Electrocoagulation Technology Research Articles

Investigation of oil content removal performance in real oily wastewater treatment by electrocoagulation technology: RSM design approach

Investigation of oil content removal performance in real oily wastewater treatment by electrocoagulation technology: RSM design approach

Efficient removal of NaOl from mineral processing wastewater using Al-electrocoagulation

Sodium oleate (NaOl) is widely used as collector for oxidised ore flotation, and residual NaOl in mineral processing wastewater is a serious threat to mine environment. In this work, the feasibility of electrocoagulation (EC) as an alternative for chemical oxygen demand (COD) removal from NaOl-containing wastewater was demonstrated. Major variables were evaluated to optimise EC, and related mechanisms were proposed to interpret the observations in EC experiments. The initial pH of the wastewater greatly affected the COD removal efficiency, which was likely to be related to the variation of predominant species. When the pH was below 8.93 (original pH), liquid HOl(l) was the predominant specie, which could be rapidly removed by EC thought charge neutralisation and adsorption. At original pH or higher, Ol− could react with dissolved Al3+ to form insoluble Al(Ol)3, which was subsequently removed through charge neutralisation and adsorption. The presence of fine mineral particles could reduce repulsion force of the suspended solids and promote flocculation, whereas the presence of water glass had an opposite effect. These results demonstrated that EC can be employed as an effective process to purify NaOl-containing wastewater. This study will contribute to deepening our understanding of EC technology for NaOl removal and provide useful information to researchers in mineral processing industry.

Stormwater runoff treatment through electrocoagulation: antibiotic resistant bacteria removal and its transmission risks

ABSTRACT Recently, increasing attention has been paid to antibiotic resistant bacteria (ARB) in stormwater runoff. However, there were little data on ARB removal through electrocoagulation (EC) treatment. In this study, batch experiments were conducted to investigate key designs for ARB removal, role of SS, effects of water matrix, and potential risks after EC treatment under the pre-determined conditions. EC treatment with 5 mA/cm2 of current density and 4 cm of inter-electrode distance was optimal with the highest ARB removal (3.04 log reduction for 30 min). The presence of SS significantly improved ARB removal during EC treatment, where ARB removal increased with the increase of SS levels when SS less than 300 mg/L. Large ARB removal was found under particles with size lower than 150 μm with low contribution (less than 10%) of the settlement without EC treatment, implying that the enhancement of ARB adsorption onto small particles could be one of the reasonable approaches for ARB removal through EC treatment. ARB removal increased firstly and then decreased with the increase of pH, while had proportional relationship with conductivity. After the optimal condition, there were weak conjugation transfer but high transformation frequency (5.5 × 10−2 for bla TEM) for target antibiotic resistance genes (ARGs), indicating that there could be still a risk of antibiotic resistance transformation after EC treatment. These suggested that the combination of EC and other technologies (like electrochemical disinfection) should be potential ways to control antibiotic resistance transmission through stormwater runoff.

Influence of key cations and anions on phosphate removal by Fe(0) electrocoagulation

The electrocoagulation technology is efficient for the removal of phosphate. The removal efficiency of phosphate in the secondary effluent is higher than that of in the synthetic wastewater. In order to identify the key factors for promoting the removal of phosphate in Fe(0) electrocoagulation (EC), this study investigated typical coexisted substances in the secondary effluent, including Ca2+, Mg2+, NH4+, HCO3−, SO42−. The results indicated that Ca2+ and Mg2+ were the key factors promoting the removal of phosphate by Fe(0) EC both under normal (5–6 mg/L) and low dissolved oxygen (DO) (≤ 1 mg/L) conditions. Under low and normal DO conditions, the phosphate removal efficiency increased from 28 % to 98 % ± 2 % (in 5 min) at 10 mA/cm2 with the addition of Ca2+ (0.2–20 mM) or Mg2+ (0.2–2 mM) but decreased to approximately 70 % with the addition of a Mg2+ of 20 mM. Under low and normal DO conditions, the aggregation time of iron oxide flocs decreased from 10 min to 5 min when the concentration of Ca2+ increased from 0 to 20 mM and Mg2+ increased from 0 to 2 mM. The aggregation stability of flocs was not sufficient when the Mg2+ concentration was 20 mM at 5 mA/cm2. Our results confirmed that Fe(0) EC was suitable for the removal of phosphate in the secondary effluent, especially containing moderate amounts of Ca2+ and Mg2+ regardless of the concentration of DO.

