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Copyright of International Journal of Engineering Transactions C: Aspects is the property of International Journal of Engineering (IJE) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wastewater treatment plants are an important pathway for microplastics (MPs) to enter the environment. In recent decades, hybrid treatment technologies such as sonoelectrocoagulation have been used to treat various types of wastewater. This study aimed to remove polypropylene microplastics from synthetic wastewater by sono-electrocoagulation process using central composite design. The central composite design was utilized to investigate the relationship among four independent variables including the number of MPs (0.003-0.03 MPs/L), sodium sulfate concentration (180-9000 mol/L), voltage (1-15 V) and reaction time (20-180 min) on the efficiency of polypropylene microplastic. Design Expert 13 software and central composite design method were used to design and analyze the experiments and results. The optimum number of concentration of MPs, sodium sulfate concentration, voltage, and reaction time were found to be 6343.36 MPs/L, 0.0181924 mol/L, 10.0356 V, and 62.21 min, respectively. In optimal conditions, polypropylene removal was found to be %90.34. Central composite design proposed a quadratic model for this process. Adequacy of the model using lack of fit statistical tests values, p-values, and F-values was checked, yielding the values of were 1.76, 0.0001 <, 19.51, respectively. The R2, R2 adjusted, R2 predicted values which were 0.9367, 0.8776, 0.6959, respectively. Considering the proper removal efficiency, the sono-electrocoagulation process can be used to remove microplastics. [ABSTRACT FROM AUTHOR]

Effluent wastewater from industrial processes needs to be properly treated before being discharged into the environment. Conventional procedures for handling this wastewater can be problematic due to the presence of toxic elements, time constraints, and complexity. However, a new electrochemical procedure has been developed as an effective method for remediation. In a recent study, refinery wastewater was successfully treated using an electrochemical technique combined with ultrasonic irradiation and photocatalysis. The study found that electrocoagulation, which uses cheap and recyclable metal electrodes, was a simple, efficient, practical, and cost-effective way to handle refinery wastewater. Various parameters were investigated, including electrode metals, operating time, applied voltage, pH, inter-electrode gap, and temperature. The aim was to determine the optimal configuration for pollutant removal. The study also focused on the synergistic effects of combining electrocoagulation and photocatalysis to improve the efficiency of contaminant removal in oily wastewater. By integrating these two treatment technologies, the researchers aimed to enhance pollutant removal rates, energy efficiency, and overall system performance. The research provided valuable insights into the feasibility, optimization parameters, and applicability of the electrocoagulation-photocatalysis process for remediating organic contaminants in oily wastewater industrial effluents. The results showed that electrocoagulation, especially when combined with ultrasonic irradiation and TiO2 photocatalysis, was highly effective in pollutant removal within a short timeframe. These findings support the implementation of this procedure for remediating most industrial wastewater.In conclusion, the study contributes to the development of more effective and sustainable water treatment strategies. The electrocoagulation-photocatalysis process shows promise in addressing the remediation of organic contaminants in oily wastewater from industrial processes. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present study is based on the application of the electrocoagulation process in removal of Eriochrome Black T dye pollutant. It is found that many factors like voltage, temperature, number of pairs of electrodes, contact time, inter electrode distance are affecting the electrocoagulation. As voltage is increased from 5 V DC to 30 V DC the removal efficiency increases linearly and attained 98.3% at 13 V DC and beyond that the removal of dye is constant. The temperature plays important role in electrocoagulation and maximum removal was observed at 28 °C, at high temperature electrocoagulation decreases. It is also found that inter-electrode distance of 0.5 cm is more favourable for removal. As the number of pair of electrodes increases the removal capacity also increases. If there is a rise in concentration of the solution from 10 ppm to 1000 ppm the efficiency decreases from 99.2% to 63.6%. The chemical oxygen demand of the treated solution drops from 1600 to 320 ppm under 13 V DC, 180 s of contact time for 25 ppm of dye solution. The energy consumption, anode dissolution also plays a crucial role in removal of dye. [ABSTRACT FROM AUTHOR]

Background: Considering the increased demand for cars in different countries during recent years, using car washes for washing vehicles has received a lot of attention. This study aimed to assess removing chemical oxygen demand (COD) from car wash effluent using the electrocoagulation method. Methods: A reactor with dimensions of 40 cm * 50 cm * 50 cm of Plexiglas with a volume of 90 L equipped with an electric current generator and an electrode was used connected to the DC current generator in the form of Al-Al. The response surface method (RSM) was applied to optimize the factors affecting COD removal in the electrocoagulation process. For this purpose, D-optimal was utilized to optimize the experiments. The effects of measurable factors such as electrolysis time (X1), current density (X2), and aeration time (X3) were examined to check COD removal. Results: According to the results, the optimal operating conditions for COD removal during electrolysis (30 min) were as follow: the current density was 18.75 A/m², and the aeration time of 30 min was 48.51%. Conclusion: In conclusion, electrocoagulation is, to some extent, a reliable and environmentally compatible technique for car wash wastewater treatment. [ABSTRACT FROM AUTHOR]

Clean water scarcity and food waste are global environmental concerns. However, food waste contains valuable bioactive compounds along with other ingredients currently get discarded in landfills, contributing to methane emissions, and exacerbating global warming. To address these issues, I developed a solution that utilizes fruit waste as bio-sorbents to purify contaminated water. Twenty-five Fruit Peel Powders (FPPs) were prepared and screened for their adsorption properties using methylene blue dye tests. Based on their effectiveness in removing divalent metal ions, oil waste, microbes, microplastics (PP), and agricultural runoffs, the FPPs were grouped into five categories, with three replicates each. Functional kinetics and dose dependency were examined using Langmuir and Freundlich adsorption isotherms for each category. To optimize the process, FPPbased adsorption chromatography (AC) was combined with electrocoagulation (EC). Statistical response surface methodology, employing a central composite design, was used to optimize the main variables: column temperature, electrolysis time, electrode distance, initial contaminant dose, and column bed contact time. Fifty different combinations of experiments were conducted, encompassing low, high, and axial points, to achieve maximum removal efficiency (R%) for all contaminants. The suitability of the models was verified through ANOVA. Under the optimized conditions, up to 91% of contaminants were successfully removed from the water, enabling a low-cost process with reduced sludge output. [ABSTRACT FROM AUTHOR]

