Neutralization of Alkaline Wasterwater with CO₂ in a continuous flow jet loop reactor

This paper investigates the feasibility of applying the jet loop reactor for the neutralization of alkaline wastewater using carbon dioxide (CO2). In this study, pH changes and CO2 removal characteristics were examined by changing influent flow rate of alkaline wastewater (initial pH=10.1) and influent CO2 flow rates. Influent flow rates of alkaline wastewater (QL,in) ranged between 0.9 and 6.6 L/min, and inlet gas flow rate (QG,in) of 1 and 6 L/min in a lab-scale continuous flow jet loop reactor. The outlet pH of wastewater was maintained at 7.2 when the ratio (QL,in/QG,in) of QL,in and QG,in was 1.1. However, the CO2 removal efficiency and the outlet pH of wastewater were increased when QL,in/QG,in ratio was higher than 1.1. Throughout the experiments, the maximum CO2 removal efficiency and the outlet pH of wastewater were 98.06% and 8.43 at the condition when QG,in and QL,in were 2 L/min and 4 L/min, respectively