The Quality of Water on Public Baths of the City of Osijek

Voda se dijeli u dvije kategorije: podzemna i površinska. Površinske vode, kao što su potoci, rijeke, jezera i mora prirodna su staništa različitih biljaka, životinja i mikroorganizama. Javna kupališta su uređena mjesta uz rijeku ili jezero gdje stanovništvo tijekom ljetnih mjeseci provodi vrijeme koristeći vodno za rekreaciju i odmor. Pod utjecajem klimatskih i hidrometeoroloških čimbenika te antropološkim djelovanjem može doći do zagađenja voda prirodnih kupališta koje mogu postati prijetnja zdravlju kupača. U cilju osiguranja zdravlja kupača, voda javnih kupališta mora udovoljavati propisanim zahtjevima Uredbe o kakvoći vode za kupanje (NN 51/2014). U ovom radu je uzorkovanjem i analizama utvrđena mikrobiološka kakvoća vode za kupanje javnih kupališta Grada Osijeka prema navedenoj Uredbi, u razdoblju od 22. svibnja do 4. rujna 2023. Na temelju rezultata ispitivanja mikrobioloških pokazatelja dana je pojedinačna i godišnja ocjena, a analizom fizikalno-kemijskih pokazatelja te statističkom obradom rezultata prikazana je njihova međusobna povezanost.Water is classified into two categories: underground and surface water. Surface waters, such as streams, rivers, lakes and seas are natural habitats for various plants and organisms. Natural bathing areas are arranged places near river or lake where the population spends time during the summer months using the water body for recreation and rest. Under the influence of climatic and hydrometeorological factors as well as anthropological activities, water pollution in natural bathing areas can occur and become a threat to the health of bathers. In order to ensure the health of the users, the water in public swimming pools must comply with the prescribed requirements of the Regulation on the quality of bathing water (NN 51/2014). In this thesis, the microbiological quality of the water for bathing in the public baths of the City of Osijek is determined according to the Regulation (NN 51/2014) in the period from May 22 to September 4, 2023. Based on the results of the analysis, an individual and annual evaluation is given. Connection between physico-chemical and microbiological parameters was investigated through the analysis and statistical evaluation of data

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