The application of the electro-coagulation process to the identified contaminated groundwater at Abala community, a suburb of Ilorin metropolis in Kwara state, Nigeria, is the subject of this study. The groundwater samples were electro-coagulated in a batch reactor of 2.5L containing 1 litre volume of contaminated groundwater for 1 hour per run using a DC power supply ranging from 10v to 20v at constant current 5amp and 2amp to 6amp at constant voltage 10v using graphite electrodes. The results revealed that electrocoagulation process can reduce turbidity, TDS, Electrical Conductivity, BOD, TOC, COD, and color by 97.3 %, 91.2 %, 91.1 %, 96 %, 99.7%, 99.7%, 79.9%, and 82.96 %, respectively. Through Atomic Absorption spectroscopy analytical study, the process also shows removal efficiency of Manganese, Iron, and Zinc of 82.96 percent, 70.0 percent, and 95.30 percent, respectively. The outcome of the electro-coagulation process met the World Health Organization (WHO), the United States Environmental Protection Agency (USEPA), and the Water Environment Partnership In Asia (WEPA) criteria for both drinking water and general industrial wastewater discharge guidelines. The electro-coagulation treatment for contaminated groundwater was efficient and effective, therefore it is recommended in this study for Nigerians. [ABSTRACT FROM AUTHOR]

Copyright of Kirkuk Journal of Science is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Landfill leachate is commonly heavily contaminated wastewater. and consists of a high number of organic compounds, inorganic salts, toxic gases and heavy metals that exert a serious threat to the environment and public health. Thus, it requires treatments before direct release into receiving waters. This paper presents the results of electrocoagulation (EC) and chemical coagulation (CC) treatment of leachate from the Erbil landfill site. The removal efficiency of chemical oxygen demand (COD), phosphate (PO43-), total suspended solids (TSS), total organic compound (TOC), and color of leachate was studied using iron and aluminum electrodes. The removal percentages were also compared to those produced by electrochemically generated Fe2+ and Al3+ dosages. The effect of different pH values on the removal efficiency of these parameters was evaluated at optimal conditions. The removal percentages for chemically added coagulants were lower than those for electrochemically generated Fe2+ and Al3+. In EC, the highest COD removal efficiency of 92% and 87% was achieved at the original concentration (C1) for iron and aluminum electrodes, respectively. The iron and aluminum electrodes also showed a maximum color removal of 90% and 95%, respectively, for the original undiluted leachate solution. Both Fe and Al electrocoagulation methods were not effective in removing TOC from the leachate of municipal solid waste. The highest removal efficiency of 78% was achieved at a 1:4 diluted solution (C2) using the Al-electrocoagulation method. The maximum removal percentage for PO43-was 94% at C1 using the Fe-electrocoagulation system. However, both systems were not very effective in removing TSS. [ABSTRACT FROM AUTHOR]

Treatment of Municipal wastewater by Electrocoagulation (EC) process using punched aluminium and zinc electrodes was studied in a batch EC cell reactor. Response surface methodology (RSM) based on Central Composite Design (CCD) was utilized to optimize the operating parameters for the removal of % Total Suspended Solids (TSS) and % Chemical Oxygen Demand (COD) from Municipal Sewage. Effect of operating parameters such as Electrode Distance (x1), Electrolysis Time (x2) and Voltage (x3) has been optimized for the removal of TSS and COD. The prediction of removal percentage of TSS and COD in various Operational circumstances is done by using Quadratic model. The significance of each operating parameter was computed by Analysis of variance (ANOVA). To achieve the maximum removal of % TSS and % COD, the optimum conditions were Electrode distance(x1)—3 cm, Electrolysis Time (x2)—70.299 minute and Voltage (x3)—6.5V. It was observed that the performance of electrocoagulation process increased up to 61.45% for COD removal, and 73.73% for TSS removal using punched electrode compared to plane electrodes. [ABSTRACT FROM AUTHOR]

Efficient removal of heavy metals from wastewater is crucial due to their harmful effects on health and the environment. Electrocoagulation is an alternative treatment technique that applies electric current to metallic electrodes, forming coagulants and precipitating contaminants. This study evaluated the efficiency of electrocoagulation in removing copper (Cu) and cadmium (Cd) from aqueous solutions. An experimental study was conducted to assess the simultaneous and independent removal of each metal. Electrodes based on 1050 aluminum alloy were used, and different pH values (2.6, 5, and 7) and electric current densities (1, 2, and 3 mA/cm²) were evaluated. The treatments were carried out for 40 min at room temperature (25 ± 1 °C). Atomic absorption spectroscopy technique was employed for monitoring and quantification of both metals. The results showed the complete removal of Cd in mixture and almost complete removal of Cu (>99 %) when used independently. The removal efficiency increased with pH and electric current density, and it was found that removal was more efficient under neutral or slightly alkaline pH conditions. The findings of this study can be useful for the implementation of this technology in the industry for the treatment of wastewater contaminated with both metals. [ABSTRACT FROM AUTHOR]

