The Diffusion Role in Adsorption of Hexavalent Chromium on Solid Olive Mill Waste

Applied Sciences

Francesca Di Nezza¹  Stefano Salvestrini²  Luigi Ambrosone³  Marco Perna³  Gennaro Bufalo⁴ 

[1] Department of Agricultural and Environmental Sciences, Via Amendola, 165A, 70126 Bari, Italy;Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania “Luigi Vanvitelli”, via Vivaldi 43, 81100 Caserta, Italy;Department of Medicine and Health Sciences "V. Tiberio", University of Molise, 86100 Campobasso, Italy;Department of Naples, INAIL-Sector Research, Certification and Verification, I-80121 Naples, Italy;

关键词: chromium (VI) ions;    intraparticle diffusion;    laponite;    olive mill waste;   

DOI  :  10.3390/app11073096

来源: DOAJ

【 摘 要 】

The removal of Cr(VI) ions from aqueous solutions with wet pomace treated with laponite was investigated. A direct comparison with untreated biomass revealed an increase in both the rate of adsorption and the amount adsorbed. A cooperative interaction between the laponite platelets and biomass surface making more adsorption sites accessible was suggested. In this process, a key role is played by intraparticle diffusion. The experimental results indicate that intraparticle diffusion plays an important role in the adsorption process. A simple diffusion-binding model is presented to discuss the experimental results. The diffusion lifetime is linearly related to the adsorbent mass. The model combined with experimental results allowed us to estimate the average free path of a Cr(VI) molecule. Particularly, it was obtained that, in 1 dm${}^3$ of solution, the diffusion path increased by nearly 1 cm per gram of adsorbent. However, this did not imply that the amount of Cr(VI) removed decreased because the total number of adsorption sites also increased.

【 授权许可】

Unknown