Toxicity of non-precious metal jewellery

Ugljični čelik je materijal koji zbog svojih svojstava i cijene ima mnogo različitih namjena. Nedostatak ovog materijala je taj što nema otpornost prema koroziji. Vrlo često se zbog toga na ugljični čelik nanose različite prevlake. U ovom radu praćena je migracija iona kroma, nikla i bakra iz prevlaka na ugljičnom čeliku koji je korišten za izradu nakita. Nakit od čelika je stavljan u kontakt s modelnom otopinom znoja da bi se simulirali uvjeti koji nastaju prilikom nošenja nakita uslijed interakcije kože (znoja) i nakita. Dobiveni rezultati su pokazali da postoji značajna migracija navedenih iona u otopinu znoja. Koncentracija migriranih iona ovisi o vremenu kontakta nakita i otopine, ali i o debljini prevlake i eventualnim oštećenjima na nakitu. Za usporedbu rezultata provedena su identična istraživanja na nakitu koji je napravljen od nehrđajućeg čelika.Carbon steel is a material that is widely used for various purposes due to its properties and price. However, it is not resistant to corrosion, which is one of the major drawbacks. Therefore, different coatings are often applied to carbon steel. In this graduate thesis, the migration of chromium, nickel and copper ions from coatings on carbon steel used for jewellery making was monitored. Steel jewellery was placed in contact with a model solution of sweat to simulate the conditions that occur during the interaction of jewellery and skin perspiration. The obtained results showed that there is a significant migration of these ions into the perspiration solution. The concentration of migrated ions depends on the contact time of the jewellery and the solution, but also on the thickness of the coating and possible damage on the jewellery. To compare the results, identical studies were performed on jewellery made of stainless steel

Application of adsorption in purification of waste water

Da bi se osigurala voda odgovarajuće kvalitete ili da bi se iz nje uklonila onečišćenja primjenjuje se velik broj različitih metoda. Odabir metode za pročišćavanje otpadnih voda ovisi o vrsti onečišćenja, ponovnoj primjeni pročišćene vode, ali i o ekonomskim čimbenicima. Danas se najčešće primjenjuje adsorpcija. Ovo je vrlo jednostavna i učinkovita metoda. Tom metodom moguće je ukloniti anorganska onečišćenja poput iona teških metala, ali i organska onečišćenja. U ovom završnom radu dan je pregled osnovnih pojmova vezanih za adsorpciju kao i pregled čimbenika koji utječu na mogućnost odvijanja adsorpcije, odnosno njezinu primjenu. Literaturno su obrađene najčešće adsorpcijske izoterme i kinetika adsorpcije. Poseban naglasak je stavljen na mogućnost korištenja adsorpcije kao metode za pročišćavanje otpadnih voda.A large number of different methods are applied to ensure proper quality of water or to remove contaminants from it. The choice of method for waste water treatment depends on the type of pollution, the reuse of the purified water, but also on economic factors.Today adsorption is most commonly used.It is a very simple and effective method.This method can eliminate inorganic contaminants, such as heavy metal ions, but also organic contaminants.This final paper provides an overview of the basic concepts related to adsorption, as well as an overview of the factors that influence the ability of adsorption to take place, i.e. its application.The most common adsorption isotherms and adsorption kineticsare processed.Particular emphasis is placed on the possibility of using adsorption as a method for purification of waste water

Application of adsorption in purification of waste water

Da bi se osigurala voda odgovarajuće kvalitete ili da bi se iz nje uklonila onečišćenja primjenjuje se velik broj različitih metoda. Odabir metode za pročišćavanje otpadnih voda ovisi o vrsti onečišćenja, ponovnoj primjeni pročišćene vode, ali i o ekonomskim čimbenicima. Danas se najčešće primjenjuje adsorpcija. Ovo je vrlo jednostavna i učinkovita metoda. Tom metodom moguće je ukloniti anorganska onečišćenja poput iona teških metala, ali i organska onečišćenja. U ovom završnom radu dan je pregled osnovnih pojmova vezanih za adsorpciju kao i pregled čimbenika koji utječu na mogućnost odvijanja adsorpcije, odnosno njezinu primjenu. Literaturno su obrađene najčešće adsorpcijske izoterme i kinetika adsorpcije. Poseban naglasak je stavljen na mogućnost korištenja adsorpcije kao metode za pročišćavanje otpadnih voda.A large number of different methods are applied to ensure proper quality of water or to remove contaminants from it. The choice of method for waste water treatment depends on the type of pollution, the reuse of the purified water, but also on economic factors.Today adsorption is most commonly used.It is a very simple and effective method.This method can eliminate inorganic contaminants, such as heavy metal ions, but also organic contaminants.This final paper provides an overview of the basic concepts related to adsorption, as well as an overview of the factors that influence the ability of adsorption to take place, i.e. its application.The most common adsorption isotherms and adsorption kineticsare processed.Particular emphasis is placed on the possibility of using adsorption as a method for purification of waste water

