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ICP-MS analysis of mineral elements in wines from Konavle, Pelješac, Hvar and Korčula : graduate thesis
No full textU ovom radu provedena je analiza 30 mineralnih elemenata u 107 uzoraka različitih sorti crnog, bijelog i rosé vina s područja Konavla, Pelješca, Hvara i Korčule. Analiza je provedena korištenjem analitičke tehnike masene spektrometrije povezane s induktivno spregnutom plazmom (ICP – MS). Prije same analize izmjerena je pH vrijednost uzoraka. Svaki uzorak je prije ICP - MS analize podvrgnut mirovalnoj digestiji u zatvorenim teflonskim posudama uz korištenje HNO 3 i H 2 O 2 . Od 30 analiziranih elemenata, berilij, kobalt, živa i vanadij nisu detektirani ni u jednom od 107 uzorka, a rezultati za olovo nisu razmatrani. Šest uzoraka pokazalo je koncentraciju bakra iznad dopuštene (1000 μg/L), uz istovremeno povišene, ali dopuštene vrijednosti nikla, kadmija, kositra, željeza i antimona, što sugerira mogući zajednički izvor kontaminacije. Cink je pokazao poveznicu sa željezom i bakrom. Svi ostali elementi su unutar dopuštenih granica, ali esencijalni su većinom prisutni u nižim koncentracijama nego u drugim istraživanjima, vjerojatno zbog tla bogatog CaCO₃ koje smanjuje dostupnost minerala zbog visokog pH.This study analyzed 30 mineral elements in 107 samples of various red, white, and rosé wines from the regions of Konavle, Pelješac, Hvar, and Korčula. The analysis was conducted using inductively coupled plasma mass spectrometry (ICP-MS). Prior to the analysis, the pH value of each sample was measured. Each sample underwent microwave digestion in closed Teflon vessels using HNO₃ and H₂O₂ before ICP-MS analysis. Out of the 30 analyzed elements, beryllium, cobalt, mercury, and vanadium were not detected in any of the 107 samples, and lead results were not considered. Six samples showed copper concentrations above the permitted limit (1000 μg/L), along with elevated but still acceptable levels of nickel, cadmium, tin, iron, and antimony, indicating a possible common source of contamination. Zinc showed a correlation with iron and copper. All other elements were within acceptable limits, but essential elements were mostly found in lower concentrations compared to other studies, likely due to CaCO₃-rich soils in Central and Southern Dalmatia, which increase soil pH and reduce mineral availability
Ibuprofen removal from aqueos solution by sorption on different low-cost sorbents : diploma thesis
No full textPovećana i nekontrolirana uporaba farmaceutika diljem svijeta postaje sve značajniji ekološki problem. Ibuprofen je među najprodavanijim lijekovima bez recepta u svijetu, što dovodi do porasta njegove koncentracije u postrojenjima za obradu otpadnih voda, a uslijed nedovoljne učinkovitosti konvencionalnih metoda obrade, pojavljuje se i u vodnim tijelima koja se crpe za vodoopskrbu. Zbog brojnih fizioloških, hormonalnih i reproduktivnih poremećaja koje uzrokuje kod vodenih organizama, jasna je potreba za razvijanjem metoda učinkovitijeg uklanjanja ibuprofena iz voda. U ovome radu ispitano je uklanjanje ibuprofena iz vodene otopine koncentracije ≈ 1 mg/L sorpcijom na prirodnom zeolitu klinoptilolitu, njegovim modificiranim oblicima (natrijevom, željezovom i sumporovom) te na nusproizvodima prerade voća - košticama maslina, trešanja i višanja. Samo su koštice višanja pri ispitanim eksperimentalnim uvjetima pokazale učinkovitost od 30,15 % u uklanjanju ibuprofena iz vodene otopine s postignutim kapacitetom od 0,025 mg/g. Neučinkovitost ostalih sorbenasa je najvjerojatnije rezultat elektrostatskog odbijanja njihove izrazito negativne površine i deprotonirane molekule ibuprofena pri pH vrijednostima tijekom sorpcije. Buduća istraživanja trebalo bi usmjeriti ka modifikaciji materijala s ciljem poboljšanja njihovih sorpcijskih svojstava, ali i prilagođavanju eksperimentalnih uvjeta svojstvima onečišćujuće tvari, u svrhu postizanja što potpunijeg uklanjanja. Također, treba raditi na uvrštavanju farmaceutika na listu prioritetnih tvari u analizi vode budući da još uvijek ne postoji zakonska regulativa s maksimalno dopuštenim koncentracijama farmaceutika u prirodnim vodama koje se crpe za vodoopskrbu. U konačnici, nužno je poraditi na odgovornom zbrinjavanju lijekova kako bi se