Removal of high concentration of chloride ions by electrocoagulation using aluminium electrode.

Wastewater containing a high concentration of chloride ions (Cl- ions) generated in industrial production will corrode equipment and pipelines and cause environmental problems. At present, systematic research on Cl- removal by electrocoagulation is scarce. To study the Cl- removal mechanism, process parameters (current density and plate spacing), and the influence of coexisting ions on the removal of Cl- in electrocoagulation, we use aluminum (Al) as the sacrificial anode, combined with physical characterization and density functional theory (DFT) to study Cl- removal by electrocoagulation. The result showed that the use of electrocoagulation technology to remove Cl- can reduce the concentration of Cl- in an aqueous solution below 250ppm, meeting the Cl- emission standard. The mechanism of Cl- removal is mainly co-precipitation and electrostatic adsorption by forming chlorine-containing metal hydroxyl complexes. The current density and plate spacing affect the Cl- removal effect and operation cost. As a coexisting cation, magnesium ion (Mg2+) promotes the removal of Cl-, while calcium ion (Ca2+) inhibits it. Fluoride ion (F-), sulfate (SO42-), and nitrate (NO3-) as coexisting anions affect the removal of Cl- ions through competitive reaction. This work provides a theoretical basis for the industrialization of Cl- removal by electrocoagulation.

Tertiary treatment of bio-treated landfill leachate by a two-step electrochemical process including electrooxidation and electrocoagulation: a bench-scale trial.

A two-step electrochemical process including electrooxidation (EO) and electrocoagulation (EC) was proposed for the tertiary treatment of bio-treated landfill leachate (BTLL). The operating conditions of sole EO and EC technology were optimized via batch tests. Batch tests indicate that EO displayed superior removal efficiency towards color (89%) and UV254 (64%) under optimal experimental conditions. EC with the electrode combinations Fe-Fe-Fe-Fe (four plates, anode-cathode-anode-cathode) performed better than the other electrode combinations (Fe-Al-Fe-Al, Al-Fe-Al-Fe, Al-Al-Al-Al) and showed excellent removal efficiency towards COD (60%) and color (85%). In continuous-flow tests of 13h, compared to sequential EC-EO process, the sequential EO-EC process was more effective than the sequential EC-EO process in reducing organic matters (COD, TOC) and residual chlorine. The sequential EO-EC process could remove 50% COD, 55% TOC, 72% UV254, and 96% color. The average concentration of residual chlorine in the final effluent of EO-EC process (147mg/L) was significantly lower than that of EC-EO process (463mg/L). UV-vis and GC-MS analyses indicate that the BTLL mainly contained humic acid and fulvic acid-like substances with unsaturated bonds. Conjugated unsaturated organics could be degraded into organic of small molecular weight after the sequential EO-EC process. EEM spectroscopic analysis revealed that soluble microbial byproducts became the predominant organics in the final effluent. This work verifies the synergism between EO and EC and provides some insights into the removal and degradation performance of organic substances in BTLL during the sequential EO-EC treatment.

