wcm.01.2022.15.21

Due to the high-water consumption of tanning plants, which produce many pollutants such as wastewater and heavy metals (chromium) as by-products enter the water bodies and pollute or harm the environment. This study investigated the removal of hexavalent chromium (VI) from wastewater using activated carbon Chat-Stem. Adsorption is a common treatment method using activated carbon because these heavy metals can be removed inexpensively, profitably, and efficiently. The approximate analysis of the moisture content of the chat stem is 6%, ash content of activated carbon is 17.35%, the volatile matter is 20.12%, fixed carbon content is 56.53%, and the bulk density of activated carbon is 0.392 g/cm3 at 360 ° C, which is in good agreement with the standard quality of activated carbon. As the process parameters changed, the increase of chromium removal efficiency was from 62.5% to 97.03%. The Maximum conditions of chromium removal efficiency were observed at the adsorbent dosage of 30 g/L, at pH of 4, and contact time at 180 minutes using the activated carbon chat stem to remove Cr from wastewater was found to be 97.03% with the desirability of 1 and the corresponding chromium removal efficiency optimized to 97.50%. The selected optimal conditions at the adsorbent dosage of 29.155 g/ml, at a PH of 3.32, and contact time of 174.651 min increasing the chromium removal efficiency to 97.83% with desirability 1 at Run 1. The surface of the chat stem before and after adsorption was characterized by FTIR. For short contact times, Langmuir and Freundlich’s adsorption isotherms were 0.9839 and 0.9995, respectively