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1
Content available Adsorption kinetics of fluoride on bone char and its regeneration
Hu J., Wu D., Rao R., Liu R., Lai W.
Environment Protection Engineering
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2017
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Vol. 43, nr 3
93--112
EN
The adsorbent of bone char (BC), produced from the pyrolysis of crushed animal bones, was dominated by the mesopores of the Brunauer Emmett Teller (BET) surface area. The optimal condition for defluoridation with BC was a pH level near 5.0. Chloride and nitrate ions could increase fluoride adsorption capacity in contrast with the effect of sulfate and carbonate ions. The interchangeability between fluoride and hydroxyl groups on BC sorbent was proved by the Fourier transform infrared spectroscopy. Langmuir equation had a better correlation coefficient than the Freundlich equation at various temperatures. Thermodynamic parameters such as Delta G degrees, Delta H degrees, Delta S degrees, Ea and S*, have been calculated to describe the nature of fluoride adsorption onto BC. Negative Delta G degrees and Delta H degrees values at various temperatures indicate a spontaneous process, and its exothermic effect, respectively. However, a positive Delta S degrees value represents an increasing process for entropy. The E-a and S* values ranging from 5 to 40 kj.mol-1 and 0 to 1, respectively, demonstrated that the adsorption is dominated by physical process, although the adsorption kinetic process was involved external diffusion, intraparticle diffusion and chemical reaction equilibrium stage. A high concentration of NaOH solution increases efficiency of removing adsorbed F- ions from the BC surface.
2
Content available Removal of fluoride ions by batch electrodialysis
Majewska-Nowak K., Grzegorzek M., Kabsch-Korbutowicz M.
Environment Protection Engineering
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2015
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Vol. 41, nr 1
67--81
EN
Suitability of conventional batch electrodialysis to fluoride removal from aqueous solutions has been investigated. The experiments were conducted with the use of laboratory installation PCCell BED-1 System at a constant current density (1.56 or 2.34 mA/cm2). The influence of initial fluoride and salt (NaCl) concentration, as well as the presence of organic matter on the process performance was studied. It was found that the separation efficiency increased upon decrease of initial fluoride content in model solutions. Permissible final concentration of fluorides in the product water (1.5 mg/dm3) was obtained for experiments with solutions of initial fluoride concentration equal to 5 mg F–/dm3 and 10 mg F–/dm3. The presence of humic acids in fluoride solutions subjected to electrodialysis treatment has no adverse effect on the defluorization and desalination efficiency. The calculated electrical energy demand depended on composition of fluoride solution and varied from 0.121 to 0.895 kWh/m3.
3
Content available remote Method of simultaneous measurement of total sulfur, chlorine and fluorine content in biogas
Gaj K., Cybulska H., Knop F.
Environment Protection Engineering
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2011
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Vol. 37, nr 1
23-30
EN
The method of determination of total content of sulfur, chlorine and fluorine compounds in biogas has been implemented and verified at real conditions. The laboratory plant and the results of periodical measurements of the composition of biogas have been described. The main effects of the research are: determination of the range of concentrations for the analysed compounds in a typical biogas from sewage sludge digestion and evaluation of average fraction of sulfur from hydrogen sulfide in total sulfur content during multiannual period.
4
Content available remote Struktura emisji związków fluoru z hutnictwa żelaza na przykładzie Huty Katowice
Mazur M., Oleniacz R., Bogacki M.
Inżynieria Środowiska / Akademia Górniczo-Hutnicza im. S. Staszica w Krakowie
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2000
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T. 5, z. 1
33-43
PL
Jeszcze kilkanaście lat temu hutnictwo żelaza uznawane było za jedno z największych źródeł emisji związków fluoru do atmosfery. Zachodzące w tym przemyśle zmiany technologiczne i surowcowe powodują jednak ciągłe zmniejszanie się jego udziału w tej emisji. W artykule przedstawiono określone na podstawie badań przeprowadzonych w ciągu ostatnich kilku lat w Hucie Katowice udziały poszczególnych procesów technologicznych w emisji związków fluoru rozpuszczalnych w wodzie (uznawanych za toksyczne) i miejsce w tej emisji procesu spalania paliw w zakładowej elektrociepłowni. Scharakteryzowano także udział fluoru w emitowanych gazach w postaci związków gazowych i stałych (rozpuszczalnych i nierozpuszczalnych w wodzie) oraz poruszono problem dalszego ograniczenia emisji fluoru z największego źródła technologicznego - procesu spiekalniczego.
