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Mechanochemical synthesis of cocrystals between hydroxybenzoic acids and urea in the solid state : diploma thesis
No full textU radu je opisana priprema kokristala hidroksibenzojevih kiselina (orto-, meta-, para-) i uree mehanokemijskom sintezom u čvrstom stanju. Kokristali su pripremljeni reakcijama suhog mljevenja i tekućinski potpomognutog mljevenja koristeći mikrolitarske količine etanola ili nitrometana. Reakcije su praćene Ramanovom spektroskopijom in situ kojom iz dobivenih vremenski ovisnih 2D Ramanskih spektara možemo dobiti uvid u kinetiku formiranja pojedinog kokristala pri određenim reakcijskim uvjetima. Kokristali meta- ili para- hidroksibenzojeve kiseline i uree, čije strukture do sad nisu bile poznate, određeni su pomoću difrakcije rendgenskim zračenjem na prahu i monokristalu. Kompeticijskim reakcijama s po dvije kiseline koje mogu tvoriti kokristal s ureom određen je odnos termodinamičke stabilnosti između sva tri kokristala. U uvjetima suhog i tekućinski potpomognutog mljevenja uvijek je preferiran nastanak kokristala s p-hidroksibenzojevom kiselinom, dok kokristal s m-hidroksibenzojevom kiselinom ni u jednom slučaju nije preferencijalno nastao te se time zaključuje kako je taj kokristal najmanje stabilan.In this thesis, we describe the formation of cocrystals of hydroxybenzoic acids (ortho-, meta-, para-) and urea by mechanochemical synthesis in the solid state. The cocrystals were formed by neat grinding and liquid assisted grinding (LAG) reactions using microliters amounts of ethanol or nitromethane. Reactions were monitored by Raman spectroscopy in situ resulting in time-dependent Raman spectra from which we can gain insight into the kinetics of cocrystal formation. The synthesized cocrystals of meta- and para-hydroxybenzoic acid and urea, whose structures were unknown, were identified by X-ray diffraction on powder and single crystal. The relationship of thermodynamic stability between these three cocrystals was determined by competition reactions between two possible hydroxybenzoic acid coformers. Under neat and LAG milling conditions, the formation of a cocrystal with p-hydroxybenzoic acid is always favored, while a cocrystal with m-hydroxybenzoic acid is not preferentially formed in any system, thus concluding that it is the least stable cocrystal
Hg(II) sorption onto natural and Fe(III) - modified zeolite - effect of solid/liquid ratio : bachelor thesis
No full textUtjecaj omjera kruto tekuće, S/L na sorpciju Hg(II) iz vodene otopine ispitan je na prirodnom i Fe(III)-modificiranom zeolitu. Sorpcija je provedena pri optimalnom pH o =1,98 te S/L = 2 – 80 g/L na prirodnom zeolitu i S/L = 2 – 36 g/L na Fe(III)-modificiranom zeolitu. Rezultati su pokazali da je optimalno S/L područje za sorpciju Hg(II) ≤ 30 g/L za prirodni zeolit te ≤ 14 g/L za Fe(III)-modificirani zeolit. Ravnotežne koncentracije Hg(II) i količine sorbirane Hg(II) na uzorcima zeolita smanjuju se porastom S/L omjera. Maksimalna učinkovitost sorpcije od 73,92% postignuta je pri S/L = 30 g/L na prirodnom zeolitu te 86,45% na Fe(III)-modificiranom zeolitu pri S/L = 14 g/L što ga izdvaja boljim sorbentom za sorpciju Hg(II).The effect of the solid-liquid, S/L ratio on the sorption of Hg(II) from aqueous solution was investigated on natural and Fe(III)-modified zeolite. Sorption was performed at optimal pH o = 1.98 and S/L = 2 - 80 g/L onto natural zeolite and S/L = 2 - 36 g/L onto Fe(III)-modified zeolite. The results showed that the optimal S/L range for Hg(II) sorption is ≤ 30 g/L for natural zeolite and ≤ 14 g/L for Fe(III)-modified zeolite. Equilibrium concentrations of Hg(II) and the amount of sorbed Hg(II) on zeolite samples decreases with increasing in S/L ratio. The maximum sorption efficiency of 73,92% was achieved at S/L = 30 g/L for natural zeolite and 86.45% for Fe(III)-modified zeolite at S/L = 14 g/L, which highlights Fe(III)-modified zeolite as the better sorbent for Hg (II) sorption
Analysis and treatment of biowaste compost leachate : diploma thesis
