Proučavanje adsorpcionih svojstava katjonski modifikovanog skroba za uklanjanje fosfata iz vodenih rastvora

Abstract

Cilj ovog rada bio je ispitivanje adsorpcionih svojstava materijala na bazi skroba za uklanjanje fosfora iz vodenih rastvora. U komunalnim i industrijskim otpadnim vodama fosfor je dosta prisutan u obliku rastvornih fosfata, pa je prečišćavanje otpadnih voda i uklanjanje fosfata od presudnog značaja za sprečavanje procesa eutrofikacije, odnosno pogoršanja kvaliteta voda usled bujanja biljnih vrsta, naročito algi i cijanobakterija. Zbog svoje jednostavnosti, ekonomičnosti i efikasnosti, adsorpcija postaje sve atraktivnija metoda za uklanjanje fosfata iz otpadnih voda. Kao adsorpcioni materijali korišćeni su katjonski skrobovi dobijeni katjonizacijom skroba sa glicidiltrimetilamonijum hloridom (CS-G) i betain hidrohloridom (CS-B). Adsorpciona ispitivanja su izvršena u šaržnom sistemu. Efikasnost adsorpcije određena je spektrofotometrijski, dok su apsorpcione krive iskorišćene za određivanje radne talasne dužine. Ispitana je kinetika procesa, adsorpcione izoterme, kao i uticaj pH vrednosti rastvora na kapacitet adsorpcije. Dobijeni rezultati su upoređeni sa modelima adsorpcionih izotermi (Langmuir i Freundlich) da bi se odredilo slaganje i dobile informacije o mehanizmu i tipu adsorpcionog procesa. Takođe, ispitan je i uticaj prisustva pojedinačnih anjona (sulfata, fluorida i nitrata) na efikasnost adsorpcije. Rezultati adsorpcionih ispitivanja su pokazali da se CS-G i CS-B mogu koristiti kao efikasni prirodni adsorbenti za uklanjanje jona fosfata iz vodenih rastvora.

The aim of this study was to investigate the adsorption properties of starch-based materials for removing phosphorus from aqueous solutions. In municipal and industrial wastewater phosphorus is quite present in the form of soluble phosphates, so wastewater treatment and phosphate removal are crucial to prevent the process of eutrophication, i.e. deterioration of water quality due to the proliferation of plant species, especially algae and cyanobacteria. Due to its simplicity, economy, and efficiency, adsorption is becoming an increasingly significant method for removing phosphate from wastewater. Cationic starches obtained by cationization of starch with glycidyltrimethylammonium chloride (CS-G) and betaine hydrochloride (CS-B) were used as adsorption materials. Adsorption tests were performed in a batch system. The adsorption efficiency was determined spectrophotometrically, while the apsorption curves were used to determine the operating wavelength. The kinetics of the process, adsorption isotherms, as well as the influence of the pH value of the solution on the adsorption capacity were investigated. The obtained results were compared with models of adsorption isotherms (Langmuir and Freundlich) in order to determine the agreement and obtain information about the mechanism and type of adsorption process. The influence of the presence of individual anions (sulphate, fluoride, and nitrate) on the adsorption efficiency was also examined. The results of adsorption studies have shown that CS-G and CS-B can be used as effective natural adsorbents to remove phosphate ions from aqueous solutions.