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background/Aim: To compare the microscopic, macroscopic and thermal damage inflicted to ovarian tissue by conventional monopolar and bipolar energy, argon plasma coagulation (APC) and diode laser. Materials and Methods: Bovine ovaries were used as a substitute for human tissue and subjected to the four aforementioned techniques and the inflicted damage was measured. Sixty fresh and morphologically similar cadaveric bovine ovaries were divided into five equal groups, each group was subjected to one of the following energy applications for both 1 and 5 s: Monopolar, bipolar electrocoagulation, diode laser, preciseAPC® and forcedAPC®. Ovarian temperatures were measured at 4 and 8 s after treatment. Formalin-fixed ovarian specimens were examined by pathologists regarding macroscopic, microscopic and thermal tissue damage. Results: None of the ovaries reached the temperature producing severe damage (40°C) after 1 s of energy transfer. Heating of adjacent ovarian tissue was least pronounced when preciseAPC® and monopolar electrocoagulation were applied (27.2±3.3°C and 28.2±2.9°C after 5 s of application, respectively). Conversely, 41.7% of the ovaries subjected to bipolar electrocoagulation for 5 s overheated. ForcedAPC® resulted in the most pronounced lateral tissue defects (2.8±0.3 mm after 1 s and 4.7±0.6 mm after 5 s). When the modalities were applied for 5 s, the electrosurgical instruments (mono- and bipolar) and preciseAPC® induced similar lateral tissue damage (1.3±0.6 mm, 1.1±1.6 mm and 1.2±1.3 mm, respectively). preciseAPC® created the shallowest defect of all the techniques (0.05±0.1 mm after 5 s of application). Conclusion: Our study hints at superior safety profiles of preciseAPC® and monopolar electrocoagulation compared to bipolar electrocoagulation, diode laser and forcedAPC® for ovarian laparoscopic surgery. [ABSTRACT FROM AUTHOR]

This paper investigated the treatment of textile wastewater polluted with aniline blue (AB) by electrocoagulation process using stainless steel mesh electrodes with a horizontal arrangement. The experimental design involved the application of the response surface methodology (RSM) to find the mathematical model, by adjusting the current density (4-20 mA/cm2), distance between electrodes (0.5-3 cm), salt concentration (50-600 mg/l), initial dye concentration (50-250 mg/l), pH value (2-12 ) and experimental time (5-20 min). The results showed that time is the most important parameter affecting the performance of the electrocoagulation system. Maximum removal efficiency (96 %) was obtained at a current density of 20 mA/cm2, distance between electrodes of 1.75 cm, salt concentration of 462.5 mg/l, dye concentration of 50 ppm, pH value of 7, and time duration of 15 min. On the other hand, the electrocoagulation efficiency was directly proportional to current density, salt concentration, and contact time, while it was inversely proportional to dye concentration. Isotherm experiments showed that the equilibrium data are best fitted to Freundlich isotherm and sips isotherm; whereas the kinetics results showed that the rate of adsorption followed the pseudo-second-order with an R2 value of 98 %. [ABSTRACT FROM AUTHOR]

This study intends to assess the removal efficiency of the chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total suspended solids (TSS) from raw tannery wastewater using electrocoagulation by aluminum electrodes as well as to determine the effects of its main operating factors. Therefore, the response surface methodology was applied through an experimental Box–Behnken design by considering the current intensity (I), treatment time (T), and pH levels as the factors. In addition, the BOD, COD, and TSS removal percentages were considered to be the response variables. The results indicate that the treatment time, current intensity, and pH level were significant for COD and TSS, whereas only the treatment time was significant at a confidence level of p-value < 0.05 for BOD. For COD, the optimal operating conditions were I = 3 A, T = 24 min, and pH = 8.4; for BOD, the optimal operating conditions were I = 3 A, T = 24 min, and pH = 5.5; and for TSS, the optimal operating conditions were I = 2.7 A, T = 19 min, and pH = 7.4. Under these conditions, removal efficiencies of 56.8%, 69.2%, 99.9% were observed for COD, BOD, and TSS, respectively. The results suggest that electrocoagulation is an effective method for removing the parameters under study; therefore, it is a viable alternative for reducing the pollution issues caused by the tannery industry. [ABSTRACT FROM AUTHOR]

Bypass wastewaters in excess of plant capacity require in-plant wastewater treatment strategies capable of lessening the contamination magnitude prior to their discharge into water bodies. This study introduces a novel hybrid potassium ferrate(VI)–iron electrocoagulation system for the treatment of bypass wastewater. To understand the synergistic effect of the hybrid system, the response surface methodology and the Box Behnken design were utilized based on four preselected variables (current density, potassium ferrate(VI) dosage, interelectrode distance, and time). The current density and potassium ferrate(VI) dosage and their interaction were found significant in achieving a higher soluble chemical oxygen demand (sCOD) removal and faster ferrous (Fe2+) oxidation. The addition of 0.10 mM potassium ferrate(VI) to the electrocoagulation cell operated for 45 min at a 22 mA/cm2 current density and 15 mm interelectrode distance increased the sCOD removal efficiency from 39.71% to 63.57%. Moreover, the addition of 0.1 mM potassium ferrate(VI) to the previously stated electrocoagulation cell conditions decreased the percentage of Fe2+ to the electrochemically supplied total iron (Fet) from 34.02% to 4.63%. The oxidation effect provided by the addition of potassium ferrate(VI) to the iron electrocoagulation cell increased the sCOD removal by about 10%. In addition, the pH increase that resulted from the dissociation of potassium ferrate(VI) promoted favorable conditions to quickly oxidize the Fe2+ ions generated at the iron anode to form the favorable Fe(OH)3 precipitates. The experimental results clearly demonstrated the synergetic effect of the coupled processes for the removal of sCOD from bypass wastewater. [ABSTRACT FROM AUTHOR]

In the present study, electrocoagulation (EC), alone or in combination with precipitation or centrifugation, was assessed as a potential pretreatment method for enhanced production of biofuels from 3-phase decanter olive mill wastewater (OMW). Experiments were performed using undiluted and diluted OMW in an EC reactor, operating with a current of 2 A and either Al or Fe electrode materials. Subsequently, diluted OMW was subjected to EC followed by precipitation or centrifugation. The effect of current density (0.05, 0.5 or 1 A) on the combined EC – centrifugation process was assessed and a high reduction of organics was observed for the higher current applied. The different fractions of the pretreated effluents were used as substrates for methane, hydrogen as well as for bioethanol production and the maximum energy recovery was determined in each case. It was shown that, EC at a current of 2 A or further combination with physical methods led to low biofuels yields. However, reduction of the current during EC to 0.05 A or 0.5 A, led to high methane and ethanol yields, with the best scenario being the production of methane yielding an energy equivalent of 1902 kJ/L OMW. • Electrocoagulation (EC) was a promising pretreatment method for OMW. • EC combined with centrifugation led to high removal efficiency of pollutants. • Low current (0.05 A) during EC enhanced biofuels production yields. • Electric energy consumption was 9 kWh/m3 for EC at the optimum conditions. [ABSTRACT FROM AUTHOR]

