Life-Cycle Assessment of Municipal Solid Waste Management Systems: A Case Study of the City of Dubrovnik

Količina proizvedenog komunalnog otpada po stanovniku u gradu Dubrovniku je u porastu, a očekuje se i daljnji značajniji porast s obzirom na gospodarski razvoj, turizam te povećanu potrošnju. Proizvedeni otpad u gradu Dubrovniku najvećim dijelom završi na odlagalištu, a samo mala količina odvojeno se prikuplja i oporabljuje. Da bi se smanjile neželjene posljedice za okoliš i društvo u cjelini, potrebno je analizirati utjecaje na okoliš procesa, proizvoda i usluga u sustavima gospodarenja otpadom, tj. u cjeloživotnom ciklusu. U ovom radu analiziran je utjecaj na okoliš sustava gospodarenja krutim komunalnim otpadom grada Dubrovnika računalnim programom IWM-EPIC/CSR procjene životnog ciklusa (engl. life-cycle assessment). Analiziran je postojeći sustav gospodarenja komunalnim otpadom grada Dubrovnika (V1) i razmatrane su tri varijante unaprijeđenog sustava gospodarenja krutim komunalnim otpadom (V2, V3 i V4), na temelju podataka o otpadu grada Dubrovnika za 2019. godinu. U varijantama V2, V3 i V4 pretpostavljeno je smanjenje količina odloženog komunalnog otpada u korist odvojenoga sakupljanja otpada po vrstama, načinu obrade i iskorištavanja otpada (materijalna ili energijska oporaba) te postizanje zadanih kvantitativnih i kvalitativnih ciljeva određenih Zakonom o gospodarenju otpadom. Nakon analize i usporedbe utjecaja na okoliš različitih varijanti sustava gospodarenja otpadom može se zaključiti da bi se primjenom varijante V4, u kojoj bi se recikliralo preko 34 % otpada, kompostiralo 54 % biorazgradivog otpada, energijski oporabilo više od 3 % uz kogeneraciju toplinske i električne energije, a na odlagalište odložilo 8 % otpada, smanjili svi važniji utjecaji na zdravlje ljudi, smanjila bi se degradacija okoliša i uvelike smanjilo crpljenje nepovratnih prirodnih bogatstava.Due to changes in economic development, tourism, and higher consumption, the daily per capita municipal solid waste generation in the city of Dubrovnik is expected to rise. Dubrovnik’s waste largely ends up in landfill, with only a small fraction collected and recovered independently. To minimise negative effects on the environment and society as a whole, it is vital to assess the environmental implications of waste management processes, goods, and services throughout their entire cycles. Using the life-cycle assessment IWM-EPIC/CSR software, this study examined the environmental impacts of Dubrovnik’s municipal solid waste management system. Based on data on Dubrovnik’s waste for 2019, the existing municipal waste management system of Dubrovnik (V1) was reviewed, and three enhanced variations of the municipal solid waste management system (V2, V3, and V4) were taken into consideration. In variants V2, V3, and V4, it was assumed that less municipal waste would be disposed of in favour of type-specific waste collection, processing, and utilisation (such as recycling or energy recovery), as well as the accomplishment of the quantitative and qualitative targets established by the Waste Management Act. After examining and contrasting the effects of various waste management system variations on the environment, it was possible to draw the conclusion that, by implementing variant V4, in which more than 34 % of waste would be recycled, 54 % of biodegradable waste would be composted, more than 3 % of energy would be recovered through cogeneration of heat and electricity, and 8 % of waste would be disposed of at the landfill, all significant negative effects on human health would be mitigated, as would environmental degradation and the extraction of irreversible natural resources

Investigation of Effects of Inhibitor on Corrosion of Carbon Steel in Water with Biocide

U ovom radu istražen je utjecaj komercijalnog inhibitora (Chemtec FI30) na proces korozije ugljičnog čelika P235 u različitim vodenim otopinama; demineraliziranoj i/ili vodovodnoj vodi uz dodatak komercijalnog biocida (Chemtec BI01). Istraživanja su provedena gravimetrijskom metodom i elektrokemijskim metodama, dok je površina ispitivanog materijala analizirana pomoću optičkog mikroskopa. Analize pokazuju da inhibitor smanjuje brzinu korozije ugljičnog čelika u ispitivanim otopinama, ima visoku djelotvornost te da se može svrstati u anodne inhibitore. Također, uočeno je da inhibitor smanjuje opću i jamičastu koroziju ugljičnog čelika u korozivnim vodenim otopinama. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna.The effect of a commercial inhibitor (Chemtec FI30) on the corrosion of P235 carbon steel in water (demineralised and/or tap water) with the addition of a commercial biocide (Chemtec BI01) was studied in the present work. This study was carried out by weight loss and electrochemical methods, while specimen’s surface was examined using optical microscope. Results obtained from gravimetric measurement revealed that P235 carbon steel corroded in aqueous solution, i.e., in a solution of demineralised and tap water (50 : 50) and a biocide (Fig. 1), and in tap water with a biocide (Fig. 5). By analysing the surface of carbon steel with an optical microscope, general and pitting corrosion was observed, which was more pronounced in tap water with biocide (Figs. 2 and 6). The addition of a commercial inhibitor significantly reduced the occurrence of corrosion damage on the surface of carbon steel (Figs. 3, 4, 7, and 8) and decreased the rate of carbon steel corrosion in all aqueous solutions (Table 1). Electrochemical investigations performed by open circuit potential measurement, linear polarisation and potentiodynamic polarisation measurement showed that the inhibitor Chemtec FI03 shifted the potential to more positive values (Figs. 9 and 10), increased polarisation resistance (Table 3), decreased the rate of carbon steel corrosion, and had high efficiency in all tested solutions (Table 4). The results obtained showed that this commercial inhibitor could be used as an effective inhibitor for the corrosion of carbon steel in aqueous media. This work is licensed under a Creative Commons Attribution 4.0 International License

Corrosion Protection of Copper in Sodium Chloride Solution using Propolis

In this investigation the possibility of inhibiting corrosion of copper using ethanol extract of propolis in 0.5 mol dm-3 NaCl solution was investigated. The measurements were carried out in 200 cm3 of NaCl solution to which 4 ml of ethanol extract of propolis was added. Also, the protective effect of propolis coating, which was formed by applying the ethanol extract of propolis to the electrode surface, followed by air drying for 24 h, was investigated. Experiments were performed using electrochemical methods: open circuit potential measurements, linear and potentiodynamic polarization method and electrochemical impedance spectroscopy measurements (EIS). The results showed that the coating of propolis significantly shifted the value of the open circuit potential of Cu to more positive values, significantly increased the value of polarization resistance and as well led to a reduction in corrosion current density. On the other hand, addition of propolis in solution yielded minor changes in the value of the stable open circuit potential of copper, but increased the value of polarisation resistance and decreased the corrosion current density. After polarisation measurements, the electrode surface was examined by optical microscopy. Quantum chemical modelling of selected constituents of propolis was undertaken in order to ascertain their contributions to the corrosion inhibition performance

Ružička days : International conference 18th Ružička Days “Today Science – Tomorrow Industry” : Proceedings

Proceedings contains articles presented at Conference divided into sections: chemical analysis and synthesis, chemical and biochemical engineering, food technology and biotechnology, medical chemistry and pharmacy, environmental protection and meeting of young chemists