Provider: - Institution: Josip Juraj Strossmayer University of Osijek. FACULTY OF FOOD TECHNOLOGY. Department of Applied Chemistry and Ecology. Sub-department of Chemistry and Ecology. - Data provided by Europeana Collections- Onečišćenje vodnih resursa spojevima dušika značajan je ekološki i zdravstveni problem. Stoga ih je važno ukloniti iz vode i jedna od najčešće korištenih metoda za uklanjanje nitrata je ionska izmjena. U radu je ispitana mogućnost adsorpcije nitratnih iona iz modelne otopine nitrata, modelne otpadne vode i otpadnih voda konditorske i mliječne industrije na tri modificirana nusproizvoda prehrambene industrije: ljuske lješnjaka, pivskog tropa i sjemenki grožđa te komercijalnog anionskog izmjenjivača. Ispitivanje adsorpcijskih svojstava navedenih materijala podrazumijevalo je mijenjanje početne koncentracije nitrata, vrijeme adsorpcije, pH vrijednost, koncentraciju adsorbensa i temperaturu. Rezultati istraživanja pokazali su smanjenje učinkovitosti uklanjanja nitrata povećanjem njihove početne koncentracije. Dobiveni podaci obrađeni su matematičkim modelima Langmuirove, Freundlichove i Dubinin-Radushkevicheve adsorpcijske izoterme. S ciljem opisivanja mehanizama adsorpcije ispitani su i kinetički modeli pri čemu je kinetički model pseudo-drugog reda najbolje opisao brzinu adsorpcije. Ispitivanja u koloni pokazali su dobra svojstva ispitanih materijala i nakon tri ciklusa, osobito u modelnoj otopini nitrata. Karakterizacija modificiranih nusproizvoda provedena je pretražnim elektronskim mikroskopom (FE SEM) kao i IR spektroskopijom. Iz dobivenih rezultata, može se zaključiti da su modificirani materijali pogodni za uklanjanje nitrata iz otpadnih voda i da su jednako učinkoviti kao i komercijalni ionski izmjenjivači.- Pollution of water resources by nitrogenous compounds presents significant environmental and health problem. Therefore, it is important to remove them, especially from wastewater treatment effluents in order to contribute to healthier environment. The most common method for nitrate removal is ion exchange. The paper examines the possibility of nitrate adsorption from model solutions of nitrate, model wastewater and waste water from confectionery and dairy industry on three modified food industry by-products: hazelnuts shells, brewers' spent grains and grape seeds, and on commercial anion exchanger. Adsorption properties of these materials were tested by changing the initial nitrate concentration, adsorption time, pH, adsorbent dosage and temperature. The results showed a reduction of nitrate removal efficiency by increasing their initial concentration. The obtained data were fitted in Langmuir, Freundlich and Dubinin-Radushkevich isotherms. To describe the mechanism of adsorption, few kinetic models were tested, and the pseudo-second order model fitted the data well. The sorption effect of tested materials sustained well during three sorption-desorption cycles, especially in model nitrate solution. Characterization of modified by-products was carried out by the scanning electron microscope (SEM) and IR spectroscopy. It can be concluded that the modified materials are suitable for nitrate removal from wastewater and might compete with commercial ion exchangers.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana