ELECTROLYSIS OF SWINE MANURE EFFLUENTS USING THREE DIFFERENT ELECTRODES Fe-Fe, Al-Al AND Fe-Al

Abstract

Swine effluent with high organic strength need to be treated to make it suitable for applying to crop/pasture fields, or discharging to any waterways. Electrocoagulation is a relatively simpler and cheaper technique over biological and chemical treatment methods currently used to treat high-strength industrial and municipal wastewater. The performance of an electrocoagulation system mainly depends on the pH, Electrical Conductivity (EC) of the medium, Chemical Oxygen Demand (COD) loading rates and catalytic activity of the electrodes used. In this research, a study was conducted to compare the pollutant removal efficiencies of three electrodes (Fe-Fe, Al-Al and Fe-Al) with three electric current levels (500, 1000 and 2000 mA) while treating swine manure effluents. The electrochemical cell consisted of two parallel rectangular plates (90×25×1.5 mm) of Iron (Fe-Fe), Aluminum (Al-Al) and Iron-Aluminum (Fe-Al, later on described as hybrid) electrodes; immersed in a beaker with 550 mL swine effluents and powered by a Direct Current (DC) supply. All studies were conducted in batches at room temperature. In general, removal efficiencies were increased with increasing current densities and electrolysis times for electrodes evaluated. Aluminum electrodes outperformed iron and hybrid (iron-aluminum electrodes) in removing Total Phosphorus (TP) at all current density levels tested. Overall, use of hybrid electrodes resulted in better COD removal. For the same treatment times (1200 s) at higher current density (21 mA cm −2 ), hybrid electrodes removed about 100% COD, which are about 1.9 and 1.3 times higher than those of aluminum and iron electrodes, respectively. Iron electrodes showed the highest removal efficiency (85%) for Total Organic Carbon (TOC) at 21 mA cm −2 current density and 1200 s treatment time. Overall, lower Specific Electrical Energy Consumptions (SEECs) per kg of Pollutants (TP, COD and TOC) were estimated for the aluminum electrodes than the other electrodes combination.

Remediation of Feedlot Nutrients Runoff by Electrocoagulation Process

“…In this research, aluminum based electrodes (Al-Al and Al-Fe) removed more TP and COD compared to Fe-Fe electrodes. This was likely due to excess active ionization when aluminum ion combined with the hydroxyl ion (OH-) and contributed to the generation of higher amounts of aluminum hydroxide (Al(OH) 3 ) (Hong et al, 2013;Lindsay et al, 1996;Rahman and Borhan, 2014). Elemental analysis of sludge revealed that except iron residue produced by the Fe-Fe electrodes and aluminum residue produced by Al-Al electrodes and both residue presented for hybrid electrode, rest of elemental residue presented in sludge was due to the sedimentation of metal residue in a sludge during an electrocoagulation process.…”

“…In the past, limited studies on the use of electrocoagulation were performed on livestock wastewater including swine (Bejan et al, 2007;Cho et al, 2010;Laridi et al, 2005;Rahman and Borhan, 2014), dairy (Bensadok et al, 2011;Şengil, 2006;Tchamango et al, 2010;Yavuz et al, 2011), slaughter house wastewater (Bazrafshan et al, 2012), industrial effluents (Ali and Yaakob, 2012;Basha et al, 2008), pharmaceutical wastewater (Yi-zhong et al, 2002), agroindustry and textile dye wastewater (Merzouk et al, 2009). However, until today, electrocoagulation was not use to treat feedlot runoff.…”

Studies on electrode combination for COD removal from domestic wastewater using electrocoagulation

“…The percentage removal of COD ( Hamada et al., 2018 ; Rahman and Borhan, 2014 ) was determined according to the following formula shown in Eq. (7) .…”

Wastewater Electrolysis for Hydrogen Production

“…For example, dairy WW treatment was performed by the electro-Fenton's process [58]. ETCG was investigated for the treatment of agro-industry WW [59] and of swine manure effluents [60]. In addition, many studies have shown that ETCG can efficiently treat effluents containing metal ions, such as As, Ni, Cr, Cd +2 , B and steel slag.…”