Removal of toxic ions from aqueous solutions using modified cellulose-based adsorbents

Predmet istraživanja ove doktorske disertacije je modifikacija celuloznih materijala kao adsorbenata za efikasno uklanjanje toksičnih jona iz vodenih rastvora. Modifikacija površine celuloze i prisustvo funkcionalnih grupa sa višim nivoom afiniteta prema toksičnim jonima veoma su važni za unapređenje adsorpcionih svojstava. U okviru ovog rada dobijena su dva različita tipa adsorbenta na bazi celuloze koji su odgovarajućim tehnikama formirani u obliku membrane. Prvi tip membrana je na bazi celuloze modifikovane magnetitom, dok su drugi tip bio-membrane na bazi modifikovane celuloze, lignina i taninske kiseline. U prvom slučaju, primenjena je optimizovana metoda za izradu magnetit (MG) modifikovane celulozne membrane (Cell-MG hibridne membrane) na bazi amino silanom funkcionalizovanog otpadnog celuloznog vlakna (Cell-NH2) i dijatomejske zemlje (D-APTES), kao i Cell-NH2 modifikovane dianhidridom dietilentriamin-pentasirćetne kiseline (Cell-DTPA). Drugi tip membrane dobijen je na osnovu dve optimizovane metode, zasnovane na reaktivnosti između amino grupa celuloznih vlakana (Cell), modifikovanih u prvom koraku sa 3-(karbometoksi) propionil-hloridom (CPC) i dietilentriaminom u drugom koraku (Cell-DETA), sa epoksi grupama Cell vlakana modifikovanih 3-glicidoksipropiltrimetoksi silanom (Cell-Glymo) i lignina modifikovanog epihlorohidrinom (EL). Taninska kiselina korišćena je kao dodatni umreživač. Dobijene bioobnovljive membrane označene su kao Cell-EL i Cell-EL-TA. Celulozna vlakna, funkcionalizovani materijali i membrane okarakterisani su određivanjem mehaničkih svojstava, termogravimetrijskom analizom, infracrvenom spektroskopijom sa Furijeovom transformacijom, Ramanovom spektroskopijom, rendgenskom difrakcionom analizom, skenirajućom elektronskom mikroskopijom sa emisijom polja i softverskom analizom slike. Određena je poroznost membrane i veličina pora, ravnotežni stepen bubrenja, tačka nultog naelektrisanja (pHpzc), sadržaj amino grupa, kiselinski i epoksidni broj. Metoda odzivnih površina primenjena je kako bi se racionalizovao broj eksperimenata povezanih sa sintezama Cell-MG hibrid, Cell-EL i Cell-EL-TA membrana. Ista metoda primenjena je za optimizaciju eksperimenata povezanih sa adsorpcijom teških metala u protočnom sistemu upotrebom Cell-MG hibrid membrane. Uticaj pH vrednosti, kontaktnog vremena, temperature, doze adsorbenta i početne koncentracije zagađujućih supstanci na adsorpciju i kinetiku proučen je u šaržnom, dok je uticaj početne koncentracije i brzine protoka proučen u protočnom sistemu. Izračunati maksimalni adsorpcioni kapacitet Cell-MG hibrid membrane u uklanjanju nikla, olova, hroma(VI) i arsena(V) primenom Lengmirovog modela iznosio je 88,2, 100,7, 95,8 i 78,2 mg·g-1. Primenom Lengmirovog modela izračunate su sledeće vrednosti kapaciteta: 53,9, 99,9, 97,8 i 63,5, 115,8, 127,5 mg·g-1 za nikl, olovo i hrom(VI), redom, koristeći Cell- EL, odnosno Cell-EL-TA. Termodinamički adsorpcioni parametri za Cell-MG hibrid, Cell-EL i Cell-EL-TA membrane ukazali su na spontane i endotermne procese. Kinetika adsorpcije najbolje se može opisati modelom pseudo-drugog reda, dok rezultati dobijeni primenom Veber-Morisovog modela ukazuju da unutarčestična difuzija kontroliše ukupnu brzinu procesa adsorpcije. Velika pažnja posvećena je unapređenju efikasnosti regeneracije sa ciljem povećanja perioda eksploatacije, pa je stoga izvršena optimizacija regeneracije membrana u odnosu na parametre desorpcije kao što su tip regeneratora, koncentracija i vreme rada. Osim moguće višestruke upotrebe membrana u adsorpciono-desorpcionim ciklusima, da bi otpadna voda iz ciklusa adsorpcije/desorpcije dostigla fizičko-hemijska svojstva koja odgovaraju propisanim vrednostima, primenjen je tretman efluenta precipitacijom. Razvoj efikasne tehnologije regeneracije obezbedio je adsorbent visokih kapaciteta, primenjiv u procesima prečišćavanja voda. Eksperiment određivanja toksičnih karakteristika adsorbenta (Cell-EL i Cell-EL-TA) nakon korišćenja (TCLP test) izveden je sa ciljem potvrde validnosti upotrebe membrana u adsorpciono-desorpcionim ciklusima i njihovog sigurnog odlaganja na deponije. Rezultati TCLP testa kao glavni kriterijumi za manipulaciju membranom i za njenu moguću primenu u uklanjanju toksičnih zagađujućih supstanci, dokazali su na osnovu utvrđenog sadržaja metala u membranama, da se istrošeni adsorbent može sigurno odložiti kao ekološki prihvatljiv materijal. Na