scholarly journals Czech and Slovak young brown coals in environmental applications

2022 ◽  
Vol 7 (1) ◽  
pp. 85-91
Author(s):  
Pavel Janoš ◽  
Juraj Lesný ◽  
Lucia Závodská ◽  
Silvie Kříženecká ◽  
Lucie Herzogová

In recent time, various kinds of young brown (low-rank) coals are utilized increasingly not only as fuels, but also as valuable materials in advanced environmental applications. It should be noted in this context that significant deposits of the young brown coals can be found both in the Czech Republic as well as in Slovakia. For their effective applications e.g. in wastewater treatment or in soil remediation, the properties of the coals should be studied in more details and numerous physico-chemical characteristics should be measured. As a part of a common Czech-Slovak project, a series of various kinds of coals was collected, including North-Bohemian oxihumolites, lignite from South Moravia and several lignites from Slovakia (Baňa Zahorie). Basic properties were measured, such as acid-base titration curves, contents of main functional groups and sorption capability towards heavy metal cations (Cu2+, Zn2+, Co2+) and some organic pollutants. The contents of humic substances – main active constituents of the young coals – were also determined. Selected environmental applications of the brown coals will be mentioned further, e.g. for the removal of metal cations from waters or in phytoremediation of contaminated soils.

2012 ◽  
Vol 30 (No. 4) ◽  
pp. 369-376 ◽  
Author(s):  
L. Veverka ◽  
M. Jelínková ◽  
K. Hron ◽  
J. Balík ◽  
J. Stávek ◽  
...  

HSSPME-GC/MS method was used to investigate the volatile compounds responsible for varietal character in the aroma of wine distillates made from 16 different red wine grape cultivars: Andre, Blue Frankish, Merlot, Cabernet Moravia, Rubinet, Pinot Noir, Ariana, Alibernet, Laurot, Dornfelder, Blauer Portugieser, Agni, Neronet, Zweigeltrebe, Cabernet Sauvignon, and Domina. The grapes were all grown in the same vineyard in South Moravia, an important viticultural region in the south of the Czech Republic bordering Austria. The isometric log-ratio transformation was used to compute variances prior to statistical analysis, and a compositional biplot was used to interpret the data and identify the main chemical markers. A comparison of the key terpenoids present in the aroma profiles indicated that these were consistent with the known relationships between the cultivars based on their parentage. There were similarities in the terpenoid elements of the aroma profiles of Blue Frankish and its relatives Andre, Laurot, Agni, and Zweigeltrebe, which are dominated by (Z)-linalool oxide, linalool, isoborneol, terpinen-4-ol and α-terpineol. On the other hand, the aroma profiles of Pinot Noir, Blauer Portugieser, Cabernet Sauvignon and their related hybrids are dominated by o-cymene, limonene, (E)-sabinyl acetate, and (E)-calamenene.  


2018 ◽  
Vol 18 (44) ◽  
pp. 20-23
Author(s):  
Jargalmaa S ◽  
Tsatsral G ◽  
Battsetseg M ◽  
Batkhishig D ◽  
Ankhtuya A ◽  
...  

Thermal analysis was used for the thermal characterization of the coal samples. The experiments were performed to study the pyrolysis and gasification kinetics of typical Mongolian brown coals. Low rank coals from Shivee ovoo, Ulaan ovoo, Aduun chuluun and Baganuur deposits have been investigated. Coal samples were heated in the thermogravimetric apparatus under argon at a temperature ranges of 25-1020ºC with heating rates of 10, 20, 30 and 40ºC/min. Thermogravimetry (TG) and derivative thermogravimetry (DTG) were performed to measure weight changes and rates of weight losses used for calculating the kinetic parameters. The activation energy (Ea) was calculated from the experimental results by using an Arrhenius type kinetic model.


2016 ◽  
Vol 11 (10) ◽  
pp. 3870-3874
Author(s):  
Lassaad Baklouti

The synthesis and the binding properties of novel phthalonitrile derivatives 1-3 towards metal cations have been described in this paper. The complexation and extraction of some transition and heavy metal cations have been followed by UV-visible spectrophotometry absorption in methanol. The conductivity studies have been used in order to confirm complex’s stoichiometries. The treatment of UV spectra by digital program showed the formation of ML (with ML2 in some cases) (M=metal, L=ligand) species. Beyond the discussion of the stability profiles of complexes particular attention is paid to the selectivity towards Cu2+ in the 1st sequence of transition metal cations and towards Hg2+ in the sequence of heavy metal cations.


