Al-Al Electrodes Research Articles

The Study of Removal of Polyvinyl Chloride (PVC) Particles from Wastewater through Electrocoagulation

Plastic was produced massively, especially using polyvinyl chloride (PVC) as a raw material. Unfortunately, this condition cause affects the environment, which creates a new pollutant issue. It is essential to study the removal of PVC microplastics in current water treatment processes. The study of wastewater treatment can be achieved using electrocoagulation, which has several benefits, including low-cost, simple chemicals, and accessible equipment operation. This research investigated the study of the removal of PVC microplastics from wastewater by electrocoagulation. The new potential of the electrocoagulation technique using Al-Al electrodes was studied systematically at various variations, i.e., electrolysis time, electrolyte concentration, initial pH, coagulation speed, and electrolyte type. The results showed that the PVC microplastics removal efficiency reached 100% after electrolysis for 60 min, electrolyte concentration of 0.01 mol/L, initial pH of 7, coagulation speed of 500 rpm, the type of electrolyte used was NaCl at a flocculation speed. These optimum conditions also reduced the value of turbidity of wastewater samples from 1.39 ± 0.02 to 1.10 ± 0.05 NTU. The results of this study provide an engineering perspective in optimizing operational parameters for removing PVC microplastics in aquatic environments.

Electric Field Features and Charge Behavior in Oil-Pressboard Composite Insulation under Impulse Voltage

Oil-pressboard/paper insulation materials are essential in transformers for ensuring their safe and stable operation, primarily due to their roles in spatial electric field distribution and charge migration mechanisms. Current spatial distribution analyses rely on computational methods that lack empirical validation, particularly for oil-pressboard/paper composites. This study leverages the principles of the Kerr electro-optic effect to develop a rapid measurement platform for electric fields within oil-pressboard/paper insulation under impulse voltage conditions, which measures the spatial electric field characteristics using Cu-Cu and Al-Al electrodes under various scenarios: with asymmetric and symmetric pressboard coverage and different numbers of insulating paper layers. Findings indicated: (1) In asymmetric pressboard models, Cu-Cu electrodes exhibit a consistent peak electric field of approximately 16 kV/mm, while Al-Al electrodes show peak values of 18.13 kV/mm and −14.98 kV/mm. Charge density patterns are similar, with Cu-Cu at about 68 μC/m2 and Al-Al at 11.2 μC/m2 and −124.8 μC/m2. (2) Symmetric models present consistent peak electric fields and charge densities for both polarities. (3) Increasing insulating paper layers elevates electric field strengths. Both electrodes show the similar peak field of about 17 kV/mm with differing paper layers due to higher charge injection from the Al electrode. (4) Utilizing the Schottky effect and field emission principles, the study clarifies charge generation and migration mechanisms. These insights could provide a theoretical foundation for designing and verifying oil-pressboard/paper insulation structures in transformers.

Comprehensive analysis of the integrated electro-coagulation and membrane filtration process for semiconductor wastewater treatment

Dissolved silica poses a significant challenge in semiconductor wastewater treatment due to its propensity to cause scaling and its resistance to removal, particularly due to its low molecular weight and its uncharged nature under neutral pH conditions. This study thus focuses on optimizing the integrated electro-coagulation (EC) and microfiltration (MF) membrane process, which involves the rapid coagulation of dissolved silica and the subsequent removal of the resulting coagulated EC flocs using a membrane. Various anode-cathode combinations were assessed in the EC process to determine the most effective electrode pairing for dissolved silica removal and system maintenance. Our findings revealed that an AlAl electrode combination facilitated efficient dissolved silica removal, reducing concentrations to levels that prevent scaling under charge loadings exceeding 450 C/L. Additionally, different types of polymeric or ceramic membranes were assessed downstream of the EC process to investigate further removal of coagulated dissolved silica flocs and to compare associated membrane fouling. Ceramic membranes exhibited superior fouling resistance, highlighting the role of EC flocs as a major contributor to membrane fouling. This study explores diverse operational conditions for the integrated EC and MF membrane process to achieve the effective removal of dissolved silica. Collectively, our findings provide valuable insights for the rapid removal of other hazardous contaminants commonly found in semiconductor wastewater, thus paving the way for more effective wastewater treatment processes.

Penyisihan COD dan TSS pada Limbah Cair Industri Tahu dengan Kombinasi Metode Elektrokoagulasi dan Filtrasi Menggunakan Media Biji Asam Jawa (Tamarindus indica L)

This study aimed to treat tofu wastewater using electrocoagulation and filtration methods with tamarind seed media. This study was conducted on a lab scale with a capacity of 2 liters, using Al-Al electrodes with a voltage of 13 volts. The variables studied were EC time (20, 30, 40, 50, and 60 minutes) and electrode plate area (90 cm2 and 99 cm2) with a thickness of 1 mm. The parameters measured were COD and TSS of tofu wastewater before and after treatment. The results showed that the electrocoagulation and filtration methods with tamarind seed media could reduce the COD and TSS levels of tofu wastewater significantly. The optimal condition was achieved at EC time of 50 minutes and plate area of 99 cm2, with COD removal of 78.7% and TSS removal of 88%. This was due to the production of metal ions (Al3+) as destabilizing agents at the anode, the formation of flocs by protein and tannin in tamarind seeds, and the pH reduction by ascorbic acid and citric acid in tamarind seeds. This method had the advantage of not using synthetic chemicals and producing a more environmentally friendly final product.

Application of the hybrid electrocoagulation–electrooxidation process for the degradation of contaminants in acidified biodiesel wastewater

• Acidified biodiesel production wastewater was treated by the hybrid EC-EO process. • Optimum operating conditions were determined for single EC, EO processes. • For single EC, EO processes, reaction rate constants were found based on kinetic models. • The specific energy consumption of the EC, EO and hybrid EC-EO processes were calculated. • Higher COD, TSS and oil-grease removal efficiencies were achieved in the hybrid EC-EO process. In this study, the treatment of biodiesel production wastewater by the hybrid Electrocoagulation (EC) - Electrooxidation (EO) processes was investigated. Before the hybrid process, biodiesel production wastewater was acidified using H 2 SO 4 and HCl at different pH values. The highest pollutant removal efficiency was achieved at pH 6 using HCl. The chemical oxygen demand (COD), total suspended solids (TSS), and oil-grease removal efficiency were 67.2%, 65.7%, and 56.9% after the acidifying of the wastewater. After the application of the acidification technique, the operating conditions of the EC and EO processes were optimized, then the hybrid EC-EO process was applied. Different electrodes were evaluated and the Al-Al electrode pair was chosen for the EC process while Ti/SnO 2 anode was chosen for the EO process. Optimum operational conditions for the EC process were 0.25 A and 60 min whereas 0.5 A and 150 min for the EO process while pH was kept as the outlet of the acidification. The COD, TSS, and oil-grease removal efficiency of the hybrid EC opt -EO opt process was 98.9, 98.2, and 99.8%, respectively. The specific energy consumption of the EC, EO, and hybrid EC-EO processes at optimized conditions were 1.02, 43.4, and 37.4 kWh/kg COD removed , respectively. The hybrid process has a higher removal efficiency than either the EC or EO procedures alone, while it uses less energy than the EO process. The hybrid EC-EO procedure, is an effective treatment method for acidified biodiesel wastewater, according to the results of the study.

Electrocoagulation of petrochemical wastewater by a novel alternative Al-Al electrodes: optimisation and modelling with the response surface method

ABSTRACT New electrocoagulation (EC) method by alternative anode–cathode Al-Al (aluminium–aluminium) electrodes was used to reduce COD in petrochemical wastewater. No report of alternative electrocoagulation using switching electrocoagulation (SEC) has been published. The effect of voltage and current density (consumption energy), switching time, total time and the number of electrodes were investigated, and the removal efficiency, isotherms and kinetic data were calculated. Then, the process was optimised with the response surface methodology (RSM) and statistically significant factors, which affect the removal efficiency identified based on the Box–Behnken design (BBD). The interactions between voltage and switching time, and total time on the COD removal were statistically significant for both, two and four Al-Al electrodes. From the analysis of variance (ANOVA), quadratic models have been employed for COD removal, showing high coefficients of determination (R 2) of 0.9692 and 0.9442 for Al-Al electrodes. The optimum conditions for voltage, switching time and total time is 5 V, 15 s and 10 min, respectively, where 98.09% of COD removal by Al-Al could be obtained. Optimised COD removal per cent per energy consumption was 8.9396%/kJ. Biodegradability improvement confirmed by COD, total dissolved solids (TDS) and surface area analysis (BET) of the raw and treated wastewater showed removal and/or demand of aluminium and metal cations and other pollutions.