The present work examined the removal of methylene blue (MB) from aqueous solutions through an electrocoagulation/hazelnut shell (EC/HNS) adsorption coupling process. The process was evaluated using a Box–Behnken design (BBD) under the response surface methodology (RSM). According to the obtained results from BBD–RSM regression analysis, we found that the experimental data are best fitted to the second-order polynomial model with coefficient of determination (R²) value of 0.9534, adjust coefficient (Radj ²) value of 0.9926 and predicted correlation coefficient (RPred ²) value of 0.9973. The maximum MB removal efficiency was obtained under optimized conditions (HNS dosage, 6 g/L; reaction time, 17.75 min; and current density, 2.6 mA/cm²). Under the optimum conditions, the MB removal rate reached 99.45%, and the RSM predictive value was 98.71% with a small deviation. These results confirmed that the RSM model accurately and reliably analysed the process of removing MB from wastewater. [ABSTRACT FROM AUTHOR]

In this work, the mass transfer of aluminum ions in the electrocoagulation reactor was investigated using limiting current density technique by employing a novel rotating impeller anode. The effect of different anode rotational speeds of 75, 100, 150, 200, and 250 rpm with various anode diameters of 9.2, 10.2, and 11.2 cm on limited current values, mass transfer coefficient and COD removal efficiency were studied. Results showed the limited current values increase with the increase of the rotational speed and diameter of the impeller anode. Furthermore, the mass transfer coefficient increases with the increase of rotational speed and impeller diameter. Data for the conditions 11,852 < Re < 58,550 and 88 < Sc < 285 were found to fit the equation for the largest diameter of 11.2 cm; Sh = 2.1 R e 0.93 S c 0.33 . Moreover, the maximum COD removal efficiency was at the largest anode diameter of 11.2 cm, validating the enhancement of aluminum mass transfer by increasing anode diameter. [ABSTRACT FROM AUTHOR]

The electrocoagulation (EC) of dye-polluted aqueous solutions was considered using iron electrodes. In a novel approach, the EC process was simultaneously integrated with ultrasound (US) and H2O2 on the basis of the electro-generation of magnetite nanoparticles via sacrifice anode. Direct red 31 (DR31) dye was chosen as model pollutant. During the short reaction time of 20 min, the US/H2O2/EC process led to the highest decolorization efficiency of 93.3% compared with the US/EC (65.3%) and H2O2/EC (54.1%) processes. The real textile wastewater sample was effectively treated and mineralized by the US/H2O2/EC process (COD removal: 86.7%; TOC removal: 58.7%). [ABSTRACT FROM AUTHOR]

The present work focuses on the feasibility of electrocoagulation (EC) process for the treatment of oil and grease wastewater generated from locomotive wash facilities. Experimental investigations have shown the influence of various factors affecting EC using continuous reactor. The effect of various operating parameters, like reaction time, electrode spacing, and applied voltage, was investigated and optimized using Box-Behnken design method. The optimized value of applied voltage and electrode spacing were found to be 28 V and 3 cm, and Chemical Oxygen Demand removal efficiency obtained was 91.9%. As a result, EC process can be an alternative method for the treatment of oily wastewater. [ABSTRACT FROM AUTHOR]

The present study deals with the treatment of electro plating effluent (EPE) by electrocoagulation (EC) using iron as a sacrificial electrode. The initial concentration of chromium (VI) and lead (Pb) is found to be 55.3 and 3.5 mg/dm3 in EPE. With four-plate configurations, a current density (CD) = 73.5 A/m2 and pH = 3.5 was found to be best. At this operating condition, maximum 91.7% Cr (VI) (i.e., 4.92 mg/dm3) and 91.3% Pb (i.e., 0.304 mg/dm3) removal obtained in 90-min EC. Anode consumption was increased with a decrease in pH. It was also observed that energy consumption increased with an increase in pH. The settling characteristics of EC treated sludge were also analyzed at different pH and settling at pH 9.5 was found to best. Study indicated that EC treatment is successfully applicable to treat heavy-metal-oriented waste water. In addition, this technique is very effective to treat real waste water (electroplating effluent) along with minimum cost. [ABSTRACT FROM AUTHOR]

In this paper, the modeling and the optimization of the removal efficiency of ketoprofen (KTP) by the electrocoagulation process were studied. The central composite design experiments (CCD) method was used to study the main effects and the interaction effects between operational parameters and to optimize the value of each parameter. According to the regression equation obtained, the current density appears to be one of the most important parameters (b2 = +22.11) controlling the removal efficiency of KTP. The positive sign of b2 coefficient suggests that the increase of current density increases the yield of removal. The second significant parameter with a negative effect was the initial KTP concentration (b3 = −16.27). This result suggests that the removal efficiency was inversely proportional to the initial concentration. In addition, according to the model, the most influencing interactions were pH-current density, pH-initial concentration, and current density-initial concentration. The model obtained by CCD led to the following optimal conditions for KTP removal efficiency (96.70%): pH = 7, i = 24.04 mA cm−2, and C0 = 5 mg L−1. [ABSTRACT FROM AUTHOR]

The current research aims to investigate the treatment of real chrome tanning effluent by continuing electrocoagulation (EC) with electrodes of aluminum (anode) and iron (cathode). Also, the kinetic study and the effect of current density and operating time on Cr (VI), turbidity, and chemical oxygen demand (COD) removal efficiency were evaluated. The results show that maximum removal efficiency of 84.7 % for Cr (VI), 88.7 % for turbidity and 81.0 % for COD occurred at a current density of 679.3 A/m². The maximum turbidity removal value was reached after 15 minutes of operation, while it took 20 minutes to remove the maximum value of Cr (VI) and COD at pH 3.5. The kinetic data were fitted to the pseudo second order model for COD and the pseudo first order for Cr (VI) showing a higher removal rate of Cr than COD. The estimated operating cost was USD 2.74/m³ of effluent. This value only included anode material and energy consumption costs. [ABSTRACT FROM AUTHOR]

