Electrocoagulation is progressively becoming an ecologically friendly water treatment method owing to its lack of secondary pollution,high active ingredient concentration,high treatment effectiveness,simple equipment,...Electrocoagulation is progressively becoming an ecologically friendly water treatment method owing to its lack of secondary pollution,high active ingredient concentration,high treatment effectiveness,simple equipment,and simplicity of automated control implementation.Herein,electrocoagulation is offered as a method for treating wastewater containing azo dyes using a revolutionary flexible electronic fabric that can be mass-producible at a reasonable price.A computer-controlled machine embroiders 316L stainless steel fiber(316L SSF)onto an insulating fabric to manufacture a flexible electronic device of cathode and anode with a monopolar arrangement on the fabric surface.Using methyl orange(MO)solution to simulate azo dye wastewater,the decolorization rate of 500 ml MO reached 99.25% under the conditions of 50 mg·L^(-1)initial mass concentration,120 min electrolysis time,15 mA·g^(-1)current density,1 cm electrode spacing,0.1 mol·L^(-1)NaCl,pH 7.6,200 r·min^(-1)rotational speed of the stirrer,and 22-25℃ room temperature.In addition,it is feasible to embroider flexible electronic fabrics with varied sizes and numbers of electrodes based on the amount of treated sewage to increase the degradation rate,which has significant practical application value.展开更多
The present work uses PEO solution to well disperse carbon fiber and identifies percolation thresholds of carbon fiber and carbon black which are used as conductive fillers.The resultant cathode plates have an average...The present work uses PEO solution to well disperse carbon fiber and identifies percolation thresholds of carbon fiber and carbon black which are used as conductive fillers.The resultant cathode plates have an average compressive strength of 27.3 MPa and flexural strength of 29.09 MPa,which demonstrate excellent mechanical properties.The Cu^(2+)removal efficiency was measured at different current densities in EC process with cement-based cathode plate,while the voltage changes were recorded.The results showed that the cement-based cathode plate operated stably and achieved 99.7%removal of 1 L of simulated wastewater with a Cu^(2+)concentration of 200 ppm at a current density of 8 m A/cm^(2)for 1 h.Characterization of floc and tested cathode plates,SEM and EDS analyses,and repeatability testing of the tested plates demonstrate the reusability of the plates,proving that cement-based plates can effectively replace metal cathode plates,reduce the cost of EC and improve the applicability of EC devices.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
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 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
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
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
Electrocoagulation of pulp and paper industry effluent with SS-304 electrode has been carried out under varying process variable such as pH, current density, time and dose of electrolyte to find out the optimum condit...Electrocoagulation of pulp and paper industry effluent with SS-304 electrode has been carried out under varying process variable such as pH, current density, time and dose of electrolyte to find out the optimum conditions. Maximum reduction efficiency of Chemical Oxygen Demand (COD) 82% and color more than 99% from pulp and paper industry wastewater at the following conditions pH = 7, current density = 24.80 mA/cm2 time = 40 min and dose of electrolytes = 1.0 g/L. Moreover, effects of electrolytes dosage on electricity consumption were observed and found to be that NaCl is better in comparison of Na2SO4 in respect of lower down the electricity consumption. But application of NaCl causes the formation of hazardous compounds as secondary pollutants within treated water. Therefore, Na2SO4 could be a potent replacement of NaCl to enhance the conductivity of paper industry effluent treated by EC process. The treated water has been compared with standard of Central Pollution control board (CPCB) and World Health organization, and found to be suitable for the reuse in irrigation.展开更多
