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Micropollutants and emerging substances pose a serious problem to environmental sustainability and remediation, due to their widespread use and applications in everyday life. This group of chemicals is diverse but with common toxic and harmful properties. Their concentration in the environment is often very low; however, due to their recalcitrant nature, they are persistent in air, water, and soil. From an engineering point of view, the challenge is not straightforward. It is difficult to remove these contaminants from complex mixtures of substances by conventional methods used in wastewater and drinking water treatment. Ozonation and ozone-based AOPs are accepted processes of degradation of resistant substances or at least enhancement of their biodegradability. The aim of this review paper is to present research trends aimed at solving problems in the research and application of ozone-based processes in the removal of micropollutants from wastewater, thus preventing leakage of harmful substances into surface water, soil, and groundwater and facilitating the reuse of wastewater. Priority substances, micropollutants and emerging pollutants, as well as processes and technologies for their transformation and elimination, are briefly specified. Results obtained by the authors in solving research projects that were aimed at eliminating selected micropollutants by ozonation and ozone-based AOPs are also presented. This review focuses on selected alkylphenols, petroleum substances, and organochlorine pesticides.

This research aimed to study the influence of lyocell with incorporated ZnO (CLY) for antibacterial activity and biodegradation of fiber blends composed of viscose (CV), flax (LI), and CLY. Fiber blended samples with an increased weight fraction of CLY fibers were composed, and single CLY, CV and LI fibers were also used for comparison. Antibacterial activity was determined for the Gram-negative Escherichia coli and the Gram-positive Staphylococcus aureus bacteria. The biodegradation of fiber blends was investigated by the soil burial test. The results show that the single CLY fibers exhibited high antimicrobial activity against both E. coli and S. aureus bacteria and that the presence of LI fibers in the blended samples did not significantly affect antibacterial activity against E. coli, but drastically decreased the antibacterial activity against S. aureus. LI fibers strongly promoted the growth of S. aureus and, consequently, impaired the antimicrobial performance of ZnO against this bacterium. The presence of CLY fibers slowed down, but did not prevent, the biodegradation process of the fiber blends, even at the highest ZnO concentration. The soil that was in contact with the fiber blended samples during their burial was not contaminated to such an extent as to affect the growth of sprouts, confirming the sustainability of the fiber blends.

The aim of the work was to study the synthesis of polyenaminones, polymers that are insoluble in water but with the ability to be chemically recycled. After overview of various pathways of synthesis, their environmental impact regarding the biodegradability that they would present in natural waters was studied. European legislation related to this area and protocols of waste recovery options were analysed. Finally, a simple life cycle assessment of selected polyenaminone was carried out.

Sažetak Univerzalno traktorsko transmisijsko ulje (UTTU) je višenamjensko traktorsko ulje namijenjeno podmazivanju transmisije, zadnjeg mosta, diferencijala, mokrih kočnica te hidrauličkog sustava uz uporabu zajedničkog uljnog spremnika. U radu je opisan razvoj i ispitivanje biorazgradljivog UTTU ulja biljnog porijekla. Svojstva ulja na osnovi uljne repice i visoko oleinskog suncokretovog ulja uspoređena su ispitivanjem na standardnim ispitnim postupcima sa svojstvima komercijalno dostupnih mineralnih UTTU ulja. Tribološka svojstva ispitivana su na visoko frekvencijskom urađaju SRV, aparatu sa četiri kuglice i na zupčaničkom ispitnom stolu FZG. Za zaključna ispitivanja korišteni su laboratorijski hidraulički sustav i probni stol sa čelnim zupčanicima., Universal tractor transmission oil (UTTO) is multipurpose tractor oil formulated for use in transmissions, final drives, wet brakes and hydraulic systems of tractors employing a common oil reservoir. In the present work the development of biodegradable vegetable based UTTO oil has been described. The properties of formulated rapeseed and high oleic sunflower based oils were investigated in the standard test procedures and compared with the commercially available mineral UTTO oil. Tribological performances of the fluids were demonstrated by using srv high frequency test device, four ball test rig and FZG spur gear test. For final tests a laboratory hydraulic system and a spur gear test rig were used.