Although the application of high intensity focused ultrasound (HIFU) has been demonstrated to be a non-invasive treatment technology for tumor therapy, the real-time temperature monitoring is still a key issue in the practical application. Based on the temperature-impedance relation, a fixed-point magnetically induced magnetoacoustic measurement technology of treatment efficacy evaluation for tissue thermocoagulation during HIFU therapy is developed with a sensitive indicator of critical temperature monitoring in this study. With the acoustic excitation of a focused transducer in the magnetoacoustic tomography with the magnetic induction system, the distributions of acoustic pressure, temperature, electrical conductivity, and acoustic source strength in the focal region are simulated, and the treatment time dependences of the peak amplitude and the corresponding amplitude derivative under various acoustic powers are also achieved. It is proved that the strength peak of acoustic sources is generated by tissue thermocoagulation with a sharp conductivity variation. The peak amplitude of the transducer collected magnetoacoustic signal increases accordingly along with the increase in the treatment time under a fixed acoustic power. When the temperature in the range with the radial and axial widths of about ± 0.46 mm and ±2.2mm reaches 69 °C, an obvious peak of the amplitude derivative can be achieved and used as a sensitive indicator of the critical status of treatment efficacy. The favorable results prove the feasibility of real-time non-invasive temperature monitoring and treatment efficacy evaluation for HIFU ablation using the magnetically induced magnetoacoustic measurement, and might provide a new strategy for accurate dose control during HIFU therapy. [ABSTRACT FROM AUTHOR]

In this research, a case study is presented for the electrocoagulation treatment of wastewater produced in a drilling oil site. The process variables of the electrolysis time and current density were investigated with the response parameters of total dissolved solids (TDS) and energy consumption. A process integration to identify the Pareto front is designed with respect to the removal of TDS and its respective electricity cost using the global solver of the LINGO 18.0 software. An essential equation generated by the response surface methodology is used in conjunction with the cost equation based on the consumption of energy in the aspect of electrocoagulation. Results in the identification of the Pareto front show a maximum TDS removal of 71.4 % with a corresponding electricity cost of 8.41 USD/m3 under the conditions of 2 min (electrolysis time) and 140.4 mA/cm2 (current density). On the other hand, the minimum cost resulted in 0.53 USD/m3 which corresponds to a TDS removal of 29.2 % under the conditions of 0.5 min (electrolysis time) and 35.1 mA/cm2 (current density). This study has established an appropriate trade-off between the TDS removal and electricity cost by producing the Pareto optimal curve. Hence, this can enable an appropriate decision-making strategy for the stakeholders for future applications in the electrocoagulation method. [ABSTRACT FROM AUTHOR]

Many people around the world rely on groundwater for drinking and sanitation, however, they are exposed to various health risks from the naturally occurring groundwater arsenic (As). Air-cathode Assisted Iron Electrocoagulation (ACAIE) using Carbon Black Pearls 2000® cathode was previously shown catalyse the removal of groundwater As by producing hydrogen peroxide (H2O2). This work explored Vulcan® XC-72, and Printex® L6 Carbon as alternative cathodes for iron electrocoagulation which are more selective towards the 2-electron oxygen reduction reaction into H2O2 compared to Carbon Black Pearls®. The cathodes were tested in an ACAIE set-up to treat synthetic groundwater spiked with 1,500 µg/L of As at different charge dosage rates (CDR) from 1.56 C/L-min to 100 C/L-min with a total charge dosage of 600 C/L for all set-ups. Although the electrocoagulation energies among the cathodes were similar, the use of Printex® cathode for ACAIE remediated the groundwater for all CDR with final As levels below 10 µg/L. This is in contrast with the less selective Carbon Black Pearls® at low CDR, and the less active Vulcan® Carbon at high CDR where the treated groundwater may still have As levels above 10 µg/L. Future research would explore modifications in the carbon materials and reactor configuration to further optimize ACAIE in removing groundwater As. [ABSTRACT FROM AUTHOR]

Fluoride (F-) has been removed successfully removal from laboratory prepared fluoride water solution through electrocoagulation using Aluminium (Al) electrode. Consequence of parameters such as pH, current density (CD), initial mass of F- and treatment hour are analyzed over F- removal. The maximum defluoridation of 85.2% occurred at pH 6.5, CD 34.72 A/m² (1A) and contact time of 50 min for starting F- concentration of 50 mg/L in the solution. The kinetic study has been performed to explore the mechanism of electrocoagulation technique, disclosed that the order of the reaction was in the span 2.0-2.07 and 0.05 for fluoride concentration and current density, respectively. This study shows that electrocoagulation using Al electrode has good potential for fluoride removal. [ABSTRACT FROM AUTHOR]

In this study, the performance of glyphosate removal in an electrocoagulation batch with two electrodes formed by the same metal type, consisting of aluminum, iron, steel and copper have been compared. The aim of this study intends to remove glyphosate from an aqueous solution by an electrocoagulation process using metal electrode plates, which involves electrogeneration of metal cations as coagulant agents. The production of metal cations showed an ability to bind together to form aggregates of flocs composed of a combination of glyphosate and metal oxide. Electrocoagulation using aluminum electrodes indicated a high percentage removal of glyphosate, 94.25%; followed by iron electrodes, 88.37%; steel electrodes, 62.82%; and copper electrodes, 46.69%. The treated aqueous solution was then analyzed by Fourier Transform Infrared Spectroscopy. Percentages of Carbon, Hydrogen, Nitrogen, Sulfur remaining in the treated aqueous solution after the electrocoagulation process have been determined. The treated water and sludge were characterized and the mechanism of the overall process was concluded as an outcome. An X-Ray Diffraction analysis of dried sludge confirmed that new polymeric compounds were formed during the treatment. The sludge composed of new compounds were also verified the removals. This study revealed that an electrocoagulation process using metal electrodes is reliable and efficient. Image 1 • Electrocoagulation performance depends on production of metal cations as coagulant. • Metal cations attract glyphosate and bind together to form aggregates of flocs. • Appearance of new polymeric compounds confirmed by FTIR, CHNS and XRD analyses. • Analytical analyses define mechanism of glyphosate removal by electrocoagulation. • Aluminum electrodes indicated a high percentage removal of glyphosate, 94.25%. [ABSTRACT FROM AUTHOR]

