Treatment of Combined Sewer Overflows Using Ferrate (VI)

Abstract

Prevention of pollution from combined sewer overflows (CSOs) is currently a major concern due to their impact on aquatic and human environment. With the stringent regulations related to the CSOs treatment, it is necessary to develop an efficient, fast and low cost treatment technique that meets the applicable criteria. In this work, the comprehensive study was done to determine the efficiency of ferrate (VI) for the treatment of CSOs. At a Fe (VI) dose of 0.24 mg/l, TCOD, SCOD, TBOD 5 , SBOD 5 , TSS, VSS, TP, TN and soluble TN removal efficiencies of 71%, 75%, 69%, 68%, 72%, 83%, 64%, 38% and 36% respectively were achieved. Kinetic studies revealed that a contact time of only 15 minutes is sufficient to achieve secondary effluent criteria. An innovative technique of using primary sludge (PS) and thickened waste activated sludge (TWAS) as a source for the in-situ synthesis of ferrate was explored. A comparative study of treatment efficiencies achieved by Fe (VI) generated from different sources was done. At 0.1 mg/l dose of Fe (VI) synthesized from PS, TCOD, SCOD, TSS, VSS, TP and TN removal efficiencies of 60%, 62%, 63%, 67%, 30% and 25% respectively were achieved.

Soil aquifer treatment of secondary effluents and combined sewer overflows in highly permeable soils typical of southwestern Ontario

“…After a wetting cycle of several days, a drying cycle is usually necessary to restore surface permeability and increase the column redox potential (Bouwer 2002). Simulated CSOs were prepared in the laboratory by diluting raw wastewater with distilled water at a ratio of 1:2 (Gandhi et al 2014).…”

Oxidation of amitriptyline and nortriptyline by ferrate(VI): efficiency and reaction pathways

“…During the oxidation process of organic pollutants and micro-organisms in water, Fe(VI) ions are reduced to Fe(III) ions or ferric hydroxide, simultaneously leading to coagulant and photocatalysis properties [15,16]. Due to its dual functions as an oxidant and as a subsequent coagulant/precipitant as ferric hydroxide, Fe(VI) is regarded as an environmentally friendly oxidant in water and wastewater treatment [17,18]. However, only a few studies have hitherto been performed on the Fe(VI) oxidation of pharmaceuticals [19][20][21][22][23], and to the best of our knowledge there has been no report on the oxidation of antidepressants by this species.…”