BACKGROUND Intracranial blister-like microaneurysms are an extremely rare disease.Rupture of intracranial aneurysms can lead to subarachnoid hemorrhage(SAH).Patients with SAH may experience severe neurological symptom...BACKGROUND Intracranial blister-like microaneurysms are an extremely rare disease.Rupture of intracranial aneurysms can lead to subarachnoid hemorrhage(SAH).Patients with SAH may experience severe neurological symptoms,including severe headache,nausea,vomiting,transient or persistent loss of consciousness,limb weakness,and blurred vision.Ruptured aneurysms should be surgically treated as soon as possible.Intravascular electrocoagulation is becoming a promising treatment method for intracranial blister-like microaneurysms.The short-term follow-up results demonstrated that this method is safe and effective.This article presents a case of endovascular electrocoagulation for the treatment of a blisterlike microaneurysm.CASE SUMMARY This article reports the case of 71-year-old female patient with an intracranial aneurysm.The patient experienced a sudden headache with vomiting for 3 hours.Brain computed tomography(CT)scan showed a subarachnoid hemorrhage.She was diagnosed with rupture of an aneurysm and subarachnoid hemorrhage.The aneurysm was located in the choroidal segment of the right internal carotid artery.The size of the aneurysm was 2.00 mm×1.80 mm×1.97 mm,and the neck of the aneurysm was less than 0.5 mm wide.We successfully treated this aneurysm with endovascular electrocoagulation,and the patient was safely returned to the ward and discharged after subsequent supportive treatment.CT angiography reexamination 3 months after surgery revealed no contrast agent extravasation in the original lesion,with a good prognosis.CONCLUSION Endovascular electrocoagulation is an effective and safe method for the treatment of intracranial blister-like microaneurysms.展开更多
Antimony （Sb） has received increasing environmental concerns due to its potential toxic and carcinogenic properties. In the present work, the electrocoagulation technique was used to treat the flotation wastewater f...Antimony （Sb） has received increasing environmental concerns due to its potential toxic and carcinogenic properties. In the present work, the electrocoagulation technique was used to treat the flotation wastewater from a heavy antimony polluted area, and the mechanism of removing Sb was also investigated. The study focused on the effect of operation parameters such as current density, initial pH and standing time on the Sb removal efficiency. Antimony concentration of below 1 mg/L in the treated wastewater was achieved, which meets the emission standards established by State Department of Environmental Protection and State Administration of China for Quality Supervision and Inspection and Quarantine of China.展开更多
The production of biodiesel through a transesterification method produces a large amount of wastewater that contains high levels of chemical oxygen demand （COD） and oil and grease （O＆G）. Currently, flotation is t...The production of biodiesel through a transesterification method produces a large amount of wastewater that contains high levels of chemical oxygen demand （COD） and oil and grease （O＆G）. Currently, flotation is the conventional primary treatment for O＆G removal prior to biological treatments. In this study, electrocoagulation （EC） was adopted to treat the biodiesel wastewater. The effects of initial pH, applied voltage, and reaction time on the EC process for the removal of COD, O＆G, and suspended solids （SS） were investigated using one factor at a time experiment. Furthermore, the Box-Behnken design, an experimental design for response surface methodology （RSM）, was used to create a set of 15 experimental runs needed for optimizing of the operating conditions. Quadratic regression models with estimated coefficients were developed to describe the pollutant removals. The experimental results show that EC could effectively reduce COD, O＆G, and SS by 55.43%, 98.42%, and 96.59%, respectively, at the optimum conditions of pH 6.06, applied voltage 18.2 V, and reaction time 23.5 min. The experimental observations were in reasonable agreement with the modeled values.展开更多
Treatment of tannery wastewater by electrocoagulation with low cell current （≤ 1A） and soluble electrodes （mild steel electrodes and aluminum electrodes） was studied. Compared with aluminum electrodes, mild steel...Treatment of tannery wastewater by electrocoagulation with low cell current （≤ 1A） and soluble electrodes （mild steel electrodes and aluminum electrodes） was studied. Compared with aluminum electrodes, mild steel electrodes were more effective for the removal of sulfide, with a removal efficiency of over 90%. But during the treatment process, black color precipitate typical to iron（Ⅱ） sulfides was produced. While aluminum electrodes were effective to eliminate the colority of the effluent, the removal efficiency of sulfide was lower than 12%. The mechanisms of the removal of chemical oxygen demand, ammonia, total organic carbon, sulfide and colority with the two soluble electrodes （mild steel and aluminum electrodes） were discussed in detail. In order to exert the predominance of diffenent types of electrodes, the tannery wastewater was treated using mild steel electrodes first followed by the filter and finally by the aluminum electrodes, the elimination rates of chemical oxygen demand, ammonia, total organic carbon, sulfide and colority were 68.0%, 43.1%, 55.1%, 96.7% and 84.3%, respectively, with the initial concentrations 2413.1 mg/L, 223.4 mg/L, 1000.4 mg/L, 112.3 mg/L and 256 dilution times, respectively. The absorbance spectra and energy consumption during electrocoagulation process were also discussed.展开更多
An electrocoagulation treatment process was developed for treatment and upgrade of petroleum refinery effluent （wastewater）, instead of the conventional methods, which can consume higher amounts of chemicals and pro...An electrocoagulation treatment process was developed for treatment and upgrade of petroleum refinery effluent （wastewater）, instead of the conventional methods, which can consume higher amounts of chemicals and produce larger amounts of sludge. The effect of the operation parameters, such as current density, initial pH, anode material, anode dissolution, energy consumption and electrolysis time, on treatment efficiency was investigated. The experimental results showed that the effluent can be effectively treated under optimal conditions. Fourier transform infrared （FTIR） analysis of the effluent, and scanning electron microscopy （SEM） coupled with energy dispersive analysis of X-rays （EDAX） of the sludge produced, revealed that the unwanted pollutants can be eliminated. The electrocoagulation treatment process was assessed by using the removal efficiency of chemical oxygen demand （COD）, total suspended solids （TSS）, and the general physicochemical characteristics of wastewater, and the results showed that the electrocoagulation is an efficient process for recycling of petroleum wastewater; it is faster and provides better quality of treated water than the conventional methods.展开更多
AIM To investigate post endoscopic submucosal dissection electrocoagulation syndrome(PEECS) of the esophagus.METHODS We analyzed 55 consecutive cases with esophageal endoscopic submucosal dissection for superficial es...AIM To investigate post endoscopic submucosal dissection electrocoagulation syndrome(PEECS) of the esophagus.METHODS We analyzed 55 consecutive cases with esophageal endoscopic submucosal dissection for superficial esophageal squamous neoplasms at a tertiary referral hospital in South Korea. Esophageal PEECS was defined as "mild" meeting one of the following criteria without any obvious perforation: fever(≥ 37.8 ℃), leukocytosis(> 10800 cells/μl), or regional chest pain more than 5/10 points as rated on a numeric pain intensity scale. The grade of PEECS was determined as "severe" when meet two or more of above criteria.RESULTS We included 51 cases without obvious complications in the analysis. The incidence of mild and severe esophageal PEECS was 47.1% and 17.6%, respectively. Risk factor analysis revealed that resected area, procedure time, and muscle layer exposure were significantly associated with PEECS. In multivariate analysis, a resected area larger than 6.0 cm^2(OR = 4.995, 95%CI: 1.110-22.489, P = 0.036) and muscle layer exposure(OR = 5.661, 95%CI: 1.422-22.534, P = 0.014) were independent predictors of esophageal PEECS. All patients with PEECS had favorable outcomes with conservative management approaches, such as intravenous hydration or antibiotics.CONCLUSION Clinicians should consider the possibility of esophageal PEECS when the resected area exceeds 6.0 cm^2 or when the muscle layer exposure is noted.展开更多
