electrocoagulation

Electrocoagulation is becoming a promising eco-friendly wastewater treatment technique. It is a low-cost wastewater treatment method suitably applied for various wastewater effluent characteristics. Nevertheless, there are different kinds of electrocoagulation; comparison among them in terms of nutrient removal is investigated in the present research. This study analyzed nitrate (NO3-) and phosphate (PO43-) removal potential of the sono-alternative and direct-current electrocoagulation process.

Batch reactor and sono-direct current (SDC)/sono-alternative current (SAC) electrocoagulation cell were employed to investigate NO3- and PO43- removal efficiency from domestic effluents. The data gathered from laboratory experiments were analyzed using response surface methodology (RSM). ANOVA was used to examine the interaction effects of diverse parameters in terms of NO3_ and PO43- removal from domestic wastewater effluents.

At extreme experimental conditions, the percentage of NO3- and PO43- removal attained with sono-direct current electrocoagulation (SDCE) and sono-alternative current electrocoagulation (SACE) were 96.5%, 96.2% and 96.8%, 96.5, respectively. The SACE was more successful in eliminating NO3-and PO43- than the SDCE process. The appearance of resistant oxide coating on the cathode and the appearance of corrosion on the anode due to oxidation processes in the case of SDCE were identified as principal factors highly affecting NO3- and PO43- removal efficiency.

With optimum process efficiency, experimental findings show that the SACE process is more capable of NO3- and PO43- removal than the SDCE process.

Considering the increased demand for cars in different countries during recent years, using car washes for washing vehicles has received a lot of attention. This study aimed to assess removing chemical oxygen demand (COD) from car wash effluent using the electrocoagulation method.

A reactor with dimensions of 40 cm * 50 cm * 50 cm of Plexiglas with a volume of 90 L equipped with an electric current generator and an electrode was used connected to the DC current generator in the form of Al-Al. The response surface method (RSM) was applied to optimize the factors affecting COD removal in the electrocoagulation process. For this purpose, D-optimal was utilized to optimize the experiments. The effects of measurable factors such as electrolysis time (X1), current density (X2), and aeration time (X3) were examined to check COD removal.

According to the results, the optimal operating conditions for COD removal during electrolysis (30 min) were as follow: the current density was 18.75 A/m2, and the aeration time of 30 min was 48.51%.

In conclusion, electrocoagulation is, to some extent, a reliable and environmentally compatible technique for car wash wastewater treatment.

Leachate contains toxic and non-biodegradable substances that are not easily treated by conventional treatment methods. This study investigated the effect of pH, current density, and reaction time parameters on the removal of cyanide (CN-), nitrate (NO3-), turbidity, and chemical oxygen
demand (COD) from leachate by electrocoagulation process.

This study was an experimental one with direct current using four parallel bipolar aluminum electrodes with 90% purity. The length, width, and thickness of the electrodes were 5 cm, 10 cm, and 2 mm, respectively. There were 6 holes with a diameter of 0.7 cm on each of the electrodes. The samples were prepared from the old leachate of solid waste landfill in Ghaemshahr, Iran.

In this study, at a current density of 33 mA/cm2 and a time of 60 minutes, the optimum removal efficiency of cyanide (100 %) was obtained at pH 5.5 and pH 10. Moreover, the maximum removal of nitrate (99.65 %) and turbidity (86.41 %) were at pH 5.5 and pH 8.3, respectively and the highest removal efficiency of COD (83.14 %) was obtained at pH 10.

The results showed that the removal of cyanide, nitrate, turbidity, and COD increases with increasing current density and reaction time. Due to the proper removal of nitrate and cyanide from leachate by electrocoagulation, nitrate and cyanide amounts were less than the allowable contamination level. Based on the results, electrocoagulation is considered an efficient and effective method for removing nitrate and cyanide from old leachate of municipal solid wastes.

Highly-concentrated phosphate and nitrate anions from sugarcane wastewater are often discharged into public waters without standardized treatments. This study assessed the effects of electrical coagulation, initial pH and reaction time in the removal of phosphate and nitrate pollutants.

We used aluminum electrodes to remove the pollutants at Hakhim Farabi Agricultural and Industrial complex, Khuzestan Province, Iran. A septic tank was used for collecting water samples followed by measuring the pH, and the concentrations of phosphate and nitrate in the samples. The pH was set at 5, 7, 9 or 11. Six aluminum electrodes were placed perpendicular to the water flow and were connected to power in a single-polar method. They were used to assess the effects of pH changes, electrical power at 10 and 30 volts and the water retention time at 15, 30, 45 or 60 min. on the efficiency of the pollutants’ removal. 

The results indicated that under equal retention time and varying pH values, as voltage increased from 10 to 30, the phosphate and nitrate removal increased progressively. It was further demonstrated that the maximum phosphate removal efficiency was achieved at pH7, while it declined at higher pH levels. The highest possible nitrate removal efficiency was achieved under alkaline pH levels. The overall results showed that at every pH and voltage, the percentage of phosphate and nitrate removal increased over time.

This study demonstrated that electro-coagulation process is an appropriate and efficient method to remove phosphate and nitrate pollutants from sugarcane wastewaters.

 Nitrates in drinking water which may come from nitrogen fertilizers applied to crops are a potential health risk. The present study was conducted to investigate the application of alternating current (AC) in electrocoagulation (EC) process for nitrate removal from aqueous solution and linear and nonlinear isotherm modeling.

 The experiments were performed in pilot scale. The effective parameters including solution pH, the initial concentration of nitrate, total dissolved solids, contact time, and current density were studied. 

 The obtained results showed that with increasing solution pH from 3 to 10, the sinusoidal removal efficiency was observed. With increasing current density from 0.5 to 2 A/cm2, the nitrate removal efficiency was ascended from 32% to 58%. The optimum electrolyte was 2 g/L of NaCl. With increasing contact time and decreasing initial nitrate concentration, the nitrate removal efficiency was enhanced. In addition, the adsorption NO3by AC EC was preferably fitted with Langmuir isotherm. 

 The results showed that the EC process could remove the nitrate to less than Iranian standard limit. The solution pH, current density, and contact time were showed the direct effect and initial concentration of nitrate depicted the reverse effect on nitrate removal efficiency