Sulfuric Medium Research Articles

Kinetics, Mechanism, and Reactivity of the Cerium(IV)-Oxalatereaction in a Sulphate Medium

This work presents an approach for studying the kinetics, mechanism, and reactivity of intermediates in a wide class of the redox reactions for which the rate-limiting step is the redox-decomposition of an intermediate complex. This approach is applied to investigate the oxalic acid (H2Ox) oxidation by cerium(IV) in sulfuric acid medium, which is an integral part of the cerium-catalyzed oscillatory Belousov–Zhabotinsky (BZ) reaction. Using experimental, mathematical and computational techniques commonly used to study metal complexes in a stable oxidation state (OS), kinetically generalized by the authors for studying variable-valence metal complexes, the characteristics of intermediate complexes of the cerium(IV)-oxalate reaction were studied, the general rate law was derived on the basis of a set of equations describing the rapid establishment of preequilibria in the system and the subsequent nonequilibrium process. A quantitative reaction model is proposed that includes two parallel reaction pathways, for which two different intermediate cerium(IV)-oxalate complexes with close reactivity have been identified and characterized that may be due to the similarity in the structure of their inner coordination spheres and an inner sphere mechanism of electron transfer in the complexes. Based on the developed model, the distribution diagram was also constructed for the computed fractions of all the detectable cerium(IV) species under conditions of the BZ reaction, which testify to the necessity to take into account under these conditions the formation of intermediate complexes CeOHOx (n = 1, 2) during oxidation of oxalic acid. The main difference of the proposed model of the cerium(IV)-oxalate reaction as part of the BZ-reaction from the previous models is the explicit accounting of the formation of intermediate cerium(IV) complexes with anions of oxalic acid and sulfate background.

Oxidation of Thioglycolic Acid by Co(III)Salophen in Binary Mixed DMSO-Water and Sodium Dodecyl Sulfate Media

Oxidation of Thioglycolic Acid by Co(III)Salophen in Binary Mixed DMSO-Water and Sodium Dodecyl Sulfate Media

Experimental investigation of sustainable Corrosion Inhibitor Albumin on low-carbon steel in 1N HCl and 1N H2SO4

Sustainable corrosion inhibitors are being developed as many of them are ecologically friendly, biodegradable, and devoid of heavy metals and other potentially dangerous compounds. Albumin, a member of the globular protein family obtained from egg white, has found its application in a variety of various applications due to its intrinsic pharmacological qualities (anti-bacterial, immunomodulating, and anti-cancer angiotensin-converting enzyme inhibition). Herein, Albumin extract containing atoms with lone pairs of electrons such as Nitrogen (N), Oxygen (O) and having an aromatic ring (unsaturation) has been investigated as an eco-friendly inhibitor for low-carbon steel. The present work studied the inhibition action of Albumin extract for low-carbon steel in 1N acidic chloride and sulfate media using gravimetric, and electrochemical methods, viz potentiodynamic polarization (PDP) and AC impedance studies (EIS). The results obtained from PDP and EIS analysis revealed that the inhibitor exhibited anodic inhibition in 1N HCl (92.72%) and mixed-type but predominantly cathodic inhibition in 1N H2SO4 (79.23%). The studied green corrosion inhibitor followed Langmuir monolayer adsorption and the formation of a protective film on a low-carbon steel surface was confirmed with AFM and FT-IR results. Thus, Albumin extract exhibited excellent corrosion resistance on low-carbon steel.

Modelling the scale-up of the iodine-assisted chalcopyrite leaching in ferric sulfate media from reactors to columns and simulating heap operations

The iodine-assisted heap leaching of chalcopyrite involves the addition of iodide in ferric sulfate media to accelerate the dissolution of chalcopyrite at ambient temperature. The previous studies using reactor leaching tests identified the solution potential, the amount of iodide added, and temperature as the factors controlling the process performance. In the present study, the iodine-assisted chalcopyrite leaching process was scaled up from reactors to 1-m and 6-m columns to further understand how these parameters control the process performance at a larger scale. This is essential to optimize the process in industrial-scale heap leach pads. The HeapSim-2D model was calibrated with the 1-m and 6-m column leach tests together with the kinetic parameter values obtained in the previous reactor leaching tests. When the iodine-assisted chalcopyrite leaching was scaled up from reactors to 1-m and 6-m columns, the leaching became slower because the ore used in the column leaching tests had larger particle sizes with partially-liberated chalcopyrite particles. The calibrated model was then used to carry out the sensitivity analyses to assess the response of the process performance to key design and operating variables, including irrigation rate, ferric concentration, total iodide concentration, temperature, and heap height. The analyses show that the copper extraction could be optimized by adjusting these key design and operating parameters.