Toxicity of non-precious metal jewellery

Ugljični čelik je materijal koji zbog svojih svojstava i cijene ima mnogo različitih namjena. Nedostatak ovog materijala je taj što nema otpornost prema koroziji. Vrlo često se zbog toga na ugljični čelik nanose različite prevlake. U ovom radu praćena je migracija iona kroma, nikla i bakra iz prevlaka na ugljičnom čeliku koji je korišten za izradu nakita. Nakit od čelika je stavljan u kontakt s modelnom otopinom znoja da bi se simulirali uvjeti koji nastaju prilikom nošenja nakita uslijed interakcije kože (znoja) i nakita. Dobiveni rezultati su pokazali da postoji značajna migracija navedenih iona u otopinu znoja. Koncentracija migriranih iona ovisi o vremenu kontakta nakita i otopine, ali i o debljini prevlake i eventualnim oštećenjima na nakitu. Za usporedbu rezultata provedena su identična istraživanja na nakitu koji je napravljen od nehrđajućeg čelika.Carbon steel is a material that is widely used for various purposes due to its properties and price. However, it is not resistant to corrosion, which is one of the major drawbacks. Therefore, different coatings are often applied to carbon steel. In this graduate thesis, the migration of chromium, nickel and copper ions from coatings on carbon steel used for jewellery making was monitored. Steel jewellery was placed in contact with a model solution of sweat to simulate the conditions that occur during the interaction of jewellery and skin perspiration. The obtained results showed that there is a significant migration of these ions into the perspiration solution. The concentration of migrated ions depends on the contact time of the jewellery and the solution, but also on the thickness of the coating and possible damage on the jewellery. To compare the results, identical studies were performed on jewellery made of stainless steel

Toxicity of non-precious metal jewellery

Ugljični čelik je materijal koji zbog svojih svojstava i cijene ima mnogo različitih namjena. Nedostatak ovog materijala je taj što nema otpornost prema koroziji. Vrlo često se zbog toga na ugljični čelik nanose različite prevlake. U ovom radu praćena je migracija iona kroma, nikla i bakra iz prevlaka na ugljičnom čeliku koji je korišten za izradu nakita. Nakit od čelika je stavljan u kontakt s modelnom otopinom znoja da bi se simulirali uvjeti koji nastaju prilikom nošenja nakita uslijed interakcije kože (znoja) i nakita. Dobiveni rezultati su pokazali da postoji značajna migracija navedenih iona u otopinu znoja. Koncentracija migriranih iona ovisi o vremenu kontakta nakita i otopine, ali i o debljini prevlake i eventualnim oštećenjima na nakitu. Za usporedbu rezultata provedena su identična istraživanja na nakitu koji je napravljen od nehrđajućeg čelika.Carbon steel is a material that is widely used for various purposes due to its properties and price. However, it is not resistant to corrosion, which is one of the major drawbacks. Therefore, different coatings are often applied to carbon steel. In this graduate thesis, the migration of chromium, nickel and copper ions from coatings on carbon steel used for jewellery making was monitored. Steel jewellery was placed in contact with a model solution of sweat to simulate the conditions that occur during the interaction of jewellery and skin perspiration. The obtained results showed that there is a significant migration of these ions into the perspiration solution. The concentration of migrated ions depends on the contact time of the jewellery and the solution, but also on the thickness of the coating and possible damage on the jewellery. To compare the results, identical studies were performed on jewellery made of stainless steel

Migracija nikla iz nakita od čelika

Uloga nakita u životu čovjeka vrlo malo se mijenjala kroz povijest. Uglavnom se nakit koristi za ukrašavanje ljudskog tijela, ali i kao statusni simbol ili za izražavanje pripadnosti određenim grupama ili kulturama. Međutim, procesi proizvodnje nakita značajno su napredovali. Istraživanja vezana uz utjecaj pojedinih komponenti iz nakita na zdravlje čovjeka također su značajno napredovala. Poznato je da tijekom nošenja dolazi do interakcije nakita s kožom. Znoj koji se oslobađa na koži utječe na migraciju teških metala. Ova pojava je posebno izražena kod nakita koji je napravljen od neplemenitih metala (npr. od ugljičnog čelika i sl.). U ovom radu istraživana je migracija iona nikla iz nakita napravljenog od različitih vrsta čelika koji je bio u kontaktu s modelnom otopinom znoja. Dobiveni rezultati su pokazali da dolazi do migracije navedenih iona. Koncentracija iona koja migrira uslijed kontakta nakita i modelne otopine znoja ovisi o vremenu kontakta

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