spriječili dugoročni učinci na bioraznolikost vodenih organizama, ali i ljude koji ovise o tim ekosustavima.The increased and uncontrolled use of pharmaceuticals worldwide is becoming a significant environmental problem. Ibuprofen is among the most sold over-the-counter drugs in the world, which leads to an increase in its concentration in wastewater treatment plants. Due to the insufficient efficiency of conventional water treatment methods, it also appears in water bodies that are pumped for water supply. Due to the numerous physiological, hormonal and reproductive disorders it causes in aquatic organisms, there is a clear need to develop methods for more effective removal of ibuprofen from water. In this paper, the removal of ibuprofen from an aqueous solution with a concentration of ≈ 1 mg/L by sorption on natural zeolite clinoptilolite, its modified forms (sodium, iron and sulfur) and on fruit processing by-products - olive, cherry and sour cherry pits was examined. Only sour cherry pits showed effectiveness (30.15%) in ibuprofen removal from aqueous solution under the tested experimental conditions, with a capacity of 0.025 mg/g. The ineffectiveness of other sorbents is most likely the result of electrostatic repulsion of their extremely negative surface and deprotonated ibuprofen molecule at pH values during sorption. Future research should be focused towards materials modification with the aim of improving their sorption properties, but also to the adaptation of experimental conditions to the properties of the pollutant, in order to achieve more effective treatment. Efforts should be made to include pharmaceutical residues on the list of priority substances in water analysis, as there is still no legal regulation specifying the maximum allowable concentrations of pharmaceuticals in natural waters used for water supply. Ultimately, responsible disposal of pharmaceutical products is necessary to prevent long-term effects on the biodiversity of aquatic organisms, as well as the people who depend on these ecosystems
Removal of carbendazim from aqueous solution by sorption on different low-cost sorbents : diploma thesis
No full textU današnje vrijeme, razvijena poljoprivredna proizvodnja predstavlja veliki ekološki problem zbog značajne uporabe pesticida koji ispiranjem iz tla mogu dospjeti u vodne ekosustave. Zbog štetnog djelovanja na žive organizme i ljudsko zdravlje, ostatke pesticida je nužno ukloniti iz voda. Stoga je u ovom radu ispitana mogućnost pročišćavanja vode onečišćene fungicidom karbendazimom (c o =0,992 mg/L) sorpcijom na različitim low-cost sorbensima – prirodnom zeolitu klinoptilolitu, njegovom modificiranom natrijevom obliku, željezovom obliku te sumporom impregniranom obliku, kao i nusproizvodima prerade voća – košticama maslina, trešanja i višanja. Pri danim eksperimentalnim uvjetima, najveći kapacitet (0,064 mg/g) pokazao je natrijev oblik prirodnog zeolita s učinkovitošću uklanjanja od 64,42 %. Međutim, ostatne koncentracije karbendazima bile su u rasponu od 0,353 mg/L do 0,933 mg/L, što je iznad dopuštenih graničnih vrijednosti od 0,5 µg/L za ukupne te 0,1 µg/L za pojedinačne pesticide u vodi za ljudsku potrošnju. Stoga, kako bi se postigla zadovoljavajuća obrada pesticidima onečišćenih voda, buduća istraživanja treba usmjeriti na odgovarajuću modifikaciju postojećih materijala kao i na kombinaciju više metoda obrade, uključujući adsorpciju, napredne oksidacijske procese ili membranske tehnike.Nowadays, developed agricultural production represents a significant ecological problem due to the extensive use of pesticides, which can leach from soil into aquatic ecosystems. Due to their harmful effects on living organisms and human health, it is necessary to remove pesticide residues from water. Therefore, this study examined the treatment of water contaminated with the fungicide carbendazim (c o =0.992 mg/L) through sorption on various low-cost sorbents – natural zeolite clinoptilolite, its modified sodium form, iron form, and sulphur-impregnated form, as well as fruit processing by-products – olive, cherry, and sour cherry pits. Under the given experimental conditions, the sodium form of natural zeolite showed the highest capacity (0.064 mg/g) with a removal efficiency of 64.42%. However, the residual concentrations of carbendazim ranged from 0.353 mg/L to 0.933 mg/L, which is above the permissible limit values of 0.5 µg/L for total and 0.1 µg/L for individual pesticides in water for human consumption. Therefore, in order to achieve a satisfactory treatment of pesticide-contaminated water, future research should be focused on the appropriate modification of existing materials as well as a combination of several treatment methods, including adsorption, advanced oxidation processes or membrane techniques
