Based on the reviewer suggestion, regeneration studies were performed briefly. Four different desorption agents such as tap water, 0.1M HCl, 0.1M H2SO4 and 0.1M NaOH were utilized to remove the adsorbed chromium ions from the Al-GNSC adsorbent. From this various desorption agents it was identified that 0.1M NaOH was more effective. Hence, the reuse of Al-GNSC from Cr(VI)-loaded material was studied for sorption and desorption cycles using sodium hydroxide as a regenerated agent. Relevant references are quoted in the revised manuscript. Reference: Sujitha Ravulapalli and Ravindhranath Kunta reported that sodium hydroxide was used as a regenerating agent for the sorption and desorption of Cr(VI) by activated carbon derived from Lantana camara plant. [Enhanced removal of chromium (VI) from wastewater using active carbon derived from Lantana camara plant as adsorbent. Water Sci Technol (2018) 78 (6): 1377–1389. https://doi.org/10.2166/wst.2018.413] Reference: M.A. Tandal and B.N.OZA. reported that Sodium hydroxide as a regenerating agent for the sorption and desorption of Cr(VI) by Granular activated carbon. [Adsorption and regeneration studies for the removal of Chromium (VI) from the waste water of electroplating industry using Granular activated carbon. Asian Journal of chemistry. Vol. 17, No.4 (2005), 2524-2530] Page 2 of 2 Comment 2:
The issue of regeneration has not been sufficiently worked out, but the authors themselves write about this, and it is not clear why NaOH was used for this.