Analysis and Modeling of the Continuous Electro-oxidation Process for Organic Matter Removal in Urban Wastewater Treatment

Abstract

Electro-oxidation (EO) is one of the most promising forefront technologies to remove pollutants from wastewater. Most of the available references have shown interesting results for biorefractory compounds, especially at laboratory scale. However, the continuous operation of an EO process has not been studied in detail, even less at pilot scale. In this work, the EO technology has been applied to treat an effluent from an Urban Waste Water Treatment plant in a pilot scale with an anodic area of 0.35 m 2 (boron-doped diamond electrodes) taking into account the previous results obtained at lab scale (electrode area 7 × 10 −3 m 2 ). A model based on the mass balance, leads to the Damkoḧler number as the main parameter to describe the removal of organic matter expressed as chemical oxygen demand (COD) at lab and pilot scales. COD reduction is possible to manage by adjusting the flow rate to the anodic area ratio. The main difficulties for the process at pilot scale came from the formation of nonconductive films, which increases near two times the energy losses.

Multilayer Heterojunction Anodes for Saline Wastewater Treatment: Design Strategies and Reactive Species Generation Mechanisms

“…The performance of EO is determined by the electrochemical generation of reactive species, which largely depends on the nature of anode materials. Nonactive anodes with high overpotentials for oxygen evolution reaction (OER), such as those based on SnO 2 , PbO 2 , and boron-doped diamond (BDD), have been extensively investigated in the previous decades. − In spite of their superior current efficiency for hydroxyl radical (·OH) generation, SnO 2 and PbO 2 anodes have poor conductivity and stability. The application of BDD anodes is hindered by their high cost and complicated fabrication.…”

Removal of Hazardous Pollutants from Wastewaters: Applications of TiO2‐SiO2 Mixed Oxide Materials

“…Destroying the pollutants to benign chemicals and/or removing these pollutants from contaminated water is imperative for a green environment. There are numerous treatment processes that have been applied for pollutant removal from wastewater, such as electrochemical oxidation [40], biodegradation [41,42] membrane process [43], coagulation [44,45], adsorption [46][47][48][49], precipitation [50], sonochemical degradation [51,52], micellar enhanced ultrafiltration, and AOP [4,9,10]. Though these methods are considered as efficient methods for pollutant removal, each method has its own benefits and drawbacks.…”

Synthesis and Stabilization of Blue-Black TiO2 Nanotube Arrays for Electrochemical Oxidant Generation and Wastewater Treatment

“…The energy consumption of EO processes (50–1000 kWh/kg COD) − are significantly higher than aerobic biological treatment (3 kWh/kg COD; assuming 320 g/m 3 of inlet COD, 50% of removal efficiency, and 0.45 kWh/m 3 of energy consumption per volume) . Foaming, which is due both to the gas evolution and the presence of naturally occurring and artificial surfactants in wastewater reduces electrochemical treatment efficiency by blocking active sites on the electrode surfaces.…”