In the present study pulp and paper industry effluent was treated with the help of aluminum electrode using electrocoagulation (EC) process with feasible sludge management. The influences of pH, time, current density ...In the present study pulp and paper industry effluent was treated with the help of aluminum electrode using electrocoagulation (EC) process with feasible sludge management. The influences of pH, time, current density and electrolytes dose were investigated and optimum conditions were established to reduce the maximum amount of Chemical Oxygen Demand (COD) and color. At optimum conditions 70% of COD and 98% of color were removed. Additionally, the behavior of electrolytes (NaCl and Na2SO4) was determined;it has shown that Na2SO4 results in the generation of less secondary pollutants than that NaCl and thereby could be used as better replacement in paper industries for electrocoagulation mediated treatment of wastewater. The residual amount of operational parameters in EC treated water was compared to the World Health Organization (WHO) and Central Pollution Control Board (CPCB) of India. It was found to be safe for utilization in irrigation. Furthermore, sludge produced during the EC process has been analyzed for physicochemical characteristics. To understand the physical and elemental phases of sludge, the analytical technique such as field emission electron microscope coupled with energy dispersive spectroscopy has been used to find out the possible management alternative.展开更多
Soil washing, ex situ mechanical technique, is one of the few permanent treatment alternatives to remove metal contaminants from soils by employing physical separation based on mineral processing technologies to remov...Soil washing, ex situ mechanical technique, is one of the few permanent treatment alternatives to remove metal contaminants from soils by employing physical separation based on mineral processing technologies to remove discrete particles or metal-bearing particles and/or chemical extraction based on leaching or dissolving process to extract the metals from the soils into an aqueous solution. However, washwater remained from soil washing process contains discrete particulate particles along with heavy metals as solution phase to be treated separately, as well as this process can produce large amount of sludge that requires further treatment, slow metal precipitation, poor settling, the aggregation of metal precipitates. Electrical treatments including electrocoagulation and electrolysis can be effective in removing these substances from washwater. This paper reviews the theoretical models in applying electrocoagulation and electrolysis to remove heavy metals and discrete particulate particles in washwater by examining and comparing the status of washwater treatment technologies which have been undertaken, mostly in the US and EU for the period 1990-2012.展开更多
During the last two decades, and particularly during the last few years, the environmental sector has shown a largely growing interest in the treatment of different types of water and wastewater by electrocoagulation ...During the last two decades, and particularly during the last few years, the environmental sector has shown a largely growing interest in the treatment of different types of water and wastewater by electrocoagulation (EC). The aim of this work was to review studies, conducted mainly during 2008-2011, on the wide and versatile range of feasible EC applications employed in the purification of different types of water and wastewater. The EC applications discussed here were divided into 7 following categories: tannery, textile and colored wastewater;pulp and paper industry wastewater;oily wastewater;food industry wastewater;other types of industrial wastewater;surface water as well as model water and wastewater containing heavy metals, nutrients, cyanide and other elements and ions. In addition, this paper presents an overview of the optimum process conditions (treatment times, current densities, and initial pH) and removal efficiencies (mostly high) achieved for the EC applications discussed. In the vast majority of the studies discussed in this review, the aforementioned values were found to be in the range of 5-60 min (typically less than 30 min), 10-150 A/m2 and near neutral pH, respectively. Both operating costs and electrical energy consumption values were found to vary greatly depending on the type of solution being treated, being between 0.004 -6.74 €/m3 and 0.002-58.0 kWh/m3, but in general they were rather low (typically around 0.1-1.0 €/m3 and 0.4-4.0 kWh/m3).展开更多
The Merrill-Crowe or Cementation process is used for concentration and purification of gold and silver from cyanide solutions. Among other available options for recovery of precious metals from cyanide solutions, Elec...The Merrill-Crowe or Cementation process is used for concentration and purification of gold and silver from cyanide solutions. Among other available options for recovery of precious metals from cyanide solutions, Electrocoagulation (EC) is a very promising electrochemical technique for the recovery of this precious metals. In this work first, an introduction to the fundamentals of the Merrill Crowe and EC process are given, then Kinetic aspects conditions and results of the both process, for the removal of gold and silver from cyanide solutions are presented, and finally the characterization of the solid products formed during the EC process with X-ray Diffraction and SEM are shown. Results suggests that The cementation of both gold and silver by suspended zinc particles conforms to well-behaved fist order kinetics and for the EC process the results show that is an excellent option to remove Au and Ag from cyanide solution by using iron electrodes. Finally, 99.5% of gold and silver were removed in the experimental EC reactor, and it was achieved in 5 minutes or less.展开更多