EN
As recently as a dozen or so years ago ferrous metallurgy was known as one of the biggest source of fluorine compound emissions to the atmosphere. Nevertheless production technology and raw material changes occuring in this industry cause continuous decreasing of their participation in the emissions. On the ground of investigations that have been carried out in the Katowice steelworks in the last few years, particular technological processing participation in the water-soluble fluorine compound emissions (which are regarded as toxic) were presented in the paper, as well as a position of fuel combustion process (that take place in the factory thermal-electric power station) in the emissions. Besides the fluorine partitioning in gaseous and solid (water-soluble and insoluble) compounds were characterized, as well as a problem of following reduction of fluorine emission from the biggest technological source - sintering process.
5
Ochrona powietrza przed emisją związków fluoru w przemyśle ceramicznym i materiałów ogniotrwałych
Łukwiński L., Klecan R.
Zeszyty Naukowe. Inżynieria Chemiczna i Procesowa / Politechnika Łódzka
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1998
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Nr 23
67-79
PL
Emisja fluoru do atmosfery związana jest z przeróbką termiczną surowców stosowanych w przemyśle ceramicznym i materiałów ogniotrwałych. Wydobycie glin ceramicznych w Polsce wynosi ok. 22 mln t/rok, a szacunkowa wielkość emisji fluoru podczas termicznej przeróbki tych surowców w temperaturze ok. 1000°C wynosi ok. 13 tys. t/rok Przedstawiono dwie metody obniżenia tej emisji o skuteczności 80 i 98%. Podano także możliwości wykorzystania powstającego fluorku wapnia.
EN
Emission of fluorine to the atmosphere is connected with thermal processing of raw materials used in the ceramic and refractory materials industries. Average output of ceramic clays in Poland is of 22 · 10 6 Mg per year, and estimated quantity of fluorine emission during thermal processing of this raw materials at 1000°C amounts about 13 · 10 3 Mg/year. Two methods of fluorine emission reduction with 80 and 98% efficiency have been presented. Possibilities of formed calcium fluoride utilization have been also noted.
6
Analiza zmian w poziomie związków fluoru w rejonie miasta Konina
Płoszewski K.
Zeszyty Naukowe. Inżynieria Chemiczna i Procesowa / Politechnika Łódzka
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1998
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Nr 23
152-163
PL
W artykule przedstawiono wyniki wieloletnich badań skażeń środowiska związkami fluoru: stężeń fluoru w powietrzu, jego opadu (fluoru rozpuszczalnego w wodzie), w glebach i roślinach. Analiza porównawcza tych wyników pozwala na sformułowanie w sposób udokumentowany uogólniającego stwierdzenia, że poziom zagrożenia środowiska przez fluor i jego związki systematycznie się obniża. Dzieje się to przede wszystkim dzięki redukcji zanieczyszczeń głównego emitenta - huty aluminium.
EN
Fluorine compounds, emitted mainly by the Konin aluminium plant, are a source of air pollution. The article presents results of multiyear studies on fluorine contamination in the environmental. The studies involved an analysis of fluorine concentration in the atmospheric air, soluble fluorine compound fall-out, soluble fluorine content in water and total fluorine (soluble and insoluble) content in soil, and fluorine content in vegetation.
7
Content available Analiza żródeł emisji związków fluoru z procesów hutnictwa żelaza
Mazur M., Bogacki M., Oleniacz R.
Ochrona Środowiska
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1998
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nr 4
27-32
EN
Ferrous metallurgy has long been known as a major emitter of fluorine compounds. In the last few years,joint investigations into the problem of fluorine emissions have been carried out,special consideration being given to the fluorine content in the raw material made use of in metallyurgical processes, as well as to the guestion of how the raw material affects the guanitity of the fluorine compounds released into the atmosphere.In the present study,concentrations of fluorine compounds were measured in the raw materials used in ferrous metallurgy,in sintering ,ironmaking and steelmaking processes,as well as in the preparation of fusing agents.All the processes were found to be amongst the major sources contributing to the atmospheric concentrations and quantities of fluorine emitted in the form of gaseous and solid compounds ( including water-soluble species which are regarded as toxic ).
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