Utilization of waste material from wine production as a binding agent in DGT technique for heavy metals analysis in aquatic systems

abstract

English

The diffusive gradients in thin films technique (DGT) was first reported by Zhang and Davison in 1994 for determination of zinc in seawater. The DGT devices conventionally employs a diffusive layer consisting of polyacrylamide or agarose hydrogel, sorption layer consisting of appropriate binding agent immobilized in hydrogel and membrane filter as a protective layer. The principle of DGT technique is based on kinetic separation of metal ions, dissolved inorganic or small labile organic complexes from aquatic system according to Fick's First Law and their accumulation in sorption layer. A major advantage of DGT technique is the in situ deployment for metal bioavailability and time-integrated measurements. In addition, DGT preconcentrates metal solutes improving problems of contamination and method detection limits. Traditional DGT device for metal analysis comprise a Chelex-100 as binding agent, which can be used for the determination of 24 cationic metals. But for greater comprehensiveness of DGT, many other materials have been employed as adsorbents due to their availability or selectivity for specific chemical species. One way of the recent research progress of DGT technique is utilization of low-cost materials an agricultural by-products as binding agents considering an economic and green-technology approach. For example, banana peels, coffee grounds or baker's yeast have already been used in DGT technique for metal ions determination. This study focuses on using of waste material from wine production as possible binding agent in DGT technique. High content of organic matter makes wine-processing waste material an excellent sorbent for removing metal ions from aquatic system because of high content of functional groups (such as carboxylic or phenolic compounds) present in the cell wall of the material. These compounds provide attractions forces to the metal causes their high-efficiency removal. First step of experimental part was preparation of material and its incorporation into agarose hydrogel to prepare binding layer. Wine waste and agarose-waste gel disks were characterized by Scanning Electron Microscopy, Energy Dispersive X-ray Spectrometry and IR spectroscopy. In order to study the binding kinetic and uptake efficiency of metal ions, the agarose-waste gel disks were deployed in 50 ml of a 1 mg.l-1 of mixed metal solution (0.05M NaNO3 at pH 5,5±0,1) under constant stirring for 48 hours in triplicate, whereas in different time intervals subsamples were taken for ICP-OES analysis. To assess the elution efficiency the agarose-waste disks were put into 50 ml of a 1 mg.l-1 of metal solution under the same conditions. 1M HNO3 and 2M HCl were used as elution agents. This study has shown good selectivity of wine waste incorporated in agarose hydrogel for Al, Cr, Cu, Fe and Pb determination from aqueous solutions in laboratory deployment, so next experiments with bioadsorbents will be performed.

Waste material; wine; adsorption; heavy metals; DGT

KŘIKALA, J.; DIVIŠ, P.

26. 11. 2021

Vysoké učení technické v Brně, Fakulta chemická

Brno

978-80-214-6002-7

Studentská konference Chemie je život 2021

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44

45

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https://www.fch.vut.cz/vav/konference/sok/vystupy/sbornik-konference-2021-abstrakty-a5-pdf-p213391