Electrocoagulation(EC) is among the most effective techniques that remove color and decontaminate effluent.Coagulants are delivered in situ by anode corrosion.In this research,indigo dye removal using iron electrodes ...Electrocoagulation(EC) is among the most effective techniques that remove color and decontaminate effluent.Coagulants are delivered in situ by anode corrosion.In this research,indigo dye removal using iron electrodes in continuous electrocoagulation process and the responsible species for decolorization were investigated.The Response Surface Methodology(RSM) was used to optimize the process parameters.The finding in this study shows that at fixed conductivity at 15,000 μS·cm^(-1) the neutral conditions(pH from 6 to 8),the low absorbance,the low flow rate and the high voltage level enhance the color removal efficiency.The high R~2 value of 97.8% and ANOVA analyses show a good correlation between the experimental and predicted results.Under the optimum conditions,which are pH of 7.5, solution concentration of 60 mg·L^(-1), inlet flow rate of 2 L·min^(-1) and voltage of 47 V, the predicted decolorization of 94.083% was achieved at 93.972% with a total cost of 0.0927 USD·m^(-3) of treated effluent.At the optimum pH(7.5),the zeta potential value(-4 mV) of the effluent during EC match with the one of iron Ⅲ hydroxide.The dye removal is ensured thanks to physical adsorption and flocculation.The results exposed in this work prove that the continuous electrocoagulation process could be successfully used for indigo dye removal at industrial scale.展开更多
BACKGROUND We hypothesized that thermal damage accumulation during endoscopic submucosal dissection(ESD)causes the pathogenesis of post-ESD electrocoagulation syndrome(PECS).AIM To determine the association between Jo...BACKGROUND We hypothesized that thermal damage accumulation during endoscopic submucosal dissection(ESD)causes the pathogenesis of post-ESD electrocoagulation syndrome(PECS).AIM To determine the association between Joule heat and the onset of PECS.METHODS We performed a retrospective cohort study in patients who underwent colorectal ESD from May 2013 to March 2021 in Japan.We developed a novel device that measures swift coagulation time with a sensor adjacent to the electrosurgical coagulation unit foot switch,which enabled us to calculate total Joule heat.PECS was defined as localized abdominal pain(visual analogue scale≥30 mm during hospitalization or increased by≥20 mm from the baseline)and fever(temperature≥37.5 degrees or white blood cell count≥10000μ/L).Patients exposed to more or less than the median Joule heat value were assigned to the high and low Joule heat groups,respectively.Statistical analyses included Mann-Whitney U and chisquare tests and logistic regression and receiver operating characteristic curve(ROC)analyses.RESULTS We evaluated 151 patients.The PECS incidence was 10.6%(16/151 cases),and all patients were followed conservatively and discharged without severe complications.In multivariate analysis,high Joule heat was an independent PECS risk factor.The area under the ROC curve showing the correlation between PECS and total Joule heat was high[0.788(95%confidence interval:0.666-0.909)].CONCLUSION Joule heat accumulation in the gastrointestinal wall is involved in the onset of PECS.ESD-related thermal damage to the peeled mucosal surface is probably a major component of the mechanism underlying PECS.展开更多
Electrocoagulation process using high current intensity to treat palm oil mill effluent(POME) was investigated in this study.Various operating parameters such as electrolysis time, inter-electrode distance and initial...Electrocoagulation process using high current intensity to treat palm oil mill effluent(POME) was investigated in this study.Various operating parameters such as electrolysis time, inter-electrode distance and initial pH were carried out to determine the efficient process condition on the removal of chemical oxygen demand(COD),biological oxygen demand(BOD) and suspended solids(SS).The highest treatment was achieved at 50 min with the removal efficiencies for COD, BOD and SS obtained as 85%, 83%, and 84%, respectively.More than 50 min treatment showed the fluctuated trends of removal efficiencies which can be considered insignificant.The application of higher current resulted in higher removals of organics while the gas bubbles also assisted in removing the pollutant particles by floatation.In an inter-electrode distance study, the removal efficiency decreased when inter-electrode distance was either higher or lower than 10 mm due to the increase of solution resistance and the decrease of anode active surface area.In initial pH study, it was found that high removal efficiencies were achieved in slightly acidic POME sample rather than in neutral or basic condition.An electrocoagulation process by using the optimum operating parameters was able to remove COD, BOD and SS up to 95%, 94% and 96% respectively.The experimental results confirm that application of high current intensity in electrocoagulation provided high treatment efficiency at a reduced reaction time.展开更多
