Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Rozklad wybranych herbicydow diazynowych i mocznikowych w srodowisku wodnym

100%

Bogacka T. , Ceglarski R.

nr 2

57-71

Toksycznosc i biodegradacja chlorowcowych pochodnych metanu w srodowisku wodnym

80%

Bogacka T. , Trzcinska B. , Grawinski E. , Ceglarski R.

nr 1

37-43

The effect of methylene chloride, chloroform, and carbon tertrachloride on the following aquatic organisms: Pseudomonas fluorescens, Scenedesmus quadricauda, Lemna minor, Daphnia magna, and Lebistes reticulatus, was investigated. Pseudomonas fluorescens bacteria were found to be most sensitive test organisms, and a toxic effect towards them was observed just at the concentration of 100 µg/l of each agent. Studies on degradation in distilled water, river-water, and aqueous ecosystem revealed moderate stability in aqueous medium of compounds under investigation. Chloroform and carbon tetrachloride were detecable in river-water still after 40 days in concentrations toxic to aqueous ecosystem. More rapid degradation of methane halogen derivatives in river-water than in distilled water indicated the presence of microorganisms living in water from natural source, and being accessory to the decomposition of these agents. Degradation in the presence of adapted microflora took, as a general rule, a slower cource. Decrease of temperature to 6°C inhibited considerably the degradation rate of the investigated contaminants. The reduction of methane halogen derivatives content during 21-day exposure in aqueous ecosystem came up to 73%. Moreover, these compounds were found not to have biocumulative properties, and not to be toxic - in concentrations up to 300 µg/l - to aqueous biocenosis homing the experimental ecosystem.

Określono toksyczność chlorku metylenu, chloroformu, i czterochlorku węgla względem wybranych organizmów wodnych: Pseudomonas fluorescens, Scenedesmus quadricauda, Lemna minor, Daphnia magna i Lebistes reticulatus. Przedstawiono dynamikę rozkładu w/w zanieczyszczeń w wodach o różnej jakości w zależności od rodzaju badanego związku, stężenia początkowego, temperatury, właściwości bioakumulacyjnych oraz stopnia adaptacji organizmów.

Rozklad chlorofenoli w srodowisku wodnym

80%

Bogacka T. , Makowski Z. , Ceglarski R.

1996

tom 47

nr 2

181-195

Wyznaczono dynamikę i kinetykę rozkładu chlorofenoli (2,4-DCF; 2, 6-DCF; 2,4,5-TCF; 2,3,6-TCF, 2,4,6-TCF; 2,3,4,6-TeCF i PCF) w warunkach modelowanych, symulujących środowisko wody rzecznej i destylowanej oraz ekosystemu wodnego. Szybkość rozkładu badano w zależności od stężenia początkowego chlorofenoli, temperatury, zdolności adaptacyjnych mikroflory do środowiska tych związków oraz właściwości kumulacyjnych.

The purpose of this study was to establish the distribution of the selected chlorophenols of point (2,4-DCF, 2,6-DCF, 2,4,5-TCF and 2,3,6-TCF) and nonpoint origin (2,4,6-TCF,2,3,4,6-TeCF and PCF) under conditions simulating the environment of river and distilled water and laboratory water ecosystem. The distribution process developed in accordance with the kinetic equation of 1st order, the average degradation half-time at 20°C amounted: model of river - 23, 58,-76, 92 days, and model of distilled water - 36, 53-47, 25 days. The rate degradation in river and distilled water indicates that the river water microoraganisms have no influence on the degradation of determined compounds. When the microflora had been adapted to the presence of chlorophenols the process of degradation was as rule more rapid both investigated temperatures (20°C and 7°C). This process was slowed down by temperature fall to about 7°C. The mixture of chlorophenols at concentration of 10 and 50µg/l when exposed for 20 days to water ecosystem under dynamic conditions, was found to be reduced up 13%. Chlorophenols were not absorbed by Elodea canadensis and Physa fortinalis and weakly by Lebistes reticulatus (cumulation coefficients - 0,42-30,27). In the case residual DCP and TCP -weakly (4,71 -46,23 µg/kg). The investigated concentrations of chlorophenols didn't exert positive effect on the aquatic biocenosis (except Lebistes reticulatus), settled in the ecosystem.