The dissolution rate of naked Al sbeet in the acidic solutions containing polybutadienoic acid(PBA) with pH vaIue of 0. 3～3. 0 at 20～60℃ has been determined by eIectrometry and gravimetry methods. The form of elect...The dissolution rate of naked Al sbeet in the acidic solutions containing polybutadienoic acid(PBA) with pH vaIue of 0. 3～3. 0 at 20～60℃ has been determined by eIectrometry and gravimetry methods. The form of electroactive Al (m ) ions occurred on the anode and the behavior of electrocoagulation ofPBA have been approached. The results lndlcate that the superlor condltlon of electrocoagulation of watersoIuble nonsaturable low polymer PBA is the adoption of the eIectroactive Alions occurred in electrolytecontaining 1. 0 g. L-l PBA + 0. 2 mol’ L-1 C’H,O, cltrlc acld with pH value of 3. 0 at 30℃. The mechanismof corrosion-inhibited 0r electrocoagulation resulted from the electroactive Al (lI) ions coordinate -COOHgroup of PBA and free l0ns of citric groups iuto the aluminum soaps with bicyclic structure are briefly discussed in tkis paper.展开更多
This paper studied the efficiency of electrocoagulation/electroflotation in removing colour from real textile wastewater by using aluminum and iron electrodes in an innovative pilot external-loop airlift reactor of 15...This paper studied the efficiency of electrocoagulation/electroflotation in removing colour from real textile wastewater by using aluminum and iron electrodes in an innovative pilot external-loop airlift reactor of 150 L. The reactor was designed to operate in batch and continuous modes. The real effluent contained 90% of disperse dye and 10% of reactive dye. A complete flotation of pollutants with acceptable mixing was achieved in this reactor using only the overall liquid recirculation induced by H2 microbubbles. The treatment of these discharges was easier using electrodes of iron rather than aluminum. The optimal initial pH was 10 for both aluminum and iron electrodes. By using iron electrodes, the maximum decolourisation efficiency and COD reduction efficiency reached respectively 96% and 65% for 90 minutes of treatment. Similarly, by using aluminum electrodes, the maximum decolourisation efficiency reached 90%, COD reduction reached 51% for 120 minutes of treatment. In the case of an initial pH slightly different to 10, the required time to reach 90% ranged from double to triple.展开更多
The aims of this study is to design and optimize the functioning of a full continuous combined process based on electrocoagulaion-adsorption on crude Tunisian clay to treat a real textile effluent.The clay characteriz...The aims of this study is to design and optimize the functioning of a full continuous combined process based on electrocoagulaion-adsorption on crude Tunisian clay to treat a real textile effluent.The clay characterization shows that the used clay is a rich-smectite clay.The response surface methodology(RSM)technique based on Box-Behnken design(BBD)was used to optimize the process.At optimum conditions which are initial pH solution of 8.24,effluent flow rate of 0.5 L·min^(-1),voltage of 70 V,and added suspension of clay flow rate of 100 ml·min^(-1) the achieved color,chemical oxygen demand(COD)and total suspended solid(TSS)removal efficiencies were respectively 96.87%,89.77%and 84.46%with0.75 USD·m^(-3) as total cost.The additional laboratory experiments at optimum conditions agree with the predicted results,which confirm the accuracy and the capability of RSM to predict results in the defined space.Finally the designed process could be a good eco-friendly alternative to treat and reuse wastewater in industrial process with reasonable cost.展开更多
