Potential of siltstone and its composites with biochar and magnetite nanoparticles for the removal of cadmium from contaminated aqueous solutions: Batch and column scale studies. (April 2020)

• Record Type: Journal Article
• Authors: Imran, Muhammad; Haq Khan, Zia Ul; Iqbal, Jibran; Shah, Noor Samad; Muzammil, Saima; Ali, Shafaqat; Muhammad, Nawshad; Aziz, Arwa; Murtaza, Behzad; Naeem, Muhammad Asif; Amjad, Muhammad; Shahid, Muhammad; Zakir, Ali; Rizwan, Muhammad
• Is Part Of: Environmental pollution. Volume 259(2020)
• Publication Date: 2020-04
• Subjects: Reusability -- Cadmium -- Adsorption -- Characterization -- Removal -- Stability; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.113938
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The present study is the first attempt to evaluate the pilot and batch scale adsorption potential of siltstone (SS) and its nanocomposites with biochar (EDB/SS), magnetite nanoparticles (MNPs/SS) and MNPs/EDB/SS for Cd removal from contaminated water. The SS, EDB/SS, MNPs/SS and MNPs/EDB/SS were characterized with FTIR, XRD, BET, SEM, TEM, TGA and point of zero charge (PZC). The effects of adsorbent dosage, contact time, initial Cd concentration, pH and presence of competing ions were evaluated on the Cd removal and its adsorption. The order for Cd removal was: MNPs/EDB/SS > MNPs/SS > EDB/SS > SS (95.86–99.72% > 93.10–98.5% > 89.66.98–98.40% > 74.90–90%). Column scale experiments yielded maximum retention (95%) of Cd even after 2 h of injection at 100 mg Cd/L. The exhausted SS, EDB/SS, MNPs/SS and MNPs/EDB/SS were reused without losing significant adsorption potential. Similarly, maximum Cd adsorption (117.38 mg/g) was obtained with MNPs/EDB/SS at dose 1.0 g/L. The results revealed that coexisting cations reduced the Cd removal due to competition with Cd ions. The experimental results were better explained with Freundlich isotherm model and pseudo 2nd order kinetic models. The results revealed that SS and its composites can be used efficiently for the removal of Cd from contaminated water. Graphical abstract: Image 1 Highlights: Batch and column scale removal of cadmium with siltstone and its nanocomposites. Cost effective strategy in Cd removal with maximum adsorption potential 117 mg/g. Column sale results showed 95% removal of Cd with higher reusability. Modeling equilibrium and kinetic sorption data.