Utilization of magnetically responsive cereal by-product for organic dye removal
| Autor: | Dimitrios Sidiras, Kristyna Pospiskova, Dorothea Politi, Eva Baldikova, Mirka Safarikova, Zdenka Maderova, Ivo Safarik |
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| Rok vydání: | 2015 |
| Předmět: |
Langmuir
Nutrition and Dietetics food and beverages Langmuir adsorption model Chemical modification 02 engineering and technology 010501 environmental sciences Straw 021001 nanoscience & nanotechnology 01 natural sciences chemistry.chemical_compound symbols.namesake Adsorption chemistry Safranin symbols Organic chemistry Freundlich equation Crystal violet 0210 nano-technology Agronomy and Crop Science 0105 earth and related environmental sciences Food Science Biotechnology Nuclear chemistry |
| Zdroj: | Journal of the Science of Food and Agriculture. 96:2204-2214 |
| ISSN: | 0022-5142 |
| DOI: | 10.1002/jsfa.7337 |
| Popis: | BACKGROUND Barley straw, an agricultural by-product, can also serve as a low-cost and relatively efficient adsorbent of various harmful compounds. In this case, adsorption of four water-soluble dyes belonging to different dye classes (specifically Bismarck brown Y, representing the azo group; methylene blue, quinone-imine group; safranin O, safranin group; and crystal violet, triphenylmethane group) on native and citric acid–NaOH-modified barley straw, both in magnetic and non-magnetic versions, was studied. RESULTS The adsorption was characterized using three adsorption models, namely Langmuir, Freundlich and Sips. To compare the maximum adsorption capacities (qmax), the Langmuir model was employed. The qmax values reached 86.5–124.3 mg of dye per g of native non-magnetic straw and 410.8–520.3 mg of dye per g of magnetic chemically modified straw. Performed characterization studies suggested that the substantial increase in qmax values after chemical modification could be caused by rougher surface of adsorbent (observed by scanning electron microscopy) and by the presence of higher amounts of carboxyl groups (detected by Fourier transform infrared spectroscopy). The adsorption processes followed the pseudo-second-order kinetic model and thermodynamic studies indicated spontaneous and endothermic adsorption. CONCLUSION The chemical modification of barley straw led to a significant increase in maximum adsorption capacities for all tested dyes, while magnetic modification substantially facilitated the manipulation with adsorbent. © 2015 Society of Chemical Industry |
| Databáze: | OpenAIRE |
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