کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4484123 | 1316910 | 2009 | 10 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Enumeration of protozoan ciliates in activated sludge: Determination of replicate number using probability Enumeration of protozoan ciliates in activated sludge: Determination of replicate number using probability](/preview/png/4484123.png)
A new approach to the enumeration of ciliate protozoa in activated sludge is described. A 25 μL sub-sample volume is optimal for routine analysis using a standard slide and 24 × 24 mm cover slip requiring between 20 and 40 min per sub-sample for full enumeration and identification of species. However, to achieve high probability (≥95%) of recovering all species large numbers of replicates are required (i.e. 23–47). To achieve high probabilities of recovery using less replicates it is necessary to neglect rare species with low densities (<0.5%); based on the assumption that they do not play a significant role in plant performance. The precise number of replicates required for different probabilities of recovering species is determined by conducting an initial pilot survey analysing a minimum of 8 replicates and using a probability equation to determine the optimum replicate number for that particular plant. Six replicate 25 μL sub-samples provided excellent species recovery (90–95% excluding up to 3 rare species), while analysing just two or three replicates, as commonly used in previous wastewater studies, only gave probabilities of 25 and 50% respectively for the same recovery. Ciliate analysis should be completed within 8 h of collection with significant changes in community structure occurring beyond this period.
Journal: Water Research - Volume 43, Issue 14, August 2009, Pages 3443–3452