Adsorption of arsenic, phosphorus and chromium by bismuth impregnated biochar: Adsorption mechanism and depleted adsorbent utilization

• Published in: Chemosphere (Oxford) Vol. 164; pp. 32 - 40
• Main Authors: Zhu, Ningyuan, Yan, Tingmei, Qiao, Jun, Cao, Honglei
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-12-2016
• Subjects: Activated carbon; Adsorption; Adsorption mechanism; Arsenic - analysis; Arsenic - chemistry; Bismuth; Bismuth - chemistry; Charcoal - chemistry; Chromium - analysis; Chromium - chemistry; Depleted adsorbents; Hydrogen-Ion Concentration; Kinetics; Methylene Blue - analysis; Methylene Blue - chemistry; Microscopy, Electron, Scanning; Models, Theoretical; Phosphates - analysis; Phosphorus - analysis; Phosphorus - chemistry; Photoelectron Spectroscopy; Spectroscopy, Fourier Transform Infrared; Surface Properties; Thermodynamics; Waste Water - chemistry; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - chemistry; Water Purification - methods; X-Ray Diffraction; Bismuth; Depleted adsorbents; Activated carbon; Adsorption mechanism
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2016.08.036

Bismuth impregnated biochar were synthesized to deal with wastewater pollution. Nitrogen adsorption-desorption isotherms, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to determine the characteristics of adsorbents and explore the main adsorption mechanism. Results showed that bismuth particle was carried successfully within the biochar matrix, making contributions to creating micropore and boost specific surface area. The loaded bismuth, served as the adsorption site, rather than the specific surface area played an important role in arsenic and phosphorus adsorption. Batch adsorption experiments demonstrated a fit Langmuir model for arsenic (As) and phosphorus (P) and a suitable Freundlich model for chromium (Cr). Thermodynamic parameters depicted the endothermic nature and the spontaneous process for phosphate and arsenic adsorption. Besides, this contaminant-loaded carbon adsorbent was further applied for the removal of methylene blue from aqueous solution.
•Bismuth activated carbons derived from wheat straw were fabricated.•Bismuth particles grown within biochar matrix.•BiBC500 showed high adsorption capacity to arsenic, phosphorus and chromium.•Adsorption mechanisms of arsenic, phosphorous and chromium were illustrated.•Phosphate depleted material could photodegrade dye pollutant.