41 research outputs found
ORGANSKA MIKROONEÄIÅ ÄENJA POPLAVNOG RIJEÄNOG SEDIMENTA RIJEKA SAVE I BOSNE NAKON KATASTROFALNE POPLAVE U PROLJEÄE 2014
The aim of this study was to determine the presence and nature of organic micropollutants in river overbank and floodplain sediments from the border between Croatia and Bosnia and Herzegovina following the catastrophic 2014 flood. The study involved ten sediment samples from the Sava and Bosna river floodplain. The volatile aromatic compounds, i.e. benzene, toluene, ethylbenzene, and xylene (BTEX), together with alkanes (the linear straight-chain alkanes and the branched alkanes, C10-C28) were determined by GC-MS method. Their estimated amounts were from <0.054 to 3.886 mg/kg, and from 10 to 406 mg/kg, respectively. Hereby, they were below allowed concentration limits for total hydrocarbons in agricultural soil of lighter texture (sandy/loam soil) which is 1000 mg/kg, whilst for heavier clayey soils the limit is 2000 mg/kg. However, their presence in itself in the investigated sediment indicates oil spill problems, whilst their possible sources might be local oil refining industries located in the local cities of Brod and ModriÄa in Bosnia and Herzegovina.Cilj ovog istraživanja bio je utvrditi prisutnost i prirodu organskih mikrooneÄiÅ”Äenja u poplavnom rijeÄnom sedimentu s manjeg podruÄja uz granicu izmeÄu Hrvatske i Bosne i Hercegovine neposredno nakon katastrofalne poplave u proljeÄe 2014. Istraživanje je obavljeno na deset uzoraka poplavnog sedimenta rijeka Save i Bosne. Hlapivi aromatski spojevi, tj. benzen, toluen, etilbenzen, i ksilen (BTEX), te alkani (ravnolanÄani i razgranati od C10 do C28) odreÄeni su pomoÄu GC-MS metode. UnatoÄ tome Å”to su njihove procijenjene vrijednosti bile ispod dopuÅ”tenih koncentracija, potrebno je uzeti u obzir uÄinak njihova razrjeÄenja u uvjetima goleme koliÄine vode. BuduÄi da te tvari ukazuju na problem izlijevanja mineralnih ulja, moguÄi izvori mikroorganskih oneÄiÅ”Äenja zabilježenih u sedimentu vjerojatno su rafinerije nafte u gradovima Brod i ModriÄa u sjeverozapadnom dijelu Bosne i Hercegovine
GoruÄi problem klimatskih promjena na Zemlji
OneÄiÅ”Äenje atmosfere i globalno zagrijavanje viÅ”e nije marginalna tema. Treba odati ogromno priznanje pojedincima diljem svijeta koji se bore s posljedicama ovog viÅ”e nego ozbiljnog problema. Vijesti o buduÄim klimatskim trendovima sve viÅ”e obiluju uskliÄnicima, a sve manje upitnicima. Obimna viÅ”egodiÅ”nja istraživanja kemizma atmosfere ukazuju na svu složenost i nepredvidivost sustava, a nebrojeni izvori njezina oneÄiÅ”Äenja predstavljaju samo dio ukupne slike. Najnovija znanstvena izvjeÅ”Äa prožeta su zebnjom da je ljudska civilizacija dosegla rub ponora zbog svog sebiÄnog i nepromiÅ”ljenog ponaÅ”anja prema Zemlji. Neupitna je potreba za hitnom i neodgodivom suradnjom svih dionika s ciljem rjeÅ”avanja, ili barem ublažavanja ovog goruÄeg problema. Svrha ovog rada je dvojaka: 1/ objasniti osnovni mehanizam uÄinka staklenika te 2/ predstaviti najveÄe izvore oneÄiÅ”Äenja atmosfere (s naglaskom na toplinskom otpadu, eng. heat waste, povezanom s potroÅ”njom fosilnih goriva), ali i neke manje poznate, no ne manje važne probleme, npr. kako digitalna revolucija utjeÄe na stanje okoliÅ”a te kako neodgovorno zbrinjavanje otpada utjeÄe na klimatske promjene. Cilj rada je potaknuti na promiÅ”ljanje o razmjerima ovdje izloženih problema oneÄiÅ”Äenja okoliÅ”a te hitnosti njihova rjeÅ”avanja, ne sutra, nego veÄ danas, jer znanost zna da je dragocjeno vrijeme prokockano
GoruÄi problem klimatskih promjena na Zemlji
OneÄiÅ”Äenje atmosfere i globalno zagrijavanje viÅ”e nije marginalna tema. Treba odati ogromno priznanje pojedincima diljem svijeta koji se bore s posljedicama ovog viÅ”e nego ozbiljnog problema. Vijesti o buduÄim klimatskim trendovima sve viÅ”e obiluju uskliÄnicima, a sve manje upitnicima. Obimna viÅ”egodiÅ”nja istraživanja kemizma atmosfere ukazuju na svu složenost i nepredvidivost sustava, a nebrojeni izvori njezina oneÄiÅ”Äenja predstavljaju samo dio ukupne slike. Najnovija znanstvena izvjeÅ”Äa prožeta su zebnjom da je ljudska civilizacija dosegla rub ponora zbog svog sebiÄnog i nepromiÅ”ljenog ponaÅ”anja prema Zemlji. Neupitna je potreba za hitnom i neodgodivom suradnjom svih dionika s ciljem