Eco-friendly cellulose–bentonite porous composite hydrogels for adsorptive removal of azo dye and soilless culture
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Cellulose hydrogels are a three-dimensional (3D) network of cross-linked cellulosic fibers that have the potential to be used as an environmentally friendly adsorbent. Bentonite clay is also a low cost inorganic adsorbent and has been frequently used to remove toxic organic compounds from water. However, in most cases, bentonite is often ground to a fine powder to increase the available surface area for adsorption, which makes its separation from an aqueous mixture difficult. In this study, we demonstrate straightforward fabrication of cellulose–bentonite (CB) porous composite hydrogels and its potential as an adsorbent for dye removal. The preparation, formation mechanism, and the adsorption performance of CB hydrogels with homogeneously dispersed clay particles were investigated. The adsorption isotherms, kinetics, and thermodynamics of CB hydrogels were examined toward an anionic dye pollutant (Congo red). The results showed that physisorption is the predominant adsorption mechanism of Congo red onto CB hydrogels. The equilibrium adsorption and kinetic data were well fitted by Langmuir isotherm and pseudo-second-order models, respectively. The theoretical maximum adsorption capacity of the CB30 hydrogel with 30 wt% clay loading was found to be 45.77 mg g−1, which was the highest value among other fabricated hydrogels. We also demonstrate the potential application of these CB hydrogels as soilless growing media for legume (Vigna radiata L.) and small flowering plants (Arabidopsis thaliana).
KeywordsCellulose composite Hydrogel Bentonite Adsorption Soilless culture
The authors gratefully acknowledge the funding from Widya Mandala Surabaya Catholic University with a Contract Number 3940/WM01/N/2017. The authors also thank National Taiwan University of Science and Technology (Taiwan Tech) for providing facility for material characterization.
- Daraei P, Madaeni SS, Salehi E, Ghaemi N, Ghari HS, Khadivi MA, Rostami E (2013) Novel thin film composite membrane fabricated by mixed matrix nanoclay/chitosan on PVDF microfiltration support: preparation, characterization and performance in dye removal. J Membr Sci 436:97–108CrossRefGoogle Scholar
- Konicki W, Pelech I, Mijowska E, Jasinska I (2014) Adsorption kinetics of acid dye Acid Red 88 onto magnetic multi-walled carbon nanotubes-Fe3C nanocomposite. Clean 42:284–294Google Scholar
- Lagergren S (1898) About the theory of so-called adsorption of soluble substances. K Sven Vetenskapsakad Handl 24:1–39Google Scholar
- Li M, Wang Z, Li B (2015) Adsorption behaviour of congo red by cellulose/chitosan hydrogel beads regenerated from ionic liquid. Desalin Water Treat 57:16970–16980Google Scholar
- Maitra J, Shukla VK (2014) Cross-linking in hydrogels—a review. Am J Polym Sci 4:25–31Google Scholar
- Montesano FF, Parente A, Santamaria P, Sannino A, Serio F (2015) Biodegradable superabsorbent hydrogel increases water retention properties of growing media and plant growth. Agric Agric Sci Procedia 4:451–458Google Scholar
- Olsson C, Westman G (2013) Direct dissolution of cellulose: background, means and applications. In: van de Ven T, Godbout L (eds) Cellulose—fundamental aspects. IntechOpen, London, pp 143–178Google Scholar
- Sun XH, Chang XL, Tuo WQ, Wang D, Li KF (2014) Performance comparison of dye-sensitized solar cell by using different metal oxide-coated TiO2 as the photoanode. AIP Adv 4:1–7Google Scholar
- Zhang S, Wang WC, Li FX, Yu JY (2013) Swelling and dissolution of cellulose in NaOH aqueous solvent systems. Cellul Chem Technol 47:671–679Google Scholar