Acid mine wastewater treatment using electrocoagulation method

The research uses the electrocoagulation method as an alternative to treat acid mine wastewater. The electrocoagulation process occurs when the anode releases Al ions as an active coagulant into the solution to form floc, which binds contaminants and particles in acid mine wastewater. This could remove 99.95% of Fe in the case of wastewater from the iron ore beneficiation plant. However, until now, there are not many Al-Al electrodes used for the case of iron ore mine acid drainage. Therefore, this research aims to understand the effect of metal ion concentrations of Fe. In addition, through this study, the influence of pH and Total Suspended Solid (TSS) during electrocoagulation of the acid mine wastewater was also investigated. Those three variables were analyzed for the voltages and electrolyte concentration. From the study, it was found that the removal of Fe increased with the increase of the voltages. The optimum reduction of the Fe concentration could be achieved at the electrolyte concentration of 0.01 M. The electrocoagulation also neutralized the pH of the wastewater from 2.83 and reduced the TSS content from 131.04 to 9.5 mg/L. It is expected from this study that more research related to the use of electrocoagulation to treat acid mine wastewater can be conducted in the future, particularly with different variations of electrodes, electrolytes, and heavy metals to be removed.

Effect of electrode configuration and voltage variations on electrocoagulation process in surfactant removal from laundry wastewater

Almost all human life requires water, one of which is washing clothes. However, city people tend to use laundry services. It is necessary to treat laundry wastewater because it contains parameters that can cause environmental pollution. A promising technique has been found to treat urban wastewater, especially laundry wastewater. An electrochemical method for water treatment is known as electrocoagulation, in which a solution of an active coagulant in the form of metal ions (aluminum or iron) is introduced into a solution. In electrocoagulation, the processes of adsorption, coagulation, precipitation, and flotation taking place. This research was conducted to determine the impact of current on electrocoagulation using Al-Al, Fe-Fe, Al-Fe, Fe-Al electrodes in reducing surfactant levels in laundry wastewater with variations in the voltage used were 20 V, 30 V, 40 V, and 60 V. The results showed that the electrocoagulation process could remove surfactants in laundry wastewater. A voltage of 30 volts with Al-Al electrode configuration was used for 30 minutes to obtain optimum conditions so that it will get a surfactant effluent concentration of 5.77 mg/L with a removal efficiency of 72.89%.

Electrochemical Degradation of DSW Using Fe- Fe and Al- Al Electrodes Taguchi and Anova Approach

Expulsion of toxins from distillery spent wash (DSW) was applied by utilizing a blend of matched aluminum and iron electrodes in a clump method of activity utilizing electrochemical procedure. The refinery spent wash was described diagnostically utilizing standard strategy for examination and the treatment results were dissected as far as COD and Colour. The examinations were directed to consider the impact of working boundaries, for example, voltage, separation between the electrodes and electrolysis time and were optimized by utilizing Taguchi and ANOVA technique. pH and stirring speed were kept constant as 7 and 500 rpm. The most extreme expulsion efficiencies of COD and Colour were monitored by considering total of 16 experiments each with three trials. The Taguchi method led to COD of 95% and color removal of 94%, optimized with Al-Al electrodes at the voltage of 25V, distance of electrodes 2 cm and the electrolysis time of 150 minutes. The most extreme COD and Colour removal efficiencies found to be 92% and 89% from Fe-Fe electrodes at the indistinguishable working conditions. In any case, the aluminum electrodes seen progressively appropriate for the deprivation of DSW when contrasted with iron electrodes.

