17 research outputs found
OneÄiÅ”Äenje tla kao posljedica odlaganja neopasnog otpada iz procesa proizvodnje Äelika
Investigated was the soil at an old metallurgical landfill site of CMC Sisak Ltd. which has been exposed to the direct influence of metallurgical nonhazardous waste for many years. Concentrations of heavy metals (Cd, Cr, Cu, Hg Ni, Pb, and Zn) after extraction in aqua regia were determined. Heavy metal concentrations, except Hg, were determined by inductively coupled optical emission spectrometry and inductively coupled plasma mass spectrometry (ICP-OES, ICP-MS). Concentration of Hg was determined by atomic absorption spectrometry.
Our objective was to assess the pollution level according to the potentially unacceptable risk limit levels for industrially used soil prescribed by the Croatian Soil Monitoring Program, and levels permitted by some EU member countries.
The results of heavy metal concentrations in composite samples of landfill soil were also compared with the results obtained from the reference sample taken in the nearby park, outside the battery limits. The obtained results qualify the analysed landfill soil as contaminated with Cu according to the legislation of all observed EU countries, with Cd according to the legislation of Italy, Poland, and Belgium (Wallonia), and with Cr according to the legislation of Finland and Poland. To allow future use of the landfill certain measures of soil treatment will be necessary.Ispitano je tlo starog metalurÅ”kog odlagaliÅ”ta tvornice CMC Sisak d. o. o., koje je dugi niz godina bilo izloženo razliÄitim utjecajima neÅ”tetnog metalurÅ”kog otpada. Sadržaj teÅ”kih metala Cd, Cr, Cu, Hg, Ni, Pb i Zn u tlu odreÄen je u uzorcima tla nakon njihove ekstrakcije metala zlatotopkom. OdreÄivanje sadržaja svih navedenih metala osim žive provedeno je metodom optiÄke emisijske spektrometrije induktivno vezane plazme (ICP-OES), dok je sadržaj žive odreÄen spektrometrijom atomske apsorpcije (AAS) primjenom hidridne tehnike.
Da bi se procijenila razina oneÄiÅ”Äenja tla, napravljena je usporedba rezultata sadržaja teÅ”kih metala u analiziranim uzorcima tla s propisanim vrijednostima za potencijalno neprihvatljiv rizik za tlo upotrebljavano u industriji prema Programu trajnog motrenja tla Republike Hrvatske kao i prema propisanim vrijednostima u nekim zemljama EU. Rezultati odreÄivanja sadržaja teÅ”kih metala u kompozitnim uzorcima tla usporeÄivani su s njihovim koncentracijama u referentnom uzorku tla uzetom s prostora obližnjeg parka, izvan tvorniÄkog kruga. Dobiveni rezultati svrstavaju analizirano tlo s odlagaliÅ”ta kontaminiranim prema propisima svih promatranih zemalja EU-a s bakrom, Italije i Poljske s kadmijem i Belgije (Valonija), Finske i Poljske s kromom. Za buduÄu upotrebu tla u istu svrhu moraju se poduzeti odgovarajuÄe mjere
Electric Arc Furnace as a Source of Emission of Polychlorinated Dibenzo-p-Dioxins and Polychlorinated Dibenzofurans in Perspective of the Council Directive 96/61 EC Concerning Integrated Pollution Prevention and Control
Jedan od vrlo istaknutih dokumenata iz zakonodavstva Europske unije relevantan za podruÄje zaÅ”tite okoliÅ”a koji se odnose na industrijska postrojenja je Direktiva 96/61 EC o cjelovitom sprjeÄavanju i kontroli oneÄiÅ”Äenja (engl.: Integrated Pollution Prevention Control, IPPC). Ta direktiva objedinjuje kontrolu emisija i kompletan uÄinak koje industrija ima na okoliÅ”, Å”to podrazumijeva prepoznavanje svih utjecaja koje pojedini industrijski procesi imaju na okoliÅ” (zrak, voda, tlo, otpad, buka, uporaba sirovina, energetska uÄinkovitost, sprjeÄavanje nezgoda itd.). Direktiva uvodi sustav dodjele "ekoloÅ”kih" dozvola za obavljanje djelatnosti i upravljanje procesima uz uporabu najboljih raspoloživih tehnika (engl.: Best Available Techniques, BAT).
