Laserfiche WebLink
Adjusted Dilutions <br />- [12.5% dilution] - An LC50 of 100% was produced in this test. Survival was 50% in the <br />100% concentration and ranged from 80-90% in the remaining concentrations. Control <br />survival was 100%. <br />- [25% dilution] - An LC50 of 92.3% was produced in this test. Survival was 45% in the <br />100% concentration and ranged from 80-100% in the remaining concentrations. Control <br />survival was 95%. <br />- [50% dilution] -An LC50 of 100% was produced in this test. Survival was 50% in the <br />100% concentration and ranged from 80-95% in the remaining concentrations. Control <br />survival was 95%. <br />Table 1: Survival and LC50 Calculations <br />DISCUSSION <br />The D. magna test of the original (non-diluted) effluent fails due to the creation of an <br />LC50 concentration of 77.46%. All three dilutions of the original effluent produced LC50s at or <br />below the 100% concentration. <br />These results demonstrate that the dilution of the effluent samples did not significantly <br />reduce toxicity; therefore, it can be deduced that high alkalinity is probably the main source, if <br />not the only source, of toxicity to the Daphnia magna species in this particular effluent sample. <br />The SeaCrest Group 6 <br />