No full textKompostiranje je prepoznato kao ekološki prihvatljiv način zbrinjavanja biorazgradljivog otpada njegovim prevođenjem u kompost. Pri tome nastaju i procjedne vode koje mogu sadržavati različite opasne tvari s negativnim utjecajem na okoliš. Stoga je potrebna obrada procjedne vode prije ispuštanja u prirodni recipijent. U ovom radu praćena je količina i sastav procjedne vode nastale tijekom procesa kompostiranja biootpada u rotacijskom komposteru valjkastog oblika (zatvoreni sustav) i otvorenoj posudi (otvoreni sustav). U procjednim vodama praćeni su pH, električna vodljivost, mutnoća, KPK, BPK te dušik po Kjeldahlu. Rezultati su pokazali da su procjedne vode karakterizirane visokim organskim opterećenjem, visokom koncentracijom amonijaka, niskim pH, visokom provodnošću i mutnoćom, a nastale količine pokazuju izraziti opadajući trend. U cilju obrade otpadne vode nastale tijekom kompostiranja biootpada, simulirana je procjedna voda iz kompostne mase uzorkovanenakon 21. dana kompostiranja. Simulirana procjedna voda obrađena je postupkom koagulacije i elektrokoagulacije, bez i s dodatkom zeolita. Učinkovitost postupaka obrade praćena je preko parametara pH, električne vodljivosti, mutnoće, KPK te dušika po Kjeldahlu. Također je praćena potrošnja aluminijevih elektroda tijekom elektrokoagulacije s i bez dodatka zeolita. Provedena je analiza operativnih troškova postupka elektrokoagulacije (utrošak električne energije, materijala elektroda te zeolita).Composting has been recognized as an environmentally friendly way of disposing of biodegradable waste by converting it into compost. Composting process also produce the leachate that contain various hazardous substances with a negative impact on the environment. Therefore, leachate treatment is required before discharge into the natural recipient. In this paper, the amount and composition of leachate generated during the biowaste composting process in a cylindrical rotary composter (closed system) and an open container (open system) were monitored. pH, electrical conductivity, turbidity, COD and Kjeldahl nitrogen were monitored in the leachate. The results showed that leachates are characterized with high organic load, high ammonia concentration, low pH, high conductivity and turbidity, while the resulting leachate amounts showing decreasing trend. In order to treat wastewater generated during composting of biowaste, leachate was simulated from the compost mass sampled on the 21st day of composting. The simulated leachate was treated by coagulation and electrocoagulation, without and with the addition of zeolite. The efficiency of the treatment process was monitored through the parameters of pH, electrical conductivity, turbidity, COD and Kjeldahl nitrogen. Consumption of aluminum electrodes during electrocoagulation with and without the addition of zeolite was also monitored. An analysis of the operating costs of the electrocoagulation procedure (consumption of electricity, electrode material and zeolite) was performed
Analysis of the water pollutions using The Environmental information system : bachelor thesis
No full textVoda je jedna od najzastupljenijih, ali i najnužnijih tvari na Zemlji. U ovom radu analizirano je onečišćenje vodnih sustava u petogodišnjem razdoblju od 2013. do 2017. na području Splitsko-dalmatinske županije primjenom Informacijskog sustava stanja okoliša. Ukupne godišnje količine ispuštanja i prijenosa onečišćujućih tvari u vode i/ili more iz sustava javne odvodnje u razdoblju od 2013. do 2017. osciliraju, dok ukupne godišnje količine ispuštanja i prijenosa onečišćujućih tvari u vode i/ili more s lokacije obveznika pokazuju trend pada te u 2017. godini iznose svega 6,62% od ukupne količine prijavljene iz sustava javne odvodnje. Unos opterećenja/tereta rijeka izražen preko hranjivih i organskih tvari te teških metala (Cu, Zn, Cr, Pb, Ni i Cd) analiziran je na postaji Cetina-HE Zakučac. Rezultati pokazuju da NO 3 -N i ukupni dušik osciliraju oko sličnih vrijednosti osim za 2015. godinu, kad je unos tereta rijekama bio smanjen zbog manjeg protoka. Od teških metala, zabilježen je povećan unos cinka u 2014., dok je u 2017. zabilježen povećan unos cinka i bakra. Kakvoća mora za kupanje je u ispitanom razdoblju duž cijele obale mora najviše kvalitete, s izuzetkom nekoliko zatvorenijih akvatorija opterećenih otpadnim vodama urbanog ili industrijskog porijekla, riječnim donosima te lučkim prometom.Water is one of the most abundant but essential substances on Earth. In this paper, water pollutions in the Split-Dalmatia County during the five-year period from 2013 to 2017 have been analysed using the Environmental Information System. Total annual quantities of discharges and transfers of pollutants into water and/or sea from the public sewerage system in the period 2013-2017 oscillate, while total annual quantities of discharges and transfers of pollutants into water and/or sea from the location of taxpayers is showing a decreasing trend and in 2017 amounted to only 6.62% of the total amount reported from the public sewerage system. Load input of nutrients, organic substances and heavy metals (Cu, Zn, Cr, Pb, Ni, Cd) were analysed on the location Cetina - HE Zakučac. The result show that NO 3 -N and total nitrogen oscillate around similar values except for 2015, when load input by river Cetina was reduced due to lower flow. Among heavy metals, an increased amount of zinc is recorded in 2014, while in 2017 an increased amount of zinc and copper were recorded. The highest quality of sea bathing waters were recorded along the entire coast, with the exception of a few closed water area loaded by wastewater of urban or industrial origin, river yields and port traffic
Analysis of volatile compounds from samples of nonflavored and flavored olive oils : diploma thesis
No full textZbog svoje specifične arome i nutricionističkih benefita maslina (Olea europea L.) jedna je od najpopularnijih biljaka Dalmacije. Kako bi se poboljšala osjetilna i nutricionistička svojstva, već poznatom mirisu i okusu maslinova ulja, dodaju se nove arome. U aromatizaciji ulja najčešće se koriste ružmarin, timijan, origano i slične aromatične biljke te plodovi citrusa. U svrhu izolacije hlapljivih spojeva tri nearomatizirana maslinova ulja i tri maslinova ulja aromatizirana gorkom narančom, origanom i ružmarinom, podvrgnuta su hidrodestilaciji te mikroekstrakciji vršnih para na čvrstoj fazi (HS-SPME). Svi uzorci hlapljivih spojeva, destilati i vršne pare, analizirani su veznim sustavom plinska kromatografija-spektrometrija masa (GC-MS). Glavni spojevi u destilatu maslinovog ulja, uzorak 1, su nezasićena masna kiselina, oleinska kiselina, aldehid nonanal te (E)- i (Z)- izomeri nezasićenog alifatskog aldehida deka-2,4-dienala. U destilatu uzorka 2 ističe se nezasićeni C 6 aldehid (E)-heks-2-enal i oleinska kiselina. Glavni spojevi destilata uzorka 3 su oleinska kiselina i etil-oleat. C 6 aldehid (E)-heks-2-enal nije identificiran u uzorcima 1 i 3, dok je C 6 alkohol heksan-1-ol identificiran u sva tri destilata, ali s malim udjelima. Navedeni spojevi su nositelji arome koja se opisuje kao „zelena“. Glavni sastojci vršnih para uzorka 1 i 2 su C 6 spojevi (E)-heks-2-enal, heksanal te heksan-1-ol. Uzorak 2 sadrži još i oleinsku kiselina. Vršne pare uzorka 3 se dosta razlikuju. Tu prevlada ester butanske kiseline, etil-butanoat i etanol. C 6 aldehidi (E)-heks-2-enal i heksanal u uzorku 3 nisu identificirani, već C 6 alkohol heks-3-en-1- ol. U destilatu maslinovog ulja aromatiziranog gorkom narančom ističe se monoterpenski ugljikovodik limonen. Glavni spojevi destilata maslinovog ulja aromatiziranog origanom su također monoterpeni. Najveći udio zauzima fenol timol te ugljikovodici p-cimen i limonen. Destilat maslinovog ulja aromatiziranog ružmarinom sadrži monoterpene timol, limonen, 1,8-cineol, p-cimen, kamfor te α-pinen. Glavni sastojci vršnih para maslinovog ulja aromatiziranog gorkom narančom su limonen i triterpenski ugljikovodik skvalen. Najistaknutiji spojevi vršnih para maslinovog ulja aromatiziranog origanom su monoterpeni limonen, p-cimen i timol. Kao i u prethodnom i u ovom uzorku identificiran je triterpenski ugljikovodik skvalen. Uzorak vršnih para maslinovog ulja aromatiziranog ružmarinom karakterizira visoki udio skvalena te oleinska kiselina.Due to it's specific aroma and valuable nutritional benefits, olive tree (Olea europea L.) is one of the most popular plants in Dalmatia. In order to improve the