MetalurÅ”ka postrojenja svojim katastrima emisija obuhvaÄaju uz dobro poznata oneÄiÅ”Äenja kao Å”to je praÅ”ina, SO2, NOx, NH3, H2SO4, HCl, HF, HCN, H2S, CO, CO2, CH4, teÅ”ke metale i niz organskih oneÄiÅ”Äenja poput benzena, fenola, policikliÄkih aromatskih ugljikovodika, polikloriranih bifenila, polikloriranih dibenzo-p-dioksina (PCDD) i polikloriranih dibenzofurana (PCDF).
Kako je primjena Direktive IPPC kompleksan postupak koji zahtijeva izobrazbu struÄnog kadra, velika investicijska ulaganja u postojeÄi proces i njegovu modernizaciju, a ponekad Äak i zamjenu, to se i ÄeliÄane, kao potencijalni emiteri iz grupe metalurÅ”kih procesa, trebaju pravodobno pripremiti za obveze koje ih oÄekuju. Nužno je pristupiti analizi propisanih zahtjeva direktive, razmotriti korake koje treba poduzeti uz prethodno utvrÄivanje troÅ”kova i razdoblja potrebnog za usklaÄivanje postojeÄih elektropeÄnih procesa proizvodnje Äelika sa zahtjevima Direktive IPPC.
U radu su prikazani zahtjevi Direktive IPPC koji se odnose na ÄeliÄane, s osvrtom na problem emisije polikloriranih dibenzo-p-dioksina i dibenzofurana, kao i naÄini na koje je moguÄe ispuniti zahtjeve kako bi se osigurali uvjeti sprjeÄavanja i kontrole oneÄiÅ”Äenja prijeko potrebnih za ishoÄenje "ekoloÅ”ke dozvole" za obavljanje djelatnosti proizvodnje elektroÄelika u okviru Europske unije, odnosno u uvjetima stupanja na snagu Direktive IPPC.As the accumulation of PCDDs/Fs in the natural environment poses a great threat, and the pollution of the environment with these highly toxic compounds from various emitters needs to be prevented, many countries have conducted an inventory of industrial sources and their emissions in order to obtain better insight into the share of particular sources in the total emission of PCDDs/Fs and to develop strategies to reduce these emissions.
Metallurgical processes like sintering of iron ore, production of steel and non-ferrous and light metals from scrap material belong to a group of stationary PCDDs/Fs emitters and their share in the total PCDDs/Fs emission into the environment is very significant. The relative significance of particular metallurgical processes varies from country to country, depending on the nature of a particular process, installed capacities and annual output levels.
As the modern approach to observing the environment includes preventive measures, as opposed to corrective post-event measures that were common practice in the past, the owners/operators of metallurgical processes are developing and introducing pollution monitoring and surveillance systems, based on which they take appropriate measures.
One of the frequently applied measures is to build and implement the ISO 14001 environmental management system that very efficiently runs production processes along with maintenance of environmental protection on a daily basis. Since the adoption of the ISO 14001 environmental management system is a voluntary decision to be made by each organization, in 1996 the European Union adopted, for the purpose of environmental protection and pollution prevention, the Directive 96/61 EC or IPPC Directive on Integrated Pollution Prevention and Control (IPPC) requiring from industrial installations, depending on their type and output level, to obtain environmental permits to run production processes using best available techniques, thus maintaining daily care for environmental protection and preservation. This Directive integrates control of emissions and overall impact of industrial installations on the environment, meaning recognition of the entire impact from particular industrial processes on the environment (air, water, soil, waste, noise, use of raw materials, energy efficiency, prevention of accidents, etc.). The IPPC Directive has introduced a system of authorization (environmental permit) that needs to be obtained in order to perform business activities and run processes using the best available techniques (BAT).
Taking into account the harmful impact of PCDDs/Fs on the environment, and their unavoidability in metallurgical processes, a series of methods has been developed for their partial prevention or at least reduction of their concentration in smoke gas discharge, and thus prevent environmental pollution through these very harmful compounds. In order to prevent the occurrence of PCDDs/Fs metallurgical processes often use methods based on the principle of selective catalyst reduction. For removal of the already generated PCDDs/Fs from waste gases methods of thermal decomposition at high temperatures or various sorption, i. e. "dry" and "wet" cleaning techniques are used.