The aim of this study was to determine the effect of electrocoagulation technology using iron electrodes on phenol removal in aqueous solutions. The removal of phenol was investigated in terms of various parameters, n...The aim of this study was to determine the effect of electrocoagulation technology using iron electrodes on phenol removal in aqueous solutions. The removal of phenol was investigated in terms of various parameters, namely, current density, phenol and NaCl concentration, pH, and alginic acid concentration. The results showed that the removal efficiency of phenol increased with increasing the current density, pH and NaCl concentration, whereas it was inversely associated with initial concentration of phenol and alginic acid concentration. According to the results, electrocoagulation is a promising process for treatment of wastewater containing high concentration of phenol.展开更多
Oilfield produced water is large quantities of salty water trapped in underground formations and subsisted under high temperatures and pressures that are brought to the surface along with oil during production. Produc...Oilfield produced water is large quantities of salty water trapped in underground formations and subsisted under high temperatures and pressures that are brought to the surface along with oil during production. Produced water(PW) contains a lot of pollutants such as hydrocarbons and metals, this water must be treated before disposal. Therefore, different techniques are being used to treat produced water. Electrocoagulation is an efficient treatment technique involving the dissolution of anodes and formation of electro-coagulants, while the simultaneous generation of H_2 bubbles at the cathode leads to the pollutant removal by flotation. Electrocoagulation(EC)method is one of the most promising and widely used processes to treat oilfield produced water. In the present work, a conventional internal-loop(draught tube) airlift reactor was utilized as electrocoagulation/flotation cell for PW treatment by inserting two aluminum electrodes in the riser section of the airlift reactor. The EC airlift reactor was operated in a batch mode for the liquid phase. Different experimental parameters were studied on the oil and turbidity removal efficiencies such as current density, initial pH, electrocoagulation time, and air injection.The experimental results showed that mixing of the oil droplets in the PW was accomplished using only the liquid recirculation resulted by H_2 microbubbles generated by EC process which enhanced the oil removal. The experimental results further showed that the EC time required achieving ≥ 90% oil removal efficiency decreases from 46 to 15 min when operating current density increases from 6.8 to 45.5 mA·cm^(-2). This reactor type was found to be highly efficient and less energy consuming compared to conventional existing electrochemical cells which used mechanical agitation.展开更多
文摘BACKGROUND Intracranial blister-like microaneurysms are an extremely rare disease.Rupture of intracranial aneurysms can lead to subarachnoid hemorrhage(SAH).Patients with SAH may experience severe neurological symptoms,including severe headache,nausea,vomiting,transient or persistent loss of consciousness,limb weakness,and blurred vision.Ruptured aneurysms should be surgically treated as soon as possible.Intravascular electrocoagulation is becoming a promising treatment method for intracranial blister-like microaneurysms.The short-term follow-up results demonstrated that this method is safe and effective.This article presents a case of endovascular electrocoagulation for the treatment of a blisterlike microaneurysm.CASE SUMMARY This article reports the case of 71-year-old female patient with an intracranial aneurysm.The patient experienced a sudden headache with vomiting for 3 hours.Brain computed tomography(CT)scan showed a subarachnoid hemorrhage.She was diagnosed with rupture of an aneurysm and subarachnoid hemorrhage.The aneurysm was located in the choroidal segment of the right internal carotid artery.The size of the aneurysm was 2.00 mm×1.80 mm×1.97 mm,and the neck of the aneurysm was less than 0.5 mm wide.We successfully treated this aneurysm with endovascular electrocoagulation,and the patient was safely returned to the ward and discharged after subsequent supportive treatment.CT angiography reexamination 3 months after surgery revealed no contrast agent extravasation in the original lesion,with a good prognosis.CONCLUSION Endovascular electrocoagulation is an effective and safe method for the treatment of intracranial blister-like microaneurysms.
