Wyniki wyszukiwania - BazTech

1

Coupling mineralogy with physicochemical parameters in view copper flotation efficiency improvement

Naumov Dejan, Stamenov Lachezar, Gaydardzhiev Stoyan, Bouzahzah Hassan

Physicochemical Problems of Mineral Processing

|

2019

|

Vol. 55, iss. 3

701--710

EN

The Chelopech epithermal arsenic bearing high-sulphidation, copper-gold deposit located in Bulgaria is often considered as the richest European gold deposit. Selected physicochemical parameters have been measured at key flotation streams inside the processing plant. Sampling campaign has followed with samples being submitted to chemical and mineral liberation analyses. A quantitative analysis has enabled to link copper flotation response to the type of copper bearing minerals and physiochemical parameters such as redox potential (Eh), dissolved oxygen (DO), EDTA extractable Cu and Fe. Data from the mineral liberation analysis (MLA) have highlighted an important process- relevant information explaining the variable floatability in different particle size ranges. A low chalcopyrite recovery can be linked to the non-sufficient amount of dissolved oxygen inside the copper selective flotation. Given the finely-disseminated copper bearing minerals, copper losses due to particle locking could be suggested as well.

2

Fungi and fungus-like organisms growing in selected lotic oxbow lakes and tributaries of the Narew River

Muszyńska E., Kiziewicz B., Godlewska A., Jankowska D., Ordak M.

Oceanological and Hydrobiological Studies

|

2017

|

Vol. 46, No. 1

85--95

EN

Mycological and hydrochemical research was conducted in two different types of reservoirs connected with the Narew riverbed (three tributaries and three lotic oxbow lakes) in two growing seasons. The obtained results seem to indicate that more favorable conditions for the development of the analyzed microorganisms prevailed in the studied tributaries of the Narew. A total of 36 species of fungi and fungus-like organisms were identified in these tributaries in spring and 35 in autumn, while respectively 32 and 26 species in the lotic oxbow lakes. Six taxa not identified in the oxbow lakes were found only in the tributaries of the river. They were: Alternaria alternata, Allomyces moniliformis, Catenaria anguillulae, Leptomitus lacteus, Rhipidium parthenosporum and Saprolegnia diclina. On the other hand, only two species occurred only in the oxbow lakes (not recorded in tributaries) (i.e. Catenophlyctis variabilis and Rhizophlyctis rosea).

3

Winter bloom of some motile phytoplankton under ice cover in a mesotrophic lake : vertical distribution and environmental factors

Lenard T.

Oceanological and Hydrobiological Studies

|

2015

|

Vol. 44, No. 2

164--171

EN

The research was carried out in mesotrophic Lake Krasne during winter with thick ice/snow cover. Water samples for biological and physicochemical analyses were collected vertically from the water column. Several phytoplankton groups were identified during the study, however, only two main groups of motile phytoplankton, Cyanophyceae (the dominant species − Planktothrix rubescens) and Cryptophyceae (Cryptomonas spp. and Plagioselmis nannoplanctica), were analyzed in the gradient of nutrients, light and thermal conditions. In the studied water column, values of physicochemical parameters did not vary in a wide range. Nevertheless, high discrepancies were noted in the values of phytoplankton biomass and the concentration of chlorophyll-a which had shallower maxima and deeper minima. Statistically significant relationships were found between the biomass of two main phytoplankton groups, light conditions (PAR) and depth, however, no significant relationships were found between the biomass, biogenic compounds and water temperature. The studies showed that in the winter season with ice/snow cover, cryptomonads and Planktothrix rubescens occupied different ecological niches and the main factor determining their distribution were light conditions. The ice/snow cover probably plays an important role in protection of P. rubescens winter filaments against photoinhibition.

4

Aquatic fungi and straminipilous organisms in lakes of the Augustowska Primeval Forest, Poland

Godlewska A., Kiziewicz B., Muszyńska E., Milewski R.