Saline waters treatment has become increasingly important for drinking water supply in a greater part of the world. However, some serious limitations had recently been discovered during water treatment, among them the...Saline waters treatment has become increasingly important for drinking water supply in a greater part of the world. However, some serious limitations had recently been discovered during water treatment, among them the boron problem seems to have a critical meaning. According to the WHO regulations (2011), the boron concentration should be reduced to less than 2.4 mg/L for drinking water. The purpose of this study is to investigate the feasibility of electrocoagulation (EC) as a pretreatment process to remove boron from saline waters. To optimize the experimental conditions of boron removal, the effects of some parameters were studied such as inter-electrode distance (die), electrode connection mode, (S/V) ratio, pHi and initial conductivity of the solution (σi). Subsequently, an experimental design methodology was implemented to evaluate statistically the most significant operating parameters. The effects of current density, EC time and initial boron concentration and their mutual interaction were investigated using 23 full factorial design. At optimal conditions, boron removal from synthetic aqueous solutions containing initial boron concentrations of 5 and 50 mg/L reached 81% and 79%, respectively. Applied to boron removal from seawater samples, EC reduces boron concentration to less to 2.4 mg/L with excessive energy consumption under optimal parameters.展开更多
Until relatively recently, little has been done of effective technique “zero effluent” to conserve energy and water. Tannery wastewater is known as complex characteristics. In this study batch electrocoagulation exp...Until relatively recently, little has been done of effective technique “zero effluent” to conserve energy and water. Tannery wastewater is known as complex characteristics. In this study batch electrocoagulation experiments were carried out to assess the removal of color and chemical oxygen demand (COD) from tannery wastewater using two types of electrode materials: aluminum and iron. The effects of current density, electrolysis time and initial pH were investigated for tannery wastewater. Therefore, the operating costs for each electrode have been calculated. Based on results, it can be concluded that iron is tremendous to aluminum as electrode material, from COD removal and energy consumption views. All the conclusions of the study revealed that treatment of tannery by EC can be applied as a step of a hybrid treatment.展开更多
This paper is a brief overview of the role of inducing the nucleated electro winning of copper by using iron electrodes in electrocoagulation (EC) process. Cyanide compounds are widely used in gold ore processing plan...This paper is a brief overview of the role of inducing the nucleated electro winning of copper by using iron electrodes in electrocoagulation (EC) process. Cyanide compounds are widely used in gold ore processing plants in order to facilitate the extraction and subsequent concentration of the precious metal. Owing to cyanide solution employed in gold processing, effluents generated have high contents of free cyanide as well as copper cyanide complexes, which lend them a high degree of toxicity. In this regard, two options for the treatment of cyanide barren solutions has been used;in two ways;first for cyanide destruction by oxidation with the use of the EC process, in theory, has the advantage of decomposing cyanide at the anode and collecting copper simultaneously by a sludge of copper magnetic iron. In both cases excellent performance can be achieved using the high capacity of the bipolar iron EC technology. We found that it is possible to reduce the copper cyanide complex from 720 mg·l-1 to below 10 mg·l-1 within 20 minutes.展开更多
A review of the literature published on topics interrelated to electrochemical treatment within wastewater by using sacrificial anodes was presented. Electrocoagulation (EC) is a technique used for water and has a gre...A review of the literature published on topics interrelated to electrochemical treatment within wastewater by using sacrificial anodes was presented. Electrocoagulation (EC) is a technique used for water and has a great ability on various wastewater treatments, industrial processed water, and medical treatment. It has potential in removing various pollutants such as chemical oxygen demand turbidity, ammonia, color, and suspended solid. One of the most necessities industries is Textile industries which release large volumes of wastewater that contains different dyes. Azo dyes contain strong N = N bond which is not easily broken by conventional methods. The discharge of this type of wastewater to natural watercourse can pose serious environmental impacts to aquatic life. Electrocoagulation (EC) method depends on several factors as electrode material, current density, operation time and PH. The review describes, discusses and compares the types of that electrode influencing the EC process in various wastewater and leachate. Both operating costs and electrical energy consumption values were found to vary greatly depending on the type of electrodes material and solution being treated.展开更多
