Electrochemical insight into the activated algal biochar assisted hydrogenotrophic denitrification at biocathode using bioelectrochemical system (BES)

In this study, activated biochar prepared using Taihu blue algae was adopted to facilitate cathodic hydrogenotrophic denitrification in bioelectrochemical system (BES). It was found that addition of algal biochar (ABC)-800N (treated with nitric acid) at biocathode reached the highest nitrate removal constant (21.79), while the control reached only 6.94. Besides, activity of nitrous oxide reductase attained 5.16 U/L for the control in day 7, while group ABC-800N reached 16.06 U/L by then. Importantly, chronoamperometry (CA) detect indicated an electron exchange capacity for group ABC-800N as 872.68 mu mol e(-)/gBC, compared to 162.81 mu mol e(-)/gBC for the control. Through chronocoulomb (CC), better charge/discharge stability can be concluded in BES reactor using ABC-800N. Therefore, activated biochar could be implemented to enhance denitrification process at biocathode in BES.