Investigation of carbonaceous materials electrosorption attributes and its performance for capacitive deionization process within the presence of humic acid

Abstract

This present investigation emphasizes on pros and cons of humic acid (HA) on electrosorption behaviour and performance efficiency of capacitive deionization (CDI) process. Electrosorptive removal of HA was examined by lab scale CDI flow cell under 100 ppm Na2SO4 as a supporting electrolyte. In addition, the electrosorption capacitance and desalination performances were also evaluated through cyclic voltammetry studies. In this perspective, we employed the carbon-based electrodes such as chemically treated activated carbon cloth (ACC), carbon aerogel electrodes grade-I (CA-I) and carbon aerogel electrode grade-II (CA-II) with active surface area for 1 cm2 and 24 cm2 respectively. The specific capacitance values of 30, 23 and 10 F g-1 were achieved for ACC, CA-1 and CA-II with 100 ppm Na2SO4 and 10 ppm HA electrolyte solution. The experimental results substantiated that ACC electrode exhibited higher removal efficiency compared to other two carbon electrodes (CA-I and CA-II). Eventually, the electrosorption removal of natural organic matter HA was observed as 15% for CA-I, 30% for CA-II and 58% for ACC electrodes in a CDI flow cell.