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Kao nusproizvod pročišćavanja otpadnih voda nastaje mulj. Urbanizacija te pooštravanje graničnih vrijednosti emisija onečišćujućih tvari u pročišćenim otpadnim vodama glavni su uzrok stvaranja sve većih količina mulja. Zbrinjavanje mulja na globalnoj razini nailazi na probleme, te ne postoji idealna metoda njegovog zbrinjavanja. Visokotermičke metode materijalne i energetske oporabe mulja naročito su zanimljive jer se osušeni mulj može koristiti kao energent, a pepeo dobiven termičkom obradom mulja na visokim temperaturama se može koristiti u građevinarstvu i poljoprivredi. Spomenute metode danas su na globalnoj razini prihvatljive metode zbrinjavanja i s ekonomskog i s tehničkog i s ekološkog aspekta te podrazumijevaju spaljivanje, uplinjavanje i pirolizu. Spaljivanje je prihvaćena metoda termičke obrade mulja dokazana u praksi, dok se piroliza i uplinjavanje sve češće koriste i imaju veliki potencijal, no zahtijevaju daljnja istraživanja. Pristupi zbrinjavanja mulja s UPOV-a teže održivom kružnom gospodarstvu, koje podrazumijeva daljnju uporabu čvrstog ostatka- nusprodukt termičke obrade mulja s UPOV-a čineći ga vrijednim resursom, a ne otpadom. U ovom radu proučavana je mogućnost korištenja pepela iz procesa termičke obrade mulja u opekarskoj industriji. Eksperimenti su provođeni s uzorcima mulja s UPOV-a Karlovac. Osušeni mulj je spaljen u laboratorijskim uvjetima na temperaturi od 800 °C. Preostali pepeo iz procesa spaljivanja mulja zatim je u laboratorijskim uvjetima korišten kao zamjenska sirovina za glinu u izradi pune opeke u masenim udjelima od 5 %, 10 % i 20 %. Proizvedene opeke od pepela su testirane prema normama HRN EN 771-1 te su svojstava opeke uspoređena s kontrolnom opekom (opekom izrađenom 100 % od gline). Postignute tlačne čvrstoće opeke s ugrađenim pepelom imale su sljedeće vrijednosti: opeka s 5 % pepela 49, 8 N/mm2, opeka s 10 % pepela 49, 8 N/mm2, opeka s 20 % pepela 37, 0 N/mm2 te kontrolna opeka 50, 4 N/mm2. Tlačna čvrstoća kao najbitniji parametar kojim se određuje kvaliteta opeke ukazuje da zamjena gline pepelom pri udjelima od 20 % utječe na smanjenje tlačne čvrstoće te samim tim i na kvalitetu opeke. Ovo istraživanje upućuje da ovakav način zbrinjavanja ima potencijal povrata tvari i/ili energije iz mulja u okviru kružnog gospodarstva kojem teži cijeli svijet.

Neutronska proba za ispitivanje naftnih bušotina razvijena je na Institutu Ruđer Bošković u okviru HRZZ projekta IP-2018-01-4060 ''Nove primjene 14 MeV neutrona''. U ovom istraživanju ispitane su daljnje mogućnosti redukcije šuma u mjerenju C/O omjera metodom pridružene alfa čestice. Mješavina kvarcnog pijeska i grafitnog praha korištena je kao materijal od interesa , dok su plastične bočice ispunjene dizel gorivom korištene kao šum (smetnja) i predstavljaju tekućinu unutar naftne bušotine (npr. nafta). Podjela alfa detektora na četiri jednaka segmenta, omogućila je podjelu volumena oko osi neutronske probe na četiri kvadranta. Materijal od interesa i dizel smješteni su u različite kvadrante i pokazano je da su C/O vrijednosti u slučajevima kad je smetnja prisutna unutar statističke greške u odnosu na slučaj kada smetnje nema., The neutron probe for testing oil wells was developed at the Ruđer Bošković Institute within the HRZZ project IP-2018-01-4060 "New applications of 14 MeV neutrons". In this study, further possibilities of noise reduction in C/O ratio measurement by the associated alpha particle method were investigated. A mixture of quartz sand and graphite powder was used as the material of interest, while plastic bottles filled with diesel fuel were used as noise (interference) and represent the liquid inside the oil well (e.g. oil). Dividing the alpha detector into four equal segments, allowed portioning the volume around the neutron probe axis into four quadrants. The material of interest and diesel were located in different quadrants and it is shown that the C/O values in cases where interference is present are within statistical errors compared to the case where there is no interference.

A recently developed concept of a neutron probe (NP) -for C/O oil logging, based on associated alpha particle technique, has been developed and demonstrated by using a specially constructed NP. The NP contains a high-temperature alpha particle detector as well as a gamma detector with high energy resolution, suitable for a high-temperature environment. The probe was tested on samples collected from Croatian oil fields and on samples prepared with known C/O ratios. This NP in comparison to conventional neutron activation probes significantly reduces the background signal coming from the borehole and measures the C/O ratio depending on the azimuth angle around the borehole longitudinal axis. The time (position) resolution was found to be 2 ns enabling inspection of the C/O ratio in rock formations’ layers down to 10 cm thickness. The NP was successfully tested for different environmental temperatures up to 175 °C. The pulse amplitude degradation coming from the gamma detector was noticed to be a function of the temperature.