Twenty percent to forty percent of patients with epilepsy are medically refractory.For these patients,epilepsy surgeries such as resecting the epileptogenic focus may provide an alternative option.However,when the epi...Twenty percent to forty percent of patients with epilepsy are medically refractory.For these patients,epilepsy surgeries such as resecting the epileptogenic focus may provide an alternative option.However,when the epileptogenic focus is located in the eloquent cortex,the resection of epileptogenic focus may lead to unacceptable functional deficits.Bipolar electrocoagulation on functional cortex(BCFC)is a surgical technique that holds the same principles with multiple subpial transections(MST)and aims to benefit patients with epilepsy whose epileptogenic zone is located in the eloquent cortex.It uses thermal injury to interrupt the horizontal fibers in the cortex while mechanical injury is used in MST.Here,we reviewed the rationale,surgical procedure,laboratory research,and clinical application of BCFC.We also discussed the ongoing challenges of BCFC.展开更多
基金financial support from the National Natural Science Foundation of China(31872901)Major State Basic Research Development Program of China(2016YFA0501602)。
文摘Electrocoagulation is progressively becoming an ecologically friendly water treatment method owing to its lack of secondary pollution,high active ingredient concentration,high treatment effectiveness,simple equipment,and simplicity of automated control implementation.Herein,electrocoagulation is offered as a method for treating wastewater containing azo dyes using a revolutionary flexible electronic fabric that can be mass-producible at a reasonable price.A computer-controlled machine embroiders 316L stainless steel fiber(316L SSF)onto an insulating fabric to manufacture a flexible electronic device of cathode and anode with a monopolar arrangement on the fabric surface.Using methyl orange(MO)solution to simulate azo dye wastewater,the decolorization rate of 500 ml MO reached 99.25% under the conditions of 50 mg·L^(-1)initial mass concentration,120 min electrolysis time,15 mA·g^(-1)current density,1 cm electrode spacing,0.1 mol·L^(-1)NaCl,pH 7.6,200 r·min^(-1)rotational speed of the stirrer,and 22-25℃ room temperature.In addition,it is feasible to embroider flexible electronic fabrics with varied sizes and numbers of electrodes based on the amount of treated sewage to increase the degradation rate,which has significant practical application value.
基金Funded by the National Natural Science Foundation of China (No.52078394)the Key Research and Development Program of Hubei Provincial (No.2020BAB081)。
文摘The present work uses PEO solution to well disperse carbon fiber and identifies percolation thresholds of carbon fiber and carbon black which are used as conductive fillers.The resultant cathode plates have an average compressive strength of 27.3 MPa and flexural strength of 29.09 MPa,which demonstrate excellent mechanical properties.The Cu^(2+)removal efficiency was measured at different current densities in EC process with cement-based cathode plate,while the voltage changes were recorded.The results showed that the cement-based cathode plate operated stably and achieved 99.7%removal of 1 L of simulated wastewater with a Cu^(2+)concentration of 200 ppm at a current density of 8 m A/cm^(2)for 1 h.Characterization of floc and tested cathode plates,SEM and EDS analyses,and repeatability testing of the tested plates demonstrate the reusability of the plates,proving that cement-based plates can effectively replace metal cathode plates,reduce the cost of EC and improve the applicability of EC devices.
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 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.
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Electrocoagulation of pulp and paper industry effluent with SS-304 electrode has been carried out under varying process variable such as pH, current density, time and dose of electrolyte to find out the optimum conditions. Maximum reduction efficiency of Chemical Oxygen Demand (COD) 82% and color more than 99% from pulp and paper industry wastewater at the following conditions pH = 7, current density = 24.80 mA/cm2 time = 40 min and dose of electrolytes = 1.0 g/L. Moreover, effects of electrolytes dosage on electricity consumption were observed and found to be that NaCl is better in comparison of Na2SO4 in respect of lower down the electricity consumption. But application of NaCl causes the formation of hazardous compounds as secondary pollutants within treated water. Therefore, Na2SO4 could be a potent replacement of NaCl to enhance the conductivity of paper industry effluent treated by EC process. The treated water has been compared with standard of Central Pollution control board (CPCB) and World Health organization, and found to be suitable for the reuse in irrigation.