2019 ◽  
Vol 4 (1) ◽  
pp. 19-22
Author(s):  
Vika Ayu Devianti ◽  
Anisa Rizki Amalia

ABSTRAKVitamin C berperan penting dalam mempertahankan daya tahan tubuh. Vitamin C mudah teroksidasi dan tidakstabil dalam bentuk larutan. Vitamin C banyak ditemukan dalam buah – buahan, diantaranya adalah apel danstroberi. Apel dan stroberi ini sering diolah dalam bentuk minuman sari buah melalui proses ekstraksi osmosis. Tujuan penelitian ini adalah untuk mengetahui pengaruh lama waktu osmosis (30 dan 60 menit) dan penambahan gula 10% terhadap kandungan vitamin C dalam minuman sari buah apel dan stroberi. Penambahan gula 10% mampu memperkecil penurunan kadar vitamin C dalam minuman sari buah. Penurunan kadar vitamin C pada sampel sari buah stroberi tanpa penambahan gula adalah 18,7% pada menit ke-30 dan 37,5% pada menit ke-60, sedangkan penambahan gula 10% mengalami penurunan sebesar 2,7% pada menit ke-30 dan 7,9% pada menit ke-60. Penurunan kadar vitamin C pada sampel sari buah apel tanpa penambahan gula adalah 24,2% pada menitke-30 dan 41,6% pada menit ke-60, sedangkan penambahan gula 10% mengalami penurunan sebesar 10,6% pada menit ke-30 dan 21,4% pada menit ke-60.Kata kunci: Vitamin C, sukrosa, minuman sari buah, apel, strawberry, osmosis ABSTRACTVitamin C plays an important in human body. Vitamin C is easily degraded by heat, light, oxygen, and heavy metal cations. Vitamin C mostly found in fruits, such as strawberry and apple. Generally strawberry and apple are processed into fruit juice by adding sugar using osmosis extraction. The objective of this research is to findout the effect of osmosis time and sugar addition towards the vitamin C level in strawberry and apple juice. The result showed that sugar addition can affect the vitamin C level in strawberry and apple juice. Sugars can decrease the oxygen solubility causing less oxygen availability for oxidation of vitamin C. The diminish of vitamin C content in apple juice with sugar addition were 10,6% and 21,4% for 30 and 60 minutes of osmosis time; while strawberry juice with sugar addition able to lowering vitamin C level until 18,7% and 37,5% for 30 and 60 minutes of osmosis time.Keywords: Vitamin C, sucrose, apple juice, strawberry juice, osmosis,


2020 ◽  
Vol 80 ◽  
pp. 1-13 ◽  
Author(s):  
Hana Skokanová ◽  
Tomáš Slach

The  concept  of  Green  Infrastructure  (GI)  is  still  relatively  new  in  the  Czech Republic. When looking at the definition of GI, one can recognise a  relationship  with  the  Czech  Territorial  System  of  Ecological  Stability  (TSES),  which  is  defined  as  “an  interconnected  system  of  natural  as  well as modified semi-natural ecosystems keeping the natural balance”. TSES is a designed system and is an integral part of territorial plans. This article focuses on TSES and its relationship to GI, how it is implemented in  a  Czech  case  study  representing  intensively  used  agricultural  region  in  South  Moravia,  what  the  main  obstacles  are  to  its  implementation  and how TSES can contribute to the connectivity of the landscape. Our results show that nearly two thirds of the planned TSES in the case study area  already  exist  to  some  degree.  There  is  a  difference  between  the  number  and  the  area  of  existing  TSES  elements:  the  area  of  existing  elements  shows  higher  relative  values  than  the  number.  This  is  mainly  due to bio-centres that exist in large forest complexes and their pre-set minimal parameters. Creation of TSES elements increases connectivity of GI, especially those characterised as core areas and bridges


2018 ◽  
Vol 5 (6) ◽  
pp. 065503 ◽  
Author(s):  
Somayyah Abdul Munim ◽  
Muhammad Tahir Saddique ◽  
Zulfiqar Ali Raza ◽  
Muhammad Irfan Majeed

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2150 ◽  
Author(s):  
M.A. Martín-Lara ◽  
M. Calero ◽  
A. Ronda ◽  
I. Iáñez-Rodríguez ◽  
C. Escudero

Bisphenol A (BPA) is an extensively produced and consumed chemical in the world. Due to its widespread use, contamination by this pollutant has increased in recent years, reaching a critical environmental point. This work investigates the feasibility of bisphenol A adsorption from industrial wastewater solutions, testing the reduction of bisphenol A in synthetic solutions by a commercial activated carbon, AC-40, in batch mode. Besides, mixtures of bisphenol A and different heavy metal cations were also studied. So far, no works have reported a complete study about bisphenol A removal by this activated carbon including the use of this material to remove BPA in the presence of metal cations. First, adsorption experiments were performed in batch changing pH, dose of adsorbent, initial bisphenol A concentration and contact time. Results showed greater retention of bisphenol A by increasing the acidity of the medium. Further, the percentage of bisphenol A adsorbed increased with increasing contact time. The selected conditions for the rest of the experiments were pH 5 and a contact time of 48 h. In addition, an increase in retention of bisphenol A when the dose of adsorbent increased was observed. Then, specific experiments were carried out to define the kinetics and the adsorption isotherm. Equilibrium data were adequately fitted to a Langmuir isotherm and the kinetics data fitted well to the pseudo-second-order model. The maximum adsorption capacity provided by Langmuir model was 94.34 mg/g. Finally, the effect of the presence of other heavy metals in water solution on the adsorption of bisphenol A was analyzed. Binary tests revealed competition between the adsorbates and a significant selectivity toward bisphenol A. Finally, the study of the adsorption performance in three consecutive adsorption–desorption cycles showed efficiencies higher than 90% in all cycles, indicating that the activated carbon has good reusability.


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