rjeÅ”avanja, ili barem ublažavanja ovog goruÄeg problema. Svrha ovog rada je dvojaka: 1/ objasniti osnovni mehanizam uÄinka staklenika te 2/ predstaviti najveÄe izvore oneÄiÅ”Äenja atmosfere (s naglaskom na toplinskom otpadu, eng. heat waste, povezanom s potroÅ”njom fosilnih goriva), ali i neke manje poznate, no ne manje važne probleme, npr. kako digitalna revolucija utjeÄe na stanje okoliÅ”a te kako neodgovorno zbrinjavanje otpada utjeÄe na klimatske promjene. Cilj rada je potaknuti na promiÅ”ljanje o razmjerima ovdje izloženih problema oneÄiÅ”Äenja okoliÅ”a te hitnosti njihova rjeÅ”avanja, ne sutra, nego veÄ danas, jer znanost zna da je dragocjeno vrijeme prokockano
Dynamics and thermodynamics of a nickel uptake from a water system onto the blast furnace sludg
This study describes the use of blast furnace sludge (BFS) for the removal of toxic Ni(II) ions from a water system.Blast furnace sludge is a by-product and a waste material of the steelmaking industry. Chemical and mineralogical characteristics of BFS are determined by Proton Induced X-ray Emission and X-ray Diffraction methods.The surface area properties are determined by the Brunauer-Emmett-Teller method. The adsorption is investigated in a batch adsorption system in view of its kinetics and thermodynamics. The kinetic experiments show that the adsorption process follows a pseudo-second order model. The adsorption mechanism is investigated by intra-particle diffusion and Boyd-Reichenberg kinetic models. Thermodynamic parameters (activation free energy change, activation enthalpy change, and activation entropy change) reveal that the adsorption of Ni(II) on BFS is spontaneous, exothermic, and chemical in nature. The results suggest that BFS is an inexpensive and efficient adsorbent for the removal of Ni(II) ions from aqueous solutions
Removal of Cr(VI) from aqueous solution by a commercial carbon black
Hexavalent chromium is classified as a human carcinogen of high carcinogenic hazard according to the US EPA. Therefore, batch adsorption experiments aiming at Cr(VI) removal from an aqueous solution were carried out using a commercial carbon black (CB) as an adsorbent. The CB wascharacterized by the BrunauerāEmmettā Teller and BarrettāJoynerāHalenda, scanning electron microscopy with energy dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy methods. Various parameters were tested, including adsorbent dose, solution pH, contact time, initial metal concentration, and temperature, so as to determine their relation to the adsorption yield. The results showed that an initial solution of pH 2.4 was most favorable for the Cr(VI) removal. The equilibrium data were analyzed by the Freundlich, Langmuir, and Temkin isotherm models. The equilibrium data best fitted according to the Freundlich isotherm model. The CB maximum adsorption capacity was found at 33.22 mg/g, thus proved to be promisingly efficient in comparison to other low-cost adsorbents. The thermodynamic parameters yielded by this study showed that theCr(VI) adsorption on the CB was the spontaneous exothermic process
KLJUÄNA ULOGA SIROVINA NA BAZI UGLJIKA U TEHNOLOGIJI 21. STOLJEÄA: INDIJSKA ISKUSTVA
Coal is a vital carbon-based raw material which is used in the production of various advanced nanomaterials. This particularly holds true for the relevant research and development trends in India. New more environmentally friendly processes are under development with respect to metallurgical coke making and quality enhancement of high-ash Indian coal. Compared with chemical and physical methods, beneficiation of high-ash coal and its combustion by-products with organic liquids (various natural oils) are much more superior in terms of costs, efficiency, and environmental implications. Nanodiamonds have emerged as a key platform for nanoscience and nanotechnology developments. Indian scientists have applied eco-friendly and cost-effective ultrasonic assisted wet-chemical method to low-quality NE Indian coal and the resulting nanodiamond particles could have a wide range of applications in the field of microelectronics, optoelectronics, and biosensing. Also, Indian scientists have been working on ultrasonic-assisted chemical synthesis of activated carbon from low-quality subbituminous coal and its preliminary evaluation towards supercapacitor applications. This article shows that coal is a versatile and valuable raw material which should be saved for future generations at all costs.Ugljen je vitalna sirovina na bazi ugljika koja se koristi u proizvodnji raznih naprednih nanomaterijala. To posebno vrijedi za relevantne trendove istraživanja i razvoja u Indiji. U razvoju su novi ekoloÅ”ki prihvatljiviji procesi za proizvodnju metalurÅ”koga koksa i poboljÅ”anje kvalitete indijskoga ugljena s visokim pepelom. U usporedbi s kemijskim i fiziÄkim metodama, obogaÄivanje ugljena s visokim sadržajem pepela i nusproizvoda njegova izgaranja organskim tekuÄinama (razna prirodna ulja) mnogo je superiornije u smislu troÅ”kova, uÄinkovitosti i ekoloÅ”kih implikacija. Nanodijamanti su se pojavili kao kljuÄna platforma za razvoj nanoznanosti i nanotehnologije. Indijski znanstvenici primijenili su ekoloÅ”ki prihvatljivu i isplativu ultrazvuÄno potpomognutu mokru kemijsku metodu na nekvalitetni indijski ugljen, a dobivene Äestice nanodijamanta mogle bi imati Å”irok raspon primjena u podruÄju mikroelektronike, optoelektronike i biosenzora. TakoÄer, indijski znanstvenici rade na ultrazvuÄnoj kemijskoj sintezi aktivnoga ugljena iz subbituminoznoga ugljena niske kvalitete i njegovoj preliminarnoj procjeni u svrhe superkondenzatora. Ovaj Älanak pokazuje da je ugljen svestrana i vrijedna sirovina koju pod svaku cijenu treba Äuvati za buduÄe generacije
BiotehnoloŔke metode bioremedijacije selena iz raznih dijelova okoliŔa: pregled
Selenium (Se) is an essential element for human health in trace amounts but is harmful in excess. Most plants contain a fairly low Se and crop Se supplements ensure adequate levels for human nutritional needs. Food is the primary source of Se for humans and due to differences in eating habits, its intake varies considerably. In the human body, selenium deficiency can lead to diseases of the endocrine, musculoskeletal, cardiovascular, reproductive, nervous and immune systems. Selenium is an important ingredient in glutathione peroxidase, the main cellular antioxidant enzyme, which can convert free radicals into peroxides, while vitamin E removes free radicals and neutralizes their potentially harmful effects. Excessive amounts of selenium in the human diet are considered toxic, causing liver and kidney damage, blood clotting, heart and liver necrosis, skin lesions, nausea, vomiting, and loss of hair and nails. Semiconducting properties of Se make it of special value for industry. Selenium is a rare element on the planet, and is a non-renewable resource due to its non-efficient and difficult recycling. Except of coal, which is commonly enriched in Se, there are no ores which could be mined for it. Herewith, the world\u27s scarce Se resources need a careful management, monitoring, recycling, and stockpiling for future generations. The first part of this review outlines selenium concentrations in soil, water, and plants in terms of essential and toxicological effects on animals and humans, while the second part briefly overviews novel biotechnological methods of bioremediation of environmental selenium.Niske koncentracije selenija (Se) bitne su za ljudsko zdravlje, ali one prekomjerne su Å”tetne. VeÄina biljaka sadrži priliÄno nizak Se, a njegovi dodatci usjevima osiguravaju odgovarajuÄe razine Se za ljudske prehrambene potrebe. Hrana je primarni izvor Se za ljude, a zbog razlika u prehrambenim navikama, njegov unos znatno varira. U ljudskom tijelu nedostatak selenija može dovesti do bolesti endokrinog, miÅ”iÄno-koÅ”tanog, kardiovaskularnog, reproduktivnog, živÄanog i imunoloÅ”kog sustava. Selenij je važan sastojak glutation peroksidaze, glavnog staniÄnog antioksidativnog enzima, koji može pretvoriti slobodne radikale u perokside, dok vitamin E uklanja slobodne radikale i neutralizira njihovo potencijalno Å”tetno djelovanje. Pretjerane koliÄine selenija u ljudskoj prehrani smatraju se toksiÄnima, uzrokujuÄi oÅ”teÄenje jetre i bubrega, zgruÅ”avanje krvi, nekrozu srca i jetre, kožne lezije, muÄninu, povraÄanje te gubitak kose i noktiju. PoluvodiÄka svojstva selenija Äine ga posebno vrijednim u industriji. Selenij je rijedak element na planetu Zemlji te je neobnovljiv resurs zbog neuÄinkovitog i teÅ”kog recikliranja. Osim ugljena, koji je obiÄno obogaÄen selenijem, orudnjenja selenija ne postoje. Stoga je oskudnim svjetskim resursima Se potrebno pažljivo upravljati, pratiti, oporabiti i skladiÅ”titi za buduÄe generacije. U prvom dijelu ovog preglednog Älanka prikazane su koncentracije selenija u tlu, vodi i biljkama u kontekstu esencijalnih i toksikoloÅ”kih uÄinaka na životinje i ljude, dok su u drugom dijelu ukratko prikazane inovativne biotehnoloÅ”ke metode bioremedijacije selenija iz okoliÅ”a
