DelAgua OXFAM-DELAGUA, Руководство пользователя

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OXFAM-DELAGUA Water Testing Kit — Users Manual
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together. Count each of the sub-colonies. Do not count colonies that are
transparent, red/pink or blue/grey. These are bacteria which do not ferment
lactose and cannot be identified without further study. They are not
thermotolerant coliforms.
Colonies may vary considerably in size. Generally, when the membrane
contains a large number of colonies, the colonies are smaller in diameter.
When colonies are fewer, they tend to be larger. This is because the colonies
compete for nutrients and will grow larger where there is no competition.
If there are large numbers of yellow colonies, count methodically using the
horizontal grid lines. In this way it is possible to count up to100 colonies on a
membrane. If there are more than 100 colonies on the membrane, the number
can be estimated by dividing the membrane into sections and counting the
number of colonies in one section. Multiply the result by the number of
sections to obtain an estimate of the total number of colonies on the
membrane.
3. Convert the count into number of thermotolerant coliforms per 100ml and
record the result on the daily report sheet (see Appendix D). The calculation is
made as follows:
Volume filtered
Thermotolerant coliforms per 100ml
100ml Number of colonies x 1
50ml Number of colonies x 2
10ml Number of colonies x 10
1ml Number of colonies x 100
5.4.8 Disposal
All contaminated materials should be sterilised before disposal to avoid creating a
risk to the public. DO NOT discard contaminated membranes and filter pads into
the environment. Refer to Section 3.6 for recommended procedures to sterilise
contaminated materials.