文摘In the present study pulp and paper industry effluent was treated with the help of aluminum electrode using electrocoagulation (EC) process with feasible sludge management. The influences of pH, time, current density and electrolytes dose were investigated and optimum conditions were established to reduce the maximum amount of Chemical Oxygen Demand (COD) and color. At optimum conditions 70% of COD and 98% of color were removed. Additionally, the behavior of electrolytes (NaCl and Na2SO4) was determined;it has shown that Na2SO4 results in the generation of less secondary pollutants than that NaCl and thereby could be used as better replacement in paper industries for electrocoagulation mediated treatment of wastewater. The residual amount of operational parameters in EC treated water was compared to the World Health Organization (WHO) and Central Pollution Control Board (CPCB) of India. It was found to be safe for utilization in irrigation. Furthermore, sludge produced during the EC process has been analyzed for physicochemical characteristics. To understand the physical and elemental phases of sludge, the analytical technique such as field emission electron microscope coupled with energy dispersive spectroscopy has been used to find out the possible management alternative.
文摘Soil washing, ex situ mechanical technique, is one of the few permanent treatment alternatives to remove metal contaminants from soils by employing physical separation based on mineral processing technologies to remove discrete particles or metal-bearing particles and/or chemical extraction based on leaching or dissolving process to extract the metals from the soils into an aqueous solution. However, washwater remained from soil washing process contains discrete particulate particles along with heavy metals as solution phase to be treated separately, as well as this process can produce large amount of sludge that requires further treatment, slow metal precipitation, poor settling, the aggregation of metal precipitates. Electrical treatments including electrocoagulation and electrolysis can be effective in removing these substances from washwater. This paper reviews the theoretical models in applying electrocoagulation and electrolysis to remove heavy metals and discrete particulate particles in washwater by examining and comparing the status of washwater treatment technologies which have been undertaken, mostly in the US and EU for the period 1990-2012.
基金supported by Maa-ja vesitekniikan tuki ry.and Academy of Finland(AquAlSi-project).
文摘During the last two decades, and particularly during the last few years, the environmental sector has shown a largely growing interest in the treatment of different types of water and wastewater by electrocoagulation (EC). The aim of this work was to review studies, conducted mainly during 2008-2011, on the wide and versatile range of feasible EC applications employed in the purification of different types of water and wastewater. The EC applications discussed here were divided into 7 following categories: tannery, textile and colored wastewater;pulp and paper industry wastewater;oily wastewater;food industry wastewater;other types of industrial wastewater;surface water as well as model water and wastewater containing heavy metals, nutrients, cyanide and other elements and ions. In addition, this paper presents an overview of the optimum process conditions (treatment times, current densities, and initial pH) and removal efficiencies (mostly high) achieved for the EC applications discussed. In the vast majority of the studies discussed in this review, the aforementioned values were found to be in the range of 5-60 min (typically less than 30 min), 10-150 A/m2 and near neutral pH, respectively. Both operating costs and electrical energy consumption values were found to vary greatly depending on the type of solution being treated, being between 0.004 -6.74 €/m3 and 0.002-58.0 kWh/m3, but in general they were rather low (typically around 0.1-1.0 €/m3 and 0.4-4.0 kWh/m3).