Sažetak Ekološki prihvatljiva maziva su ona, koja će u kontaktu s okolišem uzrokovati minimum štetnog djelovanja, i kod proizvodnje i primjene i kod zbrinjavanja otpada. Jedan od uvjeta ekološke prihvatljivosti je biološka razgradljivost maziva. Pored biološke razgradljivosti potrebna su i ekotoksikološka ispitivanja na bakterije, alge i ribe te određivanje bioakumulacije maziva., Ecologically acceptable lubricants are those that when in contact with the environment cause minimal detrimental effects, both in the process of production and application as well as in the phase of waste disposal. The biodegradability of lubricants is one of the conditions of their ecological acceptability. Along with the biodegradability condition, an ecotoxicological testing on bacterias, sea weeds (algae) and fish is necessary to determine the bioaccumulation of lubricants.

Sažetak Mazivo za horizontalne bušotine primjenjuje se u isplakama za povećanje njezinih podmazujućih svojstava prilikom provedbe postupaka bušenja. Dobro podmazuju}e svojstvo isplake je vrlo značajno zbog znatne uštede vremena, produženja trajnosti opreme, smanjivanja broja manevara i isplativije provedbe ukupnog postupka bušenja. Primjenom ekoloških povoljnih sirovina u mazivima moguće je spriječiti zagađivanje okoliša (tla i vode). Repičino ulje spada u grupu baznih ulja prihvatljivih za okoliš te osim lake i relativne brze biorazgradnje ima i druga povoljna svojstva: dobru mazivost, visoku viskoznost, dobru prionljivost na metalne površine i vrlo dobru podnošljivost na opterećenja. Loša primjenska svojstva repičinog ulja: ponašanja na visokoj i niskoj temperaturi, hidrolitička stabilnost te svojstvo pjenjenja moguće je poboljšati ugradnjom odgovarajućih aditiva., Lubricant for horizontal wells shall be applied in mud for increasing their lubricating properties during the performance of drilling procedures. A good lubricating property of drilling mud is very important for a considerable time-saving, prolongation of equipment durability, reduction of the number of manoeuvres, and more cost-effective operation of the entire drilling procedure. Pollution of the environment (soil and water) is preventable by applying environmentally more advatageous raw materials in lubricants. Rapeseed oils belongs to a group of base oils acceptable for the environment, so, in addition to an easy and relatively fast biodegradation it has also other advantageous properties as good lubricity, high viscosity, good adhesiveness to metal surfaces, and very good loadcarrying properties. It is possible to improve poor application properties of rapeseed oil: behaviour at high and low temperatures, hidrolytic stability, as well as foaming property, by admixing suitable additives.

Sažetak Za kritična mjesta podmazivanja kod kojih se postavljaju strogi ekološki uvjeti sve se više koriste biorazgradljive masti. Takve masti moraju u kratkom vremenskom razdoblju imati visok stupanj biološke razgradljivosti. Ukoliko to nemaju, mogle bi štetno djelovati ako dospiju u okoliš bilo u tlo bilo u vode. S obzirom da mazive masti na osnovi rafiniranih mineralnih ulja ne mogu zadovoljiti ove uvjete, biorazgradljive masti se izrađuju iz prirodnih ili sintetičkih estera. Biorazgradljive mazive masti moraju biti neotrovne, a u pravilu su višenamjenske s EP svojstvima, te se primjenjuju i za ručno i za automatsko podmazivanje. U radu su izneseni podaci o izradi dvije biorazgradljive mazive masti različite konzistencije na osnovi litijevih i kalcijevih sapuna i sintetičkih biorazgradljivih estera. Također su izneseni podaci o primjenskim ispitivanjima u HŽ Hrvatskim željeznicama., Biodegradable lubricating greases are becoming increasingly used for critical application spots, on which severe environmental requirements are imposed. Such greases must be characterized by a high degree of biodegradability over a short period of time. If that is not the case, they could bear a harmful impact on either environment in general, or soil and waters. Given that lubricating greases based on refined mineral oils cannot meet these requirements, biodegradable greases are made of either natural or synthetic esters. Biodegradable lubricating greases have to be non-toxic. As a rule, they are multipurpose and have EP properties, and are applied in both manual and automatized lubrication. The paper provides data on the making of two biodegradable greases different thickeners, based on lithium soaps and synthetical biodegradable esters. It also provides data on field tests performed at HŽ (The Croatian Railways) company.