Macroscopic behavior and microstructural analysis of recycled aggregate mortar bars exposed to external sulfate attack

The performance of cementitious materials made with Recycled Concrete Aggregates (RCA) and exposed to sulfate-laden environments is not yet fully understood. There are few studies on this topic, and for a full description of the mechanisms of external sulfate attack (ESA), several influencing parameters should be considered. The replacement of natural aggregates by RCA modifies the physical and chemical properties of the new material and introduces additional variables into the already complex mechanism. The high porosity of RCA contributes to accelerating the sulfate penetration from the surface, while the attached mortar increases the mineral supply that can react with the incoming sulfate.This paper describes a study on the performance of mortars made with RCA exposed to different ESA conditions. Design and exposure parameters include three cement, two specimen sizes, and two sulfate media (soil and solution). Visual inspection and measurements of expansion and weight change were used to determine the performance of the mixes. From a microstructural point of view, thermogravimetric analyses were carried out on samples obtained from the mortar bars after exposure. These results are then used to infer on the thermodynamic and kinetic aspects of ESA progression in recycled mortar. Finally, SEM/EDS analyses were also performed to further describe sulfate penetration and its relationship with cracking. The results show a limited influence of fine recycled aggregate on the mortar performance against ESA and no proportionality to its content.

Electrochemical Degradation of Diuron by Anodic Oxidation on a Commercial Ru0.3Ti0.7O2 Anode in a Sulfate Medium

This work presents the electrochemical degradation of the herbicide Diuron by anodic oxidation on a Ti/Ru0.3Ti0.7O2 metal mixed oxide anode using sulfate as the electrolyte. The study includes the influence of Diuron concentration and current density on anodic oxidation. The results evidence a first-order degradation, with the highest capacity achieved at 40 mA cm−2 and at an initial Diuron concentration of 38 mg L−1. Nevertheless, in terms of efficiency and energy demand, the operation at 10 mA cm−2 is favored due to the more efficient and less energy-consuming condition. To discern the optimum design and operation conditions, this work presents the results of a preliminary technical–economic analysis, demonstrating that, to minimize the total costs of the system, it is recommended to seek the most efficient conditions, i.e., the conditions demanding the lowest applied charges with the highest Diuron degradation. At the same time, attention must be given to the required cell voltage to not increase excessively the operating costs.

Selective extraction of Ti(IV) from acidic sulfate media by phosphonium-based ionic liquids and stripping with sulfuric acid

The Ti(IV) liquid-liquid extraction from acidic sulfate media has been investigated by the ionic liquids trihexyl(tetradecyl)phosphonium chloride [P66614+][Cl−] and trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate [P66614+][BTMPP−], diluted in 5% (v/v) 1-decanol/kerosene. The Room Temperature Ionic Liquids (RTIL) showed fast extraction kinetics reaching equilibration after 2 min, requiring a 450 rpm stirring rate. For [P66614+][Cl−] at 0.01 mol L−1, the maximum extraction efficiency was 30% from H2SO4 solution of 11 mol L−1. The IL [P66614+][BTMPP−] shows better Ti(IV) extraction than [P66614+][Cl−], and two maximum extraction conditions were observed at 0.1 and 7.3 mol L−1 H2SO4 due to the dual mechanism; both cationic and anionic exchange reactions, reaching 60% and 49% extraction efficiency, respectively.The increase in [P66614+][BTMPP−] concentration to 0.06 mol L−1, increases the extraction yield to 95.9%. The Fourier transform infrared FTIR characterization confirmed the presence of Ti(IV) in the organic phases, and the modification in the phosphonium bonds was correlated to the role of the ionic liquids in the Ti(IV) extraction. The organic phase containing 0.02 mol L−1 [P66614+][BTMPP−] can be loaded with 0.197 g/L of Ti(IV) from 7.3 mol L−1 H2SO4 media. In contrast, at 0.1 mol L−1 H2SO4, an increase in the Ti(IV) concentration promotes the polymerization in the form Ti-O-Ti-O-Ti inhibiting the extraction efficiency. The H2SO4 solution at 2 mol L−1 was the best stripping agent to achieve a high Ti(IV) recovery of 97%. The organic phase was reused for four cycles, and the extraction and stripping efficiencies remained unchanged after the third cycle. The selective separation of Ti(IV) from a mixture containing Fe(III) was reached with a separation factor of 78.4, with a 2.51% Fe(III) extraction and containing only 0.25 mg L−1 of Fe(III) in the stripping phase. The proposed system avoids the main problems associated with Ti(IV) recovery from acidic sulfate media.