As the implementation of the IPPC Directive is a complex procedure requiring highly educated experts, significant investments into production processes and their modernization, or sometimes
even replacement, steel shops need to timely prepare themselves for the obligations in order to harmonize the existing regulation with the requirements of the IPPC Directive.
The requirements of the Directive have to be studied thoroughly. The required steps have to be carefully thought through, previously identifying the cost and time frame necessary to bring the existing electric arc furnace (EAF) steel production processes into conformance with the requirements of the IPPC Directive.
The paper discusses the requirements of the IPPC Directive that are imposed on the steel business owners/operators, with a special review of the PCDDs/Fs emission. It also presents the ways in which the IPPC Directive requirements concerning these highly toxic pollutants can be fulfilled, ensuring conditions to obtain environmental permits to run this activity once the Directive has entered into force
Importance of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans Emissions from Iron and Steel Production Processes
Razvoj metalurgije i metalurÅ”kih procesa praÄen je duljim ili kraÄim razdobljima intenzivnog oneÄiÅ”Äenja okoliÅ”a, Å”to je uzrokovalo neposredno ili posredno ugrožavanje zdravlja ljudi, pojedinih biljnih i životinjskih vrsta, vodnih sustava, tla, poveÄane erozije materijalnih dobara, kao i niza drugih negativnih uÄinaka druÅ”tvene i ekonomske prirode.
Tako je npr. koncepcija integriranih željezara uvjetovala veliko poveÄanje broja izvora emisija i poveÄanje koncentracije Å”tetnih tvari u okoliÅ”u, a najveÄi oneÄiÅ”ÄivaÄi su oduvijek bili pogoni proizvodnje metalurÅ”kog koksa, postrojenja za aglomeraciju željezne rude, visoke peÄi, ÄeliÄane, ljevaonice i termoenergetska postrojenja.
Brojna fundamentalna znanstvena istraživanja dokazala su Äitav niz negativnih uÄinaka nekontrolirane emisije Å”tetnih tvari iz tih postrojenja. Uz znatne koliÄine uobiÄajenih i dobro poznatih oneÄiÅ”Äenja poput sumporovog (IV) i ugljikovih oksida, fluorovodika, amonijaka, benzena, teÅ”kih metala, fenola, cijanida, ulja i masti, troske, iskoriÅ”tenog vatrostalnog materijala, metalnih strugotina, muljeva, praÅ”ine i ogorina, javljaju se i oneÄiÅ”Äenja u relativno malim koliÄinama Äije dugotrajno djelovanje predstavlja opasnost i od njihovih niskih koncentracija kojima se uvijek ne posveÄuje dužna pozornost.
Tu skupinu oneÄiÅ”Äenja Äine postojana organska oneÄiÅ”Äenja Äiji su predstavnici policikliÄki aromatski ugljikovodici, poliklorirani bifenili, poliklorirani dibenzo-p-dioksini i poliklorirani dibenzofurani. Od svih poznatih oneÄiÅ”Äenja kojima su izvor metalurÅ”ki procesi, do sada su sa stajaliÅ”ta utjecaja emisije oneÄiÅ”Äenja iz metalurÅ”kih procesa u okoliÅ”, najmanje istraženi upravo ti spojevi.
U radu su izraÄunate prosudbe emisija polikloriranih dibenzo-p-dioksina i polikloriranih dibenzofurana u Hrvatskoj u razdoblju od 1960. do 2005. godine. Pri izraÄunu su poslužila iskustava razvijenih zemalja koje su ujedno i najveÄi proizvoÄaÄi željeza i Äelika. Dobiveni rezultati su pokazali da je ukupna emisija tih spojeva od metalurÅ”kih procesa u okoliÅ” u razdoblju 1960.- 2005. bila od QI-TEQ = 0,153-2,888 g a-1, dok je u razdoblju 1990. - 2000. ova emisija bila od 0,153-1,284 g a-1.
Kako se ne smije zanemariti udjel metalurŔkih procesa u ukupnoj emisiji polikloriranih dibenzop-
dioksina i polikloriranih dibenzofurana u okoliŔ, to je nužno u nastavku istraživanja provesti mjerenja njihovih emisija od svih aktivnih metalurŔkih procesa u Hrvatskoj, te odrediti udjel tih spojeva u svim vrstama otpada nastalog za vrijeme odvijanja procesa.Metals and metallic products are fundamental to a large number of modern industries and steel is certainly one of the most significant metallurgical products. Steel and steel castings as universal production material, that provided the grounds for the contemporary industrialization process,
will have a continuously irreplaceable role in the future, regardless of the fact that nowadays steel materials are often replaced by other materials (ceramics, polymers, etc.), whenever it is technically required and cost-justified.
