Remove of phosphorous and turbidity of swine wastewater using electrocoagulation under continuous flow

• Treatment of a real swine wastewater was studied with continuous flow EC.
• Current density is the most important process variable for both Al and Fe electrodes.
• Removal of turbidity and TP using Al and Fe electrodes.

Electrocoagulation (EC) is a process of hydroxides generating by passing electric current through electrodes of aluminum and/or iron, to remove impurities in some effluent. Thus, this study investigated the EC process for turbidity and total phosphorus (TP) removal of swine wastewater. For this purpose, two central composite rotatable design (CCRD) 22 were applied aiming at investigating the effects of current density (CD) (16.3–57.5 mA/cm2) and the hydraulic retention time (HRT), where different times were evaluated for the aluminum electrode (31.8–88.2 mL/min) and for iron electrode (61.8–118.2 mL/min). The removals of turbidity using aluminum and iron electrodes were of 91%. For aluminum electrode the removals of TP were 93% and for iron were 96%. The central composite rotatable design showed that the current density (DC) is the most important process variable for both electrode materials (Al and Fe) evaluated, since the removal efficiency was enhanced with increasing CD. The hydraulic retention time (HRT) had no significant effect. For aluminum electrode the energy and electrode consumption was of 2.2–15.3 kW h/L and of 0.56–2.01 g, respectively. For iron electrode the energy and electrode consumption was of 2.1–17.2 kW h/L and of 0.74–2.77 g. EC could be considered a promisor post-treatment effluent of the anaerobic digestion for the simultaneous removal of turbidity and TP. In the conditions of HRT and CD of this study, the iron electrode presented best removals efficiencies in relation to aluminum electrode.

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