Detection prediction and mapping of Chromium through QGIS and adsorption of hexavalent Chromium by modified bio-adsorbents: kinetic and adsorption study

Toxicity due to the presence of heavy metals in ground and surface water due to the release of effluents from industries holds the potency to cause temporary or permanent damage to the living organisms in the near vicinity of these industries. This paper aims to assess the vulnerability of groundwater resources owing to its contamination in Banthar Industrial Area. Using DRASTIC model in combination with quantum geographic information system (QGIS), a groundwater vulnerability map was developed, which indicated that the dispersal of chromium was in the range of 300-1000 mu g/l. In order to study the impact of chromium dispersion, the authors proposed a batch adsorption testing of the hexavalent chromium (Cr(VI)) using different bio-adsorbent materials, keeping a pH range of 3-9 and the contact time between 0 and 80 min. Adsorption isotherms and kinetic studies were also considered. All adsorbents followed the Langmuir isotherm (R-2 > 0.986), whereas Temkin isotherm stated the affinity of the adsorbents for the Cr(VI). The reactions between chromium and the bio-adsorbents were found to follow pseudo-second-order kinetics, which indicated that the reactions were exothermic. The results proposed that a modification in the bio-adsorbents caused an enhancement in the percent adsorption of Cr(VI) in comparison with the natural available bio-adsorbents.

Automated summary

This study assessed the vulnerability of groundwater resources in an industrial area, focusing on the dispersion of chromium and the impact on water quality. Different bio-adsorbent materials were tested for their adsorption of hexavalent chromium, showing enhanced adsorption compared to natural bio-adsorbents after modification. The study also found that the reactions between chromium and bio-adsorbents followed pseudo-second-order kinetics and were exothermic.