Electrocoagulation removal of Pb, Cd, and Cu ions from wastewater using a new configuration of electrodes

A new configuration of aluminum electrodes has been performed in an electrocoagulation reactor (ECR) to remove toxic metals from synthetic wastewater. The ECR contains four concentric-cubic electrodes that were connected to the DC power supply with a bipolar mode. The ability of this reactor to eliminate 200 ppm Pb, 200 ppm Cd and 200 ppm Cu from wastewater was investigated under the effect of pH (4–10), applied current (0.2–2.6 A), and the reaction time of (4–60 min). Two grams of NaCl were added to each experiment to enhance the electrical conductivity and minimize the passivation of cathode surfaces. The experiments, analysis, and optimization were conducted using response surface methodology type Box-Behnken design (RSM-BBD) and the Minitab-statistical software program. The highest elimination of heavy metals was: Pb-99.73%, Cd-98.54%, and Cu-98.92% at pH 10, 1.4 A of the applied current, and 60 min of the reaction time. The total real consumption of anodes under these conditions was 0.55 g, and the energy consumption was 12.71 kWh/m3. All reactions of metal removal that occurred in the present EC reactor obey the kinetic of a first-order reaction. Thermodynamics parameters of present electrocoagulation removal of heavy metals indicate an endothermic, spontaneous nature, and random irregularity at the liquid-solid interaction. The highest values of removal efficiencies and the considerably lowest values of energy and electrode consumption proved that the electrocoagulation technology applies in wastewater treatment containing toxic metals.•The anode electrodes were perforated to decrease the amount of electrode consumption, while the cathode electrodes were not perforated.•The new EC reactor eliminated Pb-99.73%, Cd-98.54%, and Cu-98.92% of 200 mg/l of each metal at pH 10, applied current of 1.4 A, and reaction time of 60 min. Moreover, the consumption of energy and electrodes was significantly low.•The performance indicator (R2) of the studied responses was higher than 0.95.

Treatment of oily wastewater by electrocoagulation technology: A general review (2018-2022)

A huge amount of oily wastewater is discharged annually from several industries like petroleum and petrochemical factories. Scientists and researchers are permanently concentrated on creating conventional technologies or identifying novel treatment options for oily wastewaters, since they need to be treated before being discharged into the soil and aquatic ecosystems. Electroc­oagu­lation technology (ECT) is an electrochemical method employed to remove numerous pollutants from domestic and industrial wastewaters. This paper aims to review the recently published articles from 2018 to 2022 concerned with ECT for oily wastewater remediation. Based on the present review, it is obvious that ECT is strongly dependent on the value of electric current or voltage applied to provide the required amounts of electro-coagulants for efficient remediation, reaction time duration for the generation of electro-coagulants and pollutants elimination, and electrode configuration such as shape, type of metal, and distance between electrodes. Other operating parameters include solution pH (since some pollutants are removed based on their cationic or anionic nature), type of electrolyte which affects the electric conductivity and ohmic drop and stirring speed that may influence the contact among numerous ions throughout the EC reactor. The core findings show that the ECT is highly effective, eco-friendly, and cost-effective in eliminating organic and inorganic pollutants from oily wastewater.

Separation of oil-water emulsions by a novel packed bed electrocoagulation (EC) process using anode from recycled aluminum beverage cans

Electrocoagulation (EC) is an emerging technology for the elimination of oil and COD content from oily wastewaters. However, higher operating costs and electrode passivation are pressing challenges for its wide speared application. To overcome this setback, the present work has attempted to develop a new and inexpensive electrode using recycled aluminum (Al) beverage cans for the treatment of oily wastewater by electrocoagulation (EC) technology. It could be an alternative to conventional plate or tube electrodes in the EC process, it is the first contribution into the literature. In current work, recycled Al beverage cans filled with steel wool was used as anode, and commercial stainless-steel mesh (304) with cylindrical shape was used as cathode. The main EC performance measure was COD removal efficiency, impacts of significant process parameters in the EC process (such as operating voltage, electrocoagulation time, stirring rate, and NaCl concentration) on the effectiveness of EC process were investigated by using response surface methodology (RSM) based Box-Behnken Design (BBD) model. The RSM analysis results demonstrated that the highest COD removal rate of 93.53% was achieved under optimal conditions of operating voltage (15 V), electrocoagulation time (10 min), stirring rate (250 rpm), and NaCl concentration (1 g/L). In addition, energy consumption analysis was performed, an electrical energy efficiency of 0.160 kWh/kg COD was achieved. Afterward, ATR-FTIR spectroscopy, scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), and XRD analysis were performed under optimal conditions to characterize anode, and generated sludge during the EC process. Collectively, the findings in this study paves the way toward the development of sustainable EC technology for separation of emulsified oil-water mixtures, which gives the importance of the circular economy and sustainable management of industrial wastewaters.

