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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.)

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]

Electrochemical wastewater treatment methods are effectively used for all type of wastewaters and pollutants. One of the huge negative impact of these processes is the energy consumption of the process. Therefore, the goal of the study is to develop a minimal energy user Electrocoagulation (EC) option with an integration of a direct photovoltaic solar panel as a subsection of electrochemical processes for the degradation of low COD (Chemical Oxygen Demand) from metal cutting wastewater. To optimize the operating parameters of the EC process such as pH, current density (C.D.) and electrolysis time (E.T.) Box-Behnken Design by RSM was used with a double criterial optimization option. COD removal and energy consumption were evaluated as responses of the model and they were well-fitted with the quadratic model. Also, it was determined that all parameters are effective on EC process. Optimum conditions were found at a pH of 7.48, a C.D. of 30 A/m², an E.T. of 65 min, an energy consumption of 3.9 kWh/m³ and a desirability of 0.954. At the optimum conditions, the energy consumption of the EC process was fulfilled from solar panel in a ratio of 71% and 1495% in overcast and sunny weather, respectively. Especially, the energy obtained by the solar panel in the sunny weather produces much more than the energy required of the process. [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]

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]

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]

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 effect of the type and concentration of the supporting electrolyte given to the water to increase the conductivity in the electrocoagulation process on the phosphate removal from synthetically prepared waters was investigated. In addition, experiments were carried out without electrolyte and the results were compared. The effect of support electrolyte type and concentration on phosphate removal efficiency, energy consumption and reaction rate was analyzed. Experiments have shown that electrolyte use has no significant effect on phosphate removal efficiency. However, it has been found that the addition of electrolyte reduces energy consumption and increases the removal rate. From the results obtained, it was determined that NaCl as the most suitable electrolyte type and 5 mM electrolyte was sufficient as the optimum dose. Under these conditions, for 100 mg L-1 PO4-P at 0.5 mA cm-2 current density, the phosphate removal efficiency was 96.98%, the energy consumption was 1.13 kWh m-3 and the first order reaction rate constant was 0.0593 min-1. [ABSTRACT FROM AUTHOR]

The current work investigates the ability of the new aluminium-based electrocoagulation (EC) cell to remediate chemical oxygen demand (COD) from synthetic wastewater. The experimental work was carried out using a rectangular EC cell (10 cm in length, 9.5 cm in width, and 7 cm in depth). The EC cell was supplied with six perforated aluminium electrodes; four of these electrodes were used in the treatment methods (connected to DC electrical current), while the first and the last electrodes were used as baffle plates (to mix water). This lab-scale unit was used to treat synthetic wastewater having 300 mg/l of COD, considering the effect of the treatment time and initial pH. After 40 minutes of treatment at a pH of 7 and a current density of 10 A/m², 51% of COD was removed by the new EC unit. The results also revealed that the removal of the COD is positively influenced by the increase of the applied current density and/or treatment time. [ABSTRACT FROM AUTHOR]

In the present study, an electrocoagulation process was applied to treat saline oilfield-produced water. The kinetics of simultaneous heavy metal and oil removal in the saline environment under different conditions including four-electrode materials of copper, zinc, iron, and aluminum, aeration and agitation rate, oil content, and salinity was investigated. The nature of the electro-generated species and possible abatement mechanisms were explored and compared by using FE-SEM/EDS, FTIR, XRD, and BET analyses. At low and high salinities, cadmium adsorption followed Langmuir and Freundlich models, suggesting the transformation of identical adsorption sites to heterogeneous ones. Cadmium removal efficiencies of 99/73% were obtained at low/high salinity with iron and 99.9 and 82% using copper and zinc electrodes in a saline environment. The cadmium adsorption capacity of different anode materials exhibited the order of copper > zinc > iron > aluminum. The adsorption capacity was considerably reduced in saline condition due to more crystalline structure and lower surface area and porosity of the particles while it was enhanced by the oil, caused by structural changes including more uniform pores, the elevated surface area, and porosity. The COD removal yield of 89% for low salinity and 80/73% at high salinity with/without aeration were achieved by iron. The highest COD removal yield of about 95% was achieved by the aluminum electrodes, compared to 85 and 87% for copper and zinc electrodes. The main removal mechanisms were outer- and inner-sphere complexation, and surface precipitation. [ABSTRACT FROM AUTHOR]

