Achieving win-win outcomes with cerium-loaded porous aluminum sludge hydrogel microspheres for enhanced phosphate removal

Aixia Chen; Luxue Lv; Ruirui Hu; Xiao Wei; Juanjuan Guan; Xin Meng

doi:10.1016/j.scitotenv.2023.161530

Achieving win-win outcomes with cerium-loaded porous aluminum sludge hydrogel microspheres for enhanced phosphate removal

Sci Total Environ. 2023 Apr 1:867:161530. doi: 10.1016/j.scitotenv.2023.161530. Epub 2023 Jan 10.

Authors

Aixia Chen¹, Luxue Lv², Ruirui Hu³, Xiao Wei⁴, Juanjuan Guan², Xin Meng²

Affiliations

¹ Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, Xi'an 710054, China; School of Water and Environment, Chang'an University, Xi'an 710054, China. Electronic address: aixiach@chd.edu.cn.
² Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, Xi'an 710054, China; School of Water and Environment, Chang'an University, Xi'an 710054, China.
³ Shaanxi Hydrotransformer Energy Technology, Xi'an 712000, China.
⁴ Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, Xi'an 710054, China; School of Water and Environment, Chang'an University, Xi'an 710054, China. Electronic address: chdwx@chd.edu.cn.

PMID: 36638994
DOI: 10.1016/j.scitotenv.2023.161530

Abstract

Breaking the technical bottleneck of traditional powdered adsorbent in phosphate adsorption application treatment, a macroscopic high adsorption performance aluminum sludge-based composite hydrogel material was constructed to synergistically solve the problems of water eutrophication and aluminum sludge resourcization. In this study, porous Ce-modified aluminum sludge hydrogel microspheres (Ce-AlS-SA) were prepared to improve the surface chemical structure and microscopic morphology of the macroscopic adsorbent material to enhance the adsorption capacity and achieve effective solid-liquid separation. The best adsorption performance of the material (Ce-AlS₁₂-SA₁) was obtained when the Ce-AlS: SA: Na₂CO₃ was 12:1:1, and obtained the optimal adsorption conditions by Response Surface Method (RSM) with 1.5 mg/L of the dosage, 4 of pH and 50 mg/L of C_phosphate. The maximum adsorption of 20.36 mg P/g was obtained by the Langmuir model at 303 K, which was 2.92 times more than raw sludge. According to the Freundlich and pseudo-second-order kinetic model, the adsorption process is chemisorption; the multi-stage adsorption process is reflected in the intraparticle diffusion and film diffusion models. The main mechanisms combined with the characterization analysis are electrostatic gravity, ligand exchange, and inner-sphere complexation. Meanwhile, Ce-AlS₁₂-SA₁ shows good resistance to interference in the coexistence of multiple ions. Therefore, this material can be recognized as a new material with in-depth, diversified and practical needs for resourceful utilization, which is expected to achieve extensive engineering applications in the future.

Keywords: Aluminum sludge; Hole making; Modification; Phosphate adsorption; Response surface method.