Open Access. Powered by Scholars. Published by Universities.®
- Discipline
Articles 1 - 3 of 3
Full-Text Articles in Life Sciences
The Role Of Copper In The Apparent Aluminum Toxicity Of Aquatic Systems, Kirk Thomas O'Reilly
The Role Of Copper In The Apparent Aluminum Toxicity Of Aquatic Systems, Kirk Thomas O'Reilly
Dissertations and Theses
The effect of variations in aluminum and copper concentrations on the growth rate and enzyme activity of the green alga Scenedesmus quadricauda was investigated. The goal was to determine which chemical species control the biological parameters. The computer program MINEQL (Westal et al 1976) was used to estimate chemical speciation. In the prevalence of both metals, algal growth rate and alkaline phosphatase activity could be correlated to cupric ion activity. The activity of isolated bacterial alkaline phosphatase was found to be a function of both total copper concentration and cupric ion activity. A model was developed to predicted the effects …
The Combined Effect Of Cu And Zn On Selenastrum Capricornutum, Helmer Colonia-Roque
The Combined Effect Of Cu And Zn On Selenastrum Capricornutum, Helmer Colonia-Roque
Dissertations and Theses
It has been demonstrated that the toxicity of heavy metals depends on their chemical speciation and can be related to their free ion activities, rather than the total metal concentrations. The objective of this study was to determine the effect of combined free ions of zinc and copper on the toxicity to the green alga Selenastrum capricornutum. This alga was grown in a defined medium, under controlled laboratory conditions, with a varying range of zinc and copper concentrations. The growth rate of the alga was inhibited at pZn = 5.93 or at pCu = 7.24. The results suggest that …
Growth Of Selenastrum Capricornutum Printz In Natural Waters Treated With Copper Sulfate, Gerald Eugene Schulz
Growth Of Selenastrum Capricornutum Printz In Natural Waters Treated With Copper Sulfate, Gerald Eugene Schulz
Dissertations and Theses
The green alga, Selenastrum capricornutum Printz, was used in an algal bioassay to determine the toxic properties of copper in various natural lake waters of Oregon. Lake water was collected and brought back to the laboratory where it was treated with various copper concentrations and inoculated with a cell suspension of the test alga. Growth of the alga was determined by direct cell counts. The copper ion activity, pH, and absorbance of the test cultures were also determined. The growth of the alga was ·found to depend upon the water tested and also upon the copper concentration used.