ovaj način su rešena glavna pitanja odlaganja iskorišćenih membrana, usled biorazgradivosti upotrebljene membrane, efikasnosti desorpcije i razvoja tehnologije za tretman efluenta uz bezbedno odlaganje zaostalih nusproizvoda. Kako bi se opisala veza između performansi adsorpcije i doprinosa nespecifičnih i specifičnih interakcija između adsorbata i Cell-MG hibrid membrane, ispitan je kapacitet uklanjanja četiri boje, pri čemu su dobijeni rezultati detaljno analizirani primenom teorije funkcionala gustine (DFT) zajedno sa proračunima molekulskog elektrostatičkog potencijala i polja molekulskih interakcija. Značajan doprinos disertaciji ostvaren je poluempirijskim kvantno-hemijskim propračunima koji su pomogli u analizi nespecifičnih i specifičnih interakcija između Cell-EL i Cell-EL-TA adsorbenta i adsorbata i njihovom doprinosu ukupnom mehanizmu vezivanja. Adsorpciona studija u protočnom sistemu sprovedena je da bi se razmotrila moguća primena Cell-MG, Cell- EL i Cell-EL-TA membrana u kontinuiranim procesima prečišćavanja voda. Za predviđanje dinamičkog ponašanja membrana u koloni, primenjeni su Bohart-Adamsov, Jun-Nelsonov, Klarkov i Modifikovani model doza-odziv. Podaci dobijeni upotrebom primenjenih modela pokazuju dobro slaganje sa eksperimentalnim rezultatima za sve proučavane parametre procesa, ukazujući na to da su modeli bili pogodni za dizajn kolone sa fiksnim slojem upotrebom Cell-MG hibrid, Cell-EL i Cell-EL-TA membrana. Predstavljeni rezultati pokazali su primetan adsorpcioni učinak ovih membrana u protočnom sistemu sa visokim potencijalom u prečišćavanju voda. U cilju procene performansi dobijene membrane su testirane u šaržnom sistemu korišćenjem model vode napravljene prema podacima nađenim za rudničke otpadne vode. Pokazalo se da dobijene membrane nemaju visoku selektivnost, ali da poseduju visoku efikasnost u uklanjanju katjona i oksianjona iz otpadnih voda. Dobijeni rezultati na laboratorijskom nivou potvrdili su njihovu potencijalnu primenljivost u procesu prečišćavanja otpadnih voda sa visokom koncentracijom zagađujućih supstanci. Poređenjem efikasnosti procesa adsorpcije i maksimalnih adsorpcionih kapaciteta adsorbenata na bazi modifikovane celuloze sa rezultatima objavljenim u literaturi, pokazano je da dobijene membrane imaju unapređenu sposobnost adsorpcije.The research subject of this doctoral dissertation is the modification of cellulose materials as adsorbents for efficient removal of toxic ions from aqueous solutions. Modification of the cellulose surface and the presence of functional groups with a higher level of affinity for toxic ions, are very important for improving the adsorption properties. Within this work, two different types of cellulose-based adsorbents were produced in the form of a membrane by appropriate techniques. The first type of membrane is based on magnetite modified cellulose, while the second type of bio-membrane is based on modified cellulose, with the addition of lignin and tannic acid. An optimized method for the production of magnetite (MG) modified cellulose membrane (Cell-MG hybrid membrane), based on amino-silane functionalized waste cellulose fiber (Cell-NH2) and diatomaceous earth (D-APTES) was applied, as well as Cell- NH2 modified with diethylenetriaminepentaacetic acid dianhydride (Cell-DTPA). The second type of membrane was obtained by two optimized methods, based on reactivity between amino groups of cellulose fibers (Cell), modified in the first step with 3-(carbomethoxy)propionyl chloride (CPC) and diethylenetriamine in the second step (Cell-DETA), with epoxy groups of Cell fibres modified with 3-glycidoxypropyltrimethoxy-silane (Cell-Glymo) and epichlorohydrin (EL) modified lignin. Tannic acid was used as an additional crosslinker. The obtained biodegradable membranes were marked as Cell-EL and Cell-EL-TA. Cellulose fibers, functionalized materials and membranes were characterized using determination of mechanical properties, Thermogravimetric analysis, Fourier-Transform Infrared Spectroscopy, Raman spectroscopy, X-Ray Difraction, Scanning Electron Microscopy, and with Image analysis software. The membrane porosity and pore size, the equilibrium-swelling ratio, the point of zero charge (pHpzc), the content of amino groups, acid and epoxy number were determined. The Response Surface Method (RSM) was applied to rationalize the number of experiments related to the synthesis of Cell-MG hybrid, Cell-EL, and Cell-EL-TA membranes. The same method was applied to optimize heavy metal adsorption experiments in a flow system using a Cell-MG hybrid membrane. The influence of pH, contact time, temperature, adsorbent dose and initial concentration of pollutants on adsorption and kinetics was studied in a batch, while the influence of initial concentration and the flow rate was studied in a flow system. The calculated maximum adsorption capacity of the Cell-MG hybrid membrane in the removal of nickel, lead, chromium(VI) and arsenic(V) using the Langmuir model was 88.2, 100.7, 95.8 and 78.2 mg·g-1. Using the Langmuir model, the following capacity values were calculated: 53.9, 99.9, 97.8 and 63.5, 115.8, 127.5 mg·g-1 for nickel, lead and chromium (VI), using Cell- EL and Cell-EL-TA, respectively. Thermodynamic adsorption parameters for Cell-MG hybrid, Cell-EL and Cell-EL-TA membranes indicated spontaneous and endothermic processes. The adsorption kinetics can best be described by a pseudo-second order model, while the results obtained using the Weber-Morris model indicate an intra-particle diffusion as a rate-limiting step. Great attention was paid to improving the regeneration efficiency in order to increase the period of exploitation, and therefore the optimization of membrane regeneration was performed concerning desorption parameters such as regenerator type, concentration and operating time. In addition, to achieve satisfactory reusability of membranes, wastewater from the adsorption/desorption cycle need to reach physicochemical properties corresponding to the prescribed values, hence the effluent treatment by precipitation was applied. The development of efficient regeneration technology has provided a high-capacity adsorbent, applicable in water purification processes. An experiment to determine the toxic properties of the adsorbent (Cell-EL and Cell-EL-TA) after use (TCLP test) was performed to confirm the validity of the membranes used in the adsorption-desorption cycles. The results of the TCLP test, as the main criteria for membrane manipulation and its possible application in the removal of toxic pollutants, based on the determined metal content in the membranes, proved the spent adsorbent can be safely disposed of as environmentally friendly material. Thus, the main issues of biodegradability of the used membrane, efficiency of desorption and development of technology for effluent treatment with safe disposal of residual by-products are solved. To describe the relationship between adsorption performance and the contribution of nonspecific and specific interactions between adsorbate and Cell-MG hybrid membrane, the four-colour removal capacity was examined, along with Density-functional theory (DFT) and calculations of molecular electrostatic potential and molecular interaction fields. A significant contribution to the dissertation was made by semi-empirical quantum-chemical calculations helped in the analysis of nonspecific and specific interactions between Cell-EL and Cell-EL-TA adsorbent and adsorbate and their contribution to the overall binding mechanism. An adsorption study in the flow system was conducted to consider the possible application of Cell-MG, Cell-EL and Cell-EL-TA membranes in a continuous water purification processes. To predict the dynamic behaviour of the membranes in the column, Bohart-Adams, Jun-Nelson, Clark and a Modified dose-response model were applied. The data obtained using the applied models show good agreement with the experimental results for all studied process parameters, indicating that the models were suitable for the design of a fixed-bed column using Cell-MG hybrid, Cell-EL and Cell-EL-TA membranes. The presented results showed a noticeable adsorption effect of these membranes in a flow system with a high application potential in water purification. Additionally, to evaluate the performance, the obtained membranes were tested in a batch system using model water made according to data found for real mining wastewater. It was shown that the produced membranes do not have high selectivity, but they have high efficiency in removing cations and oxyanions from wastewater. The obtained results at the laboratory level confirmed membrane potential applicability in the process of wastewater treatment, with a high concentration of pollutants. Comparison of the efficiency of the adsorption processes and the maximum adsorption capacities of the adsorbents based on modified cellulose with the results published in the literature, showed improved adsorption capacity of the produced membranes

Assessment of Emissions into the Atmosphere from Biogas Cogeneration Plant in Serbia

Biogas je gasna smeša koja nastaje tretmanom otpadnih tokova u procesu anaerobne digestije. Proizvodnja električne energije iz kogeneracionih postrojenja koja koriste biogas je u porastu u Republici Srbiji. U ovom radu je izvršena kvantifikacija emisija (ugljen-dioksida, sumpor-dioksida, oksida azota, metana i čestica) u atmosferu iz tipičnog biogasnog postrojenja u Republici Srbiji, instalisanog kapaciteta od 1 MW. Dobijeni rezultati su pokazali da proizvodnja električne energije iz kogeneracije biogasa predstavlja dobro rešenje u cilju smanjenja emisije gasova sa efektom staklene bašte i racionalne upotrebe prirodnih resursa

Consideration of Energy Flows in the Life Cycle of Energy Production from Biogas

The aim of this paper is to present the energy flows in the life cycle of the biogas cogeneration system, as well as their mutual relations, starting from providing of feedstock materials(corn silage and cow manure), anaerobic digestion, cogeneration up to the digestate as fertilizer on agricultural land. The cogeneration process has been considered according to the performance of the biogas plant located on the Mirotin dairy farm in Vrbas (Serbia). For evaluation of energy flows in this work were used four energy indicators. According to the Life Cycle Energy Assessment approach, results obtained in this study have shown that the biogas cogeneration process has positive energy balances and this process is energy sustainable. The applied approach in this research can be adjusted to any biogas power plant since it complies with the main material and energy balances.Cilj ovog rada je da prikaže tokove energije u životnom ciklusu biogas kogeneracionog sistema, kao i njihove međusobne odnose, počev od obezbeđivanja sirovine (kukuruzna silaža i kravlji stajnjak), anaerobne digestije, kogeneracije, pa do digestata. kao đubrivo na poljoprivrednom zemljištu. Proces kogeneracije je razmatran prema performansama biogas postrojenja koje se nalazi na farmi mleka Mirotin u Vrbasu (Srbija). Za evaluaciju energetskih tokova u ovom radu korišćena su četiri energetska indikatora. Prema LCEA pristupu, rezultati dobijeni u ovoj studiji su pokazali da proces kogeneracije biogasa ima pozitivan energetski bilans i da je ovaj proces energetski održiv. Primenjeni pristup u ovom istraživanju može se prilagoditi bilo kojoj elektrani na biogas jer je u skladu sa osnovnim materijalnim i energetskim bilansima