The development of metallurgy and metallurgical processes is accompanied by pollution of the environment that directly or indirectly endangered the health of humans, certain animal and plant species, water resources systems, and soil. It also lead to increased erosion of material goods
and caused many other adverse social and economy-related effects.
The integral steelworks concept has, for example, set off a significant increase in the number of emission sources and the increase of harmful substances concentration in the environment. The largest polluters have always been coking plants, iron ore agglomeration facilities, blast furnaces, steel mills, foundries and thermal energy plants.
Numerous fundamental scientific research works have proven a series of adverse effects caused by uncontrolled emissions of harmful substances from these plants. Beside the considerable quantities of usual and well-known polluting substances such as sulfur and carbon oxides, fluorides, ammonia, benzene, heavy metals, phenols, cyanides, oil and grease, slag, used refractory material, metallic scrapings, sludge, dust, and scale, there are also relatively small pollutions with long-lasting effects that are hazardous even in their low concentrations and they rarely receive due attention.
This polluting substance group consists of persistent organic pollutions represented by polycyclic aromatic hydrocarbon (PAH), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins
(PCDDs), and polychlorinated dibenzofurans (PCDFs). These compounds are the least explored of all known pollutions generated in the metallurgical processes, in terms of the impact of their emissions to the environment.
The paper provides elementary toxicity data for these compounds and a survey of reference data on the currently completed listings of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in the world and in Croatia, illustrating that the metallurgical process account for most of the total emission of these compounds into the environment.
Based on the experience of the developed countries that are at the same time the largest iron and steel producers, we calculated an estimate of potential emissions of dibenzo-p-dioxins and polychlorinated dibenzofurans from metallurgical processes in Croatia. The calculation took into account the coking processes, iron ore sintering processes, pig iron production, cast iron, openhearth steel and EAF steel production.
The estimated total emission of dibenzo-p-dioxins and polychlorinated dibenzofurans from metallurgical processes to the environment in the time period between 1990 and 2000 in Croatia was m = 3.987 g I-TEQ and annual emission in the same period ranged from QI-TEQ = 1.284 g a-1 in 1990 to QI-TEQ = 0.153 g a-1 in 1995.
Emissions of these compounds from metallurgical processes that were active in less recent past were also calculated and the values in the time period between 1960 and 2000 ranged from m =2.888 g I-TEQ in 1980 to m = 0.153 g I-TEQ in 1995.
Based on the data on the existing facilities for steel production in electric arc furnaces we estimated that annual emission of dibenzo-p-dioxins and polychlorinated dibenzofurans could amount to QI-TEQ ~ 0.260 g a-1, whereas the future emission of these compounds from the existing cast iron facilities could be QI-TEQ ~ 0.100 g a-1.
In the research follow-up for the impact of metallurgical processes on the overall emission of these compounds to the environment, it is required to measure their emissions from all active metallurgical processes. For the sake of better comprehension of emission flows of dibenzo-p-dioxins and polychlorinated dibenzofurans from metallurgical processes it is necessary to determine the contents of these compounds in all kinds of waste generated in the observed metallurgical processes and to select technical solutions to improve each individual process and to reduce their emissions to the environment
Heavy Metals in Steel Mill Electric Arc Furnace Dust
U okviru gospodarenja otpadom, koje obuhvaÄa i odabir rjeÅ”enja za njegovo zbrinjavanje, bilo uporabom u vlastitim tehnoloÅ”kim procesima, bilo preraÄen u drugim industrijskim granama ili odgovarajuÄom obradom prije eventualnog odlaganja na propisanim odlagaliÅ”tima, u Željezari Sisak se pristupilo sustavnom istraživanju fizikalno-kemijskih karakteristika metalurÅ”kog otpada kao i njegovog ponaÅ”anja u interakciji sa okoliÅ”em.