Nusproizvod pročišćavanja otpadnih voda je mulj. Problemi s adekvatnim zbrinjavanjem mulja pojavili su se s naglom izgradnjom uređaja za pročišćavanje otpadnih voda (UPOV). U Republici Hrvatskoj trenutno ne postoji nacionalna strategija za zbrinjavanje muljeva s UPOV-a, a slični problemi prisutni su na svjetskoj razini. Uzrok tome su i brojne zabrane i ograničenja koje se vežu uz zbrinjavanje mulja. Ogrjevna vrijednost suhog mulja ekvivalentna je nekim vrstama ugljena i stoga su posebno atraktivne tehnologije oporabe energije iz mulja, uz istovremeno maksimalno smanjenje količine otpada kao i dobivanje sirovine koju će tržište prepoznati kao vrijednu. Mnoga istraživanja upravo su usmjerena na tehnologije spaljivanja te sofisticiranije tehnologije poput pirolize i uplinjavanja. Primjena spomenutih tehnologija osim povrata energije nudi mogućnost izdvajanja vrijednih elemenata prisutnih u pepelu (fosfor), a kemijski sastav pepela pogodan je za korištenje u građevinarstvu (opeka, beton i dr.). U ovom radu dan je pregled mogućnosti termičke obrade mulja s UPOV-a, te daljnje korištenje pepela u proizvodnji opeke.

Trend izgradnje uređaja za pročišćavanje otpadnih voda (UPOV) stvorio je probleme nastanka značajnih količina mulja. Prema statističkim podacima EUROSTAT-a ukupna proizvodnja mulja s UPOVa na razini 28 država članica EU, može se približno procijeniti na oko 10 milijuna tona suhe tvari (ST)[1]. Termičkom obradom smanjuje se masa i volumen mulja, te se izdvajaju ili uništavaju potencijalno opasne tvari iz mulja, promiče se ponovna uporaba nusproizvoda i njihovo recikliranje radi zaštite okoliša, optimizira se korištenje zemljišnih resursa, smanjuju se emisije CO2 i štite se podzemne vode. Visokotemperaturni procesi obrade mulja (spaljivanje, uplinjavanje, piroliza) zahtijevaju mulj s nižim udjelom vlage, a sušenje mulja zahtijeva značajan utrošak energije. Stoga su daljnja istraživanja poboljšanja energetske učinkovitosti od izuzetne važnosti. Kod sušenja materijala s visokim udjelom vlage posebno se ističe mikrovalno sušenje zbog brzog zagrijavanja i niske potrošnje energije. Za razliku od ostalih izvora zagrijavanja, mikrovalovi na frekvenciji 2, 4 GHz zagrijavaju volumetrijski, a ne površinski, te imaju dubinu prodiranja nekoliko centimetara, što je dokazano sušenjem mulja s UPOVa [2]. Mikrovalno sušenje efikasno uništava mikroorganizme, stabilizira štetne tvari u dehidriranom mulju i pozitivno utječe na okoliš [3]. U ovom radu analiziran je utjecaj različitih postupaka sušenja na svojstva mulja. Mulj s UPOV-a Zagreb i Karlovac podvrgavan je konvencionalnom načinu sušenja konvekcijom pri temperaturi T=105 °C te mikrovalnom sušenju mulja pri snazi P=360 W. Mikrovalnim sušenjem postignuto je kraće vrijeme sušenja mase mulja 600 g za čak 14 puta u odnosu na konvencijsko sušenje, uz manju potrošnju energije.

Today's trends are focused on investigating the efficiency of oily wastewater treatment with electrochemical processes due to the fact that they do not depend on temperature changes of the influent, do not require the addition of chemicals and do not require pH adjustment during treatment. Among different electrochemical processes, state- of-the-art confirms the high efficiency of electrocoagulation (EC) process. The use of Fe and Al electrodes achieves a relatively high efficiency of oil and grease removal, as well as COD removal. However, there is a need to investigate the efficiency of hybrid processes that combine different electrochemical processes, such as advanced oxidation processes (AOP) and EC. In this paper, oily wastewater from oil and grease separators was used, and the treatment was performed on a pilot plant using a combination of electrochemical AOP and EC processes. Two tests were performed, the first analysing the treatment efficiency of oily wastewater, which was completely mixed without pretreatment, and the second analysing the effect of primary sedimentation (1st stage of treatment) on the overall treatment efficiency. In the treatment of oily wastewater by applied electrochemical processes without primary sedimentation, the removal efficiency of total oil and grease was about 70%, and COD about 50%. With additional primary sedimentation prior to AOP-EC process, the total removal efficiency of total oil and grease was about 90%, and COD about 70%. The results indicate the high efficiency of oily wastewater treatment by a hybrid AOP and EC process, and the application of primary sedimentation has been proven with higher overall treatment efficiency.