Analysis of hybrid process of electrocoagulation with aluminium electrodes, zeolite and ultrasound : bachelor thesis
No full textBudući su otpadne vode iz procesa kompostiranja složenog sastava, sve je veća potreba za razvojem hibridnih procesa njihove obrade. U ovom radu provedeno je ispitivanje hibridnih procesa obrade na bazi elektrokoagulacije sa aluminijevim elektrodama, zeolitom i ultrazvukom. Uspoređeni su hibridni procesi elektrokoagulacije sa sintetskim zeolitom te hibridni procesi elektrokoagulacije sa sintetskim zeolitom i ultrazvukom provedeni simultano i dvostupanjski. Analiza učinkovitosti hibridnih procesa provedena je temeljem usporedbe fizikalno-kemijskih pokazatelja praćenih u otopinama, promjene mase anoda i katoda te testa taloživosti suspenzije. Rezultati su pokazali da je hibridni proces elektrokoagulacije sa zeolitom najbolji izbor za obradu otpadne kompostne vode s obzirom na najveće smanjenje kemijske potrošnje kisika (KPK) i mutnoće te dobro taloženje flokula. Međutim, budući je povećana potrošnja elektroda, ekonomičniji odabir bi bio simultano provođenje elektrokoagulacije uz dodatak zeolita i ultrazvuka.As the wastewater from the composting process has a complex composition, there is an increasing need to develop hybrid processes for its treatment. In this work, different hybrid processes based on electrocoagulation with aluminum electrodes, zeolite and ultrasound were investigated. A comparison was made between the hybrid processes of electrocoagulation with synthetic zeolite and the hybrid processes of electrocoagulation with synthetic zeolite and ultrasound, carried out simultaneously and in two stages. The effectiveness of the hybrid processes was analyzed on the basis of the comparison of the physical and chemical indicators monitored in the solutions, the change in the mass of the anodes and cathodes and the suspension settling test. The results showed that the hybrid process of electrocoagulation with zeolite is the best choice for the treatment of compost wastewater, as it reduces the chemical oxygen demand (COD) and turbidity and produces good floc settling. However, as the consumption of electrodes has increased for economic reasons, simultaneous electrocoagulation with zeolite and ultrasound would be a better choice
Removal of Tartrazine Yellow dye from aqueous solution by electrocoagulation : diploma thesis
No full textU radu je promatran je utjecaj gustoće struje (0.008, 0.016 ili 0.024 A/cm 2 ) na učinkovitost uklanjanja Tartrazine Yellow (TY) boje. Vrijeme elektrokoagulacijskog (EK) procesa je variralo u granicama od 10 do 50 min, a početna pH vrijednost onečišćene otopine od 3.0 do 7.0. Tijekom EK procesa dolazi do promjene pH, temperature, električne provodnosti te koncentracije TY boje. Dobiveni rezultati ukazuju na veliku učinkovitost uklanjanja TY boje, koja svih eksperimentalnih uvjeta raste i postiže konstantnu vrijednost. Maksimalna učinkovitost uklanjanja TY boje od 99.39 % postignuta je nakon 37 minuta pri i = 0.024 A/cm 2 i pH vrijednosti 3.0. Tijekom EK procesa sagledavana je potrošnja anodnog materijala koja se povećava s porastom gustoće struje. Izgled anoda nakon provedenog procesa ukazuje na opći oblik korozijskog napada čija intenzivnost ovisi o primijenjenoj struji. Operativni troškova procesa ovise o eksperimentalnim uvjetima te je uočeno da se povećavaju s porastom gustoće struje, a opadaju porastom podešene početne pH vrijednosti TY otopine.In this paper, the current density (0.008, 0.016 or 0.024 A/cm 2 ) on the efficiency of Tartrazine Yellow (TY) dye removal was investigated. The duration of the electrocoagulation (EC) process varied from 10 to 50 minutes and the initial pH of the contaminated solution from 3.0 to 7.0. During the EC process, the pH, temperature, electrical conductivity, and concentration of the TY dye changed. The results show a high efficiency in removing TY dye, which increases and reaches a constant value under all experimental conditions. The maximum TY dye removal efficiency of 99.39% was achieved after 37 minutes at i = 0.024 A/cm 2 and a pH of 3.0. During the EC process, the consumption of the anode material was observed to increase with the increase in current density. The appearance of the anodes after the process indicates a general form of corrosion attack, the intensity of which depends on the applied current. The operating costs of the process depend on the experimental conditions and were observed to increase with the increase in current density and decrease with the increase in the adjusted initial pH of the TY solution
Thermal analysis of polyethylene oxide composite with addition of the magnesium oxide : diploma thesis
No full textU ovom radu istražen je utjecaj dodatka magnezijeva oksida (MgO) na toplinska svojstva i stabilnost kompozita na bazi poli(etilen-oksida) (PEO). Korištenjem diferencijalne pretražne kalorimetrije (DSC) i termogravimetrijske analize (TGA) ispitane su toplinske karakteristike PEO/MgO kompozita. Dodatak MgO snižava karakteristiĉne toplinske prijelaze PEO kompozita, ukljuĉujući temperaturu staklastog prijelaza (T g ), zbog smanjenja kristalnosti. TakoĊer, pogoršava toplinsku stabilnost PEO u kompozitu jer snižava temperaturu poĉetka razgradnje kompozita.This paper investigates the effect of magnesium oxide (MgO) addition on the thermal properties and stability of poly(ethylene oxide) (PEO)-based composites. The thermal characteristics of PEO/MgO composites were examined using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The addition of MgO reduces the characteristic thermal transitions of the PEO composite, including the glass transition temperature (T g ), due to the reduction in crystallinity. Furthermore, it worsens the thermal stability of the PEO composite by lowering the decomposition onset temperature
Glucosinolate profile and spectroscopic analysis of isolated desulfoglucosinolates from croatian wallflower (Erysimum croaticum) : diploma thesis
No full textGlukozinolati su specijalizirani biljni metaboliti usko povezani s porodicom Brassicaceae. Struktura se sastoji od β- D -glukopiranoze i O-sulfatirane (Z)-tiohidroksimatne skupine te promjenjivog bočnog lanca. Djelovanjem enzima mirozinaze nastaju razgradni produkti, poznati po brojnim biološkim aktivnostima, od kojih je najzanimljivije njihovo antikancerogeno djelovanje. U ovom radu određen je glukozinolatni profil hrvatskog šeboja (Erysimum croaticum), endemske biljke s Biokova, korištenjem UHPLC-DAD-MS/MS tehnike. Glukozinolati su izolirani u desulfatiranom obliku pomoću ion- izmjenjivačkih kolona prema metodi ISO 9167-1. Analizom MS2 i UV spektara dobivene su kvalitativne i kvantitativne informacije o glukozinolatnom profilu biljke. Ovaj profil je jedinstven za sve biljne organe i sastoji se od dva glukozinolata: glukorafenina i (3E)-4-(metilsulfanil)but-3-enil-glukozinolat. Cvat sadrži najveću koncentraciju glukozinolata (679,74 µmol/g suhog biljnog materijala), dok stabljika ima najmanju (123,85 µmol/g suhog biljnog materijala). Glukorafenin je dominantan u većini biljnih organa, osim u korijenu. Dva analizirana desulfoglukozinolata imaju dovoljno različito vrijeme zadržavanja što omogućava odvajanje na dvije frakcije koje sadržavaju pojedinačne desulfoglukozinolate. Strukture izoliranih desulfoglukozinolata su potvrđene NMR spektroskopijom.Glucosinolates are specialized plant metabolites closely related to the Brassicaceae family. The structure consists of β- D -glucopyranose and O-sulfated (Z)-thiohydroximate group and a variable side chain. Degradation products are produced by the action of the enzyme myrosinase, and are known for numerous biological activities, with their anticarcinogenic effects being the most interesting. In this study, the glucosinolate profile of Croatian wallflower (Erysimum croaticum), an endemic plant from Biokovo, was determined using UHPLC-DAD-MS/MS technique. Glucosinolates were isolated in desulfated form using ion-exchange columns according to the ISO 9167-1 method. Qualitative and quantitative information about the plant's