文摘The Merrill-Crowe or Cementation process is used for concentration and purification of gold and silver from cyanide solutions. Among other available options for recovery of precious metals from cyanide solutions, Electrocoagulation (EC) is a very promising electrochemical technique for the recovery of this precious metals. In this work first, an introduction to the fundamentals of the Merrill Crowe and EC process are given, then Kinetic aspects conditions and results of the both process, for the removal of gold and silver from cyanide solutions are presented, and finally the characterization of the solid products formed during the EC process with X-ray Diffraction and SEM are shown. Results suggests that The cementation of both gold and silver by suspended zinc particles conforms to well-behaved fist order kinetics and for the EC process the results show that is an excellent option to remove Au and Ag from cyanide solution by using iron electrodes. Finally, 99.5% of gold and silver were removed in the experimental EC reactor, and it was achieved in 5 minutes or less.
文摘The dissolution rate of naked Al sbeet in the acidic solutions containing polybutadienoic acid(PBA) with pH vaIue of 0. 3～3. 0 at 20～60℃ has been determined by eIectrometry and gravimetry methods. The form of electroactive Al (m ) ions occurred on the anode and the behavior of electrocoagulation ofPBA have been approached. The results lndlcate that the superlor condltlon of electrocoagulation of watersoIuble nonsaturable low polymer PBA is the adoption of the eIectroactive Alions occurred in electrolytecontaining 1. 0 g. L-l PBA + 0. 2 mol’ L-1 C’H,O, cltrlc acld with pH value of 3. 0 at 30℃. The mechanismof corrosion-inhibited 0r electrocoagulation resulted from the electroactive Al (lI) ions coordinate -COOHgroup of PBA and free l0ns of citric groups iuto the aluminum soaps with bicyclic structure are briefly discussed in tkis paper.
文摘This paper studied the efficiency of electrocoagulation/electroflotation in removing colour from real textile wastewater by using aluminum and iron electrodes in an innovative pilot external-loop airlift reactor of 150 L. The reactor was designed to operate in batch and continuous modes. The real effluent contained 90% of disperse dye and 10% of reactive dye. A complete flotation of pollutants with acceptable mixing was achieved in this reactor using only the overall liquid recirculation induced by H2 microbubbles. The treatment of these discharges was easier using electrodes of iron rather than aluminum. The optimal initial pH was 10 for both aluminum and iron electrodes. By using iron electrodes, the maximum decolourisation efficiency and COD reduction efficiency reached respectively 96% and 65% for 90 minutes of treatment. Similarly, by using aluminum electrodes, the maximum decolourisation efficiency reached 90%, COD reduction reached 51% for 120 minutes of treatment. In the case of an initial pH slightly different to 10, the required time to reach 90% ranged from double to triple.
文摘The aims of this study is to design and optimize the functioning of a full continuous combined process based on electrocoagulaion-adsorption on crude Tunisian clay to treat a real textile effluent.The clay characterization shows that the used clay is a rich-smectite clay.The response surface methodology(RSM)technique based on Box-Behnken design(BBD)was used to optimize the process.At optimum conditions which are initial pH solution of 8.24,effluent flow rate of 0.5 L·min^(-1),voltage of 70 V,and added suspension of clay flow rate of 100 ml·min^(-1) the achieved color,chemical oxygen demand(COD)and total suspended solid(TSS)removal efficiencies were respectively 96.87%,89.77%and 84.46%with0.75 USD·m^(-3) as total cost.The additional laboratory experiments at optimum conditions agree with the predicted results,which confirm the accuracy and the capability of RSM to predict results in the defined space.Finally the designed process could be a good eco-friendly alternative to treat and reuse wastewater in industrial process with reasonable cost.