sensory and nutritional properties, various aromas are added to the olive oils. Rosemary, thyme, oregano and various Citrus fruits are most often used in the aromatization of oils. For the purpose of isolating volatile compounds, three non-flavored olive oils and three olive oils flavored with bitter orange, oregano and rosemary, were subjected to hydrodistillation and solid phase microextraction method (HS-SPME). All volatile compound samples were analyzed by gas chromatography-mass spectrometry (GC-MS). The main compounds in the olive oil distillate, sample 1, are unsaturated fatty acid, oleic acid, aldehyde nonanal and (E)- and (Z)-isomers of deca-2,4-dienal. In the sample 2 distillate, unsaturated C 6 aldehyde (E)-hex-2-enal and oleic acid stand out. The main compounds of sample 3 distillate are oleic acid and ethyl oleate. C 6 aldehyde (E)-hex-2- enal, was not identified in samples 1 and 3, while C 6 alcohol hexan-1-ol was identified in all three distillates, but with small proportions. These compounds are carriers of so-called "green" aromas. The main constituents of headspace vapours of samples 1 and 2 are C 6 compounds (E)-hex-2-enal, hexanal and hexan-1-ol. Sample 2 also contains oleic acid. The headspace vapors of sample 3 are different with ethyl butanoate and ethanol as main compounds. The C 6 aldehydes (E)-hex-2-enal and hexanal in sample 3 were not identified, but the C 6 alcohol hex-3-en-1-ol was. In the distillate of olive oil flavored with bitter orange the monoterpene limonene stands out. The most prominent compounds of oregano flavored olive oil distillate are also monoterpenes. The largest share takes phenol thymol, and hydrocarbons p- cymene and limonene. The rosemary flavored olive oil distillate contains monoterpenes thymol, limonene, 1,8-cineole, p-cymene, camphor and α-pinene. The main ingredient of the headspace vapors of bitter orange flavored olive oil is limonene, as well as the triterpene squalene. The most prominent compounds of the headspace vapors of oregano flavored olive oil are monoterpenes limonene, p-cymene and thymol. As in the previous sample, the triterpene squalene was identified too. The sample of headspace vapors of rosemary flavored olive oil is characterized by an extremely high content of squalene followed by oleic acid
Impact of simultanes application of mechanical stirring and ultrasound irradiation on the growth rate dynamics of borax crystals : diploma thesis
No full textGlavni cilj ovoga rada bio je ispitati istovremeno djelovanje mehaničkog miješanja i ultrazvuka na dinamiku rasta kristala boraksa. Sonokristalizacija hlađenjem izvršena je u staklenom kristalizatoru, pri čemu je volumen kapljevine iznosio 2,65 dm 3 , a brzina hlađenja 6 °C h -1 . Brzine miješanja SBT miješala odgovarale su onima potrebnima za postizanje stanja potpune suspenzije (N JS ) po Zwieteringovom kriteriju, a amplitude ultrazvučnog djelovanja (A) iznosile su redom 0, 20, 25 i 30 %. Određena je promjena koncentracije matične otopine potenciometrijski, kao i promjena apsolutne prezasićenosti pri navedenim ultrazvučnim amplitudama pri čemu dobiveni rezultati pokazuju da ultrazvuk utječe na promjenu apsolutne prezasićenosti, a samim time i na promjenu veličine kristala. Prikazana je i promjena veličine kristala s vremenom koja pokazuje prosječno sitnije kristalne produkte s povećanjem amplitude ultrazvuka. Također, određeno je i vrijeme dostizanja konačne veličine kristala te utjecaji ultrazvuka i miješanja na brzinu rasta kristala i njihovu veličinsku raspodjelu metodom laserske difrakcije gdje je uočljivo da se vrijeme potrebno za nastajanje kristala konačne veličine povećava s povećanjem amplitude ultrazvuka, ali i da se raspodjela veličina kristala sužava. Određena je i snaga potrebna za izvođenje eksperimenta. Dobivene vrijednosti ukazuju na to da je utrošak snage izražen po jediničnoj masi otopine boraksa čak do 10 puta veći kod ultrazvučnog djelovanja nego kod mehaničkog miješanja. S obzirom na rezultate eksperimenta, više amplitude ultrazvuka ne čine proces sonokristalizacije učinkovitijim te se amplituda ultrazvuka od 20% čini optimalnom zbog toga što ima najkraće vrijeme dostizanja konačne