U radu je prikazana obrada klaoničkih otpadnih voda kombinacijom termičke predobrade i glavne elektrokemijske obrade uz simultano ozoniranje. Ispitana je učinkovitost uklanjanja karakterističnih pokazatelja te količina generiranog mulja obzirom na vrstu elektroda (nehrđajući čelik, željezo, aluminij), vrijeme obrade (5-30 minuta) i jakost struje (50-100 A). Otpadna voda je karakterizirana vrlo neugodnim mirisom, visokim vrijednostima boje (17400 CoPt), mutnoće (4230 NTU) ukupne suspendirane tvari (1730 mg dm-3), kemijske potrošnje kisika (3720 mg dm-3) te biokemijske potrošnje kisika (1870 mg dm-3) te povišenim vrijednostima amonija (128 mg dm-3) i fosfata (93 mg dm-3). Termičkom predobradom je uklonjeno 98,23% mutnoće, 89,94% boje, 75,14% ukupne suspendirane tvari (UST), 49,73% BPK5 i 36,29% KPK. Set elektroda od nehrđajućeg čelika se pokazao najučinkovitijim u uklanjanju organskih pokazatelja i amonija, a rezultirao je i najmanjim volumenom otpadnog mulja, dok su aluminijeve elektrode najučinkovitije u uklanjanju boje, ali uz najveću produkciju mulja. Najbolji rezultati su dobiveni kombinacijom sve tri vrste elektroda uz istovremeno ozoniranje uz kontaktno vrijeme 20 minuta, jakost struje od 70 A i napon od 10 V. Nakon elektrokoagulacije/elektroksidacije pomoću elektroda od nehrđajućeg čelika, elektrokoagulacije/ozoniranja pomoću željezovih elektroda, elektrokoagulacije/ozoniranja pomoću aluminijevih elektroda te završnog ozoniranja uklonjeno je 100% boje, mutnoće i UST, 99,77% KPK te 99,25% BPK5, 99,98% fosfata, 99,80% amonija i 43,86% ukupne otopljene tvari, a svi mjereni pokazatelji su zadovoljavali uvjete za ispust u okoliš., The paper presents slaughterhouse wastewater treatment implemented as a combination of thermal pre-treatment and main electrochemical treatment, with a simultaneous ozonation. The efficiency of the characteristic indicator removal and the quantity of generated sludge according to electrode types (stainless steel, iron and aluminium), treatment time (5-30 minutes) and amperage (50-100 A) was tested. The wastewater is characterized by a very unpleasant odour, high colouring value (17400 CoPt), turbidity (4230 NTU), total suspended solids (1730 mg dm-3), chemical oxygen demand (3720 mg dm-3) and biochemical oxygen demand (1870 mg dm-3) as well as increased values of ammonium (128 mg dm-3) and phosphates (93 mg dm-3). Thermal pre-treatment removed 98.23% turbidity, 89.94% colour, 75.14% total suspended solids (TSS), 49.73% BOD5 and 36.29% COD. A stainless steel electrode set proved to be the most efficient in the removal of organic indicators and ammonium and the lowest sludge volume, whereas aluminium electrodes were the most efficient in colour removal, although with the highest sludge production. The best results were achieved by a combination of all three electrode types, with a simultaneous ozonation of 20-minute contact time, amperage of 70 A and voltage of 10 V. Following the electrocoagulation / electrooxidation by stainless steel electrodes, electrocoagulation / ozonation by iron electrodes and electrocoagulation / ozonation with aluminium electrodes and the final ozonation, 100% colour, turbidity and TSS were removed as well as 99.77% COD and 99.25% BOD5, 99.98% phosphates, 99.80% ammonium and 43.86% total dissolved solids. All measured indicators complied with the conditions for discharge into the environment.

U radu je ispitana mogućnost primjene elektrokemijskih metoda (elektroredukcije, elektrokoagulacije, indirektne anodne oksidacije) korištenjem željezovog i aluminijevog seta elektroda sa ili bez dodatka elektrolita za obradu otpadne vode koja nastaje u procesu površinske zaštite metala. Otpadna voda je karakterizirana visokim vrijednostima cinka (2029 mg dm-3) i željeza (78, 4 mg dm-3) te povišenim vrijednostima Cr(VI) (5, 4 mg dm-3) i kemijske potrošnje kisika (820 mg dm-3) koje premašuju granične vrijednosti za ispust u okoliš za 1014, 39, 56, odnosno 6, 6 puta. U svrhu optimizacije procesa u radu je ispitan utjecaj vrste elektroda (željezo, aluminij), kontaktnog vremena (5-30 minuta), mase elektrolita (0, 5-1, 5 g NaCl) te jakosti struje (20-50 A) na stupanj uklanjanja navedena četiri pokazatelja. Između dvije testirane elektrode, željezova se pokazala značajno efikasnijom u uklanjanju svih mjerenih pokazatelja, a naročito Cr(VI) i KPK. Statistički značajno bolji rezultati u uklanjanju KPK za obje elektrode su postignuti dodatkom elektrolita te porastom jakosti struje s 20 na 40 A. Najveći udio anorganskog onečišćenja se ukloni u prvih 5 minuta obrade. Najbolji rezultati su postignuti kombinacijom dviju elektroda uz dodatak klorida kao elektrolita. Nakon 15 minuta elektroredukcije/ elektrokoagulacije/indirektne anodne oksidacije pomoću željezovih elektroda, 15 minuta elektrokoagulacije pomoću aluminijevih elektroda te 20 minuta koagulacije/flokulacije i oksidacije zrakom uklonjeno je 99, 79% Cr(VI), 99, 97% Fe, 98, 23% Ni, 99, 23% Cu, 99, 999% Zn, 98, 00% Pb i 86, 46% KPK a svi mjereni pokazatelji su zadovoljavali uvjete za ispust u okoliš, dok su se izlazne koncentracije teških metala kretale od 0, 009 do 0, 023 mg dm-3.

Svrha ovog rada je razvoj sustava za pročišćavanje procjednih voda starih odlagališta komunalnog otpada simultanom primjenom elektrokemijskih, ultrazvučnih i elektromagnetskih metoda u laboratorijskim uvjetima i pilot postrojenju. Procjedna voda je uzeta s dva sanitarna odlagališta (Piškornica i Tarno) i podvrgnuta elektrokemijskoj obradi primjenom elektroda od nehrđajućeg čelika, željeza i aluminija uz istovremenu obradu ultrazvukom i recirkulaciju kroz elektromagnetsko polje. Reakcije zagađivala iz procjednih voda s elektrokemijski generiranim hipokloritom, kromatima i slobodnim radikalima, kao i termička razgradnja u kavitacijskim mjehurićima su odgovorni za brzo i efi kasno uklanjanje organske tvari i amonija s učinkovitosti uklanjanja KPK, BPK5 i amonijaka preko 99 % nakon 85 minuta obrade. Uklanjanje teških metala do 99,93 % uglavnom je postignuto elektrokoagulacijom pomoću elektroda od željeza i aluminija. Svi mjereni pokazatelji u obrađenoj vodi kako u laboratorijskim uvjetima tako i na pilot postrojenju su bili znatno niži u odnosu na njihove maksimalno dopuštene koncentracije za vode koje se mogu ispustiti u prirodni prijemnik., The purpose of this paper is to develop a treatment system for leachate from old municipal landfills by means of electrochemical, ultrasound and electromagnetic methods in laboratory conditions and at a pilot plant. The leachate was taken from two sanitary landfills (Piškornica and Tarno) and subjected to electrochemical treatment by implementing electrodes made of stainless steel, iron and aluminium, and a simultaneous treatment with ultrasound and recirculation through electromagnetic fi eld. The reactions of pollutants from the leachate with the electrochemically generated hypochlorite, chromates and free radicals as well as thermal decomposition in cavitation bubbles are responsible for fast, efficient removal of organic matter and ammonium. The removal efficiency of COD, BOD5 and ammonium is over 99 % after 85-minute treatment. The removal of heavy metals up to 99.93 % is mostly achieved by means of electrocoagulation with iron and aluminium electrodes. All measured indicators in treated water, both in laboratory conditions and at the pilot plant, were significantly lower with respect to their maximum permitted concentrations in waters that can be discharged into a natural receiving body.

Podzemne vode Panonskog bazena predstavljaju složen sustav s kompleksnom strukturom kontaminanata s visokim koncentracijama teških metala i arsena, visokom obojenošću i mutnoćom, visokim koncentracijama suspendiranih tvari, amonija i drugih hranjivih soli te visokim organskim opterećenjem. Uzroci smanjene kvalitete podzemne vode mogu se podijeliti na prirodne i antropogene. S obzirom na kompleksnost sastava podzemne vode, potrebno je primijeniti kombinirani pristup obrade voda da bi se udovoljilo nacionalnim propisima te smjernicama Svjetske zdravstvene organizacije. U ovoj doktorskoj disertaciji razvijena je nova metoda i sustav pročišćavanja podzemne vode koji jamči istodobno uklanjanje širokog spektra zagađivala i visoku kvalitetu pročišćene vode s obzirom na sve mjerene parametre, a neovisan je o temperaturnim promjenama i o ulaznom opterećenju. U tu svrhu korištena je kombinacija elektrokemijskih metoda (elektrokoagulacija, elektroredukcija, elektrooksidacija) i naprednih oksidacijskih procesa (UV+ozon), (UV+H2O2). Uzorci podzemnih voda uzeti su s područja istočne Slavonije u Osječko-baranjskoj županiji, na lokaciji Darde te u Vukovarsko-srijemskoj županiji na lokacijama Andrijaševaca, Antina, Komletinaca i Vrbanje (Hrvatska). Uzorci voda iz Vojvodine uzeti su s područja vodocrpilišta Zrenjanina i Temerina (Srbija). Uzorci voda iz Arizone uzeti su sa 6 lokacija na području grada Camerona/Tuba Cityja (SAD). Laboratorijskim (“jar”) testovima optimizirani su parametri kao što su: materijal elektroda, broj elektroda, ukupna površina reaktorskih elektroda za svaku vrstu materijala, razmak elektroda, jakost struje, trajanje procesa. Cilj je bio postići optimalan odnos stupnja pročišćavanja, utrošene energije i vremena aplikacije, te istodobno generirati što manju količinu otpadnog mulja. Dokazane su prednosti elektrokemijske obrade u odnosu na postojeće metode fizičko-kemijske obrade. Na osnovu dobivenih parametara konstruirano je pilot-postrojenje kapaciteta 1 m3/dan na kojemu je bila provjerena učinkovitost razvijene metode. Na osnovu dobivenih rezultata i provedene optimizacije radnih parametara procesa osigurana je tehnološka baza za konstrukciju i proizvodnju nove generacije industrijskih uređaja za pročišćavanje pitkih voda. Uz neznatne prilagodbe metodu je moguće primjeniti i za obradu različitih tipova industrijskih efluenata. Dobivena saznanja iskorištena su konkretno kod konstrukcije industrijskog uređaja za pročišćavanje procjednih voda kapaciteta 10 m3/dan, instaliranog na odlagalištu „Viševac“ kod Rijeke. Groundwater of Pannonian Basin presents a complex system with a complex mixture of contaminants with high concentrations of heavy metals and arsenic, highly staining and turbidity, high concentrations of suspended solids, ammonia and other nutrients, and high organic load. The causes of reduced quality of groundwater can be divided into natural and anthropogenic. Considering the complex structure of groundwater it is necessary to apply a combined approach of water treatment in order to satisfy both national regulations and guidelines of the World Health Organization. In this doctoral thesis, a new method and system of purification of groundwater is developed that guarantees the simultaneous removal of wide range of contaminants and high quality of purified water considering all measured parameters, and is independent of temperature changes and input load. For this purpose a combination of electrochemical methods (electrocoagulation, electroreduction, electrooxidation) and advanced oxidation processes (UV+ozone), (UV+H2O2) was used. Groundwater samples were taken in the area of Eastern Slavonia in Osijek-Baranja County on location in Darda, and in Vukovar-Srijem County in locations Andrijaševci, Antin, Komletinci and Vrbanja (Croatia). Samples of water were taken in Vojvodina in the area of cities Zrenjanin and Temerin (Serbia). Samples of water were taken in Arizona on six locations in the city of Cameron/Tuba (USA). By the laboratory (“jar”) tests the parameters were optimized such as the material of electrodes, number of electrodes, the overall surface of the reaction plates for each type of material, electrode distance, electric current, duration of the process. The aim was to achieve an optimal ratio of purification, energy and application time, and at the same time generate an even smaller amount of sludge. On the basis of these obtained parameters the pilot plant capacity of 1 m3/day was constructed and the effictiveness of the developed method was proven. Based on the obtained results and performed process optimization of the working parameters, the technology base for the design and fabrication of a new generation of industrial units for purification of drinking water was provided. With someminor adjustments, the method can be applied for the treatment of various types of industrial effluents. The resulting findings are used specifically for the construction of the industrial leachate treatment plant capacity of 10 m3 / day, installed at the landfill "Viševac" near Rijeka.

