Efficient removal of Cr(VI) containing tunnel wastewater by sludge biochar loaded with ferrous sulfate
Year: 2024
Type: article
Abstract: The ease of agglomeration reduced the removal of pollutants by FeS particles. Hence, sludge biochar was employed as a support to produce FeS-loaded biochar composites (FeS@BC) using a solvothermal method, for removing Cr(VI) from wastewater. The performance and mechanism of Cr(VI) removal on FeS@BC were investigated through adsorption experiments and characterization techniques. The adsorption tests revealed that under optimal conditions of solution pH of 3 and dosage of 40 mg, FeS@BC achieved a removal efficiency of over 97 % for 50 mg/L Cr(VI). The presence of Cl - and NO - 3 did not affect Cr(VI) removal, whereas sulfate, phosphate, and carbonate inhibited the removal process. Low concentrations of humic acid (1–5 mg/L) held a negligible influence on removing, but elevated concentrations of humic acid inhibited Cr(VI) removal. The behavior of FeS@BC in removing Cr(VI) complied with to the pseudo-second-order and the Langmuir model. At 308.15 K, the largest removal capability of FeS@BC for Cr(VI) reached 185.874 mg/g. Thermodynamic studies confirmed that the Cr(VI) removing processes on FeS@BC were a spontaneous, entropy-driven, endothermic chemical adsorption. The primary mechanism for removing Cr(VI) on FeS@BC included reduction, electrostatic adsorption, complexation, and precipitation, with the reduction process playing a crucial role. This indicated that sludge biochar loaded with FeS was an ideal material for removing Cr(VI) from wastewater. ● FeS-loaded sludge biochar was prepared by the thermal dissolution method. ● The maximum removal capacity of FeS@BC for Cr(VI) reached 185.874 mg/g. ● The removal mechanism involved complexation, reduction, electrostatic interactions, and precipitation.
Source: Desalination and Water Treatment
Author: Zhihui Zhao
Institution: Chongqing Industry Polytechnic University
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,000
OpenAlex ID: W4402564617