showed more than91% rejection for both studied antibiotics. In the optimized conditions, ceftriaxone (CRO) and cefixime(CFM) rejections using TFC-0.5 membrane were 99.9 and 99.7%, respectively. Moreover, the CS@FS-co-PC TFC NF membranes show outstanding separation performance for pharmaceutical wastewater treatment(COD removal efficiency of 92.0%±1.1, TDS removal of 56.1 ± 1.0%, and complete turbidity removal). The present study aimed to prepare a TFC membrane that can indicate high antibiotic rejection and resistanceto fouling for pharmaceutical wastewater treatment applications.

Photocatalytic decolorization of auramine and its kinetics study in the presence of two different sizes titanium dioxide nanoparticles at various buffer and non-buffer media

Morteza Montazerozohori,Masoud Nasr-Esfahani,Zohreh Moradi-shammi,Ameneh Malekhoseini 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

In this research, photocatalytic decolorization and its kinetics study of auramine dye at various aqueousbuffer and non-buffer media using nano-titanium dioxide in two different sizes of 15 and 70 nm in aphotocatalyic reactor under 400W high pressure mercury lamp irradiation under aerobic condition isdescribed. The effects of some physico-chemical parameters such as photocatalyst dosage, medium pHand irradiation time were investigated in the presence of two different nano-photocatalysts and then theresults were compared with each other. Kinetics study of photocatalytic treatment of auramine dyeresulted that the dye decolorization approximately follows a pseudo-first order kinetic behavioraccording to the Langmuir–Hinshelwood model. Ultimately, the observed rate constants, experimentalhalf-times, adsorption constants and decolorization rate constants at surface at buffer and non-buffermedia under aerobic conditions were evaluated.

Experimental investigation on UHPC beams reinforced with GFRP and steel rebars and comparison with prediction equations

Parvin, Yousef Abbasi,Shaghaghi, Taleb Moradi,Pourbaba, Masoud,Mirrezaei, Seyyed Saeed,Zandi, Yousef Techno-Press 2022 Advances in concrete construction Vol.14 No.1

In this article, the flexural and shear capacity of ultra-high-performance fiber-reinforced concrete beams (UHPFRC) using two kinds of rebars, including GFRP and steel rebars, are experimentally investigated. For this purpose, six UHPFRC beams (250 × 300 × 1650 mm) with three reinforcement ratios (ρ) of 0.64, 1.05, and 1.45 were constructed using 2% steel fibers by volume. Half of the specimens were made of UHPFRC reinforced with GFRP rebars, while the other half were reinforced with conventional steel rebars. All specimens were tested to failure in four-point bending. Both the load-deformation at mid-span and the failure pattern were studied. The results showed that utilizing GFRP bars increases the flexural strength of UHPFRC beams in comparison to those made of steel bars, but at the same time, it reduces the post-cracking strain hardening. Furthermore, by increasing the percentage of longitudinal bars, both the post-cracking strain hardening and load-bearing capacity increase. Comparing the experiment results with some of the available equations and provisions cited in the valid design codes reveals that some of the equations to predict the flexural strength of UHPFRC beams reinforced with conventional steel and GFRP bars are reasonably conservative, while Khalil and Tayfur model is un-conservative. This issue makes it essential to modify the presented equations in this research for predicting the flexural strength of UHPFRC beams using GFRP bars.