Revision of Ciliates in Activated Sludge from Sat, 2008-03-01 17:03


Predicting effluent quality in biological wastewater-treatment processes using ciliated protozoa: an interactive, "user-friendly" guide on CD-ROM

Introduction



Ciliated protozoa (ciliates) are an important component of the microbial community in aerobic biological wastewater-treatment plants with about 175 species reported. They commonly number 50 million cells per litre in the mixed liquor of the activated-sludge process where their major role is the removal of dispersed bacteria by predation. It has long been known that ciliates can be used as reliable indicators of effluent quality in biological aerobic sewage-treatment processes. The advantage of using ciliates as bioindicators is that of speed, with an accurate prediction of effluent quality being available within an hour or two of sampling. Ciliates are rarely used on site in this way, however, mainly because of the difficulty that non-specialists have in identifying them. The main aim of this project is to produce a multimedia, user-friendly guide that can be used by specialists and non-specialists alike for both training and routine monitoring.

Amphileptus pleurosigma, 4k

Above: Amphileptus pleurosigma, a free-swimming ciliate. Scale bar = 50 micrometres.


With Internet Explorer 5 or 6 and Netscape 7, video clips should display
below; with Netscape 4, Explorer for Mac and some other browsers they
may open a new window. If the files do not work, check your Quick
Time Plug-in
. The image quality of these clips has been reduced
by compression necessary for the Web.

Download Video clip Amphileptus
claparedei
(2 Mb)

Showing typical swimming activity, several peripherally-located
contractile vacuoles and two ovoid macronuclei.

Download Video
clip
Euplotes moebiusi (1.6 Mb)

(1) Dorso-ventral view of stationary cell, showing pattern of cirri
on ventral surface; (2) lateral view of moving cell, showing typical
crawling activity on floc.

Download Video clip
Carchesium polypinum (2.5 Mb)

Low magnification - showing that separate branches of the colony
can contract independently of one another. Higher magnification
- showing; 1, zooids (mature adult cells) on end of stalks, and
2, developing telotroch (larval stage) with its extra row of cilia
near the posterior end of the cell which it uses for locomotion.




Data
used to compile the Guide

In order to mitigate the problem of recognising organisms observed
in fresh samples under the microscope, photographs and/or video
clips in vivo are provided in addition to descriptions and
line diagrams. There are video clips for the 75 or so species most
commonly encountered and/or which are of the greatest indicator
value. These digitised images are included in order to show key
behavioural patterns, eg swimming, feeding etc. Taxonomic descriptions
are presented in a way that emphasises the differences between the
species known to occur in wastewater treatment, rather than emphasising
the features of systematic importance.

Euplotes aediculatus, 5k

Above: Euplotes aediculatus, a crawling ciliate. Scale bar = 50 micrometres.

How the Guide will work

Samples are identified by date and location within the sewage-treatment
plant and a profile of ciliate diversity is built using the system.
The key is essentially pictorial and multi-entry, meaning that users
can skip questions that they cannot answer with confidence. Once
an identification is reached, the user can review all data associated
with the species and confirm or decline the identification for accumulation
into the sample profile. There are numerous short-cuts that can
be taken for more experienced users. Species are quantified on a
scale of abundance (eg few, several, many) rather than counted.

Carchesium  polypinum, 5k
Above: Carchesium polypinum, an attached ciliate. Scale bar = 50 micrometres.


The sample profile is then used in conjunction with ecological data,
saprobic indices etc, obtained from the literature in order to calculate
an effluent-quality index. Once the ciliate analysis of a particular
sample is complete, an automated function will provide a prediction
of effluent quality as defined by the biochemical oxygen demand
(BOD).

Results accumulated from the user's wastewater-treatment plant may be used
to improve the accuracy of local effluent predictions and data may
be shared internationally over the Internet via a central server.
The profiles themselves can be compared along the length of a process-track
(eg an RBC reactor or an activated-sludge channel) which can serve
as an indicator of hydraulic performance to detect problems such
as short-circuiting or inadequate mixing. The fact that the results
of the analysis should be available within an hour or two of sampling
will enable remedial action to be taken with minimum delay.



Availability

The guide will be
available shortly.

If you have some
experience of both ciliates and sewage treatment and are prepared
to beta-test the guide, please contact us for a pre-release version.



Project
co-ordinators

David McL Roberts (The Natural
History Museum, UK )
Alan Warren (The Natural History Museum, UK)

Colin R Curds (The
Natural History Museum, UK)

Humbert Salvado
(Department of Animal Biology, University of Barcelona, Spain)

Sat, 2008-03-01 13:25 -- dmr
http://www.gravatar.com/avatar/f35ee71c5e0593120623aa46627d298a.jpg?d=https%3A//ciliateguide.myspecies.info/sites/all/modules/contrib/gravatar/avatar.png&s=100&r=G
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith