Abstract:
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.