Efficient degradation of PFOA in water by persulfate-assisted and UV-activated electrocoagulation technique using Fe foam electrode

Perfluorooctanoic acid (PFOA), as a persistent organic pollutant, has been normally present in groundwater, surface water and seawater. It has been widely studied for its persistence, immunotoxicity and bioaccumulation. However, it is extremely difficult to be degraded due to high energy of the C-F bond. In this study, PFOA was removed from simulated and real industrial wastewater with Fe foam electrode by electrocoagulation (EC) technology. To achieve better degradation, persulfate (PS) and ultraviolet (UV) light were employed in the EC technology to realize the degradation of PFOA (PEC-PS). After 60 min treatment, the PEC system showed outstanding performance in that 87.5% of PFOA was degraded and 54.6% of PFOA was defluorinated under optimal conditions with smaller energy consumption and lesser iron sludge generation. Sulfate radical (SO4•−) was generated by the activation of ferrous ions under the synergy of UV light and electric energy. In this process, •OH and SO4•− and electron transfer are crucial in the reaction with PFOA and intermediates. The degradation mechanism of PFOA was summarized according to the quenching experimental results and the contribution of various reactive substances. The potential degradation pathways of PFOA were proposed according to the intermediates obtained through the HPLC-MS. It was found that PFOA showed a decomposition with the gradual losing of −CF2− units. The PEC-PS process of using Fe foam as electrode showed high-efficiency degradation and better recoverability, indicating the great potential of PEC-PS technique in efficient and thorough cleaning of PFOA in actual industrial wastewater.

Electrocoagulation technique for removing Organic and Inorganic pollutants (COD) from the various industrial effluents: An overview

The treatment and reuse of industrial wastewater plays a foremost role in succeeding environmental protection and water security. The electrochemical treatment technology has attracted a great deal of attention because of its compact, high particulate removal, free from chemicals, automation, and minimum sludge generation. The objective of the study is to review the existing literature on COD (Chemical oxygen demand) removal from various industrial effluents using electrocoagulation technology, as well as the factors that influence the process. Electricity is passed through electro plates dipped in wastewater during the electrocoagulation process. Metal hydroxide formations occur, which removes pollutants from wastewater via the sedimentation and flotation mechanisms. After a thorough review of various literatures, a detailed discussion on the process influencing parameters such as pH, Current Density, Electrolysis Time, Conductivity, Stirring Speed, and Retention Time has been done which gives useful information on future scope of research in this area.

A comprehensive review on green perspectives of electrocoagulation integrated with advanced processes for effective pollutants removal from water environment

The rapidly expanding global energy demand is forcing a release of regulated pollutants into water that is threatening human health. Among various wastewater remediating processes, electrocoagulation (EC) has scored a monumental success over conventional processes because it combines coagulation, sedimentation, floatation and electrochemical oxidation processes that can effectively decimate numerous stubborn pollutants. The EC processes have gained some attention through various academic and industrial publications, however critical evaluation of EC processes, choices of EC processes for various pollutants, process parameters, mechanisms, commercial EC technologies and performance enhancement via other degradation processes (DPs) integration have not been comprehensively covered to date. Therefore, the major objective of this paper is to provide a comprehensive review of 20 years of literature covering EC fundamentals, key process factors for a reactor design, process implementation, current challenges and performance enhancement by coupling EC with pivotal pollutant DPs including, electro/photo-Fenton (E/P–F), photocatalysis, sono-chemical treatment, ozonation, indirect electrochemical/advanced oxidation (AO), and biosorption that have substantially reduced metals, pathogens, toxic compound BOD, COD, colors in wastewater. The results suggest that the optimum treatment time, current density, pulse frequency, shaking speed and spaced electrode improve the pollutants removal efficiency. An elegant process design can prevent electrode passivation which is a critical limitation of EC technology. EC coupling (up or downstream) with other DPs has resulted in the removal of organic pollutants and heavy metals with a 20% improved efficiency by EC-EF, removal of 85.5% suspended solid, 76.2% turbidity, 88.9% BOD, 79.7% COD and 93% color by EC-electroflotation, 100% decolorization by EC-electrochemical-AO, reduction of 78% COD, 81% BOD, 97% color by EC-ozonation and removal of 94% ammonia, 94% BOD, 95% turbidity, >98% phosphorus by aerated EC and peroxicoagulation. The major wastewater purification achievements, future potential and challenges are described to model the future EC integrated systems.