文摘Saline waters treatment has become increasingly important for drinking water supply in a greater part of the world. However, some serious limitations had recently been discovered during water treatment, among them the boron problem seems to have a critical meaning. According to the WHO regulations (2011), the boron concentration should be reduced to less than 2.4 mg/L for drinking water. The purpose of this study is to investigate the feasibility of electrocoagulation (EC) as a pretreatment process to remove boron from saline waters. To optimize the experimental conditions of boron removal, the effects of some parameters were studied such as inter-electrode distance (die), electrode connection mode, (S/V) ratio, pHi and initial conductivity of the solution (σi). Subsequently, an experimental design methodology was implemented to evaluate statistically the most significant operating parameters. The effects of current density, EC time and initial boron concentration and their mutual interaction were investigated using 23 full factorial design. At optimal conditions, boron removal from synthetic aqueous solutions containing initial boron concentrations of 5 and 50 mg/L reached 81% and 79%, respectively. Applied to boron removal from seawater samples, EC reduces boron concentration to less to 2.4 mg/L with excessive energy consumption under optimal parameters.
文摘Until relatively recently, little has been done of effective technique “zero effluent” to conserve energy and water. Tannery wastewater is known as complex characteristics. In this study batch electrocoagulation experiments were carried out to assess the removal of color and chemical oxygen demand (COD) from tannery wastewater using two types of electrode materials: aluminum and iron. The effects of current density, electrolysis time and initial pH were investigated for tannery wastewater. Therefore, the operating costs for each electrode have been calculated. Based on results, it can be concluded that iron is tremendous to aluminum as electrode material, from COD removal and energy consumption views. All the conclusions of the study revealed that treatment of tannery by EC can be applied as a step of a hybrid treatment.
文摘This paper is a brief overview of the role of inducing the nucleated electro winning of copper by using iron electrodes in electrocoagulation (EC) process. Cyanide compounds are widely used in gold ore processing plants in order to facilitate the extraction and subsequent concentration of the precious metal. Owing to cyanide solution employed in gold processing, effluents generated have high contents of free cyanide as well as copper cyanide complexes, which lend them a high degree of toxicity. In this regard, two options for the treatment of cyanide barren solutions has been used;in two ways;first for cyanide destruction by oxidation with the use of the EC process, in theory, has the advantage of decomposing cyanide at the anode and collecting copper simultaneously by a sludge of copper magnetic iron. In both cases excellent performance can be achieved using the high capacity of the bipolar iron EC technology. We found that it is possible to reduce the copper cyanide complex from 720 mg·l-1 to below 10 mg·l-1 within 20 minutes.
文摘A review of the literature published on topics interrelated to electrochemical treatment within wastewater by using sacrificial anodes was presented. Electrocoagulation (EC) is a technique used for water and has a great ability on various wastewater treatments, industrial processed water, and medical treatment. It has potential in removing various pollutants such as chemical oxygen demand turbidity, ammonia, color, and suspended solid. One of the most necessities industries is Textile industries which release large volumes of wastewater that contains different dyes. Azo dyes contain strong N = N bond which is not easily broken by conventional methods. The discharge of this type of wastewater to natural watercourse can pose serious environmental impacts to aquatic life. Electrocoagulation (EC) method depends on several factors as electrode material, current density, operation time and PH. The review describes, discusses and compares the types of that electrode influencing the EC process in various wastewater and leachate. Both operating costs and electrical energy consumption values were found to vary greatly depending on the type of electrodes material and solution being treated.
基金supported by theNational Natural Science Foundation of China (81790654,81790650) Capital Health Research and Developmentof Special (2016-1-8012).
文摘Twenty percent to forty percent of patients with epilepsy are medically refractory.For these patients,epilepsy surgeries such as resecting the epileptogenic focus may provide an alternative option.However,when the epileptogenic focus is located in the eloquent cortex,the resection of epileptogenic focus may lead to unacceptable functional deficits.Bipolar electrocoagulation on functional cortex(BCFC)is a surgical technique that holds the same principles with multiple subpial transections(MST)and aims to benefit patients with epilepsy whose epileptogenic zone is located in the eloquent cortex.It uses thermal injury to interrupt the horizontal fibers in the cortex while mechanical injury is used in MST.Here,we reviewed the rationale,surgical procedure,laboratory research,and clinical application of BCFC.We also discussed the ongoing challenges of BCFC.