In this research, reduction of sludge production and improvement of sludge stabilization degree were aimed, and in this regard, the samples received from an urban wastewater treatment plant were subjected to electrocoagulation (EC) as a disintegration technique. A monopolar EC reactor was designed and iron electrode was used for sludge disintegration. The effect of reaction time, pH and varying current densities on disintegration degree (DD) was determined, and the optimum conditions were found as pH 7, 30 min (reaction time), and 150 A/m2 (current density). DD was found as 84.23%, and soluble chemical oxygen demand was found as 675.2 mg/L under optimum conditions. In this research, the disintegration stage of sludge was defined with the best second-order kinetic model. The operating cost was estimated as 0.078 €/m3 for optimum conditions. Also, the EC-induced disintegration ability of sludge was determined using total suspended solids, total organic carbon, capillary suction time, particle size distribution, specific surface area and viscosity. The findings showed that EC technique can be an effective means for sludge disintegration. [ABSTRACT FROM AUTHOR]

• Al electrodes were more effective than Fe electrode in TOC removal. • The most suibatle current density is determined as 25 mA/cm2. • pH = 5 was determined as the optimum operating pH. • Under the most suitable conditions 65% TOC removal was achieved. • Operating cost was calculated as 1.5 $/m3. In situ treated real textile wastewater was subjected to electrocoagulation for reuse in agricultural irrigation The effect of several parameters such as electrode type (Al and Fe), current density (12.5–100 mA/cm2), initial pH (5–10), and electrocoagulation time (0–120 min) were investigated to determine the optimum electrocoagulation condition. Monopolar electrodes connected in parallel were used for all experiments. The performance of the experiments was mainly evaluated using the Total Organic Carbon (TOC) removal. The Al electrode, 25 mA/cm2 of current density and a pH=5 was selected as the optimum conditions. Under these conditions 42.5% TOC, 18.6% chemical oxygen demand (COD), 83.5% turbidity, 64.7% of the total suspended solids, and 90.3–94.9% color removal efficiencies were achieved. The operating cost was calculated by considering the energy and electrode consumption and evaluated as 1.5 $/m 3 of treated wastewater. The electrocoagulation reaction followed the second order reaction kinetics. [ABSTRACT FROM AUTHOR]

• Electrocoagulation and Biological Fungal integrated system for tannery wastewater. • Chromium Cr+6 content reduced 97% via integrated physicochemical and biologic process. • COD content has removed 96% by integrated Electrocoagulation and Fungal Treatment. • Cost-effective electrocoagulation scenario gives the treatment cost of 0.66 $ m−3. The wastewater from tannery industry, using single treatment technology has not been enough to remove the chromium (Cr6+) or high organic content (COD). Electrocoagulation (EC) and Biological Fungal Treatment (BFT) which endure against toxic and/or highly organic content, are promising technologies to eliminate impurities of tannery wastewaters. In this study, the treatment performance of integrated EC and BFT processes via response surface methodology (RSM) was investigated for the tannery wastewater to determine the effects of operating variables. The factors of electrode combination (Al–Fe), pH (4–8), current density (0.54–0.81 A), and electrolysis time (15–60 min) are investigated for EC and inoculum rate (0.5–2%) reaction time (6–36 h) and pH (4–6) are also investigated for BFT. The operating cost of the combined process was calculated as 1.73 $.m−3. It was determined that efficient COD (63.8%) and Cr6+ (90%) removal were achieved via EC (pH 8.0, 60 min reaction time and 0.81 A current). The optimum condition of BFT for COD and Cr6+ removal are at pH 5.0, 36 h reaction time and 2% inoculum rate. Total efficient COD (96%) and Cr6+ (97%) removal were achieved at EC and BFT with the combined system. [ABSTRACT FROM AUTHOR]

Contamination of the ground water with fluoride is a great problem worldwide. Removal of fluoride (F−) ions from simulated natural waters containing fluoride by electrocoagulation (EC) using aluminum electrodes, has been investigated in a discontinuous lab cell. Two types of water have been studied: local tap water and deionized water-based luoride solutions of sodium fluoride with addition of sodium chloride to reach the desired conductivity. The effect of four operating parameters has been followed for a current density fixed at 5 mA/cm2 within the following ranges: fluoride concentration (5–50 mg/L), temperature (25–55 °C), conductivity (1–6 mS/cm) and initial pH (4–8.5). In accordance with published data, the presence of 61 mg/L buffering hydrogencarbonate ions in the tap water was found to substantially reduce the Al(III) amount required for a given abatement in comparison with deionized water. Performance comparison of the discontinuous electrocoagulation treatment between the two types of water has been discussed for 90% abatement of F− introduced, in terms of the amount of Al(III) dissolved over the initial fluoride concentration, the parameters of a previous adsorption model and the fraction of Al(III) flocs not involved in the adsorption. EC performances were shown to be governed by the solution pH for the two types of water, with little effect of the other operating conditions: at initial pH 6, F− abatement was found to require two or three times less trivalent aluminium than at initial pH 8.5. • Fluoride ions can be removed efficiently from water by electrocoagulation. • Lower aluminium amounts are required with hydrogencarbonate anions. • Temperature, concentration and conductivity impact on the treatment performance. • In any condition, more efficient treatment is obtained with pH lower than 7.5. [ABSTRACT FROM AUTHOR]