Electrochemical treatment for leachate membrane retentate: Performance comparison of electrochemical oxidation and electro-coagulation technology.

With the widespread use of membrane in advanced treatment of leachate, China produces a large amount of leachate membrane retentate (LMR) (≈23.4 million tons) annually, which is usually treated by incineration or recirculation in engineering, but these technologies have many drawbacks. LMR is suitable for electrochemical treatment due to its high electrical conductivity. This study compared the performances of electrochemical oxidation (EO) and electro-coagulation (EC) technology on LMR treatment under different experimental conditions, including anode material, current density, initial pH and reaction time. We found that EO optimal conditions achieved 70.1%, 83.1%, 78.7%, 98.7%, and 69.7% removal of total organic carbon (TOC), UV absorption (at 254nm), chromaticity, ammonia nitrogen (NH3-N), and total nitrogen (TN), respectively. Compared with EO, EC exhibited a similar removal ability for orgainics and better removals of chroma, but much less performance for removing nitrogen pollutants in the same reaction time, that is, removals of NH3-N and TN were only 31.5% and 36.2%, respectively. Meanwhile, EC showed much higher instantaneous current efficiency of COD than EO under its optimal reaction time (120min). In addition, the UV-Vis spectra and 3D fluorescence spectra indicated that EO exhibited relatively outstanding performance in decomposing dissolved organic matter (DOM) with rather complicated structures than EC. Also, the flow field-flow fractionation technique demonstrated that EO preferentially destroy humic-like, large molecular weight DOM, and converting them to smaller molecules, which resulted in more volatile organic compounds in EO samples than EC samples. While EC had little selectivity in the removal of organics, except humic-like DOM with relative small molecular. These findings can provide a theoretical basis for the electrochemical treatment of LMR.

Adopting electrocoagulation technology for removing arsenic from contaminated water

The increasing demand for drinkable water has speeded the expansion of groundwater use. Unfortunately, many geogenic contaminants like arsenic significantly decrease the quality of groundwater. Arsenic in water has harmed at least 0.3 billion people globally. Researchers used various types of treatment technologies to treat arsenic from synthetic wastewater, such as reverse osmoses, adsorption, and electrocoagulation. The electrocoagulation technique has gained popularity due to its increased removal efficiency compared to traditional treatments, low cost, and low sludge generation. This research aims to analyse arsenic treatment and examine the effect of technique variables on the removal performance to determine the best process variables for water purification. The outcome highlighted that arsenic removal improved with higher current densities needing less operating time. As a result, the removal effectiveness of arsenic from water using the electrocoagulation approach went from 88% to 96% in an alkaline environment, which is preferable. The best working settings for arsenic removal include a current density of 6 mA/m2 and a treating time of 30 minutes to reach 81% arsenic removal effectiveness. The best pH level for treating arsenic-contaminated water has been identified as 9.