veličine kristala i energetski je manje zahtjevna od onih pri 25 i 30 %.The primary goal of this thesis was to examine the effect of simultaneous application of mechanical stirring and ultrasound irradiation on borax crystals growth rate dynamics. The cooling sonocrystallization has been conducted in a glass crystallizer with the liquid volume being 2.65 dm 3 and the cooling rate of 6 °C h -1 . Stirring speeds of the SBT stirrer matched the ones required for achieving the state of a complete suspension (N JS ) by Zwietering's criterion, while amplitudes of the ultrasound were as follows: 0, 20, 25 and 30 %.The change of the mother liquor's concentration was determined potentiometrically as well as the change of the absolute supersaturation during above-mentioned amplitudes. According to results, ultrasound irradiation affects absolute supersaturation as well as the change of crystal size during the process. Given the measured sizes of crystals, change in crystal size over time was shown and it is noticeable that continuous sonocrystallization yields averagely smaller crystals. Also, the time required for crystals to attain their final size, effects of both stirring and ultrasound irradiation on the growth rate and the crystal distribution determined by laser diffraction were presented for each amplitude. In general, the time required for attaining the crystalline product of final size extends with an increase of ultrasound amplitude. At the same time, crystal size distribution narrows. Power needed to perform the experiment was also determined. Results suggest that power consumed per unit mass of borax solution by stirring is up to 10 times lower than that of ultrasound irradiation. Considering all obtained results, it can be said that higher ultrasound amplitudes do not imply a more effective sonocrystallization process and therefore, the amplitude of 20 % seems like the optimal one with reasons being that it ensures the shortest time needed for attaining the final size of the crystal as well as not being as costly in terms of energetics as the amplitudes of 25 i 30 %
Polymer waste management : bachelor thesis
No full textU ovom radu provedena je analiza proizvodnje i oporabe polimernih materijala u svijetu, a napose u Europskoj uniji. Hrvatska kao članica Europske unije dužna je ispunjati njihove zahtjeve i visoke standarde gospodarenja polimerni otpadom te u korisne svrhe trošiti dobiveni novac iz EU fondova. Proizvodnja i potrošnja polimera u svijetu stalno raste, a time i količina polimernog otpada. Polimerni otpad predstavlja jedan od većih ekoloških problema današnjice. Njegovim odlaganjem bez prethodne oporabe i iskorištavanja vrijednih svojstava, gomilaju se odlagališta otpada i na taj način se ne koristi u svrhu dobivanja resursa. Velike količine završe i nekontrolirano u okolišu, van odlagališta otpada, posebno u morima i oceanima. Odlaganje kao najjeftiniji ali i najmanje poželjan način zbrinjavanja polimernog otpada prisutan je i u Hrvatskoj, a upravo Hrvatska odlaže preko 70 % polimernog otpada. Odlaganje plastičnog otpada znači posebno ekonomsku, ali i ekološku štetu, iako je generalno plastični otpad neutralan i pridonosi stabilnosti odlagališta. Rješenje koje se nudi u svrhu sprječavanja odlaganja polimernog otpada je oporaba polimernog otpada. Zadaća oporabe je ušteda sirovina i smanjenje količine otpada. Da bi se riješio problem otpada općenito potrebno je razviti dobar sustav gospodarenja otpadom sukladno hijerarhiji propisanoj Zakonom o održivom gospodarenju otpadom.In this paper, an analysis of the production and recovery of polymer materials was conducted, focusing mainly on the European Union. Croatia, as a member of the EU is obligated to meet the requirements and high standards of waste management and to utilize the money from the EU funds in order to meet these requirements. The production and consumption of polymers is constantly growing in the world and so does the polymer waste. Polymer waste is one of the major environmental problems. By disposing of it without prior recovery and by exploiting valuable properties landfills are piled up and thus not used for resource purposes. Large quantities end up uncontrolled in the environment, outside landfills, especially in the seas and oceans. The use of landfills, being one of the cheapest but also impractical ways of disposal, is also present in Croatia, as Croatia itself uses landfills to dispose 70 % of its polymer waste. Landfill waste disposal represents especially economic damage. Plastic waste is neutral and it contributes to the stability of the landfill – however it represents ecological problem, too. One solution which is being presented in order to prevent landfill disposal of polymer waste is recycling. The main aim of recycling is the conservation of raw material and reduction of waste. In order to solve the problem of waste in general it is necessary to develop a good waste management system prescribed by the Law on Sustainable Waste Management
Electrochemical characterization of antioxidants on modified electrodes: Carotenoids : bachelor thesis
No full textBrojna istraživanja pokazuju kako konzumacija namirnica bogatih tvarima s antioksidacijskim djelovanjem imaju izrazito povoljan utjecaj na zdravlje čovjeka. Uloga antioksidansa je spriječiti štetne oksidacijske procese slobodnih radikala. Unošenjem različitih biljnih vrsta (voća, povrća, orašastih plodova, začinskoga bilja...) osobito onih iz prirodnog i organskog uzgoja sprječavamo reakcije koje mogu dovesti do mnogih degenerativnih promjena u stanicama čovjeka, te narušiti ljudsko zdravlje. Primjena različitih elektrokemijskih metoda u analizi antioksidacijske aktivnosti u posljednjem desetljeću naišla je na veliki interes u znanstvenim krugovima. Danas istraživanja idu u smjeru pronalaska i razvoja metodologije pripreme elektrode/senzora za brzu jednostavnu, selektivnu i osjetljivu karakterizaciju bioaktivnih tvari u prirodnim uzorcima, bez njihove predobrade. Elektrokemijske metode određivanja antioksidacijske aktivnosti na različitim elektrodama nailaze već danas na primjenu, osobito u karakterizaciji prirodnih bojila – KAROTENOIDA. Cilj ovog rada je pregledom literature pokazati kako je jednostavnim elektrokemijskim metodama moguće je odrediti antioksidacijski kapacitet β-karotena, koji je primjer najzastupljenijeg prirodnog bojila i antioksidansa, te radi svojih povoljnih svojstava primjenu pronalazi u raznim industrijama.Numerous studies show that the consumption of foods rich in antioxidants has a very positive effect on human health. The role of antioxidants is to prevent harmful oxidative processes of free radicals. By consuming different types of plants (fruits, vegetables, nuts, herbs...), especially naturally and organically grown, we prevent reactions that can lead to many degenerative changes in human cells and affect human health. The use of various electrochemical methods in the analysis of antioxidant activity has found great interest in scientific circles over the last decade. Current and new research are directed towards finding and developing a methodology for preparing electrodes/sensors for a fast, simple, selective and sensitive characterization of bioactive substances in natural samples without pre-treatment. Electrochemical methods for the determination of antioxidative activity of different electrodes are already available today, especially for the characterization of natural dyes - CAROTENOIDS. β-Carotene as the most common natural dye and antioxidant can be used in the food industry, but also in many other branches of industry. The aim of this review article is to demonstrate possibility of determination of the antioxidant capacity of β-carotene using simple electrochemical methods
Treatment of olive pomace lachate wastewater by aeration and fenton like process : bachelor thesis