Electrocoagulation-flocculation of aquaculture effluent using hybrid iron and aluminium electrodes: A comparative study

This work investigated the treatment of fish pond wastewater (FPW) using electrocoagulation – flocculation (ECF) through aluminium (Al) and iron (Fe) electro-coagulants. The feasibility of using this method has been determined in terms of turbidity (TUR), biochemical demand oxygen (BOD), chemical demand oxygen (COD), and reduction of colour (COL). The study analysed the role of pH, current dosage, electrolysis time, settling time, temperature, and concentration of NaCl on the ECF process. Also, the influence of using the hybrid of Al and Fe in different configurations (Al-Al, Fe-Fe, Fe-Al, and Al-Fe) was taken into account for the ECF process. The perikinetics kinetics of the process flocculation was studied. The coefficient of regression (R2) was used to confirm the theoretical applicability of perikinetics flocculation. The forecast of the time evolution of aggregating particles or species was included. The optimum pH was 2. Al-Al electrode had a higher TUR removal (87.87%). Fe-Fe electrodes were the best for reducing COL (73.56%). Al-Al was proven to be the best electrode configuration for BOD removal (76.90%) and COD removal (86.4 %). The ECF kinetic data partially followed Von Smoluchowski's equation for the Brownian perikinetics flocculation theory. The mechanisms that accounted for the distribution of particles were sweep flocculation and charge neutralisation. The ECF was very effective for reducing FPW pollutants.

Electrocoagulation for nitrate removal in groundwater of intensive agricultural region: a case study of Harran plain, Turkey

This study focuses on the mechanism of Nitrate (NO3−) removal from aqueous solutions by electrocoagulation (EC) using aluminum (Al) and iron (Fe) electrodes and on the reduction of high nitrate levels in the groundwater of an arid/semi-arid region. Influence of initial pH, varying electrode material, inter-electrode distance, initial conductivity, and nitrate concentration over percentage removal of nitrate as well as energy consumption were all studied. The process was carried out by batch method at room temperature (25 °C). Tests were performed on a synthetic water sample prepared in the laboratory and ten samples collected from the Harran Plain region. According to the results of experimental studies, optimum experimental conditions were found to be with Al electrodes and initial pH = 6, run time = 210 min, current density = 2.31 A/m2, inter-electrode distance = 10 mm, and conductivity = 1000 µs/cm for removal of 80.1% nitrate (initial concentration = 250 mg/L). The energy consumption for experimental setup and real groundwater were 2.07 kWh/m3 and 1.925 kWh/m3, respectively. As the Al electrode distance was increased from 10 to 20 mm, the percentage of nitrate removal decreased from 80.1 to 62.3% because of the decrease in electrostatic attraction. It was found that Fe electrodes did not have a significant effect on nitrate removal (12.4%). The removal efficiency of Ugurlu groundwater that has the highest nitrate concentration was found to be 62.0% for Al electrode and 39.0% for Fe electrode. The Al-Al electrode combination used in the studies yielded better efficiency than the Fe–Fe electrode combination. It is thought that this method will also be applicable to regions with the same characteristics as the arid/semi-arid study region.

Chemistry Laboratorium Liquid Waste Treatment Using Electrocoagulation Method

Laboratory liquid waste is one of the problems encountered in universities. Before discharged into the aquatic environment, the liquid waste must pass through the processing first. One way that can be done to reduce the contamination of laboratory waste is by lowering the heavy metal content contained in the waste by using electrocoagulation method. Electrocoagulation becomes one of the alternative waste treatment because this method is easy and simple to do, but produces high efficiency of metal removal. In this research has been tested the liquid waste treatment laboratory by using electrocoagulation method. The processing of liquid waste by electrocoagulation using Al-Al electrodes, gives a very significant metal removal result. Including decreased levels of organic compounds and total solids in waste decreased. However, the waste from the treatment with electrocoagulation has not met the required quality standard in West Java Provincial Regulation No. 6 of 1999 on the Standard of Waste Water Quality. Because of the high concentration of metal in laboratory liquid waste, it is necessary to process the waste before and after the electrocoagulation process. Keywords: Al electrode, electrocoagulation, laboratory liquid waste

The impact of electrode material in the treatment of landfill leachate by electrocoagulation process

This paper presents the results of the electrocoagulation treatment of leachate by the application of iron and aluminum as an electrode material. It was examined the influence of the current density and electrolysis duration on the removal efficiency of total nitrogen (N). Duration of electrolysis was 30 minutes, and based on the experimental results it was found that the optimal current density is 25 mA/cm2. The highest removal efficiency of total nitrogen, achieved under these conditions, amounts 29.58% by the application Fe-Fe electrode pair, while removal of 7.70% is achieved by application Al-Al electrode pair.

