Quantitative Study on Microbial Pollution of River ... - GANGAPEDIA

♦ It should affect the quality of water — (i) before
drains from city discharge; (ii) inside city; and (iii) after
the river leaves the city.
SAMPLE SAMPLE COLLECTION
COLLECTION
Sample collection is a very important part of river study
because conclusions drawn are based only on the testing
of collected samples. The purpose of taking samples is
to obtain information, which in some way typifies the
aquatic system from which samples are drawn 12 . Grab
Sampling procedure was adopted as recommended by
Standard Method for microbiological analysis. Samples
were collected during lean season, on monthly basis, for
a period of four months from March 2004 to June 2004.
Three sets of water samples, from each sampling location
and for every sampling date, were collected for this study.
(i) Water samples for microbiological examination,
other than Helminth eggs, for BOD and COD
determination were collected in non-reactive
borosilicate glass bottles of 500 ml capacity each that
had been cleansed and rinsed carefully, given a final
rinse with distilled water and sterilized. Samples were
taken from the river by holding the bottle near its base
in the hand and plunging it, neck downward, below
the surface. Then turning the bottle until neck points
slightly upward and mouth is directed toward the
current. The sampling bottle was not filled up to the
brim and 20 mm to 30 mm space was left for effective
shaking of the bottle 13 .
(ii) Water samples for Helminth eggs were collected in
Table able 1 1 1 Summary Summary of of analytic analytic methods methods and and observed observed values
values
non-reactive plastic bottles of 5 l capacity, which had
been cleansed and finally rinsed with distilled water 14 .
(iii) Water samples for DO determination were
collected in BOD bottles (non-reactive borosilicate
glass bottles of 300 ml capacity). The DO was fixed by
standard procedure Onsite, just after collection 13 .
SAMPLE SAMPLE PRESER PRESERVATION
PRESER TION TION AND AND STORAGE
STORAGE
Microbiological analysis of water samples was started
as soon as possible after collection to avoid unpredictable
changes in the microbial population 15 . As the samples
cannot be processed within 1 h after collection, therefore
for most accurate results, samples were brought in iced
insulated container, during transport from Delhi to IIT
Roorkee laboratory.
ANAL ANALYSIS ANAL YSIS OF OF SAMPLES
SAMPLES
The Samples were analyzed in accordance with the
standard methods. The techniques, instruments and
principles involved in arriving at different parameters
are tabulated in Table 1.
RESUL RESULTS RESUL RESULTS
TS
The variation in water quality parameters determined
through the analysis on site and in laboratory at Indian
Institute of Technology, Roorkee (India) were reported
in Table 1. The longitudinal profile of various microbial
parameters is shown in Figure 2. The Longitudinal
profiles of BOD, COD and DO values were shown in
Figure 3.
Parameters Parameters Principle Principle Principle
Instruments/ Instruments/ technique technique used used
Observed Observed values values
values
Minimum Minimum Maximum Maximum Maximum Average verage
Temperature, °C Metric Thermometer 19 36 28
pH Metric Digital pH meter 7 9.2 7.5
TDS, mg/l Metric Digital TDS meter 190 700 460
Turbidity, NTU Nephelometric Digital Turbidity Meter 3.6 52.0 32.1
DO, mg/l Volumetric Modified Winkler’s method
BOD, mg/l Volumetric Winkler’s method, incubation for 3 days
COD, mg/l Closed Reflux, colorimetric Hach COD system (DR/ 4000 U
TC, MPN/100 ml MPN index Lauryl tryptose broth, incubation
FC, MPN/100 ml MPN index EC Medium, incubation temperature
HPC, CFU/ml Total plate count Pour plate method, plate count agar,
Coliphages, per ml Equations (APHA 9211 D 3) Inte-relationship
Titrant — N/40 Na 2 S 2 O 3 Ind — starch 0.0 8.2 1.5
at 27°C (IS : 3025 part 4, 1993) 3.0 52.0 34.2
spectrophotometer) set at λ = 600 nm 6.0 120.0 75.5
temperature 35 ± 0.5°C for 24 h to 48 h 2.1E04 4.3E07 9.3E06
44.5 ± 0.2°C for 24 ± 2 h 3.9E03 3.9 E 07 4.6 E 06
incubation temperature 35°C for 48 h,
digital colony counter 2.4E03 1.5E06 2.6E05
between TC and coliphages, FC
Helminth eggs, