Evaluation of hydroxyapatite/poly(acrylamide-acrylic acid) for sorptive removal of strontium ions from aqueous solution

• Published in: Environmental science and pollution research international 2019-09, Vol.26 (25), p.25641-25655
• Main Authors: Hassan, Hisham Soliman, El-Kamash, Ahmed Mohamed, Ibrahim, Haneen Abdel-Salam
• Format: Article
• Language: English
• Subjects: Acrylamide; Acrylamide - chemistry; Acrylates - chemistry; Acrylic acid; Acrylic Resins - chemistry; Acrylics; Aquatic Pollution; Aqueous solutions; Atmospheric Protection/Air Quality Control/Air Pollution; Composite materials; Durapatite - chemistry; Earth and Environmental Science; Ecotoxicology; Endothermic reactions; Environment; Environmental Chemistry; Environmental Health; Environmental science; Hydroxyapatite; Ions; Kinetics; Polymerization; Polymers; Radioactive Waste; Radioactive wastes; Radioisotopes; Research Article; Sorption; Strontium; Strontium - analysis; Strontium - chemistry; Thermodynamics; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-019-05755-1

A composite polymer, hydroxyapatite/poly(acrylamide-acrylic acid), was synthesized by gamma-induced polymerization. The factors affecting the sorption process were evaluated. The removal increased with time and achieved equilibrium after 1 h for all initial concentration ranges (10–50 mg/L). The highest removal of Sr(II) was achieved using 50 mg/L at pH 6. The sorption process was found to follow a pseudo-first-order mechanism. The equilibrium data are best described by the Langmuir model, with a monolayer capacity of 53.59 mg/g. The values of thermodynamic parameters indicate that the sorption process is endothermic ( ΔH > 0), increases randomness ( ΔS > 0) and is spontaneous ( ΔG < 0). The results imply that the composite could be used as a promising low-cost material for the removal of radionuclides from radioactive waste.