ElektropeÄna praÅ”ina, kao metalurÅ”ki otpad, razvrstana je prema US EPA klasifikaciji iz 1980. godine u opasni tehnoloÅ”ki otpad oznake K061. ElektropeÄna praÅ”ina Željezare Sisak svrstana je u opasni otpad na temelju ispitivanja fizikalno-kemijskih karakteristika od strane za to ovlaÅ”tenog laboratorija i dodijeljen joj je kljuÄni broj *10 02 03, sukladno pravnim propisima Republike Hrvatske. Kako zbrinjavanje opasnog otpada nije moguÄe izravnim odlaganjem na tlo, ukazala se potreba pronalaženja rjeÅ”enja za zbrinjavanje elektropeÄne praÅ”ine na ekoloÅ”ki prihvatljiv i ekonomski opravdan naÄin. Naime, elektropeÄna praÅ”ina iz procesa proizvodnje Äelika u ÄeliÄani Željezare Sisak, svojedobno je služila kao dodatak pri izradi sinter-mjeÅ”avine za potrebe proizvodnje sirovog željeza visokopeÄnim postupkom.
Zbrinjavanje elektropeÄne praÅ”ine na taj naÄin bilo je jedino ekonomski opravdano radi iskoriÅ”tavanja njezinog željezonosnog dijela, dok ekoloÅ”ka prihvatljivost tog naÄina zbrinjavanja opasnog otpada nije bila zadovoljena. Naime, teÅ”ke kovine od elektropeÄne praÅ”ine kao toksiÄni sastojci samo su mijenjali svoju matiÄnu osnovu tj. iz elektropeÄne praÅ”ine bivali preseljeni i ukoncentrirani u mulj ispiraÄa visokopeÄnih otpadnih plinova.
Zatvaranjem proizvodnje sirovog željeza u visokim peÄima, napuÅ”ten je i taj, ionako nepotpun naÄin zbrinjavanja elektropeÄne praÅ”ine, a novonastale koliÄine se otada privremeno odlažu u krugu tvornice i svakim su danom sve veÄa opasnost za okoliÅ”.
Radi pronalaženja moguÄnosti i odabira optimalnog postupka zbrinjavanja nagomilanih koliÄina opasnog metalurÅ”kog otpada provode se sustavna istraživanja od kojih je ovdje prikazan samo dio koji se odnosi na ispitivanje sadržaja teÅ”kih kovina u elektropeÄnoj praÅ”ini, kao i meÄusobne povezanosti
udjela teÅ”kih kovina Zn, Pb, Cd s masenim udjelom željeza Äiji oksidi Äine osnovu tog otpada. Ostale kovine poput bakra, kroma i nikla nisu istraživane na isti naÄin kao Zn, Pb i Cd s obzirom da je ispitivana praÅ”ina nastala u postupcima proizvodnje ugljiÄnih Äelika te su u njoj koncentracije tih kovina vrlo niske.Within the scope of corporate waste management, Sisak Steelworks initiated a thorough and systematic examination of physical and chemical properties of metallurgical waste and of its behaviour in interaction with the environment.
Electric arc furnace (EAF) dust has been categorized as hazardous technological waste and it can not be directly disposed of to the ground / in a land fill. Therefore, it is necessary to find a way to dispose of it in an environmentally friendly and economically acceptable manner.
In order to elaborate different options and chose the optimal practice for the disposal of the accumulated volumes of hazardous metallurgical waste, comprehensive and systematic research has been conducted. This paper provides only a partial survey of the research of the heavy metal Zn, Pb, Cd content in electric arc furnace dust as well.
Qualitative chemical analysis of samples of electric arc furnace dust was conducted on all observed samples and the presence of Fe, Zn, Pb, Mn, Cu, Al, Ca, Mg, K, S, P, C, O and Cl was established.
The results of qualitative chemical analysis of monthly average samples of electric arc furnace dust obtained by other methods established that the mass fraction of iron was between 41.08 and 48.58 %, zinc between 3.75 and 8.10 %, lead between 0.94 and 2.07 %, and cadmium between 0.010 and 0.027 %. The results of the Zn, Pb, Cd fraction analysis in the observed samples of electric arc furnace dust are considerably lower, than the content of those metals in EAF dusts presented in the available references, where the mass fraction of zinc varies between 0.14 and 50 %, lead between 0.03 and 6.8 %, and cadmium between < 0.01 and 1.8 %.
Quantitative analysis of Fe, Zn, Pb and Cd fraction was carried out in grain-metrical fractions of individual samples of EAF dust as well. The results have shown that the concentrations of Fe tend to increase with smaller fraction grains compared to an average sample, whereas concentrations of Zn, Pb and Cd in the same proportion display a descending tendency.