Assessing the electrochemical degradation of reactive orange 84 with Ti/IrO2–SnO2–Sb2O5 anode using electrochemical oxidation, electro-Fenton, and photoelectro-Fenton under UVA irradiation

Today, water shortage problems around the world have forced the search for new treatment alternatives, in this context, electrochemical oxidation technology is a hopeful process for wastewater treatment, although it is still needed exploration of new efficient and economically viable electrode materials. In this way, mixed metal oxide anodes look like promising alternatives but their preparation is still a significant point to study, searching for finding low-cost materials to improve electrocatalytic efficiencies. In an exploration of this kind of highly efficient materials, this work presents the results obtained using an MMO Ti/IrO2–SnO2–Sb2O5 anode. All the prepared anodes exhibited excellent physical and electrochemical properties. The electrochemical oxidation of 100 mL and 200 mg L−1 Reactive Orange 84 (RO 84) diazo dye was studied using 3 cm2 of such synthesized anodes by applying current densities of 25, 50, and 100 mA cm−2. Faster and more efficient electrochemical oxidation occurred at 100 mA cm−2 with 50 mM of Na2SO4 + 10 mM NaCl as supporting electrolyte at pH 3.0. The degradation and mineralization processes of the above solution were enhanced with the electro-Fenton process with 0.05 mM Fe2+ and upgraded using photoelectron-Fenton with UVA light. This process yielded 91% COD decay with a low energy consumption of 0.1137 kWh (g COD)−1 at 60 min. The evolution of a final carboxylic acid like oxalic was followed by HPLC analysis. The Ti/IrO2–SnO2–Sb2O5 is then an efficient and low-cost anode for the photoelectro-Fenton treatment of RO 84 in a chloride and sulfate media.

Avrami Model for the Description of Nucleation and Growth of Tellurium During Cementation by Copper in the Sulfate Media

Avrami Model for the Description of Nucleation and Growth of Tellurium During Cementation by Copper in the Sulfate Media

Liquid-Liquid Extraction of Metal Ions Using Aqueous Biphasic Systems

An investigation was conducted for the study of extraction of metal ions using aqueous biphasic systems. The extraction of iron, zinc and copper from aqueous sulphate media at different kinds of extractants SCN− , Cl- and I- , different values of pH of the feed solution, phase ratio, concentration of metals, concentration of extractant, concentration of polymer, and concentration of salt was investigated. Atomic absorption spectrophotometer was used to measure the concentration of iron, zinc and copper in the aqueous phase throughout the experiments. The results of the extraction experiments showed the use of SCN− as extractant, pH=2.5, phase ratio=1.5, concentration of metals 1g/l, concentration of extractant 0.06 %, concentration of polymer =50 %, and concentration of salt=20% gave the highest value of percent removed. Also increase of extractant concentration increases the percent removed. The results clarified that increasing the metal ions concentration in the aqueous phase causes to decease the percent removed. The addition of an inorganic salt (sodium sulphate) up to (20%) increased the dehydration of polymer chains and then increases the percent removed.

Valorization of fly ash by nickel ferrite and vanadium oxide recovery through pyro-hydrometallurgical processes: Technical and environmental assessment

The fly ash (FA) from the combustion of heavy oil in power stations is characterized by fine particles containing toxic metals. The sample utilized in this study was gathered from the dust precipitators of seven heavy-oil-consuming Iranian power plants. Substantial quantities of heavy metals, particularly vanadium, iron, and nickel, have been detected in the sample, indicating both its potential utility and hazard to the soil and groundwater. The harmful consequences of FA disposal on the environment have led to the adoption of recycling as a treatment approach in this study. The valorization of FA was investigated by producing nickel ferrite (NiFe2O4) and vanadium pentoxide (V2O5) through a novel approach using a combination of pyro-hydrometallurgical processes, which resulted in proposing a recycling closed-loop flowsheet. Roasting was first practiced to form NiFe2O4 by reacting the nickel and iron content of the FA. The NiFe2O4 showed a low dissolution against inorganic acids (H2SO4, HCl, and HNO3). The vanadium content of the FA showed a remarkable recovery in H2SO4 (91%) and HCl (95.6%), while the dissolution of Ni was limited to 16.85% and 17.5%, respectively. The produced NiFe2O4 acted well in response to the magnetic field, and its purity was further increased to 95–96% through a two-stage process consisting of grinding and magnetic separation. The nano-sized spherical NiFe2O4 with saturation magnetization of 34.66 and 30.82 emu. g−1 was obtained from H2SO4 and HCl residues, respectively. The dissolved vanadium was recovered as V2O5 via oxidation-precipitation in sulfate media and oxidation-ammonium precipitation in chloride solution. The purity of V2O5 in sulfate and chloride media was 93% and 98.5%, respectively. Finally, a life cycle assessment (LCA) study was performed on the suggested methods to track the ecological effects of extracting V and Ni from oil combustion FA. According to the performed LCA, H2SO4 was determined as the proper leaching reagent considering the environmental and technical aspects.

Elimination of sulfamethoxazole by anodic oxidation using mixed metal oxide anodes

The degradation of sulfamethoxazole (SMX) was studied by anodic oxidation (AO) process using mixed metal oxide (MMO) electrodes with different Ru/Ir ratios. Each electrode was characterized morphological and electrochemically. The electrolyzes were performed in NaCl and Na2SO4 applying two current densities (10 and 50 mA cm−2). The electrode with the highest composition of Ir, Ru/Ir (30/70), showed greater SMX degradation and generation of oxidizing species and was used to treat the antibiotic by AO and AO assisted by solar energy in natural water and actual municipal wastewater effluents.The efficiency in SMX degradation depends on the type of electrode used (MMO) and electrolytic medium. All MMO electrodes, reached almost total degradation of SMX in chloride medium. However, 60 % degradation of SMX in sulfate medium was achieved with anode with lower Ru/Ir ratio. Additionally, degradation of SMX in complex matrices can be successfully carried out by solar-assisted AO and AO processes, without the need to adjust the pH, at room temperature and using anode with lower Ru/Ir ratio. Finally, the AO process assisted by solar energy reduced electrolysis times and the cell's potential, leading to lower energy consumption.

Sulphate and acid resistance of HVFA concrete incorporating nano silica

High Volume Fly Ash (HVFA) concrete has been shown to be a viable alternative construction material to Portland cement concrete to improve sustainability and durability. In addition, nano silica been found to be a significant contributor towards increasing the early age strength and the durability properties of HVFA concrete. This study reports an investigating of the resistance of HVFA concrete with 65% and 80% replacement of cement, with nano silica and hydrated lime, exposed to acid and sulphate solutions over a 2-year period. The change in physical appearance, mass and length was monitored, together with detailed mechanical, chemical and microscopy analysis at 12 and 24 months. The results indicate that the HVFA concrete mixes provided enhanced resistance compared to Portland cement concrete. The HVFA 80% cement replacement performed better in acid media while, the HVFA concrete mix with 65% cement replacement was superior in sulphate media.

The role of the iodide/iodine couple as a redox mediator in the dissolution of chalcopyrite in sulfate media. An electrochemical study

A detailed study has been made of the effect of the addition of iodine/iodide on the electrochemistry of the dissolution of chalcopyrite in acidic sulfate media containing iron(III). Mixed potential measurements have revealed that the potential is higher with iodine as an oxidant compared to iron(III) although the solution potentials are similar. Potentiostatic measurements in the absence of the oxidants at the measured mixed potentials have shown that chalcopyrite should dissolve some five times faster with iodine as the oxidant. Linear sweep voltammetry has confirmed the much higher reversibility of the iodine/iodide couple on a chalcopyrite surface than that of the iron(III)/iron(II) couple. Limited dissolution tests have confirmed that chalcopyrite dissolves more rapidly with iodine as the oxidant at rates similar to those predicted from the electrochemical measurements. A preliminary spectrophotometric study of the kinetics of the oxidation of iodide by iron(III) in sulfate media has shown that the rate is significantly slower than previously assumed and that the reaction occurs in two stages with tri-iodide as the initial product that is slowly oxidised to iodine. At the low concentrations necessary for economic application, iodide ions do not effect the rate of oxidation of iron(II) by dissolved oxygen in chloride solutions. It is suggested that the use of iodide as a redox mediator during heap leaching of chalcopyrite ores by acidic ferric sulfate lixiviants is unlikely to change current problems with the slow rate of dissolution under ambient conditions.