Distillery industrial wastewater(DIW) treatment by the combination of sono(US), photo(UV) and electrocoagulation(EC) process

The color and Chemical Oxygen Demand (COD) reduction in distillery industrial effluent (DIW) was investigated utilizing photo (UV), sono (US), electrocoagulation (EC), UV + US, UV + EC, US + EC, and US + UV + EC technologies. The empirical study demonstrated that the UV + US + EC process removed almost 100% of color and 95.63% of COD from DIW while consuming around 6.97 kWh m−3 of electrical energy at the current density of 0.175 A dm−2, COD of 3600 mg L−1, UV power of 32 W, US power of 100 W, electrode pairings of Fe/Fe, inter–electrode distance of 0.75 cm, pH of 7, and reaction time of 4 h, respectively. The values found were much greater than those produced using UV, US, EC, UV + US, UV + EC, and US + EC methods. The influence of various control variables such as treatment time (1–5 h), current density (0.075–2.0 A dm−2), COD (1800–6000 mg L−1), inter-electrode distance (0.75–3.0 cm), electrode pairings (Fe/Fe, Fe/Al, Al/Fe, Al/Al), UV (8–32 W), and US (20–100 W) on the color and COD reduction were investigated to determine the optimum operating conditions. It was observed that, an increase in treatment time, current density, UV and US power, decrease in the COD, and inter-electrode distance with Fe/Fe electrode combination improved the COD removal efficiency. The UV and US + EC processes' synergy index was investigated and reported. The results showed that, the US + UV + EC treatment combination was effective in treating industrial effluent and wastewater.

Simultaneous removal of Cr(VI) and Cu(II) from acid wastewater by electrocoagulation using sacrificial metal anodes

• In MP-P mode, EC with Al-Al-Al-Al combination outperformed other Fe and/or Al combinations. • Al EC was highly efficient for simultaneous removal of Cr(VI) and Cu(II) from acid wastewater. • Appropriate concentration of Cu(II) promoted removal of Cr(VI) and total Cr, and vice versa. • Removal mechanisms were elucidated via characterization of scums, precipitates, and cathode deposits. Removal of heavy metals from acid wastewater is an important concern in the field of water treatment. Here, electrocoagulation (EC) technology with Fe and/or Al anode was investigated for the simultaneous elimination of Cr(VI) and Cu(II) from wastewater (initial pH: 3.5–4.0). In the energy-efficient monopolar parallel mode, the EC with Al-Al-Al-Al combination (anode–cathode-anode–cathode) showed the highest removal efficiency among different electrode combination modes, whereas the EC with Fe-Fe-Fe-Fe combination showed the lowest removal efficiency. The main electrochemical parameters of Al EC were further optimized based on cost-effectiveness analysis. Operating cost, including energy consumption, sludge treatment, and anode loss was estimated. The sludge treatment cost accounted for the largest percentage of the operating cost (82.4%) whereas energy consumption cost was the lowest (4.8%). At the initial pH of 3–6, Al EC displayed desirable removal efficiency towards Cu(II) (77.6%–97.9%), Cr(VI) (84.2%–96.4%), and total Cr (83.1%–94.9%). At the conductivity of 899–2300 μS/cm, excellent pollutant removal efficiency was maintained (90.2%–99.8%). Appropriate concentration of Cu(II) promoted the removal of Cr(VI) and total Cr, whereas too high concentration of Cu(II) inhibited their removal and vice versa. Through SEM-EDS and XRD analyses of the scums, precipitates, and cathode deposits, possible mechanisms of Cr(VI) and Cu(II) removal were proposed.

Removal of nutrients and other emerging inorganic contaminants from water and wastewater by electrocoagulation process

The continual discharge of emerging inorganic pollutants into natural aquatic systems and their negative effects on the environment have motivated the researchers to explore and develop clean and efficient water treatment strategies. Electrocoagulation (EC) is a rapid and promising pollutant removal approach that does not require any chemical additives or complicated process management. Therefore, inorganic pollutant treatment via the EC process is considered one of the most feasible processes. The potential developments of EC process may make the process a wise choice for water treatment in the future. Thus, the present study mainly focuses on the use of EC technology to remove nutrients and other emerging inorganic pollutants from water medium. The operating factors that influence EC process efficiency are explained. The major advancement of the EC technique as well as field-implemented units are also discussed. Overall, this study mainly focuses on emerging issues, present advancements, and techno-economic considerations in EC process.