Results of the Zn, Pb and Cd fraction analysis in the EAF dust samples from Sisak Steelworks compared to the mass fraction of those metals in EAF dust from other steel mills imply that the measured concentrations of zinc, lead, and cadmium are much higher. Therefore, it is not economically viable to recycle this dust for the lead, zinc or cadmium recovery.
Consequently, the disposal of this kind of hazardous metallurgical waste must first be handled in another, environmentally acceptable and economically justifiable way. Additional investigations must be carried out before the final decision is made
Naturalna radioaktywnoÅÄ w kruszywie z żużla stalowniczego
Present day steelmaking slags are being successfully used as a high quality mineral aggregate for the building industry. With this, it is of vital importance to be familiar with the technical significance of the secondary application of steel slag, because some steel slag might contain increased concentration of substances harmful to human health. In terms of steel slag impact on the environment, radionuclides are the least researched of all pollutants emitted from the metallurgical processes. This paper presents the results of radiochemical testing of steel slag and steel slag aggregates for the purpose of its use in the production of construction material. Obtained results of measurements show that 40K, 226Ra and 232Th in all examined steel slag samples have the activity concentration from 45.3 to 62.9Bqkg-1, 15.2 to 21.4Bqkg-1 and 12.9 to 15.4Bqkg-1, respectively. Results of measurements of radionuclide activity concentrations of 226Ra, 232Th and 40K in slag aggregates show similar values for all radionuclides ranges as follows: 40K from 14.1 to 23.3Bqkg-1; 232Th from 8.6 to 14.4Bqkg-1 and 226Ra from 14.8 to 26.8Bqkg-1. Activities index (I1, I2, I3) of 226Ra, 232Th and 40K were compared with values recommended by Croatian legislation. Radium equivalent concentrations (Raeq) of 226Ra, 232Th and 40K for examined steel slag and steel slag aggregates are harmounious with the results presented by other authors for the same by-product. The testing has been conducted on steel slag created during the production of carbon steel by electric arc furnace in Steel Mill of CMC Sisak, Croatia.Obecnie żużle stalownicze sÄ
z powodzeniem używane do wytwarzania wysokiej jakoÅci kruszywa mineralnego dla budownictwa. Z tego powodu, istotnego znaczenia nabiera znajomoÅÄ wtĆ³rnego zastosowania żużli, ponieważ niektĆ³re żużle mogÄ
zawieraÄ zwiÄkszone stÄżenie substancji szkodliwych dla zdrowia ludzkiego. Pod wzglÄdem wpÅywu żużli na Årodowisko, radionuklidy sÄ
najmniej zbadane ze wszystkich zanieczyszczeÅ emitowanych z procesĆ³w metalurgicznych. W pracy przedstawiono wyniki badaÅ radiologicznych żużla stalowniczego i kruszyw przeznaczonych do produkcji materiaÅĆ³w budowlanych. Otrzymane wyniki badaÅ prĆ³bek żużla wskazujÄ
, że aktywnoÅÄ promieniotwĆ³rcza: 40K, 226Ra, 232Th wynosi odpowiednio: 45.3 do 62.9Bqkg-1; 15.2 do 21.4Bqkg-1; i 12.9 do 15.4Bqkg-1. W przypadku kruszywa otrzymano podobne wyniki dla wszystkich radionuklidĆ³w tj.: 40K od 14.1 do 23.3Bqkg-1; 232Th od 8.6 do 14.4Bqkg-1; i 226Ra od 14.8 do 26.8Bqkg-1. Indeks aktywnoÅci (I1, I2, I3) dla 226Ra, 232Th i 40K zostaÅ porĆ³wnany z wartoÅciami rekomendowanymi przez chorwackie prawo. RĆ³wnoważne stÄżenia radu (Raeq) dla 226Ra, 232Th i 40K dla badanych kruszyw sÄ
zgodne z wynikami przedstawionymi przez innych autorĆ³w dla tego samego materiaÅu. Badania przeprowadzone zostaÅy na żużlu stalowniczym otrzymanym w trakcie produkcji stali w Åukowym piecu elektrycznym w hucie stali CMC Sisak w Chorwacji
Radioactivity of some building and raw materials used in Croatia
In the present study, the activity concentrations of 226Ra, 232Th, 40K in some building and raw materials used in Croatia were measured by using a gamma-ray spectrometer with the HPGe detector. The average activity concentrations of the studied different building and raw materials ranged from 11.6 Å” 1.7 (concrete) to 251.2 Å” 25.7 Bqkg-1 (GBFS), 14.0 Å” 2.7 (concrete) to 54.4 Å” 8.3 (coal fly ash) and 147.2 Å” 19.0 (concrete) to 773.7 Å” 82.0 Bqkg-1 (tuff) for 226Ra, 232Th and 40K, respectively. Radium equivalent activity, activity concentration index, absorbed gamma dose rate indoor due to the external exposure and corresponding annual effective dose were determined to estimate the exposure risk arising due to the use of these building and raw materials
