Ispitivanje adsorpcionih svojstava ilovače za uklanjanje jona olova i arsena iz vodenih rastvora

Abstract

Olovo i arsen predstavljaju značajnu grupu neorganskih polutanata koji su prisutni u životnoj sredini, pre svega u vodenim sistemima, pa je njihovo uklanjanje veliki tehničkotehnološki izazov. Zbog toga se sve više pažnje posvećuje razvoju pristupačnih, efikasnih i ekološki prihvatljivih adsorbenata. Prirodni materijali na bazi oksida metala (SiO2, Al2O3, Fe2O3), poput ilovače, predstavljaju efikasne adsorbente za uklanjanje katjonskih i anjonskih vrsta iz vodenih rastvora. U ovom radu adsorpciona svojstva ilovače ispitivana su u šaržnom sistemu, promenom pH vrednosti početnog rastvora, dok su masa adsorbenta, vreme i temperature procesa bili konstantni. Značajnu ulogu u odvijanju adsorpcionog procesa ima pH vrednost rastvora, stoga se eksperiment zasnivao na određivanju efikasnosti procesa pri vrednosti pH rastvora 4, 5 i 6. Strukturne karakteristike ilovače su određene primenom rendgenske difrakcione analize (engl. X-Ray Difraction, XRD), infracrvenom spektroskopijom sa Furijeovom transformacijom (engl. Fourier-Transform Infrared Spectroscopy, FTIR) i skenirajuće elektronske mikroskopije (engl. Scanning electron microscopy, SEM). Koncentracija jona nakon procesa adsorpcije određena je pomoću indukovano spregnute plazme sa masenom spektrometrijom (engl. Inductively Coupled Plasma Mass Spectrometry, ICP-MS). Maksimalna efikasnost uklanjanja jona olova postignuta je na pH vrednosti 5 (94,2 %), dok je za jone arsena optimalna pH vrednost bila 6 (35,1 %).

Lead and arsenic represent an important group of inorganic pollutants that can be found in the environment, primarily in aquatic systems. Their removal from water systems is a big environmental problem, but also a significant technological challenge. Therefore, an increasing attention is paid to the development of widely available, efficient and environmentally friendly adsorbents. Natural metal oxide-based materials (SiO2, Al2O3, Fe2O3), such as loam, are effective adsorbents for removal of cationic and anionic species. The adsorption experiments were performed in a batch system, varying the pH value of the initial solution, while the mass of adsorbent, time and temperature were constant. The influence of pH value has a leading influence to the adsorption process so the process efficiency was determined at the pH values set at: 4, 5 and 6. The structural characteristics of the loam was performed using X-ray diffraction analysis (XRD), Fourier-Transform Infrared Spectroscopy (FTIR) and scanning electron microscopy (SEM). The concentration of ions after their removal was determined using inductively coupled plasma mass spectrometry (ICP-MS). The maximum removal of lead ions was obtained at pH 5 (94.2%), while for arsenic ions, it was at pH 6 (35.1%).