This work analyzed the use of electrocoagulation as substitute for sugarcane clarification process using sulfitation. It was evaluated technological parameters (Icumsa color and turbidity), phenolic compounds content and CIELAB color parameters. Four kinetics of reduction color from sugarcane juice were carried out. The essays were divided according to the voltage applied: 35, 45, 55 and 65 V (also based on previous tests). Higher voltage treatments achieved greater reduction of Icumsa color, turbidity and total phenolic compounds. However, none of treatments impacted simple phenolic content analyzed in this work. Tristimulus analysis presented some pattern that went beyond technological analysis, including that 65 V essay changed the pigmentation of sugarcane juice and had an early stabilization on chroma. This kind of results could be useful for industry, once they could correlate quality with different color parameters and finally improve the clarification in general with finer settings of technique according to different situations. Unlabelled Image • The electrocoagulation treatment significantly reduced Icumsa color, turbidity and total phenolic compounds. • All treatments did not influence in simple phenolic content analyzed in this work. • Electrocoagulation can change the pigmentation, chroma and lightness of sugarcane juice. [ABSTRACT FROM AUTHOR]

A large quantity of water is used at oil refineries; Consequently, high amounts of wastewater are produced. The main aim of this study is to evaluate COD removal rate using an electrocoagulation process as well as a photocatalytic process with ZnO nanoparticles. Subsequently, the combined treatment was also implemented to reach energy savings and higher performance. At the optimum condition of the EC process (COD concentration of 900m/L, current density of 20mA/cm², pH of 8.5 and NaCl concentration of 0.5 g/L), COD removal rate was 94% after 60 min. For the photocatalytic process at optimum conditions (COD concentration of 600mg/L, ZnO concentration of 80g/m², pH of 5 and irradiation power of 32 W), 76% of COD removal efficiency was obtained, after 300 min. Thereafter, the combined system was implemented, with initial COD concentration of 1000 mg/L at the optimum conditions; First, the COD removal efficiency was achieved to be 47% after 8.5 min using the EC process; after that, the effluent entered the concrete photoreactor for 120 min, which lead to 85% of COD reduction and final COD concentration reached to 75 mg/L. The GC-Mass analysis was also performed which approved the removal of oil comnpounds from the wastewater. [ABSTRACT FROM AUTHOR]

This study aims to optimize the electrocoagulation(EC) process of emulsified oil removal from polymer-flooding sewage (PFS), producing in the oil recovery process and characterized by multiple chemical additives, high viscosity, and high stability. Response surface methodology (RSM) and Box-Behnken statistical experimental design (BBD) were applied to investigate the effects of tilt angles of electrodes, flow rate, and current density as well as the interactions on oil removal and energy consumption. All the experiments were performed in a continuous-flow pattern with an integrated unit combined with reaction and subsequent separation zone. The experimental results suggested that EC technology was very efficient in oily wastewater treatment and was able to achieve 97% oil removal after the system enters into the stable stage with a flow rate of 5.5 L h−1 ，applied current density of 18.9 mA cm−2 and tilt angle 80°. At this time, the energy consumption is 3.50 kWh m−3. Besides, for both of the oil removal and energy consumption, flow rate has the most significant impact, and the current density follows. The results of variance (ANOVA) analysis showed a high correlation coefficient (R2)value of 0.990 and 0.996 for oil removal and energy consumption, respectively, which ensures an adequate fit of the second-order regression. • Application of a novel integrated apparatus for polymer-flooding sewage treatment by electrocoagulation • Study and optimization of the EC process by response surface methodology • Evaluation of the electrocoagulation performance from the aspect of oil removal and energy consumption • 97% of oil was removed at optimum operating conditions with the energy consumption of 3.5 kWh m−3. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • MW radiation mode plays a key role in MW-CWPO. • MW pulsation reaches higher mineralization degree and better H 2 O 2 exploitation. • Energy consumption can be reduced to one third by using the correct strategies. • MW-CWPO is competitive in terms of energy consumption with other intensified AOP. Abstract Over the past few years, microwave technology (MW) has been successfully coupled to different advanced oxidation processes for wastewater treatment. This intensification method provides a rapid and homogeneous heating and, in presence of microwave absorbing materials, hot spots can be generated. These have shown a significant contribution on the overall efficiency of the process. Up to the date, there is no information on the influence of the radiation mode on the system. To gain knowledge on this issue, three different operation modes were studied in the MW-assisted catalytic wet peroxide oxidation of phenol: (i) controlled temperature (120 °C), (ii) controlled continuous MW and (iii) controlled pulsated MW. Other experimental conditions were [Phenol] 0 : 100 mg·L−1, [H 2 O 2 ] 0 : 500 mg·L−1, [graphite]: 500 mg·L−1, pH 0 :3. The pulsated method reached 90% mineralization degree and complete H 2 O 2 decomposition using 240 kJ, three times less energy than the controlled temperature run. Continuous MW showed a slightly inferior performance (X TOC : 82%), ascribed to a worse energy dissipation from the hot spots on the material. After reaction, only biodegradable short chain carboxylic acids remain in the effluent and there are no significant modifications on the catalyst crystallinity, despite the extreme conditions produced by hot spot formation. Under these conditions TOC abatement follows a pseudo-second kinetic order (E A,TOC ≈ 30–40 kJ·mol−1), whereas H 2 O 2 decomposition fits by a pseudo-first order (E A,H2O2 ≈ 33–52 kJ·mol−1). Additionally, the specific energy consumption (EC TOC) for the controlled power runs was lower than that of other intensified AOP, making MW-CWPO a competitive technology for wastewater treatment. [ABSTRACT FROM AUTHOR]

In the present work a combined process is proposed for recovery of metallic copper from industrial electroplating wastewaters comprising electrocoagulation, acidic digestion and electrowinning. The wastewater with the initial Cu2+ ion concentration of 92 mg/L was first subjected to electrocoagulation where it successfully decreased under the upper allowed limit of 2 mg/L. Then, the obtained electrocoagulation sludge was treated with sulfuric acid for digestion and with caustic soda to reach pH 4.8 for precipitation and separation of insoluble aluminum hydroxide, whereas Cu2+ ions remain in solution. Finally, pure metallic copper was produced by electrowinning from the obtained concentrated Cu2+ ions solution. The work proposes the possibility of effectively treating toxic industrial electroplating wastewater accompanied by recovery of significant amounts of valuable pure metals, such as copper. [ABSTRACT FROM AUTHOR]