ZnaÄaj emisije polikloriranih dibenzo-p-dioksina i dibenzofurana iz procesa proizvodnje željeza i Äelika (Importance of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans Emissions from Iron and Steel Production Processes)
Metals and metallic products are fundamental to a large number of modern industries and steel is certainly one of the most significant metallurgical products. Steel and steel castings as universal production material, that provided the grounds for the contemporary industrialization process,will have a continuously irreplaceable role in the future, regardless of the fact that nowadays steel materials are often replaced by other materials (ceramics, polymers, etc.), whenever it is technically required and cost-justified.The development of metallurgy and metallurgical processes is accompanied by pollution of the environment that directly or indirectly endangered the health of humans, certain animal and plant species, water resources systems, and soil. It also lead to increased erosion of material goodsand caused many other adverse social and economy-related effects.The integral steelworks concept has, for example, set off a significant increase in the number of emission sources and the increase of harmful substances concentration in the environment. The largest polluters have always been coking plants, iron ore agglomeration facilities, blast furnaces, steel mills, foundries and thermal energy plants.Numerous fundamental scientific research works have proven a series of adverse effects caused by uncontrolled emissions of harmful substances from these plants. Beside the considerable quantities of usual and well-known polluting substances such as sulfur and carbon oxides, fluorides,ammonia, benzene, heavy metals, phenols, cyanides, oil and grease, slag, used refractory material, metallic scrapings, sludge, dust, and scale, there are also relatively small pollutions with long-lasting effects that are hazardous even in their low concentrations and they rarely receivedue attention.This polluting substance group consists of persistent organic pollutions represented by polycyclic aromatic hydrocarbon (PAH), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins(PCDDs), and polychlorinated dibenzofurans (PCDFs). These compounds are the least explored of all known pollutions generated in the metallurgical processes, in terms of the impact of their emissions to the environment.The paper provides elementary toxicity data for these compounds and a survey of reference data on the currently completed listings of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in the world and in Croatia, illustrating that the metallurgical process account for most of the total emission of these compounds into the environment.Based on the experience of the developed countries that are at the same time the largest iron and steel producers, we calculated an estimate of potential emissions of dibenzo-p-dioxins and polychlorinated dibenzofurans from metallurgical processes in Croatia. The calculation took into account the coking processes, iron ore sintering processes, pig iron production, cast iron, openhearth steel and EAF steel production.The estimated total emission of dibenzo-p-dioxins and polychlorinated dibenzofurans from metallurgical processes to the environment in the time period between 1990 and 2000 in Croatia was m = 3.987 g I-TEQ and annual emission in the same period ranged from QI-TEQ= 1.284 g a-1 in 1990 to QI-TEQ = 0.153 g a-1 in 1995.Emissions of these compounds from metallurgical processes that were active in less recent past were also calculated and the values in the time period between 1960 and 2000 ranged from m =2.888 g I-TEQ in 1980 to m = 0.153 g I-TEQ in 1995.Based on the data on the existing facilities for steel production in electric arc furnaces we estimated that annual emission of dibenzo-p-dioxins and polychlorinated dibenzofurans could amount to QI-TEQ ~ 0.260 g a-1, whereas the future emission of these compounds from the existing cast iron facilities could be QI-TEQ ~ 0.100 g a-1.In the research follow-up for the impact of metallurgical processes on the overall emission of these compounds to the environment, it is required to measure their emissions from all active metallurgical processes. For the sake of better comprehension of emission flows of dibenzo-p-dioxins andpolychlorinated dibenzofurans from metallurgical processes it is necessary to determine the contents of these compounds in all kinds of waste generated in the observed metallurgical processes and to select technical solutions to improve each individual process and to reduce their emissions to the environment