Background: Nowadays, synthetic azo compounds as environmental pollutants are widely used in different application. In this research the treatability of effluent polluted with reactive black 5 azo dye using ELECTROCOAGULATION (EC) and ELECTROCOAGULATION/ flotation (ECF) processes with aluminum electrodes investigated in a lab scale batch experimental reactor.Methods: In present study an ELECTROCOAGULATION flotation reactor in a lab scale to an approximate volume of 1 liter which is equipped with four Al0Al electrodes with dimensions of 200*20*2 mm was proposed. The effects of operational parameters such as initial pH, current density, contact time, initial dye concentrations and flotation were evaluated.Findings: The results indicated that the highest dye removal rates in the EC process were observed in natural pH of solutions, 12.71 mA/Cm2 current density and 100 mg/l initial dye concentration at 30 min contact time. In these conditions up to 81% of dye was removed in the EC process. Based on the result obtained in this study, it was found that much higher dyes removal could be achieved by ECF (86%) process than that by EC process in the same conditions.Conclusion: EC and ECF processes using aluminum electrodes for dye removal could be a promising process.

This paper demonstrates technique of water purification using electro-coagulation method. This system is composed of DC electric source 200 V 30 A connect to the anode and cathode terminals. The DC power supply can be received from utility or solar energy. The sample of raw water from reservoir is used to conduct experimental reaction with ELECTROCOAGULATION system in order to improve water quality. The water purification experimental was implemented by batch processing with varying electrolysis time. The parameter of electro-coagulation and water quality parameters are collected such as electric voltage, electric current, water temperature, pH, dissolved oxygen (DO), total dissolved solid (TDS) and electro-conductivity. The result found that the water quality has improved with the standard of domestic water supply and also drinking water standard.

Background The leather industry is one of the most polluting industries in the country (Iran)، which annually produces several hundred tons of industrial sewage. ELECTROCOAGULATION is one of the purification methods for this wastewater. This research aimed to remove COD and turbidity from real wastewater originating from one of the leather tanning units in Charmshahr industrial park with use of ELECTROCOAGULATION process. Method The research was conducted in laboratory scale in a 480-millimeter EC reactor. The wastewater was collected from a leather tanning unit. The main variables considered were current intensity (1. 5، 2. 5، 3. 5 and 5 A)، retention time (5، 10، 15 and 30min)، initial pH (5، 6 and 8. 6) and electrode material (i. e.، iron، aluminum، and steel). Results The optimum conditions in the ELECTROCOAGULATION process to achieve the maximum removal efficiency for COD equal to 63. 57% were obtained in an experiment with time of 5 minutes، the current density of 23. 5% mA/cm2، pH=8. 62 and 2 steel electrodes. Also، in an experiment with time of 30 minutes، the current density of 23. 5 mA/cm2، pH=8. 62 and 4 electrodes، the removal rate of 62. 88% was obtained. Conclusions The results of the present study showed that the ELECTROCOAGULATION can be an effective method for tannery wastewater pre-treatment and the optimum conditions can be obtained using aluminum electrodes، time of 5 minutes، the current density of 7 mA/cm2 and pH of 8. 62.

ELECTROCOAGULATION (EC) and ELECTROCOAGULATION/flotation (ECF) processes are simple and efficient in water and wastewater treatment. In recent years, many investigations have focused on the use of these processes for treating of polluted water. The purpose of this study was to investigate the efficiency of EC and ECF processes in removal of high turbidity water using different electrodes in different circumstances. In present study an ELECTROCOAGULATION and ELECTROCOAGULATION/ flotation reactor in a lab scale to an approximate volume of 6 liters which is equipped with four Al-AL and Fe-Fe electrodes (200 * 20 * 2 mm) was used for removing of high turbidity water. The effects of operating parameters such as type of electrodes, initial water turbidity, applied voltage (10 to 30 v), initial pH of the solution (3 to 12) and reaction times (5 to 30 minutes) were evaluated. The batch experimental results showed that initial turbidity water, initial pH of the solution, different applied voltages up to %88 turbidity as initial turbidity of 1200 NTU have been removed when using Al-Al and Fe-Fe electrodes and reaction times highly effective on the turbidity removal efficiency in these processes. In ECF process, 84% in optimum condition. However, in EC process the maximum removal was found up to 68% of initial turbidity when using Al-Al and Fe-Fe electrodes in same operation. Based on the result obtained in this study, the type of electrodes in EC and ECF processes significantly affect the removal rate of high turbid water. Also, it was found that much higher turbidity removal could be achieved by ECF process than that by EC process in the same condition.

Background: ELECTROCOAGULATION is a technique involving the electrolytic addition of coagulating metal ions directly from sacrificial electrodes. These ions coagulate with turbidity agents in the water, in a similar manner to the addition of coagulating chemicals such as alum and ferric chloride, and allow the easier removal of the pollutants. Purpose of this study was to conduct experimental investigation of water turbidity removal using the ELECTROCOAGULATION method.Methods: Removal of turbidity from raw water in batch system was investigated by different voltage (10, 15, 20, 25, 30V), electrodes (Al, Fe and St) and electrolyzes time (0 to 40 min.), electrodes distance 2 cm and pH=7.5.Results: The experimental results showed that the removal efficiency depends on the electrolyze time, types of electrodes and the applied current. From the experiments carried out at 20V, it was found that in 20 minutes the removal efficiency for Al, Fe and St electrodes was 93, 91 and 51 percent respectively.Based on turbidity removal efficiency, Al is prior to Fe and St as sacrificial electrode material.Conclusion: In an era when environmental phenomena attract a great attention, ELECTROCOAGULATION methods can be said to be a promising cleaning and purifying method for water treatment.