Highlights • IAFCEC is most cost-effective for Cr(VI) treatment and power generation. • In-situ produced iron hydroxides were used for direct co-precipitation of Cr(VI). • IAFCEC can obtain 100% Cr(VI) removal within 4 h with operating cost of 0.2 USD m3. • Merits of system are evident as it is less dependent upon operating parameters. Abstract Metal-air fuel cell electrocoagulation is one of the most cost-effective and innovative treatment options for metals in water. Here, the removal mechanism of chromium (Cr(VI)) was assessed using an iron-air fuel cell electrocoagulation (IAFCEC) system. Simultaneously, the effects of such treatment were also investigated with respect to a list of parameters controlling groundwater quality. During the IAFCEC operation, in-situ production of stable iron hydroxides (e.g., maghemite, hematite, and goethite) was experienced due to the sacrificial oxidation of the iron anode electrode. Therefore, these iron hydroxides were responsible for direct co-precipitation of aqueous Cr(VI). The removal efficiency of the system was assessed by varying the initial concentrations of Cr(VI) such as1, 5, and 10 mg L−1). The IAFCEC, when operated with low concentrations of competing anions (e.g., silicate, phosphate, magnesium, and calcium), was capable of treating 6 L of water containing 1 mg L−1 Cr(VI) per day with an operating cost of 0.2 USD m−3. This study demonstrates the IAFCEC as one of the most cost-effective treatment methods for Cr(VI) removal based on evaluation of performance relative to other options commonly available. [ABSTRACT FROM AUTHOR]

Highlights • Max. COD removal at 600 mA for 30 min:Al-Al = 68 ± 9%; (Fe-Fe)+air = 60 ± 30%; and Mg-Mg = 27 ± 3%. • Max. OP removal rates (i.e., mg-P/mmol-e):Al-Al, Fe-Fe, and (Fe-Fe)+air = 6.8; Mg-Mg = 0.9. • <0.5 mg-P/L OP achieved in all cases at linearized rate. • Electrocoagulation did not consume alkalinity. • Electrocoagulation with aluminum improved nitrification rates. Abstract Primary influent from a municipal wastewater treatment plant was electrochemically treated with sacrificial aluminum, iron, and magnesium electrodes. The influence of sacrificial anodes on the removal of chemical oxygen demand, total nitrogen, total phosphorus, and orthophosphate during sedimentation was investigated. Nitrification kinetics were assessed on treated supernatant and biogas production was monitored on settled solids. Changes in alkalinity, conductivity, and pH were also recorded. Aluminum and iron electrodes provided high rates of orthophosphate removal (i.e., 6.8 mg-P/mmol-e). Aluminum and iron electrodes also provided similar treatment to equivalent doses of alum and ferric salts (i.e., 38–68% chemical oxygen demand, 10–13% total nitrogen, and 67–93% total phosphorus). The estimated stochiometric ratio of aluminum and iron dosed to orthophosphate removed was approximately 1.3:1 and 4.1:1, respectively. Magnesium electrodes, on the other hand, removed orthophosphate at rates 8–9 times slower than aluminum and iron (i.e., 0.9 mg-P/mmol-e). Magnesium had to be dosed at a ratio of 13.5:1 orthophosphate for phosphorus removal. Orthophosphate removal by magnesium electrodes was most likely limited by electrolysis reactions responsible for increases in pH (i.e., 0.52 pH units/mmol-e). Magnesium electrodes removed 49% chemical oxygen demand and 21% total nitrogen at the high molar ratios required for orthophosphate removal. [ABSTRACT FROM AUTHOR]

Highlights • Molding the electro-dissolution of the Al anode during EC operation. • Predicting both dissolved Al concentration and pH evolution during EC operation. • Simulating the EC operation for arsenic removal from water. Abstract The study of the electro-dissolution of aluminum electrodes during the electrocoagulation process is important for understanding the mechanisms involved in the process. This study involved the experimental determination of both total and dissolved aluminum concentrations during the electrocoagulation processes operation. The total aluminum concentration was fitted with the Faraday's equation and was obtained 1.6 of current efficiency, indicating a super-faradaic behavior of the electrochemical process at the given operating conditions. Additionally, a mathematical model was developed considering the electrochemical dissolution of the Al anode, water electrolysis, hydrolysis of dissolved Al and water dissociation reaction involved in the electrocoagulation process. The simulated results showed a good prediction of the evolution of both concentration of dissolved aluminum and pH during the electrocoagulation process operation. The model was also employed to simulate the removal of arsenic from water by electrocoagulation showing a good prediction of the experimental results at the operating conditions considered. [ABSTRACT FROM AUTHOR]

The electrocoagulation (EC) combined treatment processes have shown promising performances in which the removal of pollutants from industrial wastewater was greatly enhanced. The integration of a free radical producing step with EC has been considered as one of these new combinations that show synergy and improvements in the overall cleaning process performance. This review is devoted to discuss and analyze references on free radicals-assisted EC processes. Different combinations of free radical mechanisms were cited in the literature during the last two decades. They included ozone, advanced oxidation and ultrasound energy-assisted EC. It was noted that most of those studies were lab-scale processes that used synthetic wastewaters rather than real wastewaters. In addition the performances of those combined processes were improved compared to the EC process alone. This review considers the main parameters of free radical EC processes such as mechanisms, kinetic models, scale-up and cost estimation. Many concluding remarks were stated to give insights for possible future investigations. It seems from the results that the ozone-assisted EC is the most efficient combination since its removal efficiency is high in most applications. On the other hand, the combination of ultrasonic energy with EC was reported to reduce electrode passivation. [ABSTRACT FROM AUTHOR]