Determining the performance for an integrated process of COD removal and CO2 capture

Sludge water with high COD and CO2 emission in industry pollutes the environment. In order to effectively mitigate the COD and CO2, this study developed an integrated process of COD removal and CO2 capture by utilizing CO2 to intensify the COD removal process. The mass transfer model and gas and liquid two phase flow model were developed and validated by the experiment. The dynamical characteristic, COD removal and CO2 capture performance were accurately investigated. The effect of the flue gas, Ca(OH)(2) solution and sludge water on the COD removal and CO2 capture were discussed in detail. Due to the bond effect of Ca-O-C and large contact area, the highest CO2 capture efficiency reached 93.1% at simultaneous COD removal. The CO2 intensification effect on the COD removal was analyzed by the density functional theory. It was found that CO2 made the Ca(OH)(2) remove COD more stably due to CO2 controlling the free ions. The CO2 and Ca(OH)(2) regenerated efficiency respectively reached 85.3% and 88.9% by the electrochemical method. (C) 2020 Elsevier Ltd. All rights reserved.