Biogas tehnologija u funkciji proizvodnje energije

Potreba za smanjenjem upotrebe fosilnih goriva, zbog štetnog uticaja na životnu sredinu i sve veća potražnja za energijom, doveli su do proizvodnje energije iz obnovljivih izvora. Pristup čistoj i obnovljivoj energiji postao je imperativ za društveni napredak. Poboljšanje postojećih resursa biomase u efikasne nosioce energije kao što je biogas iz anaerobne digestije ima potencijal da obezbedi čistu i pouzdanu energiju, uz zaštitu životne sredine, racionalno korišćenje prirodnih resursa i stvaranje novih radnih mesta. Uz smanjenje emisije gasova staklene bašte, biogas poboljšava energetsku sigurnost i, kao obnovljivi izvor energije, omogućava eksploataciju otpadnih tokova. Biogas proizveden u sistemu anaerobne digestije se obično sagoreva u kogeneracionoj jedinici da bi se proizvela toplota, električna energija i energija za hlađenje. Konačno, biogas se može prečistiti u biometan, koristiti kao gorivo u vozilima ili ubrizgati u nacionalne mreže prirodnog gasa. Digestat kao nusproizvod anaerobne digestije je pouzdan materijal za upotrebu kao đubrivo u poljoprivredi. U ovom radu sumirano je korišćenje biogasa za proizvodnju toplotne, električne energije, rashladne energije, kao i goriva sa pregledom postojećih tehnologija za njegovu upotrebu. Takođe, ovaj rad pruža priliku da se razmotri uloga biogasa u budućim energetskim sistemima.The need to reduce the use of fossil fuels, due to the harmful impact on the environment and the growing energy demand, have led to the production of energy from renewable sources. Access to clean and renewable energy has become imperative for social progress. Improving existing biomass resources into efficient energy carriers such as biogas from anaerobic digestion has the potential to provide clean and reliable energy, with environmental protection, rationally using natural resources and generation of new jobs. Along with reducing greenhouse gas emissions, biogas improves energy security and, as a renewable energy source, enables the exploitation of waste streams. Biogas produced in an anaerobic digestion system is usually burned in a cogeneration unit to produce heat, electricity, and cooling energy. Finally, biogas can be purified into biomethane, used as a fuel for vehicles, or injected into national natural gas networks. Digestate as a by-product of anaerobic digestion is a reliable material for use as a fertilizer in agriculture. This paper summarizes the use of biogas for the production of heat, electricity, cooling energy, as well as fuel with an overview of existing technologies for its use. Also, this paper provides an opportunity to consider the role of biogas in future energy systems

Removal of hexavalent chromium Cr(VI) from aqueous solutions using cellulose-magnetite membrane CelMag-M

The industries of leather-tanning, mining and textile dyeing, generate large amounts ofchromium-containing wastewater. Hexavalent Cr(VI) is highly poisonous and extremelymobile in the surface-water and groundwater in a broad pH range and therefore it hasbeen identified as a potentially carcinogenic substance. The aim of the presented workwas to develop cellulose-based membrane functionalized with magnetite, which couldbe used as an efficient adsorbent for the removal of hexavalent chromium Cr(VI) ionsfrom aqueous solutions. Cellulose-based filter (CF) was functionalized with magnetitein three-step process. In the first and second step CF surface was modified usingan ethanolic solution of (3-aminopropyl)triethoxysilane (APTES), anddiethylenetriaminepentaacetic acid dianhydride, respectively. The introduction of aminoand carboxylic groups provided successful precipitation of magnetite in the third step.The obtained cellulose-magnetite membrane (CelMag-M) was characterized by FTIRand SEM analysis. Adsorption of Cr(VI) onto CelMag-M was studied using batchadsorptiontest. Under optimum pH conditions, the maximum experimental adsorptioncapacity of CelMag-M for Cr(VI) was found to be 111.2 mg g–1. The adsorption processwas endothermic, the equilibrium adsorption data could be best fitted to the Langmuiradsorption isotherm model and kinetics was in agreement with the pseudo-second-orderrate equation

