Significant Improvement of Adsorption for Phosphate Removal by Lanthanum-Loaded Biochar

• Published in: ACS omega 2023-07, Vol.8 (28), p.24853-24864
• Main Authors: Xia, Sainan, Liang, Shengrong, Qin, Yixue, Chen, Weijie, Xue, Bin, Zhang, Bingbing, Xu, Guomin
• Format: Article
• Language: English
• ISSN: 2470-1343; 2470-1343
• DOI: 10.1021/acsomega.3c00788

Due to eutrophication, removing phosphate ions from wastewater has received a lot of attention. In order to improve the phosphorus adsorption capacity of the material, this study used biomass pyrolysis to create a series of biochars modified with metal chloride ions. In accordance with adsorption tests, lanthanum-loaded biochar (LCBC) had a significant phosphorus adsorption capacity of approximately 666.67 mg/g, which was 30 times greater than that of pristine biochar. Adsorption kinetic analysis revealed that the LCBC’s adsorption process could be fitted to the pseudo-secondary kinetic equation, indicating that chemical processes were primarily responsible for controlling the adsorption process. Zeta potential, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analysis showed that the main adsorption mechanism of LCBC for phosphate removal was electrostatic attraction of protonated H+ with negatively charged mono-hydrogen phosphate and dihydrogen phosphate ions and complexation reaction of the CO on the carboxyl group and PO on the phosphate group with the oxygen on the phosphate group and hydroxyl group. According to regeneration performance results, LCBC performed relatively better than as-prepared adsorbents, and the phosphate removal rate was approximately 75.1% after the fifth regeneration cycle. The study provided a potential approach for creating and preparing an adsorbent with high adsorption for phosphate removal.