We performed systematic reviews addressing predefined clinical questions to develop recommendations with the GRADE approach regarding management of patients with overt upper gastrointestinal bleeding. We suggest risk assessment in the emergency department to identify very-low-risk patients (e.g., Glasgow-Blatchford score 5 0-1) who may be discharged with outpatient follow-up. For patients hospitalized with upper gastrointestinal bleeding, we suggest red blood cell transfusion at a threshold of 7 g/dL. Erythromycin infusion is suggested before endoscopy, and endoscopy is suggested within 24 hours after presentation. Endoscopic therapy is recommended for ulcers with active spurting or oozing and for nonbleeding visible vessels. Endoscopic therapy with bipolar electrocoagulation, heater probe, and absolute ethanol injection is recommended, and low- to very-low-quality evidence also supports clips, argon plasma coagulation, and soft monopolar electrocoagulation; hemostatic powder spray TC-325 is suggested for actively bleeding ulcers and over-the-scope clips for recurrent ulcer bleeding after previous successful hemostasis. After endoscopic hemostasis, high-dose proton pump inhibitor therapy is recommended continuously or intermittently for 3 days, followed by twice-daily oral proton pump inhibitor for the first 2 weeks of therapy after endoscopy. Repeat endoscopy is suggested for recurrent bleeding, and if endoscopic therapy fails, transcatheter embolization is suggested. [ABSTRACT FROM AUTHOR]

The purpose of this study is to identify differences in variations of contact time and number of electrode plates in electrocoagulation process on the decrease of total Coliforms in Bandung City hospital wastewater. An experimental research with factorial randomized design. The volume of wastewater sample to check the total Coliforms was a minimum of 100 ml, using 3 treatments and 6 repetitions. Data analysis used was two-way ANOVA test. The results showed that there was no significant difference between the number of plates (p = 0.269), contact time (p = 0.537), and the number of plates and contact time (p = 0.863) with the total Coliforms in electrocoagulation process. The use of 6 plates and 90 min contact time showed the best results in reducing total Coliforms, with effectiveness reaching 88.38%. This means that the concept is quite effective to use as a substitute for disinfectant. [ABSTRACT FROM AUTHOR]

Considerable amounts of produced water (PW) are usually accompanied with the production of oil. This study proposed a combination of electrocoagulation (EC) - electro- Fenton (EF) process for oxidation organic compounds in PW to reduce the chemical oxygen demand (COD) to below regulation limits. The PW used in this study was collected from oilfield in the Midland Oil Company. Pretreatment of the PW was conducted using batch EC technique with aluminum electrodes to eliminate the suspended and dissolved solids and to reduce the COD and treatment cost. Optimization of EC process revealed that optimum current density, pH, and reaction time were 7.83 mA/cm², 7.24, 20.40 minutes respectively. Under these conditions the COD removal percentage was 73.97% starting from initial COD of 1730 mg/l.Batch and continuous electro-Fenton processes were investigated using dimensionally stable anode Ti-RuO2/IrO2 and activated carbon fiber felt (ACFF) cathode. The effect of crucial process variables on COD removal efficiency was investigated using response surface methodology. A second order polynomial model equations were constructed and the results was analyzed by the analysis of variance (ANOVA). It was concluded that a combination of electrocoagulation followed by electro-Fenton process is effective for treating oilfield produced water and further improvement can be achieved by photo assisting the process. A total COR removal efficiency of 98% was achieved. [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]

The present study employs a novel technique combining Fenton reaction with sinusoidal alternating current electrocoagulation (FSACEC), which is used to remove chemical oxygen demand (COD) in the simulated electroplating wastewater with the advantages of low energy consumption and small sludge. Fe2+, produced from the dissolution of Fe anodes in the FSACEC process, reacts with H2O2 to generate more ·OH and forms the iron hydroxide precipitates. The higher efficiency of COD removal is achieved through both effects of the oxidation reaction and the physical adsorption. The scanning electron microscopy (SEM) analysis shows that the particle size of FSACEC products is between 30 and 40 nm, which is less than the Fenton-direct current electrocoagulation products. The effect of the current concentration (IV), initial pH (pH0), and the addition of hydrogen peroxide (30% H2O2) was discussed on the optimal process parameters. In pH0 2.0 wastewater, applying current concentration of 1 A dm−3, the addition 20 cm3 dm−3 30% H2O2, the removal efficiency of COD reached 94.21% and the residual COD in wastewater was only 60 mg dm−3 after 90 min of operation. In order to investigate the maximum removal efficiency in a certain period of operation, the larger current concentration is applied to remove COD. The FSACEC process exhibits the higher removal COD efficiency and wider operation range of pH0 than the single Fenton technique. The FSACEC process is in accordance with the kinetic law of the pseudo-second-order kinetic adsorption model. [ABSTRACT FROM AUTHOR]

The electrocoagulation (EC) treatment of textile dyeing effluent was carried out in a 2 dm³ electrolytic batch reactor using aluminium as a sacrificial electrode. With the four-plate setup a current density of 110.16 A/m², pH 6 and electrode gap 2 cm was found to be optimal. Maximum chemical oxygen demand and colour reduction of 93% and 73% respectively was achieved. The metal ion discharge rate of aluminium was found strongly dependant on initial pH (pHi) of effluent. At lower pHi (pH 2) anode consumption increases while energy consumption decreased. At the optimum condition, the loss of aluminium electrode was 38.86 mg/dm³ effluent and energy consumption was 16.09 Wh/dm³. The settling characteristics of electrocoagulation sludge were also analyzed at different pH. It was observed that the settling characteristic of treated slurry provided better results at pHi 10. Besides, scum and residues were also characterized at different pH. [ABSTRACT FROM AUTHOR]

A combination of electrocoagulation and coagulation-flocculation processes was used for re-refining effluent from lubricating oils. The efficiency of the process was evaluated based on the chemical oxygen demand (COD), color, and turbidity of the refined effluent. Electrocoagulation (EC) and coagulation-flocculation parameters, such as the initial pH (3.00, 4.41, and 9.00), and current density (4, 9, and 16 A/m2), and the use of aluminum polychloride coagulant and superfloc A300 flocculant were studied. EC performed at pH 9, with a current density of 16 A/m2 and 7 V, resulted in removal efficiencies of 85.14%, 99.81%, and 99.85%, for COD, color, and turbidity, respectively. The removal efficiencies increased to 96%, 99.87%, and 99.94% for COD, color, and turbidity, respectively, by the further coagulation-flocculation treatment in the presence of 13.8 mg/L aluminum polychloride coagulant and 80 mg/L Superfloc A300 flocculant. [ABSTRACT FROM AUTHOR]

This study evaluated the removal of silver nanoparticles (AgNPs), coated with different stabilizers, from aqueous media using the electrocoagulation technique. The AgNPs dispersions were synthesized by chemical reduction with silver nitrate as precursor, sodium borohydride as reducing agent and sodium carboxymethylcellulose (CMC), polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) as stabilizers with initial concentrations of 1 and 3% (w/v). The dispersions were named AgNPs-CMC1, AgNPs-CMC3, AgNPs-PVA1, AgNPs-PVA3, AgNPs-PVP1, and AgNPs-PVP3. Electrocoagulation treatments of AgNPs-PVA1, AgNPs-PVP1 and AgNPs-PVP3 dispersions resulted in total silver removals above 99.90% in 10 min. For the AgNPs-PVP3 dispersion 99.98% of removal was obtained in 20 min. After 15 min of electrolysis, The AgNPs-CMC1 and AgNPs-CMC3 dispersions showed a reduction in total silver concentration of 71.72 and 52.15%, respectively. Therefore, these results showed that the removal of AgNPs from the aqueous medium by electrocoagulation is possible, but their efficiency and viability depends on the nature, the molecular structure and the concentration of stabilizers. Furthermore, the toxicity analysis using the Vibrio fischeri bacteria demonstrated that only the dispersions stabilized with PVP became suitable for disposal after the electrocoagulation treatment. [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]