Evaluation of commercial bottled water quality from the health aspect

The term bottled water means water packed in a health-correct packaging and available in the market for human consumption. Consumers still have insufficient knowledge of importance of the certain ingredients and their harmful or beneficial effect on the human organism. There is not enough expert information about the harmfulness of certain ingredients in the water, but many countries in the world have adopted legal regulations in which quality parameters of bottled water are standardized (EEC, WHO1, EPA, IBWA, FDA). The race for profit and the lack of necessary quantities of bottled waters moved declarations in to the second plan. The declaration on bottled waters should describe also the physiological characteristics, since the consumption of high-mineral water may lead to adverse effects on the health of consumers, primarily children. In such declared water, missing physiological characteristics of water, redox statuses, and possible consequences on the health, are neglected due to excessive consumption of waters with high mineral content. Due to the increased content of mineral substances and high sodium intake, the allowed daily intake should be declared for water loaded with mineral substances. Redox status of water represents a health factor and it is completely defined by the pH value, redox potential and rH2 factor, parameters which were the subject of this study in this work. The oxide-reduction potential of water, EROX, represents the mixed potential of all present redox pairs and directly affects the behavior of water relative to the agents to which comes into contact2. The results pointed to the necessity of a fuller declaration of bottled water, because in that case bottled water gained in importance and would decrease the consequences of the possible bad effects on health due to excessive consumption of water rich with minerals. Test results demonstrated that our market has a wide range of bottled waters, and that the health aspect can be estimated through the oxidation-reduction properties

Possibility of waste biomass of hops utilisation for adsorption of Ni2+ ions from aqueous solutions

Загађење водених екосистема изазвано никлом представља озбиљну еколошку претњу током последњих неколико деценија и од великог је еколошког значаја. Ова забринутост произилази из чињенице да је никл биоразградив, високотоксичан и да потенцијално може изазвати бројне штетне ефекте по здравље људи. У овом раду испитана је биосорпција јона никла при различитим контактним временима коришћењем отпадне биомасе хмеља. Висока вредност коефицијента корелације од 0,999 указује да кинетика адсорпције прати модел псеудо-другог реда. Хмељ је показао висок потенцијал у уклањању Ni2+ из водених раствора са ефикасношћу до 86%. Коришћење отпадне биомасе хмеља бити ефикасна, економична и еколошки погодна опција за очување животне средине.Nickel pollution of aquatic ecosystems has been a serious environmental threat during the last few decades and is of great environmental importance. This concern stems from the fact that nickel is biodegradable, highly toxic, and can potentially cause numerous adverse effects on human health. In this work, the biosorption of nickel ions at different contact times was investigated using hop biomass waste. The high correlation coefficient value of 0.999 indicates that the adsorption kinetics follows a pseudo-second-order model. Hops showed high potential for Ni2+ removal from aqueous solutions with an efficiency ofup to 86%. The use of waste biomass of hops can be an efficient, economical and ecologically suitable option for the preservation of the environment

Supplementary data for the article: Perendija, J.; Veličković, Z. S.; Cvijetić, I.; Rusmirović, J. D.; Ugrinović, V.; Marinković, A. D.; Onjia, A. Batch and Column Adsorption of Cations, Oxyanions and Dyes on a Magnetite Modified Cellulose-Based Membrane. Cellulose 2020, 27 (14), 8215–8235. https://doi.org/10.1007/s10570-020-03352-x

Supplementary material for: [https://doi.org/10.1007/s10570-020-03352-x]Related to published version: [https://cherry.chem.bg.ac.rs/handle/123456789/4204

