ADVANCED TREATMENT OF BIOLOGICALLY PRETREATED TANNERY EFFLUENT BY ELECTRO FLOATATION TECHNIQUES. THIRUMURTHY INBARAJ, P. VIJAYALAKSHMI AND G. MUTHURAMAN
In the present work, electro floatation treatment of tannery effluent was used for reduction of COD by addition of surfactant as well as flocculent was investigated. The influence of critical parameters such as current density, electrode material, pH, addition of surfactant and flocculent on the reduction of COD have been discussed. Maximum degradation was found to be at the current density of 0.15 A/cm2 at pH of 6. Stable electrodes such as commercial Titanium coated with Ru or Ir oxides was not significantly reducing the effluent Chemical Oxygen Demand (COD) compared to soluble anodes such as Fe/Al/Mn. Additionally, coagulation of suspended solids was sighted under the presence of Fe and Al electrodes and further addition of Tween 20 (surfactant) and FeCl3 (flocculent) enhances the COD removal from tannery effluent. Under these experimental conditions approximately 72.2% of COD removal and 90% of total solids removal was achieved. This observation intends the potential role of the mentioned critical parameters in the treatment of the tannery effluent. This technique has also been noticed for an effective elimination of color as well as previously utilized bacterial consortium from the treated tannery effluent.