Podzemne vode Panonskog bazena predstavljaju složen sustav s kompleksnom strukturom kontaminanata s visokim koncentracijama teških metala i arsena, visokom obojenošću i mutnoćom, visokim koncentracijama suspendiranih tvari, amonija i drugih hranjivih soli te visokim organskim opterećenjem. Uzroci smanjene kvalitete podzemne vode mogu se podijeliti na prirodne i antropogene. S obzirom na kompleksnost sastava podzemne vode, potrebno je primijeniti kombinirani pristup obrade voda da bi se udovoljilo nacionalnim propisima te smjernicama Svjetske zdravstvene organizacije. U ovoj doktorskoj disertaciji razvijena je nova metoda i sustav pročišćavanja podzemne vode koji jamči istodobno uklanjanje širokog spektra zagađivala i visoku kvalitetu pročišćene vode s obzirom na sve mjerene parametre, a neovisan je o temperaturnim promjenama i o ulaznom opterećenju. U tu svrhu korištena je kombinacija elektrokemijskih metoda (elektrokoagulacija, elektroredukcija, elektrooksidacija) i naprednih oksidacijskih procesa (UV+ozon), (UV+H2O2). Uzorci podzemnih voda uzeti su s područja istočne Slavonije u Osječko-baranjskoj županiji, na lokaciji Darde te u Vukovarsko-srijemskoj županiji na lokacijama Andrijaševaca, Antina, Komletinaca i Vrbanje (Hrvatska). Uzorci voda iz Vojvodine uzeti su s područja vodocrpilišta Zrenjanina i Temerina (Srbija). Uzorci voda iz Arizone uzeti su sa 6 lokacija na području grada Camerona/Tuba Cityja (SAD). Laboratorijskim (“jar”) testovima optimizirani su parametri kao što su: materijal elektroda, broj elektroda, ukupna površina reaktorskih elektroda za svaku vrstu materijala, razmak elektroda, jakost struje, trajanje procesa. Cilj je bio postići optimalan odnos stupnja pročišćavanja, utrošene energije i vremena aplikacije, te istodobno generirati što manju količinu otpadnog mulja. Dokazane su prednosti elektrokemijske obrade u odnosu na postojeće metode fizičko-kemijske obrade. Na osnovu dobivenih parametara konstruirano je pilot-postrojenje kapaciteta 1 m3/dan na kojemu je bila provjerena učinkovitost razvijene metode. Na osnovu dobivenih rezultata i provedene optimizacije radnih parametara procesa osigurana je tehnološka baza za konstrukciju i proizvodnju nove generacije industrijskih uređaja za pročišćavanje pitkih voda. Uz neznatne prilagodbe metodu je moguće primjeniti i za obradu različitih tipova industrijskih efluenata. Dobivena saznanja iskorištena su konkretno kod konstrukcije industrijskog uređaja za pročišćavanje procjednih voda kapaciteta 10 m3/dan, instaliranog na odlagalištu „Viševac“ kod Rijeke., Groundwater of Pannonian Basin presents a complex system with a complex mixture of contaminants with high concentrations of heavy metals and arsenic, highly staining and turbidity, high concentrations of suspended solids, ammonia and other nutrients, and high organic load. The causes of reduced quality of groundwater can be divided into natural and anthropogenic. Considering the complex structure of groundwater it is necessary to apply a combined approach of water treatment in order to satisfy both national regulations and guidelines of the World Health Organization. In this doctoral thesis, a new method and system of purification of groundwater is developed that guarantees the simultaneous removal of wide range of contaminants and high quality of purified water considering all measured parameters, and is independent of temperature changes and input load. For this purpose a combination of electrochemical methods (electrocoagulation, electroreduction, electrooxidation) and advanced oxidation processes (UV+ozone), (UV+H2O2) was used. Groundwater samples were taken in the area of Eastern Slavonia in Osijek-Baranja County on location in Darda, and in Vukovar-Srijem County in locations Andrijaševci, Antin, Komletinci and Vrbanja (Croatia). Samples of water were taken in Vojvodina in the area of cities Zrenjanin and Temerin (Serbia). Samples of water were taken in Arizona on six locations in the city of Cameron/Tuba (USA). By the laboratory (“jar”) tests the parameters were optimized such as the material of electrodes, number of electrodes, the overall surface of the reaction plates for each type of material, electrode distance, electric current, duration of the process. The aim was to achieve an optimal ratio of purification, energy and application time, and at the same time generate an even smaller amount of sludge. On the basis of these obtained parameters the pilot plant capacity of 1 m3/day was constructed and the effictiveness of the developed method was proven. Based on the obtained results and performed process optimization of the working parameters, the technology base for the design and fabrication of a new generation of industrial units for purification of drinking water was provided. With someminor adjustments, the method can be applied for the treatment of various types of industrial effluents. The resulting findings are used specifically for the construction of the industrial leachate treatment plant capacity of 10 m3 / day, installed at the landfill "Viševac" near Rijeka.

U radu je prikazan novi kombinirani pristup u obradi otpadnih voda od prerade maslina trostupanjskom centrifugalnom ekstrakcijom. U cilju uklanjanja organskih/anorganskih onečišćivala iz otpadne vode ispod graničnih vrijednosti propisanih za ispust u okoliš testirane su i optimizirane tri kemijske metode (oksidacija ozonom, oksidacija ozonom + koagulacija pomoću FeCl3, oksidacija ozonom + taloženje pomoću CaO) u svrhu predobrade i tri elektrokemijske metode (elektrooksidacija, elektroredukcija i elektrokoagulacija) u svrhu glavne obrade. Otpadna voda je okarakterizirana tamno smeđom bojom, neugodnim mirisom, niskim pH (5, 34), visokom elektrovodljivošću (53, 4 mS/cm) i visokim vrijednostima KPK (84000 mg/L), BPK5 (29300 mg/L) i UOU (13700 mg/L). Između korištenih kemijskih metoda predobrade, oksidacija ozonom u kombinaciji s taloženjem pomoću CaO se pokazala najefikasnijom rezultirajući uklanjanjem 96, 59 % boje, 96, 04 % mutnoće, 98, 29 % suspendirane tvari, 65, 60 % KPK, 88, 57 % BPK5, 85, 61 % UOU, 99, 58 % fosfata, 47, 23 % amonija i 99, 43 % željeza te je ista odabrana za predobradu otpadne vode. Kombinacijom navedene predobrade i elektrokemijskih metoda stupanj uklanjanja, gore navedenih pokazatelja, se kretao od 99, 51 do 100 %, pri čemu je dobiven bistar efluent, bez boje i mirisa, a svi ostali mjereni pokazatelji su zadovoljavali granične vrijednosti za ispust u okoliš.