No full textU radu je dobivena simulirana procjedna voda komine masline kontinuiranim ispiranjem komine destiliranom vodom tijekom tri dana. U uzorku su određeni pokazatelji kakvoće vode (pH vrijednost, mutnoća, električna provodnost, KPK, BPK 5 , dušik po Kjeldahlu) koji su ukazali da prema zakonskim propisima ovakva voda nije pogodna za ispust u površinske vode ni u sustav javne odvodnje. Aeracijom procjedne vode vrijednost KPK se smanjuje za 13%, a BPK 5 za 44% čime voda zadovoljava uvjete za ispust u sustav javne odvodnje, ali ne i u površinske vode. Primjenom Fenton sličnog procesa pri različitim pH vrijednostima, različitim koncentracijama Fe 3+ iona i različitim omjerima množinskih koncentracija Fe 3+ : H 2 O 2 utvrđeno je da se najbolji učinak smanjenja KPK od 19% postiže pri minimalnoj koncentraciji Fe 3+ iona od 9 mg/L, pH vrijednosti od 3,03 i pri omjeru množinskih koncentracija (Fe 3+ : H 2 O 2 ) od 1:30. Primjenom aeracije i Fenton sličnog procesa KPK vrijednost se ukupno smanjuje za 32% i kao takva ne zadovoljava uvjete za ispust u površinske vode, ali zadovoljava uvjete za ispust u sustav javne odvodnje.The simulated leachate of olive pomace is obtained by continuous leaching of the olive pomace using destilled water during three days. Water quality parameters (pH value, turbidity, electrical conductivity, COD, BOD 5 , Kjeldahl nitrogen) were determined in the sample and according to legislative, leachate is not suitable for discharge into surface water or into the public sewage system. Aeration of wastewater reduces COD values by 13% and BOD 5 by 44%, which means that the water meets the conditions for discharge into public drainage system, but not into surface waters. Using a Fenton like process at different pH values, different mass concentrations of Fe 3+ ions and different molar concentration ratios of Fe 3+ : H 2 O 2 , it was found that the best removal efficiency of 19% is achieved at a minimum concentration of Fe 3+ ions of 9 mg/L, pH value of 3,03 and at a molar concentration ratio (Fe 3+ : H 2 O 2 ) of 1:30. Summary, aeration and Fenton like process reduced the COD value up to 32%, but treated leachate does not meet the requirements for discharge into surface waters, where meets the requirements for discharge into the public sewage syste
Developing HACCP system in cheese production : bachelor thesis
No full textNakon što je Republika Hrvatska stupila u Europsku uniju, donosi se novi Zakon o hrani i Zakon o higijeni hrane i mikrobiološkim kriterijima za hranu. 1.siječnja 2009. godine donesena je Odredba Zakona o hrani (NN 46/07). Od tada svi subjekti u poslovanju s hranom, osim primarne proizvodnje, dužni su uspostaviti sustav upravljanja sigurnošću hrane, koji se temelji na HACCP sustavu. Prema tome, svi subjekti u poslovanju s hranom od tog datuma bili su dužni implementirati HACCP sustav u svoje pogone. Danas je sustav kontrole kvalitete hrane važan dio svake organizacije koja se bavi proizvodnjom i preradom hrane. Važnu ulogu u kontroli kvalitete hrane ima set standarda ISO, koji daje niz uputa i preporuka za implementaciju. Cilj ovog rada je opisati implementaciju HACCP sustava u procesu proizvodnje tvrdog sira. Potrebno je provesti analizu opasnosti tijekom cijelog procesa proizvodnje te odrediti kritične kontrolne točke (KKT) i kritične granice. U radu je opisano uspostavljanje sustava nadzora za kontrolu KKT te popravne radnje u slučaju pojave opasnosti, važnost preduvjetnih programa i kontrola kvalitete.After joining the European Union, Republic Croatia passed a Food Act and a Law of food hygiene and microbiological criteria. On January 1 st , 2009 the Regulation of the Food Act was passed. Since then all food business operators, except at the level of primary production, are required to establish a food safety management system, which is based on the HACCP system. Accordingly all food business operators, from that date, were required to implement the HACCP system in their facilities. Today, food quality control systems are an important part of any food production and processing organization. An important role in food quality control system is played by a set of ISO standards, which gives a series of instructions and recommendations for implementation. The purpose of this paper is describe the implementation of the HACCP system in hard cheese production. It is necessary to conduct a hazard analysis during the process and determine critical control points (CCP) and critical limits. In this paper I described the establishment of a supervisory control system for CCP and corrective actions in case of danger, the importance of prerequisite program and quality control