The influence of water and packaging quality on bottled water health safety

The term bottled water refers to the water that is packaged in a health-correct packaging and that is available on the market for human consumption. Consumers still have insufficient knowledge of the importance of certain ingredients and their harmful or beneficial effects on the human body. Nowdays there are many legal acts in the world that regulate the quality of bottled water. In order to assess the impact of packaging quality on the quality of bottled water, it is necessary to look at the regulation, both in the field of water and in the field of packaging polymer. The information provided on the declaration is insufficient to see the quality of the bottled water itself, and there is no indication of the potential toxic elements that can migrate from the packaging into the water. Although PET is considered as inert material according certain components that are added to PET production can migrate in the water, that must be regurarly controlled. Declarations of such products must follow the updating and monitoring of potentially toxic parameters in accordance with European and world regulations. The impact of packaging, transport and storage on the change of bottled water quality from the aspect of potentially toxic substances has been shown in many studies in the world, however, studies of this type are rare in our country.Pod pojmom flaširane vode podrazumeva se voda koja se pakuje u zdravstveno ispravnu ambalažu i koja je na tržištu dostupna za ljudsku upotrebu. Kod potrošača postoji još uvek nedovoljna upućenost u značaj pojedinih sastojaka i njihovo štetno ili korisno dejstvo na ljudski organizam a u svetu postoji mnogo zakonskih akata u kojima su normirani parametri kvaliteta flaširane vode. Da bi se ocenio uticaj kvaliteta ambalaže na kvalitet flaširane vode neophodno je istovremeno sagledati regulativu iz obe oblasti. Podaci koji se navode na deklaraciji nedovoljni su za sagledavanje kvaliteta same vode koja se flašira, a nema ni ukazatelja na potencijalno toksične elemente koji mogu migrirati iz ambalaže u vodu. Iako se voda pakuje u PET koji se smatra inertnim materijalom, određene komponente koje se dodaju pri proizvodnji PET materijala mogu da migriraju u vodu koja se prema tome mora redovno kontrolsati. Deklarisanje ovakvih proizvoda mora pratiti ažuriranje i praćenje potencijalno toksičnih parametara u skladu sa evropskom i svetskom regulativom. Uticaj ambalažiranja, transporta i skladištenja na promenu kvaliteta flaširanih voda sa aspekta potencijalno toksičnih supstanci, do sada je već pokazan u mnogim studijama u svetu, ali su retke studije iz ove oblasti u našoj zemlji

Mikrobne gorive ćelije: održiva tehnologija za proizvodnju energije i prečišćavanje otpadnih voda

Energy is the main driver of economic growth and it is of vital significance for the modern socieity survival. Future economic growth is dependent of the long-term availability of energy from the sustainable and ecologicaly accepted sources. Microbial fuel cell (MFC) is a new approach to the wastewater treatment with the simulntanious energy production. MFC is an electrochemical device that uses bacteria to generate electricity from biodegradation of organic substrates. Bacteria obtain the energy required for metabolism by electron transfer from an electron donor, such as glucose or acetate, to an electron acceptor, such as oxygen. The application of a microbial fuel cell for the treatment of wastewater has many advantages: the process is clean, safe noise-free, the emissions are low, and the efficiency is high with direct energy production. The subject of this review paper is a detailed development of microbial fuel cells, working principle, types of used microorganisms, as well as potential application.Energija je osnovni pokretat ekonomskog rasta i od vitalnog je značaja za opstanak modernog društva. Budući ekonomski rast zavisi od dugoročne dostupnosti energije iz izvora koji su pristupatni i ekološki prihvatljivi. Mikrobne gorivne ćelije (MFC - microbial fuel cell) mogu predstavljati potpuno novi pristup u prečišćavanju otpadnih voda uz proizvodnju održive čiste energije. MFC je elektrohemijski uredaj koji koristi bakterije za proizvodnju električne energije iz biorazgradljivih organskih supstrata. Bakterije dobijaju energiju potrebnu za metabolizam prenosorn elektrona sa donora elektrona, kao što su glukoza ili acetat, do akceptor elektrona, kao što je kiseonik. Prednosti korišćenja mikrobne gorinve ćelije u prečišćavanju otpadnih voda su sledeće: čist postupak, bezbedan i bez buke, niske emisije i visoka efikasnost uz direktnu proizvodnju energije. Predmet ovog rada je detaljni pristup u pregledu mikrobnih gorivnih ćelija, principa rada, vrste mikroorganizama kao i njihova potencijalna primena