基金supported by the Innovative Program of the Chinese Academy of Sciences (No. kzcx2-yw-102)the National Nature Science Foundation of China (No. 40525011, 40632011)
文摘Antimony （Sb） has received increasing environmental concerns due to its potential toxic and carcinogenic properties. In the present work, the electrocoagulation technique was used to treat the flotation wastewater from a heavy antimony polluted area, and the mechanism of removing Sb was also investigated. The study focused on the effect of operation parameters such as current density, initial pH and standing time on the Sb removal efficiency. Antimony concentration of below 1 mg/L in the treated wastewater was achieved, which meets the emission standards established by State Department of Environmental Protection and State Administration of China for Quality Supervision and Inspection and Quarantine of China.
基金supported by the Energy Policy and Planning Office, Ministry of Energy Royal Thai Government under the grant for supporting conservation of energy
文摘The production of biodiesel through a transesterification method produces a large amount of wastewater that contains high levels of chemical oxygen demand （COD） and oil and grease （O＆G）. Currently, flotation is the conventional primary treatment for O＆G removal prior to biological treatments. In this study, electrocoagulation （EC） was adopted to treat the biodiesel wastewater. The effects of initial pH, applied voltage, and reaction time on the EC process for the removal of COD, O＆G, and suspended solids （SS） were investigated using one factor at a time experiment. Furthermore, the Box-Behnken design, an experimental design for response surface methodology （RSM）, was used to create a set of 15 experimental runs needed for optimizing of the operating conditions. Quadratic regression models with estimated coefficients were developed to describe the pollutant removals. The experimental results show that EC could effectively reduce COD, O＆G, and SS by 55.43%, 98.42%, and 96.59%, respectively, at the optimum conditions of pH 6.06, applied voltage 18.2 V, and reaction time 23.5 min. The experimental observations were in reasonable agreement with the modeled values.
文摘Treatment of tannery wastewater by electrocoagulation with low cell current （≤ 1A） and soluble electrodes （mild steel electrodes and aluminum electrodes） was studied. Compared with aluminum electrodes, mild steel electrodes were more effective for the removal of sulfide, with a removal efficiency of over 90%. But during the treatment process, black color precipitate typical to iron（Ⅱ） sulfides was produced. While aluminum electrodes were effective to eliminate the colority of the effluent, the removal efficiency of sulfide was lower than 12%. The mechanisms of the removal of chemical oxygen demand, ammonia, total organic carbon, sulfide and colority with the two soluble electrodes （mild steel and aluminum electrodes） were discussed in detail. In order to exert the predominance of diffenent types of electrodes, the tannery wastewater was treated using mild steel electrodes first followed by the filter and finally by the aluminum electrodes, the elimination rates of chemical oxygen demand, ammonia, total organic carbon, sulfide and colority were 68.0%, 43.1%, 55.1%, 96.7% and 84.3%, respectively, with the initial concentrations 2413.1 mg/L, 223.4 mg/L, 1000.4 mg/L, 112.3 mg/L and 256 dilution times, respectively. The absorbance spectra and energy consumption during electrocoagulation process were also discussed.
基金the financial support from the Ministry of Higher Education and Scientific Research-Iraq
文摘An electrocoagulation treatment process was developed for treatment and upgrade of petroleum refinery effluent （wastewater）, instead of the conventional methods, which can consume higher amounts of chemicals and produce larger amounts of sludge. The effect of the operation parameters, such as current density, initial pH, anode material, anode dissolution, energy consumption and electrolysis time, on treatment efficiency was investigated. The experimental results showed that the effluent can be effectively treated under optimal conditions. Fourier transform infrared （FTIR） analysis of the effluent, and scanning electron microscopy （SEM） coupled with energy dispersive analysis of X-rays （EDAX） of the sludge produced, revealed that the unwanted pollutants can be eliminated. The electrocoagulation treatment process was assessed by using the removal efficiency of chemical oxygen demand （COD）, total suspended solids （TSS）, and the general physicochemical characteristics of wastewater, and the results showed that the electrocoagulation is an efficient process for recycling of petroleum wastewater; it is faster and provides better quality of treated water than the conventional methods.
基金Supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Science and ICT,No.NRF-2015R1C1A1A01054352
文摘AIM To investigate post endoscopic submucosal dissection electrocoagulation syndrome(PEECS) of the esophagus.METHODS We analyzed 55 consecutive cases with esophageal endoscopic submucosal dissection for superficial esophageal squamous neoplasms at a tertiary referral hospital in South Korea. Esophageal PEECS was defined as "mild" meeting one of the following criteria without any obvious perforation: fever(≥ 37.8 ℃), leukocytosis(> 10800 cells/μl), or regional chest pain more than 5/10 points as rated on a numeric pain intensity scale. The grade of PEECS was determined as "severe" when meet two or more of above criteria.RESULTS We included 51 cases without obvious complications in the analysis. The incidence of mild and severe esophageal PEECS was 47.1% and 17.6%, respectively. Risk factor analysis revealed that resected area, procedure time, and muscle layer exposure were significantly associated with PEECS. In multivariate analysis, a resected area larger than 6.0 cm^2(OR = 4.995, 95%CI: 1.110-22.489, P = 0.036) and muscle layer exposure(OR = 5.661, 95%CI: 1.422-22.534, P = 0.014) were independent predictors of esophageal PEECS. All patients with PEECS had favorable outcomes with conservative management approaches, such as intravenous hydration or antibiotics.CONCLUSION Clinicians should consider the possibility of esophageal PEECS when the resected area exceeds 6.0 cm^2 or when the muscle layer exposure is noted.
文摘Electrocoagulation(EC) is among the most effective techniques that remove color and decontaminate effluent.Coagulants are delivered in situ by anode corrosion.In this research,indigo dye removal using iron electrodes in continuous electrocoagulation process and the responsible species for decolorization were investigated.The Response Surface Methodology(RSM) was used to optimize the process parameters.The finding in this study shows that at fixed conductivity at 15,000 μS·cm^(-1) the neutral conditions(pH from 6 to 8),the low absorbance,the low flow rate and the high voltage level enhance the color removal efficiency.The high R~2 value of 97.8% and ANOVA analyses show a good correlation between the experimental and predicted results.Under the optimum conditions,which are pH of 7.5, solution concentration of 60 mg·L^(-1), inlet flow rate of 2 L·min^(-1) and voltage of 47 V, the predicted decolorization of 94.083% was achieved at 93.972% with a total cost of 0.0927 USD·m^(-3) of treated effluent.At the optimum pH(7.5),the zeta potential value(-4 mV) of the effluent during EC match with the one of iron Ⅲ hydroxide.The dye removal is ensured thanks to physical adsorption and flocculation.The results exposed in this work prove that the continuous electrocoagulation process could be successfully used for indigo dye removal at industrial scale.
文摘BACKGROUND We hypothesized that thermal damage accumulation during endoscopic submucosal dissection(ESD)causes the pathogenesis of post-ESD electrocoagulation syndrome(PECS).AIM To determine the association between Joule heat and the onset of PECS.METHODS We performed a retrospective cohort study in patients who underwent colorectal ESD from May 2013 to March 2021 in Japan.We developed a novel device that measures swift coagulation time with a sensor adjacent to the electrosurgical coagulation unit foot switch,which enabled us to calculate total Joule heat.PECS was defined as localized abdominal pain(visual analogue scale≥30 mm during hospitalization or increased by≥20 mm from the baseline)and fever(temperature≥37.5 degrees or white blood cell count≥10000μ/L).Patients exposed to more or less than the median Joule heat value were assigned to the high and low Joule heat groups,respectively.Statistical analyses included Mann-Whitney U and chisquare tests and logistic regression and receiver operating characteristic curve(ROC)analyses.RESULTS We evaluated 151 patients.The PECS incidence was 10.6%(16/151 cases),and all patients were followed conservatively and discharged without severe complications.In multivariate analysis,high Joule heat was an independent PECS risk factor.The area under the ROC curve showing the correlation between PECS and total Joule heat was high[0.788(95%confidence interval:0.666-0.909)].CONCLUSION Joule heat accumulation in the gastrointestinal wall is involved in the onset of PECS.ESD-related thermal damage to the peeled mucosal surface is probably a major component of the mechanism underlying PECS.