The purpose of this work was development and application of the purification system suitable for the treatment of groundwater used for human consumption as well as watering of the plants in the system for the hydroponic cultivation of tomatoes. For that purpose the well water from the 60 m deep water layer situated near the city of Županja (Eastern Croatia) was processed. Most of the measured parameters exceeded upper permissible limit (UPL) for drinking water. The highest increase over UPL was found for the parameters phosphates (34.7 times), color (14.6 times), iron (8.6 times), arsenic (7.4 times), CODMn (7.4 times), turbidity (5.3 times), ammonia (2.4 times) and manganese (1.5 times). Due to the complex composition of the treated water, the purification system required the combination of electrochemical treatment, using iron and aluminum electrode plates with simultaneous ozonation followed by post treatment with hydrogen peroxide and ozone. The electrocoagulation/ozonation approach was used for the removal of heavy metals, suspended solids, color, turbidity, phosphates and partially organic matter while the rest of the organic contaminants and ammonia were removed by the treatment with sodium peroxide. Following the combined electrochemical treatment and post treatment with hydrogen peroxide and ozone all measured parameters in the treated water were in agreement with regulated values. The combined treatment resulted in total removal of arsenic, turbidity, ammonia and organic contaminants while the removal of other parameters of interest was up to 97.98%.

The subject of this research was the characterization and the treatment of the acid mine drainage (AMD) originating from the sulfide ore mining and metallurgical activities in the Bor copper mining and smelting complex, Serbia. The AMD from the Bor mining complex (Bor-Krivelj-Cerovo) and smelting /refining of copper was characterized by low pH value (usually below 4) and high concentrations of heavy metals whose concentrations vary depending on the source. If entire complex was considered 7 different sources of the wastewaters could be defined. The treatment of the AMD included pretreatment/pH adjustment with CaO until pH 8 followed by electrocoagulation using iron (I = 50 A ; U = 10 V ; t =5 min.) followed by aluminum electrode sets (I = 50 A ; U = 10 V ; t =10 min.). Each electrode set contained of ten quadratic, one millimeter thick plates (75 x 250 mm) in the parallel arrangement, separated by an electro insulator. The distance between plates was 10 mm in both electrode sets. In the end of electrochemical treatment the suspension was recirculated in strong electromagnetic field for 10 minutes and subjected to slow mixing for another 15 minutes while the settlement time was 30 minutes. Waste sludge from the combined treatment process could be reused for another cycle of the pH adjustment/pretreatment of the acid mine drainage instead of CaO, and afterwards, due to its inertness, it could be used for overlaying layer of the flotation waste heap during its recovery work.

During last twenty years, the antifouling paints based on toxic tributhyltin are being replaced with less toxic compounds. To prevent fouling to boat’s hulls thus minimizing boat transport costs, people invented several possible solutions. Use of paints based on heavy metals is one of them. Annually, boats are being washed using high pressure wash machines thus generating approximately 100 L of wastewater that contains various types of heavy metals. The aim of this study was to test toxicity of such wastewater on human peripheral blood lymphocytes (HPBLs) and Salmonella typhimurium strains TA98 and TA100. In order to test cytotoxicity we have performed differential acridine orange and ethidium bromide vital staining on HPBLs. The results showed significant decrease in cell viability after both 4 h and 24 h exposure period. Genotoxic potential of tested wastewater was evaluated on HPBLs using comet assay. Similar results are observed for both exposure periods, where the percentage of migrated DNA resulted with 2.31-fold increase after 4 h and 1.86-fold increase after 24 h exposure period, compared to vehicle control samples. As models for mutagenicity testing S. typhimurium strains TA98 and TA100 were used. Interestingly, the wastewater failed to induce any significant, reproducible increase either in the presence or absence of metabolizing system S9 mix. The possible explanation of high genotoxicity could be either due to effective repair processes, or relatively high cytotoxicity of tested sample thus not inducing mutagenicity in S. typhimurium strains. In order to give possible solution for this potentially toxic wastewater, we have purified it using ozonation/electrocoagulation treatment processes. The same set of tests was done on purified wastewater where the level of some heavy metals decreased up to 100%. In that manner, the cytotoxicity, genotoxicity, and mutagenicity tests resulted with the same results as detected in vehicle control samples. Taken together, boat washing is potentially hazardous source of heavy metals leaching into sea water. Because of large number of boats and boatyards along the sea coasts it could present threat to environment, marine organisms, and humans, if not treated adequately.

Groundwater of the Pannonian basin which covers the parts of Hungary, Romania, Croatia, Serbia and Slovakia represents the complex system with elevated to high values of heavy metals and arsenic, color, turbidity, suspended solids, ammonia, and other nutrients as well as natural organic matter. When considering the human health risk, among the mentioned contaminants, arsenic is of the highest importance. The purpose of this work was development of the pilot plant purification system and its application onto groundwater taken from the production well water in the Vinkovci County (Eastern Croatia). The highest increase of the parameters over upper permissible limit UPL was found for the arsenic (13.8 times), phosphates (11.7 times), color (6.2 times), mercury (4.7 times), turbidity (3.3 times), ammonia (2.4 times), nickel (1.8 times) and iron (1.5 times). Due to the complex composition of the treated water, the purification system consisted of the combined electrochemical treatment, using iron and aluminum electrode plates with simultaneous ozonation followed by post treatment with UV, ozone and hydrogen peroxide. The combined treatment resulted in the total removal of arsenic, phosphates, color, turbidity, suspended solids and ammonia while the removal of other contaminants of interest was up to 96.7%.