POVIÅ ENE RAZINE OPASNIH ELEMENATA U TRAGOVIMA (CD, CU, PB, SE, ZN) U TKIVIMA PTICA U KONTEKSTU RAÅ KIM UGLJENOM ONEÄIÅ ÄENA OKOLIÅ A
The mining and burning of Croatian RaÅ”a coal had resulted in release of various contaminants into the local environment. They have remained in the local soil, water, and plants, and became available to animals through their consumption. In this study, tissue samples from a total of 12 birds from the RaÅ”a area and 8 birds from a control area were subjected to multi-element analysis (Al, V, Cr, Mn, Fe, Co, Cu, Zn, As, Se, Mo, Cd, Pb) by ICP-MS. The obtained results showed increased Se and Cd concentrations in some bird tissue samples compared to the control area. The highest concentrations of Cu, Zn, and Se were found in the liver, while the highest concentrations of Cd and Pb were found in the kidneys. Although some hazardous trace elements were elevated in the tissues of game species, the risk of consuming meat and offal of such species has been found to be very low.Rudarske i industrijske aktivnosti povezane s raÅ”kim ugljenom rezultirale su ispuÅ”tanjem raznih oneÄiÅ”ÄujuÄih tvari u lokalni okoliÅ”. Te tvari i dalje su prisutne u lokalnome tlu, vodi i biljkama te su dostupne životinjama unosom hrane. U ovome istraživanju uzorci tkiva ukupno 12 ptica iz podruÄja RaÅ”e te 8 ptica iz kontrolnoga podruÄja podvrgnuti su multielementnoj (Al, V, Cr, Mn, Fe, Co, Cu, Zn, As, Se, Mo, Cd, Pb) analizi s pomoÄu metode ICP-MS. Dobiveni rezultati pokazali su poviÅ”ene koncentracije Se i Cd u nekim uzorcima tkiva ptica u usporedbi s kontrolnim podruÄjem. NajveÄe koncentracije Cu, Zn i Se naÄene su u uzorcima jetre, dok su najviÅ”e koncentracije Cd i Pb naÄene u bubrezima. Iako su neki opasni elementi u tragovima poviÅ”eni u tkivima prikupljenih divljih ptica, analizom podataka utvrÄeno je da je rizik od prehrambena unosa (meso i iznutrice) tih vrsta vrlo nizak
COMPARATIVE REVIEW OF CROATIAN AND INDIAN AIR POLLUTION STUDIES WITH EMPHASIS ON POLLUTANTS DERIVED BY COAL COMBUSTION
Zdravlje ljudi, okoliÅ” i klima pod velikim su utjecajem složenih interakcija oneÄiÅ”ÄujuÄih tvari u atmosferi. Gotovo sve ljudske aktivnosti uzrokuju ispuÅ”tanje oneÄiÅ”ÄujuÄih tvari u zrak. Njihovo razumijevanje i kvantifikacija prvi je korak prema kontroli i ublažavanju oneÄiÅ”Äenja zraka. OpÄi cilj ovoga rada jest prikaz rezultata odabranih hrvatskih i indijskih znanstvenih radova koji se bave oneÄiÅ”Äenjem zraka, posebice onih s naglaskom na sumpor i aerosole povezane s elektranama na ugljen. Dvije zemlje u osnovi se razlikuju s obzirom na njihovu veliÄinu, zemljopisna obilježja, povijest, gospodarstvo i industrijski potencijal. MeÄutim, obje zemlje imaju odreÄene veze s pridobivanjem fosilnih goriva i njihovom uporabom u elektranama i industriji veÄ desetljeÄima. Prikazani su razliÄiti znanstveni pristupi u istraživanjima te državne politike u legislativi oneÄiÅ”Äenja zraka.Human health, the environment, and climate are being profoundly aff ected by complex pollutant interactions in the atmosphere. Almost all human activities cause the emissions of air pollutants. Their understanding and quantifi cation is the fi rst step towards the control and mitigation of air pollution. The general aim of this paper is to summarise the fi ndings of selected Croatian and Indian papers addressing air pollution, particularly those focusing on sulphur and aerosols associated with coal-fi red power plants. The two countries are essentially diff erent regarding their size, geography, history, economy, industrial potential, to name but a few. However, they both have had certain relations to the fossil fuel extraction and its usage in power stations and industry for decades. Various research approaches are presented, together with a brief outline of national air pollution policies