glucosinolate profile was obtained by analyzing MS2 and UV spectra. This profile is unique for all plant organs and consists of two glucosinolates: glucoraphenin and (3E)-4- (methylsulfinyl)but-3-enyl-glucosinolate. The flower contains the highest concentration of glucosinolates (679.74 µmol/g of dry weight), while the stem has the lowest (123.85 µmol/g of dry weight). Glucoraphenin is dominant in most plant organs, except in the root. The two analyzed desulfoglucosinolates have sufficiently different retention times allowing separation into two fractions containing individual desulfoglucosinolates. The structures of isolated desulfoglucosinolates were confirmed by NMR spectroscopy
Life-cycle assessment of municipal waste management systems in Croatia's leading tourist towns : diploma thesis
No full textHrvatska, popularno turističko odredište, imala je visoku sezonalnost turizma između 2015. i 2021., što je doprinijelo povećanju komunalnog otpada u hrvatskim turističkim gradovima. U ovom radu analizirane su količine komunalnog otpada u pet vodećih hrvatskih turističkih gradova od 2015. do 2021., tj. u Zagrebu, Poreču, Rovinju, Splitu i Dubrovniku te je uočeno da količina prikupljenog komunalnog otpada varira u skladu s promjenom turističkog ekvivalenta stanovništva (TES). Navedeno je izraženije u gradovima s većim vrijednostima TES-a, poput Poreča, Rovinja i Dubrovnika. Također, analiziran je utjecaj na okoliš sustava gospodarenja krutim komunalnim otpadom navedenih gradova u godini s najvećim brojem ostvarenih noćenja turista, tj. u 2019. godini, računalnim programom IWM-EPIC/CSR procjene životnog ciklusa (engl. life-cycle assessment). LCA je pokazala da su sustavi gospodarenja otpadom u Poreču i Rovinju imali manji negativan utjecaj na okoliš u 2019. od onih u većim gradovima poput Zagreba, Splita i Dubrovnika.Croatia, a popular tourist destination, has a high seasonality between 2015 and 2021, which results in increasing municipal waste in Croatian tourist towns. This paper analyzes municipal waste in five major Croatian tourist towns (Zagreb, Poreč, Rovinj, Split, and Dubrovnik) from 2015 to 2021., revealing that the amount of collected municipal waste varies in tandem with the change in tourist population equivalent (TES). This is more prominent in towns with higher TES values, such as Poreč, Rovinj, and Dubrovnik. In addition, the IWM-EPIC/CSR life-cycle assessment software was used to examine the environmental impact of the indicated cities' solid municipal waste management systems in the year with the highest number of tourist overnight stays, namely 2019. The LCA showed that waste management systems in Poreč and Rovinj had a lower negative impact on the environment in 2019 than those in larger towns like Zagreb, Split, and Dubrovnik
Influence of storage conditions on the quality of virgin olive oils : diploma thesis
No full textDjevičansko maslinovo ulje najviše razine kvalitete je iznimno vrijedan proizvod ploda masline zbog brojnih zdravstvenih koristi kao i poželjnih senzorskih svojstava pa mu je cijena znatno viša u odnosu na cijenu drugih biljnih ulja. Kako bi se izbjegle potencijalne mogućnosti patvorenja drugim uljima ova ulja su predmet stalnih provjera kvalitete i autentičnosti. Kvaliteta djevičanskih maslinovih ulja ovisi o mnogo čimbenika, a jedan od važnijih je način i uvjeti skladištenja. Da bi se usporile promjene u fizikalno-kemijskom sastavu i senzorskim svojstvima ulja važan je ispravan način čuvanja (skladištenja). U prvom redu ulje treba čuvati od negativnih utjecaja svjetla, temperature, kisika i vlage. Cilj ovog diplomskog rada je utvrditi kako različiti uvjeti čuvanja ulja utječu na kvalitetu djevičanskih maslinovih ulja. Analize su provedene na uljima iz maslinika sa dva lokaliteta. Ulja sorti Oblica i Leccino iz jednog maslinika te ulja sorti Oblica i Levantinka iz drugog maslinika. Ulja su čuvana na dva načina; u tamnoj staklenoj boci, na tamnom mjestu pri sobnoj temperaturi te u inox spremniku s natprostorom dušika odnosno bez natprostora dušika. Ispitivanja kvalitete provodila su se tromjesečno kroz period od 18 mjeseci. Rezultati analiza pokazali su kako protekom vremena skladištenja rastu vrijednosti fizikalno-kemijskih pokazatelja kvalitete, smanjuju se intenziteti pozitivnih osjetilnih