High removal efficiency of ammonium from aqueous solution by colloidal silver nanoparticles: batch adsorption

• Published in: Urban water journal Vol. 21; no. 3; pp. 323 - 336
• Main Authors: Vu, Thi Mai, Nguyen, Thi Minh Phuong, Van, Huu Tap, Hoang, Van Hung, Nga, Luong Thị Quynh, Hoang, Le Phuong, Ravindran, Balasubramani
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 15-03-2024; Taylor & Francis Ltd
• Subjects: Adsorption; Ammonium; Ammonium compounds; Aqueous solutions; Langmuir model; Nanoparticles; pollution; Silver; silver nanoparticles
• ISSN: 1573-062X; 1744-9006
• DOI: 10.1080/1573062X.2023.2290614

This study aimed to use colloidal silver nanoparticles (AgNPs) for ammonium adsorption. Several factors were considered, including pH value, contact time, amount of adsorbent, and beginning ammonium content. The ideal parameters for ammonium adsorption onto the AgNPs were an a pH of 9, a contact period of 60 minutes, a concentration of 1.824 mg AgNPs/25 mL of ammonium solution, and a starting concentration of 80 mL, as determined. The optimum ammonium adsorption capacity onto the AgNPs was 276.84 mg/g, and the Langmuir model described the isotherm adsorption with R
2
, KL, and calculated q
max
values of 0.9339, 0.518  L/mg, and 263.37 mg/g, respectively. The experimental data were most closely matched by the Elovich model, as seen by its R
2
, α, and β values of 0.885, 0.055, and 0.180, respectively. Temperature release values for the exothermic adsorption were 23,084 kJ/mol at 20°C, −23872 kJ/mol at 30°C, and 24,660 kJ/mol at 40°C.