Comparison of Palm Oil Mill Effluent Electrocoagulation by Using Fe-Fe and Al-Al Electrodes: Box-Behnken Design

This present research aims to compare the COD removal of palm oil mill effluent (POME) by electrocoagulation using iron and aluminum electrodes. Response surface method coupled Box-Behnken design is applicable to investigate the effect of various process parameters (voltage, operating time and electrolyte concentration) and optimum condition. The optimum condition by using iron electrode is in 43 minutes, 20 volts and 0.06 M NaCl with the COD removal of 95.045%. By using electrode aluminum, optimum condition is 40.35 minutes, 19 volts and 0.1 M NaCl with the COD removal of 89.941%. Energy consumption of iron electrode and aluminum electrode are 0.189 and 0.209 kWh/mg decomposed COD with energy costs of Rp. 255 and Rp. 282/mg decomposed COD. This indicates that energy and cost consumption of electrocoagulation by using Al electrode are higher than those by using iron electrode. Based on the investigation during research, iron electrode is better for reducing COD while the aluminum is better in removing color in POME.

Electro-coagulation treatment of raw and autoclaved landfill leachate with aluminum electrodes: case study of Djebel Chakir (Tunisia)

Landfilling is a common practice worldwide for solid waste management. The leachate generated at landfill sites contains various organic and inorganic pollutants while it should be treated properly. In this study, the electrocoagulation (EC) process was recognized for its simplicity and effectiveness which was used for the treatment of leachate from the Djebel Chakir landfill site in northern Tunisia. In addition, we investigated the effect of microorganisms (e.g., bacteria, fungi, spore) on sludge production by the application of autoclaving treatment on raw leachate. The application of low current density (15 mA/cm2) within 2 h of treatment and using Al-Al electrodes revealed significant improvement of performance when autoclaving was applied. The chemical oxygen demand (COD) and nitrogen removal increased from 39 to 64% and from 13 to 30%, respectively. The sludge volume was reduced from 40 to 10%, and thus, its handling and disposal costs would be significantly decreased. The energy consumption rate was stable after 40 min of treatment at about 0.8 kWh/kg COD removed. Our study shows that removal of microorganisms by autoclaving prior to the EC process is promising for landfill leachate treatment. However, since autoclaving is far from being practical and cost-effective at full-scale plant, research on coupling EC with an alternative disinfecting process might be of great interest.

The Efficiency of Electrocoagulation and Electroflotation Processes for Removal of Polyvinyl Acetate From Synthetic Effluent

Polyvinyl acetate (PVAc) is a type of thermoplastic resin generated by a polymerization of vinyl acetate. Effluent of this polymer is highly rich with chemical oxygen demand (COD) and total solids (TS). Due to lack of studies on the above problem, the current study aimed at obtaining a sufficient method for the effluent pre-treatment. In fact, the study discussed PVAC effluent treatment by electrocoagulation (EC) and electroflotation processes.The study considered the effect of various operating parameters such as pH and current density, initial concentration of pollutant, inter-electrode distance, electrolysis times, and types of electrode materials (iron and aluminum); COD and TS removal efficiency and optimal values of operational parameters were calculated. In the study, COD and TS reduction rates in the optimized conditions in batch flow reactor were 83% and 78%, and 80% and 72% for Fe and Al electrodes, respectively. Optimized conditions were taken as 24 mA cm -2, 20 g/L PVAC, and neutral pH in 20 minutes for Al-Al electrodes and 15 minutes for Fe-Fe electrodes, 1 cm distance between electrodes with parallel-type monopole of connection modes. According to the results, electrochemical process with batch flow tends to be a suitable pre-treatment process that is inexpensive, easily operated, and highly sufficient for effluent treatment, which contains polyvinyl acetate.

The Efficiency of Electrocoagulation and Electroflotation Processes for Removal of Polyvinyl Acetate From Synthetic Effluent

Polyvinyl acetate (PVAc) is a type of thermoplastic resin generated by a polymerization of vinyl acetate. Effluent of this polymer is highly rich with chemical oxygen demand (COD) and total solids (TS). Due to lack of studies on the above problem, the current study aimed at obtaining a sufficient method for the effluent pre-treatment. In fact, the study discussed PVAC effluent treatment by electrocoagulation (EC) and electroflotation processes.The study considered the effect of various operating parameters such as pH and current density, initial concentration of pollutant, inter-electrode distance, electrolysis times, and types of electrode materials (iron and aluminum); COD and TS removal efficiency and optimal values of operational parameters were calculated. In the study, COD and TS reduction rates in the optimized conditions in batch flow reactor were 83% and 78%, and 80% and 72% for Fe and Al electrodes, respectively. Optimized conditions were taken as 24 mA cm -2, 20 g/L PVAC, and neutral pH in 20 minutes for Al-Al electrodes and 15 minutes for Fe-Fe electrodes, 1 cm distance between electrodes with parallel-type monopole of connection modes. According to the results, electrochemical process with batch flow tends to be a suitable pre-treatment process that is inexpensive, easily operated, and highly sufficient for effluent treatment, which contains polyvinyl acetate.

Electrochemical dissolution of aluminium in electrocoagulation experiments

Six experiments are presented to highlight important features of aluminium dissolution when used in electrocoagulation procedure employed to remove oily contaminations from water. First, using a common oil-in-water emulsion: diluted milk, we show that the electrochemically generated coagulant ions are active only in the first few seconds following their generation—hence, the electrocoagulation cells’ construction should promote the mixing of the nascent Al colloid with the water phase. For this reason, the use of the narrow-gap cells is suggested. Second, in experiments with Al-Al electrode pairs and dilute, neutral, unbuffered, aqueous solutions we (i) estimate the maximum amount of Al dissolution on the cathode and (ii) show how the rate of Al dissolution changes with frequency if the cell voltage polarity is alternating.

Efficiency of aluminum and iron electrodes in removal of colour, turbidity and total suspended solid from biologically treated municipal wastewater

The present investigation was undertaken to observe the effect of different combinations of aluminium and iron (Al-Al, Al-Fe, Fe-Fe and Fe-Al) electrodes on the removal of colour, turbidity (TD) and total suspended solids (TSS) of biologically treated municipal wastewater ( BTMW) using applied potential (V), operating time (OT) and initial pH. The maximum removal of colour (98.7 %) and TSS (96.89 %) was found with the use of Al-Al combination with optimum operating conditions (Voltage: 40 V; OT: 40 mins.; IED: 1.0 cm; EA: 160 cm2; initial pH: 7.5 and ST: 30 mins). It was interesting to note that TD of BTMW was completely removed at these optimal operating conditions. The economic evaluation of electrode combinations was observed to be in the order of Fe-Al (1.17 US $/m3)> Al-Fe (1.11 US $/m3)> Fe-Fe (1.08 US $/m3) >Al-Al (1.01 US $/m3) in terms of energy and electrode consumption. Thus, the BTMW can be effectively treated with the Al-Al electrode combination in comparison to other electrode combinations (Al-Fe , Fe-Fe and Fe-Al).

Treatment of Distillery Spent Wash by Using Chemical Coagulation (CC) and Electro - coagulation [EC

There is an urgent need to find best suitable economic technology to knock out the problems due to distillery industries creating pollution and ecological imbalance. In the present study electro-coagulation treatment is carried out by using different combination of aluminum and iron electrodes in a batch reactor. Also chemical coagulation treatment is carried out by using alum and lime dose to treat distillery spent wash. Maximum 96.09% colour removal was obtained by using Al-Al electrodes for pH 8 and maximum COD removal was obtained 85.7 % by using Al-Al electrodes for pH 3. Further experiments are carried out by using alum and lime coagulant dose to treat distillery spent wash maximum 66. 27 % COD was removed by using alum. Alum is more effective than lime to remove chemical oxygen demand.