A pilot plant study of the treatment of electroplating wastewaters using elctroreduction with iron electrode plates, electrocoagulation/ozonation using aluminium electrode set followed by ozonation was presented. The initial effluent was highly enriched in heavy metals and elevated levels of organic contaminants. The concentrations of Cr6+, Fe, Ni, Cu, Zn, Pb, TOC, and COD exceeded the upper permissible limits of 63, 220.2, 1.1, 7, 131.3, 1.7, 12.3 and 11.4 times, respectively. The heavy metal removal was forced either by the coagulation/flocculation using Fe2+, Fe3+, and Al3+ ions released into the treated solution by electrochemical corrosion of the sacrificial iron and aluminium electrodes, precipitation of the metal hydroxides as well as co-precipitation with iron and aluminium hydroxides. The principle mechanisms of the organic matter destruction were oxidation by ozone and the indirect oxidation with chlorine/hypochlorite formed by the anodic oxidation of chloride already present in the wastewater. Following the combined treatment, the removal efficiencies of the parameters Cr6+, Fe, Ni, Cu, Zn, Pb, TOC, and COD were 99.94%, 100.00%, 95.86%, 98.66%, 99.97%, 96.81%, 93.24%, 93.43%, and 77.78%, respectively. All the parameters in the final effluent were in agreement with regulated values.

The maintenance and repair of reinforced concrete structures, especially those submerged in the sea-water, requires effective inspection and monitoring techniques for assessing the state of corrosion in reinforcement material. An underwater inspection system was developed which is able to monitor the reinforcement corrosion. The system is remotely operating vehicle (ROV) equipped with the sealed tube neutron generator (NG). By rotating the NG and by using the associated alpha particle technique it is possible to measure the concrete cover depth together with the reinforcing bar diameter. The possibility to estimate the carbon and chloride content in the concrete was investigated. Iron plates of different thickness, covered by 6 cm thick concrete block, were successfully detected and the thickness of the concrete cover was estimated. In addition, reinforced bar of one and three centimeters in diameter was identified and measured.

The purpose of this work was development and application of the purification system suitable for the treatment of groundwater used for human consumption. The system should satisfy the following basic criteria: (a) no need for external addition of the chemicals (coagulants/flocculants, adsorbents, acids, basis) ; (b) applicable for simultaneous removal of wide range of contaminants present in the treated water (microbiological, inorganic, organic) ; (c) low sensitivity to the changes in the composition of the treated water ; (d) high quality of treated water with regard to all measured parameters. For that purpose Eastern Slavonia groundwaters with elevated values of heavy metals, color, turbidity, suspended solids, ammonia and organic contaminants were used. Due to the complexity of the composition of the treated water the purification system required electrochemical treatment using appropriate elctrochemical reactors followed by simultaneous ozonation/UV treatment. All measured parameters in the purified water were significantly lower compared to regulated values. Under the optimum treatment conditions removal efficiency of color, turbidity, suspended solids, nickel and arsenic was 100%. Removal efficiency of Fe, Mn, Cr, Zn, Cu, COD and ammonia was 99.4%, 95.7%, 98.2%, 74.0%, 99.1%, 93.8% and 94.0% respectively and increased with increasing initial concentration.

The aim of this research was development of appropriate procedure for the treatment of landfill leachate taken from the Piškornica, Mraclinska Dubrava and Viševac sanitary landfills. Due to the complex nature of the effluent a combined treatment approach was applied. The pretreatment step included simultaneous treatment with calcium oxide and electrocoagulation/electrooxidation by stainless steel electrode set. The main treatment included electrocoagulation/electrooxidation using the set of stainless steel, iron and aluminum electrodes. Pretreatment allows the destruction of the humic and fulvic acids and optimization of pH values for the formation of reactive oxidative species, as well as the transformation of NH4-N into volatile NH3-N. This pretreatment allows the softening of the water and 100% removal of the bacteria, between 90 and 96% removal of color, turbidity and suspended solids, approximately 65% removal of NH3-N and more than 98% removal of fluorides, phosphates and heavy metals, while the hardly biodegradable organic matter decomposes into more easily degradable carboxylic acids. In the presence of added calcium oxide and electrochemically generated coagulant the removal of the fluorides, phosphates and heavy metals occur trough the formation of poorly soluble fluorapatite, hydroxyl apatite, and various hydroxides. During the main treatment electrochemically generated reactive oxidative species carried out rapid decomposition of the organic matter and ammonia, resulting in the removal of COD up to 98%, color and turbidity up to 99% and ammonia up to 97%. Following the electrochemical treatment the suspension was passed through an electromagnet in order to speed the separation of the sludge from the treated water. Applied treatment approach resulted in clear, colorless and odorless effluent with the values of all measured parameters significantly lower compared to the upper permissible limit for discharge into the environment.

It was already shown in the previous work that the tagged neutron inspection system (TNIS), which uses the associated particle imaging (API) technique, was able to detect explosive in a sea-going cargo container filled with an iron matrix with density 0.2 g/cm3 [1]. It was also shown the possibility of TNIS to detect the explosive in the organic matrix with density ≤ 0.25 g/cm3 [2]. In this work the possibility of TNIS to identify materials hidden behind or in front of dense organic goods is investigated. A paper target, which is a good explosive simulant, is put close to the flour surroundings. A triangle diagram is made from the number of counts in the carbon peak, number of counts in the oxygen peak and the number of counts in the transmitted neutron peak. Identification of the paper target is possible if some appropriate knowledge about the surroundings is known.

