@conference{
author = "Stanković, Katarina and Vujasin, Radojka and Egerić, Marija and Matović, Ljiljana and Petrović, Đorđe Ž. and Kumrić, Ksenija",
year = "2021",
abstract = "Most heavy metals, such as Cr (chromium), Pb (lead), Cd (cadmium), Ni (nickel), Cu (copper) and Fe (iron), are extremely toxic above a tolerance limit. These heavy metals in wastewater are not biodegradable and can cause serious harm to human health and ecological environments.1 One of the top-priority toxic heavy metal in wastewater is chromium.2 In natural waters, chromium exists in both trivalent Cr(III) and hexavalent Cr(VI) forms. Cr(VI) is the most toxic one and have the tolerance limit 0.1 mg/L into surface water and 0.05 mg/L in potable water.3 Various methods, such as ion exchange, sedimentation, electrochemical process, cementation, coagulation, adsorption and solvent extraction have been developed for the removal of Cr(VI) and other toxic metals from wastewater.4 Among these methods, in some papers,5-8 adsorption has been used as one of the most effective method for the removal of Cr(VI) from aqueous solutions. Characteristics of adsorption, such as low cost, easy to perform, efficient and reversible method with high operating speed, make this method as most commonly used for the removal of Cr(VI) from aqueous solutions.9 Several adsorbents, like activated alumina,10 zeolites,11 natural bisorbents such as chitosan,12 but also activated carbon13 have been used for the removal of Cr(VI) from aqueous solutions. Due to the high cost, commercial activated carbon is not available in less developed countries and there is a considerable attention to produce activated carbon from less expensive and available materials. As a low-cost adsorbent, activated carbon can be produced from materials such as rice husk, seeds husk, tea leaves, sawdust, oil palm shell, coconut husk and coconut shell.14 Activated carbon is one of the most important adsorbents which is applied in different areas. In these areas it is important to determine and remove low concentrations of some pollutants, such as heavy metals. Very good features of this adsorbent are the main reason why it is used, such as large surface area, porous structure, high adsorption capacity, selective adsorption and low cost. Also, it is important to note that activated carbon has microcrystalline structure with different size and shape of pores, while surface groups plays important role in the adsorption process. Carbon - oxygen surface groups are the most important and they influence the surface characteristics, such as polarity and physicochemical properties of adsorbent. There are two processes for preparation of activated carbon, chemical activation which involves presence of chemical agents, and physical activation, which involves carbonization.15-16 For this research, low-cost powdered activated carbon made from coconut shell was used as adsorbent to remove Cr(VI) from aqueous solutions. Characterization of activated carbon, produced from coconut shell, was accomplished using scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) method. The effects of three 57. savetovanje SHD 137 adsorption parameters, such as solution pH, contact time and initial Cr(VI) concentration, were investigated with respect to the removal efficiency of Cr(VI) from aqueous solutions. Adsorption equilibrium characteristics were analyzed by using the two adsorption models, namely the Langmuir and the Freundlich isotherms., Praškast ugljenični materijal proizveden iz kokosove ljuske korišćen je kao adsorbent za uklanjanje Cr(VI) jona iz vodenih rastvora. Karakterizacija adsorbenta rađena je primenom dve analitičke tehnike, skenirajućom elektronskom mikroskopijom (SEM) i BET metodom. Eksperimenti adsorpcije rađeni su u šaržnom režimu, kako bi se istražili uticaji pH rastvora, vremena kontakta i početne koncentracije Cr(VI) jona. Eksperimentalni rezultati su pokazali da je efikasnost uklanjanja Cr(VI) najveća u pH intervalu od 2,0 do 3,5, a da se ravnoteža uspostavlja nakon 60 minuta. Dva ravnotežna adsorpciona modela, Langmirov i Frojndlihov, korišćena su za fitovanje dobijenih podataka. Frojndlihova izoterma je obezbedila najbolju korelaciju za adsorpciju Cr(VI) jona na ugljeničnom materijalu proizvedenom iz kokosove ljuske. Na osnovu dobijenih rezultata može se zaključiti da ugljenični materijal proizveden iz kokosove ljuske predstavlja jeftin i efikasan adsorbent koji bi potencijalno mogao biti korišćen za tretman otpadnih voda koje sadrže toksični Cr(VI).",
publisher = "Belgrade : Serbian Chemical Society",
journal = "57th Meeting of the Serbian Chemical Society : Book of Abstracts, Proceedings",
title = "Chromium(VI) removal from aqueous solutions using powdered coconut shell activated carbon as a low-cost adsorbent, Uklanjanje hroma(VI) iz vode primenom praškastog ugljeničnog materijala dobijenog iz kokosove ljuske kao jeftinog adsorbenta",
pages = "136-142",
url = "https://hdl.handle.net/21.15107/rcub_vinar_12081"
}