Can electrocoagulation technology be integrated with wastewater treatment systems to improve treatment efficiency?

Considerable amounts of domestic and industrial wastewater that should be treated before reuse are discharged into the environment annually. Electrocoagulation is an electrochemical technology in which electrical current is conducted through electrodes, it is mainly used to remove several types of wastewater pollutants, such as dyes, toxic materials, oil content, chemical oxygen demand, and salinity, individually or in combination with other processes. Electrocoagulation technology used in hybrid systems along with other technologies for wastewater treatment are reviewed in this work, and the articles reviewed herein were published from 2018 to 2021. Electrocoagulation is widely employed in integrated systems with other electrochemical technologies or conventional methods for effective removal of different pollutants with less cost and sometimes over shorter durations of operation. It has also been observed that the hybrid effects besides increasing the removal efficiency can overcome the disadvantages of using electrocoagulation alone, such as less sludge formation, high cost of operation and increased life of the used electrodes, and stable flux of water with longer periods of operation. More than 20 types of other technologies have been combined efficiently with electrocoagulation.

Comparative Study of Chemical Coagulation and Electrocoagulation for the Treatment of Real Textile Wastewater: Optimization and Operating Cost Estimation.

Pollutants derived from real textile wastewater present a high environmental risk. This work involves the study of the removal of chemical oxygen demand (COD), color, and turbidity from Tunisian real textile wastewater by two different water treatment technologies: chemical coagulation (CC) and electrocoagulation (EC). A comparative study between these two methods was conducted based on the separation performance and operating cost (OC). The effects of different operational parameters including electrolysis time (t), voltage, and pH for EC and the coagulant concentration, initial pH, and time of slow mixing (tsm) for CC were studied using response surface methodology. The developed quadratic models for the responses were in good agreement with the experimental data. The experiments proved the efficiency of both chemical and electrochemical techniques for the treatment of textile effluent. Indeed, by using EC, the reduction efficiencies of COD, color, and turbidity were 63.05, 99.07, and 96.31%, respectively, under optimal conditions (pH 9, t = 36.26 min, and voltage 4 V). For CC treatment, the achieved removal efficiencies of COD, color, and turbidity were 54.02, 96.21, and 93.7%, respectively, at pH 8.57, a coagulant concentration of 204.75 mg/L, and a tsm of 28.41 min as optimal operating conditions. The OC obtained for EC and CC was about 0.47 and 0.2 USD/m3, respectively. Even if the OC of the EC process was higher as compared to the CC process, the treated water obtained by EC meets the Tunisian Standards (NT 106.03 and NT 09-14) for textile wastewater discharge into the environment and demonstrates a high potential for its reuse in various industrial activities. EC technology can be integrated into a wastewater management system that ensures a zero liquid discharge of wastewater into the environment.

Development and applicability of Aluminium - Copper alloy electrodes for dairy wastewater treatment

The dairy sector is classified as a high-water-utilizing sector throughout its production stages. Dairy wastewater treatment implemented through electrocoagulation is one of the rapidly emerging technologies. Electrode selection is a critical factor determining the applicability and adaptability of electrocoagulation technology. The performance evaluation and applicability of metal alloy electrode is not that much explored in dairy wastewater treatment. Therefore a novel performance evaluation of alloy electrodes derived from Al and Cu combinations developed by mixing 1%, 5% and 10% Cu in Al named as AC1, AC5, and AC10 produced by stir casting technique is evaluated in this present study for determining their wastewater treatment efficiency. The various water quality parameters were analyzed for each electrode combination, and the best possible combination was identified. The results open the applicability of alloy electrodes in wastewater treatment. Among the selected alloy electrodes, AC10 is more suitable for dairy effluent treatment with turbidity and COD removal of 81.64 ± 3.21% and 98.29 ± 0.92%, respectively, with a limited reaction time of 54 min and minimal electrode loss. The scope of alloy electrodes for wastewater treatment is explored in this article.