Manganese (Mn) was removed from aqueous solutions through electrocoagulation using Al electrodes. Effects of initial Mn concentration (185–405 mg l−1), the input voltage (1–11 V), inter electrode distance (1–5 cm), and initial pH (2–11) on Mn removal were investigated. Experiments were designed with an orthogonal central composite design on the four variables using the response surface methodology. Analysis of variance was applied and the final Mn concentration was expressed by a mathematical equation. Optimum values of the four factors to get the highest removal were also obtained. As the results showed, electrocoagulation using Al electrodes was able to remove Mn from aqueous solutions efficiently. An equilibrium state was achieved within 195 min. The mathematical model was appropriate to describe experimental data with a high regression coefficient. Kinetics and isotherm data were described appropriately by pseudo-second-order and Langmuir models, respectively. The optimum operating conditions were obtained as pH 9, initial Mn concentration 360 mg l−1, inter electrode distance 2 cm, and input voltage 10 V. The highest removal efficiency was 92% which is considered a high value. [ABSTRACT FROM AUTHOR]

Indigo carmine (IC) is a dye that is widely used in textile industries. Since the dyes lixiviation reaches about 30%, these compounds are largely discharged in effluents, thus contaminating rivers and lakes. The IC presents high toxicity, causing topic irritation and carcinogenic effects. Electrocoagulation (EC) is based on the electrical dissolution of iron and aluminum ions used to promote the formation of metal hydroxide coagulants capable of destabilizing and aggregating pollutant compounds. In this context, this work aimed to investigate the use of electrodes obtained from the direct compression of metallurgical filing wastes on the EC remediation of IC. Electrodes of bronze, aluminum, steel and metal waste were produced and their performances were evaluated in NaCl 0.05 mol L−1 and tap water solutions at 2.5 and 5 V. The IC dye discoloration reached 84% for the aluminum commercial electrode, 90% for the steel commercial electrode and 96% for the bronze commercial electrode, respectively, in 80 min of treatment. For electrodes produced from chips (swarf), there was a discoloration of 72% for the aluminum electrode, 92% for the steel electrode and 90% for the bronze electrode, respectively, in the same time of treatment. These results showed that electrodes obtained from chips and commercial electrodes had similar electrochemical efficiency in the removal of IC dye from wastewater. Also, the use of metallic debris as electrodes makes its application an economically viable option on a large scale, since they have high effectiveness and lower cost and their replacement can solve the electrode passivation. [ABSTRACT FROM AUTHOR]

This paper discusses a systematic study of Congo red dye removal by electrocoagulation process with an aluminium electrode pair. The statistical modelling technique, response surface methodology is used for the design of experiments. The various operating parameters chosen are reaction time (10–60 min), initial dye concentration (20–80 mg/L), pH of the solution (5–11) and the applied voltage (5–20 V) with removal efficiency and energy consumption as responses. The results show the leading role of various parameters on maximizing removal efficiency and minimizing energy consumption, and the optimum conditions obtained are initial dye concentration of 65 mg/L, solution pH of 9.5, the reaction time of 25.08 min and an applied voltage of 8.75 V. According to the experimental results, the maximum removal efficiency obtained is 89.344% with an energy consumption of 9.4589 W h. The analysis of variance (ANOVA) results in a regression coefficient of 0.9701 and 0.9993 for removal efficiency and energy consumption, respectively, and it indicates only 0.29% and 0.01% chance of deviation for the developed model from the actual operating conditions. The various characterization results affirm the removal of dye with in situ formed coagulants of aluminium by adsorption and charge neutralization mechanism. The kinetic study reveals that the pseudo-second-order model is the best-fitted model for the removal of Congo red dye. [ABSTRACT FROM AUTHOR]