基金Supported by Universiti Malaysia Pahang Research Grant(RDU1803143)
文摘Electrocoagulation process using high current intensity to treat palm oil mill effluent(POME) was investigated in this study.Various operating parameters such as electrolysis time, inter-electrode distance and initial pH were carried out to determine the efficient process condition on the removal of chemical oxygen demand(COD),biological oxygen demand(BOD) and suspended solids(SS).The highest treatment was achieved at 50 min with the removal efficiencies for COD, BOD and SS obtained as 85%, 83%, and 84%, respectively.More than 50 min treatment showed the fluctuated trends of removal efficiencies which can be considered insignificant.The application of higher current resulted in higher removals of organics while the gas bubbles also assisted in removing the pollutant particles by floatation.In an inter-electrode distance study, the removal efficiency decreased when inter-electrode distance was either higher or lower than 10 mm due to the increase of solution resistance and the decrease of anode active surface area.In initial pH study, it was found that high removal efficiencies were achieved in slightly acidic POME sample rather than in neutral or basic condition.An electrocoagulation process by using the optimum operating parameters was able to remove COD, BOD and SS up to 95%, 94% and 96% respectively.The experimental results confirm that application of high current intensity in electrocoagulation provided high treatment efficiency at a reduced reaction time.
文摘The aim of this study was to determine the effect of electrocoagulation technology using iron electrodes on phenol removal in aqueous solutions. The removal of phenol was investigated in terms of various parameters, namely, current density, phenol and NaCl concentration, pH, and alginic acid concentration. The results showed that the removal efficiency of phenol increased with increasing the current density, pH and NaCl concentration, whereas it was inversely associated with initial concentration of phenol and alginic acid concentration. According to the results, electrocoagulation is a promising process for treatment of wastewater containing high concentration of phenol.
文摘Oilfield produced water is large quantities of salty water trapped in underground formations and subsisted under high temperatures and pressures that are brought to the surface along with oil during production. Produced water(PW) contains a lot of pollutants such as hydrocarbons and metals, this water must be treated before disposal. Therefore, different techniques are being used to treat produced water. Electrocoagulation is an efficient treatment technique involving the dissolution of anodes and formation of electro-coagulants, while the simultaneous generation of H_2 bubbles at the cathode leads to the pollutant removal by flotation. Electrocoagulation(EC)method is one of the most promising and widely used processes to treat oilfield produced water. In the present work, a conventional internal-loop(draught tube) airlift reactor was utilized as electrocoagulation/flotation cell for PW treatment by inserting two aluminum electrodes in the riser section of the airlift reactor. The EC airlift reactor was operated in a batch mode for the liquid phase. Different experimental parameters were studied on the oil and turbidity removal efficiencies such as current density, initial pH, electrocoagulation time, and air injection.The experimental results showed that mixing of the oil droplets in the PW was accomplished using only the liquid recirculation resulted by H_2 microbubbles generated by EC process which enhanced the oil removal. The experimental results further showed that the EC time required achieving ≥ 90% oil removal efficiency decreases from 46 to 15 min when operating current density increases from 6.8 to 45.5 mA·cm^(-2). This reactor type was found to be highly efficient and less energy consuming compared to conventional existing electrochemical cells which used mechanical agitation.