svojstava te opada sadržaj ukupnih fenolnih spojeva u uljima.Virgin olive oil of the highest level of quality is an extremely valuable product of olive fruit due to numerous health benefits as well as desirable sensory properties, so its price is significantly higher than the price of other vegetable oils. In order to avoid the potential adulterations with other seed oils, these oils are the subject of constant quality and authentication check. The quality of the virgin olive oils depends on many factors, and one of the most important is storage conditions. In order to slow down changes in the physical- chemical composition and sensory properties of oil, the propriate way of storage is important. In the first place, the oil should be kept from the negative effects of light, temperature, oxygen and humidity. The aim of this diploma thesis is to determine how different conditions of storage affect the quality of virgin olive oils. The analyses were carried out on oils from olive orchards from the two localities. Oils from the Oblica and Leccino variety from same olive orchard and oils from Oblica and Levantinka variety from other olive orchard. The oils were storaged in two ways; in a dark glass bottle in dark place at room temperature and in the stainless steel tank with nitrogen or no nitrogen above. Quality analyzes were conducted every 3 months over a period of 18 months. The results of the analyses have shown that as the storage time progresses, the values of physico-chemical quality indicators increase, the intensities of positive sensory properties decrease and the content of total phenolic compounds in oils decreases
SELECTION OF OPTIMAL PRECIPITATING AGENT FOR ZINC REMOVAL FROM AQUEOUS SOLUTIONS BY CHEMICAL PRECIPITATION : bachelor thesis
No full textIndustrijskom revolucijom započelo je intenzivnije onečišćenje okoliša različitim štetnim tvarima. Značajnu ulogu u onečišćenju prirodnih voda imaju industrijske otpadne vode, koje su jedan od glavnih izvora emisije teških metala u okoliš. S ekološkog i zdravstvenog stajališta važno je prije emisije industrijske otpadne vode adekvatno pročistiti. Najčešće metode obrade takvih voda su kemijsko taloženje, ionska izmjena, adsorpcija i membranske tehnike. U ovome radu provedeno je uklanjanje cinka iz vodenih otopina koncentracija 100 mg/L i 500 mg/L metodom kemijskog taloženja uz prethodnu neutralizaciju do pH područja 7,0-7,5; 8,0-8,5 i 9,0-9,5 različitim taložnim sredstvima - suspenzijama vapnenog mlijeka pripravljenim iz tehničkog vapna različite čistoće te natrijevim hidroksidom. Uklanjanje cinka uspješno je provedeno uz neutralizaciju u pH području 9,0-9,5 korištenjem svih ispitanih taložnih sredstava, s ostatnom koncentracijom cinka ispod maksimalno dopuštene. Uzimajući u obzir učinkovitost taložnog sredstva, cijenu te količinu nastalog otpadnog mulja, optimalno taložno sredstvo za ispitane eksperimentalne uvjete je suspenzija vapnenog mlijeka pripravljena iz tehničkog vapna čistoće 94,3%.With the industrial revolution, more intensive environment pollution with various harmful substances began. Industrial wastewaters, as one of the main sources of heavy metal emissions into the environment, play a significant role in the pollution of natural waters. From an ecological and health point of view, it is important to adequately purify industrial wastewaters before emission. The most common methods of their treatment are chemical precipitation, ion exchange, adsorption and membrane techniques. In this bachelor thesis, the removal of zinc from aqueous solutions containing 100 mg Zn/L and 500 mg Zn/L was carried out by chemical precipitation with prior neutralization to a pH ranges of 7.0-7.5; 8.0-8.5 and 9.0-9.5, respectively, using different precipitating agents - milk of lime prepared from technical lime of different purity and sodium hydroxide. Zinc removal was successfully performed with neutralization in the pH range of 9.0-9.5 using all precipitating agents tested, with the residual zinc concentration below the maximum allowed. Taking into account the effectiveness of the precipitating agent, costs and the amount of waste sludge generated, the optimal precipitating agent for the tested experimental conditions is milk of lime prepared from the technical lime with 94.3% of purity