The purpose of this work was the development and testing of a simple cost-effective treatment of waste waters originated from electroplating processes using waste Fe(II)-sulfate and wood fly ash. Ferrous-sulfate was employed for Cr(VI) reduction whereas neutralization and heavy metal removal from EWW was performed using wood fly ash. Optimum amount of ferrous sulfate and wood fly ash needed for successful treatment of EWW, optimum pH value of the treated solution and mixing time were determined. Various leaching tests were conducted on the remaining waste mud, which bound heavy metals from the waste water in order to determine a safe way to its permanent disposal. Heavy metals removal efficiency varied from 97.5% for Cu to 99.973% for Zn. Satisfying results can be achieved already at the pH 8. The method is suitable for the purposes of waste water treatment and disposal in compliance with environmental laws. Reported new procedure is technically simpler, cheaper and requires less space compared to the classical methodology because all reactions (chromate reduction, neutralization and heavy metals removal) could be conducted in only one container. Significant improvement in waste water treatment lies in the fact that both reagents (ferrous-sulfate and fly ash) are used in their original form (solid state) whereby any sort of preliminary processing isn’ t needed.

Jedno od suvremenih ekoloških rješenja sanacije komunalnog i industrijskog otpada je industrijsko i energetsko postrojenje na bazi Pyromex tehnologije koja gotovo u potpunosti bez ostatka tretira komunalni i industrijski otpad iz kojeg se dobivaju proizvodi primjenjivi u građevinarstvu, gnojivo i energetski briketi koji uplinjavanjem omogućavaju proizvodnju električne energije primjenjive u industriji, domaćinstvima i kao energetska baza za pogon gradskog, prigradskog i međugradskog tračničkog prometa pa i nekih novijih prometnih sustava kao što su recimo magnetska lebdeća vozila (MAGLEV).

Production of the coagulant using bauxite waste (red mud and waste base) as raw material and the results of the testing of this new product in laboratory and field condition (pilot plant, full scale plant) were presented. Results showed that red mud could be used as a low-coast solution for heavy metals removal from its own waste base and other industrial wastewaters after partial dissolution with diluted sulphuric acid and neutralisation with the waste base. This coagulant is especially suitable for the treatment of the wastewaters generated from the pressure washing of boats in the marinas. The coagulant produced from the red mud has few advantages compared to the commercial Fe and Al salts: 1. Coagulation/flocculation process could be done in one step without coagulant aid or any other chemical addition, 2. pH measurement during the purification could be avoided due to the negligible pH variations of the treated solution, 3. allow one step removal of the cationic and anionic species from the wastewater, 4. one dose of coagulant is sufficient for five repeated cycles of heavy metals removal, 5. negligible leaching of the heavy metals from the waste mud under normal environmental conditions, 6. safe for the transport, storage and handling.

Electroplating wastewaters have significantly contributed to the pollution of agricultural soil and water in Croatia. A total of 104 registered electroplating facilities existed in the year 2002. In most cases, EWW having a pH below 2 and metal levels few hundred to thousand times higher than the allowed values have been discharged directly into the surrounding agricultural soil and local streams. The aim of this work was to present a new, simple cost-effective system for the treatment of waste waters from electroplating and other surface processes highly enriched in heavy metals (Cr (VI), Zn, Ni, Fe) using other waste materials such as waste Fe(II)-sulfate and wood fly ash. The former was employed as a reducing agent and the latter was a neutralizing agent as well as a coagulant. Removal efficiency for analyzed elements ranged from 97.500% for copper to 99.973% for zinc. Satisfying results can be achieved already at the pH 8. The method is suitable for the purposes of wastewater treatment and disposal in compliance with environmental laws. Furthermore, it is technically simple, cost-efficient and requires less space compared to the classical methodology. According to the composition of its water extractable fraction remaining waste ash could be safely deposited on domestic waste repositories.

Long-term observations of soil water content as well as determination of physical and chemical properties of different types of soils in Croatia were made in order to provide the necessary background information for landmine explosive detection. Soil water content is the key attribute of soil as a background in neutron backscattering technique (NBT) landmine detection application. If the critical value of the soil water content is reached, the detection of landmine explosives is not possible. It is recommended that soil moisture content for NBT application does not exceed 0.1 kg.kg-1 [1]. Nineteen representative samples of different soil types from different parts of Croatia were collected in order to establish soil bank with the necessary physical and chemical properties determined for each type of soil. In addition soil water content was measured on daily and weekly basis on several locations in Croatia. This procedure also included daily soil moisture measurements in the test field made of different types of soils from several locations in Croatia. This was done in order to evaluate the behavior of different types of soils under the same weather conditions.

Neutron Backscattering (NB) sensors have been proposed for Humanitarian De-mining applications. Recently, an hand held system integrating a NB sensor in a Metal Detector has been developed within the DIAMINE Contract(IST-2000-25237). Results obtained in term of performance of the NB systems and limitations in its use are presented.

Biogoriva za pogon motornih vozila svojim tehničkim karakteristikama zadovoljavaju propisane zahtjeve za goriva. Osnovna prednost biogoriva je manje onečišćenje okoliša u direktnoj i indirektnoj primjeni, te boljim mazivim svojstvima. Frakcije biobenzina ispitivane u ovom radu dobivene nestandardnim postupkom NTPR, po svojim karakteristikama vrlo su slične frakcijama benzina dobivenog iz nafte. Dobivene frakcije biodizela također su po svojim karakteristikama vrlo slične frakcijama dizela dobivenog iz nafte, odnosno frakcijama biodizela dobivenog standardnim postupkom transesterifikacije repičinog ulja.

Uporaba protivobraštajnih boja za premazivanje trupa broda znatan je izvor teških metala u sedimentima, u morskoj vodi i u bioti. One sprečavaju obraštanje broda različitim organizrnima time što su veoma toksične. jedan dio tako nanjete boje otapa se za zadržavanja brodice u moru, ali se najvećim dijelom te boje ispuštaju unutar prostora marina ili luka i lučica, pri pranju brodova prskalicom, kad se skida stari sloj prije nanošenja novog, što se radi otprilike jedanput godišnje. Svrha ovog rada je prikazati rezultate testiranja uređaja za pročišćavanje otpadnih voda iz prališta marina. Rezultati ukazuju da se primjenom ovakvog uređaja višestruko smanjuje glavni antropogeni izvor zagađenja u marinama.