Oceanological and Hydrobiological Studies

|

2013

|

Vol. 42, No. 4

451--459

EN

We analyzed species composition of aquatic fungi and straminipilous organisms in six lakes located within the Augustowska Primeval Forest, Poland. Mycological observations conducted in the spring and autumn seasons together with hydrochemical analysis in the 2010–2012 revealed the presence of 44 species (10 aquatic fungi and 34 straminipilous organisms). Among the taxa detected, there were some potential pathogens of economically valuable fish species and spawn, including Achlya americana, Ac. polyandra, Saprolegnia ferax and S. parasitica. Some of the species were crustacean pathogens, such as Lagenidium giganteum, Myzocytium microsporum and M. zoophthorum. There were also some common human pathogens Aspergillus niger and Candida tropicalis. Some species, such as Achlya klebsiana, Ac. prolifera, Nowakowskiella elegans, N. macrospora, Pythium debaryanum, Py. inflatum, Rhizophlyctis rosea and Saprolegnia litoralis were common phytosaprobionts. The largest number of species of fungi and straminipilous organisms was identified in Lake Sajenek (22), the fewest in Lake Białe (12). The quantitative composition and qualitative differentiation of mycobiota were influenced by the content of biogenic compounds and the amount of organic substance. The elevated levels of these parameters (Lake Sajenek) stimulated the growth of fungi and straminipilous organisms, whereas very low concentrations of biogenic compounds and a small amount of organic matter (Lake Białe) had an inhibitory effect. Statistical analysis of the results was conducted to determine the correlations between the number of fungal and straminipilous species and the hydrochemical parameters, i.e. water temperature, the level of nitrogen compounds (nitrate nitrogen, ammonium nitrogen), calcium carbohydrate, magnesium carbohydrate, water oxidizability and the content of dry residue, dissolved substances and suspension.

5

Modelowanie wpływu wybranych czynników fizykochemicznych na retencję w sekcji "mokrej" maszyny papierniczej

Olejnik K.

Przemysł Chemiczny

|

2006

|

T. 85, nr 8-9

1293-1296

PL

Celem pracy było stworzenie komputerowego programu modelującego pracę sekcji formującej maszyny papierniczej, pozwalającego na symulowanie fizykochemicznego stanu układu wodno–masowego oraz umożliwiającego przewidywanie różnych zjawisk mogących wystąpić w trakcie wprowadzania zmian w procesie (np. zmiana surowca, zmiana produkowanego asortymentu, przymknięcie obiegu wodnego itp.). Zaprezentowano przykładowe symulacje obrazujące wpływ dozowania środków retencyjnych na zmiany potencjału elektrokinetycznego w ciągu technologicznym maszyny papierniczej. Wydaje się, że prezentowany model, mimo swych ograniczeń może być cennym narzędziem do wstępnej oceny wielu interesujących problemów np. ewentualnych skutków stosowania różnych dodatków chemicznych w procesie produkcji papieru.

EN

The dynamic simulator developed for the wet-end section and used for a fibrous pulp of a deciduous unbeaten pulp contg. TiO2, approached the effect of two unspecified com. retentants added to prep. a 75-g/m2 paper enabled the electrokinetic potential to be predicted in the paper machine water loop. Zeta could reflect the effect of the retentants, but could not help intercompare the efficiency of various polyeletrolytes.

6

Phytoplankton of humo-eutrophic Lake Plotycze (Sobiborski Landscape Park, Eastern Poland)

Pęczuła W., Zykubek A.

Oceanological Studies

|

1998

|

Vol. 27, No. 2

45-50

EN

Phytoplankton structure (abundance, taxonomical structure, species diversity) as well as physico-chemical factors (tem-perature, pH, electrolytic conductivity, oxygen concentration) were observed in a natural, shallow, small lake. The comparison of three zones within the studied lake showed distinct trophic differentiation. The biodiversity indices, which were used in this analysis, appeared to be useful in determining the lake functions.