Emission plasma spectrometry in analysis of chromium sorption on iron nanoparticles

Emisijskom plazma spektrometrijom analiziran je sadržaj kroma u modelnim vodenim otopinama nakon sorpcije Cr(VI) na neutralnim nanočesticama željeza (nZVI). Pri tome su prethodno sintetizirane nanočestice željeza postupkom redukcije s NaBH4 koje su korištene u eksperimentima te im je ispitana čistoća obzirom na sadržaj ostalih metala metodom ICPAES. Uspoređene su djelotvornosti uklanjanja Cr(VI) iz vodenih otopina sa i bez modifikacije s 1,5-difenilkarbazidom kao kompleksirajućim reagensom i promjena u efikasnosti uklanjanja Cr(VI). U koncentracijskom području 1-5 mg L-1 Cr(VI) uz dodatak kompleksirajućeg reagensa utvrđena je bolja efikasnost uklanjanja (96%) u odnosu na otopine bez dodatka liganda. Pri većim sadržajima Cr(VI) u modelnim otopinama manje su izražene varijacije u efikasnosti uklanjanja u odnosu na otopine bez dodataka 1,5- difenilkarbazida.The content of Cr(VI) in model aqueous solutions after sorption of Cr(VI) on zero valent iron nanoparticles (nZVI) was analysed with emission plasma spectrometry. The iron nanoparticles were prepared by reduction method with NaBH4 and used in experiment, their purity was examined considering the content of other metals using ICP-AES. The efficiency of Cr(VI) removal from aqueous solutions was compared with and without modification by 1,5-diphenylcarbazide as a complexing reagent. In concentration range 1-5 mg L-1 of Cr(VI) with the addition of complexing reagent is determined better removal efficiency (96%) compared to the solutions without the addition of ligand. At the higher content of Cr(VI) in model solutions were less marked variations in removal efficiency as compared to the solutions without added 1,5-diphenylcarbazide

Evaluation of chemical status of Kopački rit surface water bodies through analysis of selected heavy metals through one-year period

Močvarni ekosustavi predstavljaju najproduktivnije ekosustave na Zemlji. Zbog izmjene suhe i vlažne faze osiguravaju raznolikost ekoloških uvjeta na istom staništu te podržavaju veliku bioraznolikost flore i faune. Dinamika plavljenja Kopačkog rita posljedica je njegovog geografskog smještaja na području ušća Drave u Dunav. Kemijsko stanje površinske vode utvrđuje se na temelju prosječne (PGK) i maksimalne godišnje koncentracije (MGK). Teški metali ubrajaju se u grupu najopasnijih anorganskih onečišćujućih tvari zbog bionerazgradivosti, bioakumulacije i zbog ugradnje u hranidbene mreže. Otopljeni u vodi nalaze se u ionskom obliku i ne mogu se biološki razgraditi, ali se mogu bioakumulirati. U sklopu projekta Naturavita na području Kopačkog rita provedeno je uzorkovanje i analiza žive, nikla, kadmija i olova te njihovih spojeva na 19 postaja kroz jednogodišnji period od 12 ciklusa. Prema rezultatima, za sve mjerne postaje izmjerene prosječne (PGK) i maksimalne godišnje koncentracije (MGK) ne prelaze SKVO iz Uredbe o standardu kakvoće vode (NN 96/2019) te je na svim postajama postignuto dobro kemijsko stanje.Wetlands are the most productive ecosystems on Earth. Due to the undergoing wet – dry cycles, they ensure the diversity of ecological conditions and support high biodiversity. The dynamics of the Kopački rit floodplain water regime is a consequence of its geographical location in the area of the Drava – Danube confluence. The chemical status of surface water is based on the annual average concentrations (AAC) of the substances and on the maximum annual concentration (MAC). Heavy metals are among the most dangerous inorganic pollutants due to biodegradability, bioaccumulation, toxicity and due to incorporation into food chains. Dissolved in water, they are in ionic form and non-biodegradable and tend to accumulate in living things in the process of bioaccumulation. As part of the Naturavita project in the Nature Park Kopački rit, sampling and analysis of mercury, nickel, cadmium, lead and their compounds were carried out at 19 locations through one-year period of 12 field survey cycles. According to the obtained results, at all sampling locations, the measured average (AAC) and maximum annual concentrations (MAC) do not exceed allowable concentration according to Regulation on water quality standard (OG 96/2019). Good chemical status has been achieved at all sampling locations

Ružička days : International conference 19th Ružička Days “Today Science – Tomorrow Industry” : Proceedings

Dear colleagues, we are extremely honoured to present to you the Proceedings of the international conference 19th Ružička Days, which was successfully held on September 21–23, 2022, in Vukovar, Croatia, in the hometown town of our famous Croatian scientist and first Nobel laureate, professor Leopold (Lavoslav) Ružička. The main goals of the Conference were to promote excellence, originality and innovation of interdisciplinary scientific research as well as the practical application of the obtained results through collaboration with industry, emphasizing thus the recognizable slogan of the Ružička Days conference: "Today Science – Tomorrow Industry". In addition, the Conference gave the opportunity for meetings, exchanging the ideas, opinions, experiences and cooperation among participants from different working surroundings. It is also important to point out that since 2008, within the international conference Ružička Days, Meeting of Young Chemists has also been held, where high school students, with the help of their mentors, present papers in the field of chemistry, with the aim to direct students and young people to the technical and natural sciences, especially chemistry. In its seventh issue (2011, 2013, 2015, 2017, 2019, 2021) the Proceedings publishes scientific and professional full papers of high quality in the following sections: Chemical analysis and synthesis (10), Chemical and biochemical engineering (3), Food technology and biotechnology (4), Chemistry in agriculture and forestry (1), Environmental protection (9) and 8th Meeting of Young Chemists (3). Full-length papers were subjected to an international review procedure done by eminent experts from the corresponding fields, to whom we express our gratitude, but they were not subjected to linguistic proofreading. On behalf of the Scientific and Organizing Committee of the 19th Ružička Days we cordially thank all the authors, reviewers, participants, lecturers, organizers, especially the international organizers EuCheMS and EHEDG, auspices and sponsors, and all the others who, in any way, supported the Conference and contributed to the preparation of the Proceedings, especially to our highly skilled and committed associates, who have put a lot of effort in the preparation of these Proceedings. At the very end, special thanks to our young, future scientists and their mentors who are faithful participants of the Meeting of Young Chemists of the Ružička Days conference. Enjoy the extremely interesting scientific and professional papers contained in these Proceedings, until the next 20th jubilee of Ružička Days in 2024! We are looking forward to meeting you again in Vukovar! Yours sincerely, Chief Editors Jurislav Babić Vesna Ocelić Bulatović Dajana Kučić Grgi