Resistance to Sulphate and Acid Attack of Rice Husk Ash and Fly Ash Based Composite Cement

The current exploration work contains the preparation and examination of the properties of cement-based composite materials. Two kinds of composite materials specifically, Rice Husk Ash Composite Cement and Fly Ash Composite Cement were examined. Rice Husk Ash Composite Cement and Fly Ash Composite Cement was treated with Na2SO4 and HCl solution to check the resistance towards sulphate and acid attack respectively. Sulfate attack has been resolved in this work by estimating weight loss/gain of Ordinary Portland Cement (OPC) and the Composite Cements created from FA and RHA when plunged into 0.5 M and 0.75 M Na2SO4 solution. A loss in weight has been seen at the underlying stage i.e. Following 7 and 14 days when OPC is immersed in sulfate media, however, in the long run there was gain in weight of the composite made with OPC. The loss of weight occurred when the entire test sample is treated with 1.0 M HCl. Results on acid resistance and sulphate attack revealed that Composite cements are better acid resistant but more susceptible to sulphate attack. It was also observed that FAC composite is more susceptible to sulphate attack than RHAC composite. The Ca(OH)2 leaching tests indicate that Composite Cements are effective in reducing the amount of Ca(OH)2 leaching compared to pristine OPC. Dhaka Univ. J. Sci. 71(1): 49-55, 2023 (Jan)

New electrochemical reactor design for emergent pollutants removal by electrochemical oxidation

This paper presents the theoretical and experimental confirmation of the performance of a novel pre-pilot reactor design implementing a boron-doped diamond (BDD) anode to destroy emerging pollutants by electrochemical oxidation. Turbulent flow simulation and secondary current distribution modeling with a COMSOL Multiphysics software were used to assess the engineering capabilities of the reactor along with the oxidant BDD(·OH) electrogeneration at the anode. The antibiotic ciprofloxacin (CIP) was chosen as model molecule to assess the oxidation power achieved with the pre-pilot batch plant. In sulfate medium where BDD(·OH) was the main oxidant, faster degradation was determined by increasing current density, CIP content, and pH. The effect of pH was explained by the transformation of the cationic form of CIP in acidic medium into its more easily oxidizable anionic form in alkaline medium. In chloride medium, CIP was more rapidly removed by the faster attack of the generated active chlorine. The degradation was decelerated in carbonate medium by its scavenging effect and in the presence of humic acid by its competitive oxidation with BDD(·OH). The antibiotic abatement also dropped down in tap water and synthetic urine. An almost total mineralization was achieved with a constant energy cost per unit COD mass of 0.6 ± 0.1 kWh (g COD)−1. The initial N of CIP was pre-eminently converted into nitrate, alongside nitrite and ammonia to lesser extent. Recalcitrant acetic, oxalic, and formic acids were detected as final carboxylic acids.

Co-Extraction of Uranium and Mercury Using Ion Exchange from Cemented Radioactive Waste Sulfuric Leachate in Iodide Media

The production of medical isotopes in Chalk River Laboratories facilities (Chalk River, ON, Canada) has resulted in a large quantity of cemented radioactive waste (CRW) containing valuable elements such as uranium. From the perspective of recovering and ultimately recycling valuable elements from CRW, the solubilization of key constituents such as uranium, mercury, and cesium has been previously investigated using H2SO4/KI. However, to achieve recycling of these elements, separation must be performed as they are co-solubilized. In this study, the extraction of uranium and mercury by chelating resin Lewatit TP260 from surrogate cemented radioactive waste (SCRW) leaching solution in sulfuric media and in the presence of iodide was investigated. Extraction of U and Hg was assessed as a function of the concentration of KI (0.12 M to 0.24 M) used during the SCRW dissolution process. Continuous experiments showed that the Lewatit TP260 functional group, aminomethylphosphonic acid, had a high affinity for U. Mercury was also extracted onto the Lewatit TP260. However, the presence of iodide in the SCRW leaching solution increased the competition between the adsorbed mercury of the stationary phase and the iodide–mercury complexes of the mobile phase. Additionally, the reusability of the resin was tested through extraction and desorption cycles. Due to the presence of trivalent cation, the capacity of Lewatit TP260 for U and Hg decreases with the number of cycles.

Comparing the effects of jouravskite and ettringite on the hydration of the clinker

Manganese enters the clinker from alternative fuel and alternative raw materials. It is present in the iron ores utilized in the cement burning and is found in the slags employed as supplementary cement materials. The jouravskite, as a member of the ettringite family, may form in limestone cement when exposed to sulfate media. To understand its effect on the hydration process, the expansion of small cylindrical clinker pastes doped with synthesized jouravskite and ettringite in magnesium sulfate solutions was measured with a micrometer; and the compressive strength of representative cubes was monitored. The phases formed were characterized by means of X-ray diffraction, infrared spectroscopy and scanning electron microscopy. The jouravskite is found to be a strong retarder for clinker hydration probably due to its adsorption on the cement hydrates.

Direct Extraction of Ni(II) from Acidic Polymetallic Sulfate Media with a Novel Synergistic Extraction System of DNNSA-MSL211

Direct extraction of Ni(II) from Fe(III), Al(III), Ca(II), Mg(II), and Mn(II) is a bottleneck issue in the hydrometallurgy processes of laterite-nickel ore, spent batteries, and other secondary sources. One of the biggest challenges in achieving direct extraction of Ni(II) is the lack of stable and efficient extractants. Hence, a novel bipyridine extractant MSL211 was designed and synthesized in this paper. With its strong steric resistance and electrostatic interaction, MSL211 can form a stable eight-membered chelating ring with Ni(II), thereby having a high bonding ability toward Ni(II). Therefore, based on the high bonding ability of MSL211 toward Ni(II) and the low extraction capacity of DNNSA for Fe(III), an efficient synergistic extraction system of DNNSA-MSL211 was proposed. The synergistic extraction system of DNNSA-MSL211 realizes direct extraction of Ni(II) from Fe(III), Al(III), Ca(II), Mg(II), and Mn(II) without neutralization, precipitation, and solid/liquid separation processes, which are inevitable but problematic processes in the current hydrometallurgy processes for removing Fe(III), Al(III), and Mn(II). The effects of the molar ratios of DNNSA:MSL211, shaking time, temperature, O/A ratios, and equilibrium pH on the extraction behavior of Ni(II) were investigated. Under optimum conditions, the extraction efficiency of Ni(II) was as high as 97.62%, and the separation coefficient of Ni(II) over all impurities was greater than 400. To elucidate the mechanism of the high selectivity of DNNSA-MSL211 toward Ni(II), DFT calculations were carried out to calculate the binding energy (ΔE) and Gibbs free energy (ΔG(ext)) of the extraction process. Furthermore, this paper investigated the entire ″extraction-stripping″ process, demonstrating that the synergistic extraction system of DNNSA-MSL211 avoids neutralization, precipitation, and solid/liquid separation processes, minimizes hazardous waste generation, and shortens process flow while meeting the objectives of sustainable and clean production.

Electrooxidation of Phenol on Boron-doped Diamond and Mixed-metal Oxide Anodes: Process Evaluation, Transformation By-products, and Ecotoxicity

Phenolic pollutants raise health and environmental concerns due to their widespread occurrence in industrial wastewaters. Electrooxidation was studied for phenol degradation in different supporting electrolytes: NaCl, Na2SO4, H2SO4. Experiments were performed at constant current density 20 mA cm−2. Two anode materials were tested ‒ boron-doped diamond (BDD) and mixed-metal oxide (MMO). Degradation process and its impact was investigated from technological, analytical, and ecotoxicological viewpoints. Removal efficiency was monitored by phenol index spectrophotometric method and phenol removal quantified with HPLC-DAD. Additionally, transformation by-products were tracked with GC-MS and LC-MS, as well as ion chromatography. Finally, ecotoxicity was investigated using Daphnia magna. Electrooxidation was efficient and had low energy consumption. The use of BDD anode led to higher removal efficiencies and induced more progressive degradation to simple organic acids, compared to MMO. Selection of electrolyte affected degradation pathways and detoxification pattern. Treatment by BDD in NaCl led to complete phenol removal in 30 min, but undesired chlorinated aromatic by-products were formed. Treatment in sulphate medium led to slower processes irrespective of pH, but less problematic by-products with minimal ecotoxicological impact emerged. By using multi-aspect methodology, this study reevaluates phenol electrooxidative degradation and contributes to better understanding of electrooxidation performance in water treatment.