A Novel Multilayer Fiber Mesh Electrode for Ammonia Nitrogen Removal from Wastewater

Abstract

A novel multilayer fiber mesh electrode was developed and manufactured at the pilot scale to treat ammonia nitrogen wastewater containing chlorine. The performance of the new electrode was investigated and evaluated in a lab-scale reactor and a pilot-scale reactor. The results of electrochemical characterization methods showed that the multilayer fiber mesh electrode had better performance than the plate electrode under the same conditions. Moreover, the ammonia removal efficiency with the multilayer fiber mesh electrode reached 100% in 30 min, which was five times that with the traditional plate electrode. The influences of different operating parameters, such as current density, pH value, and chloride ion concentration, were investigated in the lab-scale reactor. Interestingly, the ammonia removal efficiency in the reactor with the multilayer fiber mesh electrode was higher when the pH value was lower, which was totally different from the results using the plate electrode. The main reason for this phenomenon is that more active chlorine free radicals generated at low pH values can be effectively utilized in the through-flow reactor with the multilayer fiber mesh electrode. Furthermore, the current efficiency of the reaction and the anode efficiency of the electrode showed good performance. Furthermore, this configuration was effective in removing ammonia from real leachate in the pilot-scale test. The multilayer fiber mesh electrode in flow-through mode was shown to be a promising material for the treatment of ammonia nitrogen wastewater containing chloride ions.

Graphical Abstract