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EN
The accumulation of poly(3-hydroxybutyric acid) in activated sludge was investigated. Fed-batch culture was carried out using sodium acetate as the source of carbon. A lack of nitrogen was a stimulating factor of accumulation P(3HB). Two experimental series were run. In series 1, nitrogen was fed into abacterial culture once for the first 24 hours, in series 2 ? for 6 hours each day of the experiment. The effect of operational conditions was evaluated based on the accumulation of P(3HB) in biomass, specific growth rate of microorganisms (m) yield coefficients (YP(3HB)/C, YP(3HB)/X), and productivity P(3HB). It was proved that the degree of accumulation of P(3HB) in activated sludge was comparable in both series. The highest P(3HB) yield of 0.59 g P(3HB)/g COD was attained in series 1 at the 12 th our after ceasing the nitrogen feeding. In series 1, between the 36 th and 48 th hour, the productivity reached the level of about 34 mg P(3HB)/l?h). In series 2, YP(3HB)/C and the productivity accounted for 0.21 g P(3HB)/g ChZT and 21.58 mg P(3HB)/l?h, respectively. The limiting factor of P(3HB) productivity was low specific growth rate of microorganisms of activated sludge. The maximum specific growth (max) reached 0.03 h-1 in series 1 and 0.022h-1 in series 2.
EN
Many of the Polish sandy coasts covered by several dune ridges are in danger, threatened by high wave storms and sea level rise. Some of the sandy coasts are accumulative. Accumulated on beach sand may cause growth and development of ridge. When upper beach at the front of the first dune is densely covered by plants sand may be fixed on beach. In this way on the upper beach may be built small hillocks or shadow dunes. It is important to know how fast a new dune ridge rises. This paper shows the importance of dune field formation on the upper beach in front of the foredune for new dunes accumulation. This field has possibilities to change in an initial dune ridge. Continuous aeolian accumulation of the sand on the dune field leads to the building of a new dune ridge. This process was observed on spit of Swina Gate Barrier on west Polish coast. The accumulation was forced by pioneer vegetation, which was covering hillocks and trapping transported sand from the beach. Also speeds and wind directions (measured in Swinoujscie) may cause bigger and faster accumulation. Author observed this process during five years on area of accumulative dune coast (the Swina Gate Barrier, west Polish coast). Before the beginning of the investigations, the upper beach in front of the foredune was covered by separated hillocks fixed by pioneer vegetation. After five years these hillocks became the new foredune ridge.
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issue 1-2
79-81
EN
Sulfate-reducing bacteria (e.g. Desulfotomaculum acetoxidans) exist in animal intestine. These bacteria are able to bind heavy metals (e.g. cadmium or lead). Comparative investigations on the composition of cellular walls of Desulfotomaculum acetoxidans - depending on the initial Fe2+ supplement in the medium (7.5, 57.5 and 507.5 M) were performed. Iron(II) was cumulated as FeS or as pyrite (FeS2). However, if the initial amount of iron was higher, its majority (46% 85%) was transported onto the membrane. It was determined that the siderophore found in Desulfotomaculum acetoxidans was deferroxamine as in animals.
EN
The bioaccumulation of polonium in the Baltic mussel Mytilus trossulus was studied experi-mentally in an attempt to discover the differences between food and water as sources of polonium. The 209Po isotope was used as tracer for accumulation and excretion. The highest 209Po con-centration was found in the hepatopancreas of mussels exposed to spiked water for 24 days. Both parts of the experiment (exposure to food and water) showed that while the rate of bioaccumula-tion of polonium by Mytilus trossulus was very high, the excretion rate was also relatively high. Furthermore, in both cases the duration of the accumulation-excretion (a-e) cycle of polonium in Mytilus trossulus was 10 days. Finally, a simple mathematical model approximating the experimental data was developed.
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