Preparation and characterization of nano- Fe(OH)3, its composites with two natural zeolites, and granulation of them for nitrate removal from polluted water

• Published in: Physica scripta 2023-03, Vol.98 (3), p.35024
• Main Authors: Khatamian, Maasoumeh, Nami, Shamin Hosseini, Mosayeb, Shahin Gholizadeh Haji, Divband, Baharak
• Format: Article
• Language: English
• Subjects: Fe(OH); granules; nanocomoposite; nanoparticles; nitrate removal; zeolite
• ISSN: 0031-8949; 1402-4896
• DOI: 10.1088/1402-4896/acbbf2

The development of a cost-efficient, highly effective, and granular shape adsorbent is highly desired for nitrate removal. In this study, two different Fe(OH) 3 nanoparticles with amorphous and crystalline structures, and nanocomposites were successfully synthesized using the ultrasonic-assisted co-precipitation. Both nanoparticles were scrutinized using FTIR, SEM, and XRD. Crystallized Fe(OH) 3 /zeolite nanocomposites were not efficient for nitrate removal;hence, the rest of the study was carried out with amorphous Fe(OH) 3 nanoparticles (Am-Fe(OH) 3 ). Clinoptilolite and analcime were acid-washed and used as a support for synthesized Am-Fe(OH) 3 nanoparticles. Nanocomposites of clinoptilolite and analcime were abbreviated as Fe(OH) 3 /Clin and Fe(OH) 3 /Anc, respectively. The nanocomposites were characterized by BET, FTIR, SEM, EDS, and XRD techniques. Subsequently, granules of the above-mentioned nanocomposites were prepared using the wet gelation method and alginate. Two crucial features of pH and adsorbent:alginate ratio, were assessed and optimized as 11–12 and 1:3, respectively. The performance of granules were investigated regarding pH, time, and adsorbent dosage. Fe(OH) 3 /Clin and Fe(OH) 3 /Anc granules removed 96.82% and 34.02% of nitrate from a contaminated solution with initial concertation of 50 mg l −1 . Overall, Fe(OH) 3 /Clin granule was an effective adsorbent for nitrate removal. The maximum adsorption capacity of Fe(OH) 3 /Anc and Fe(OH) 3 /Clin were 0.4443 mg g −1 and 5.6211 mg g −1 for 0.2 g of each adsorbent, respectively. Both adsorbents displayed good compatibility with the pseudo-second-order kinetic model.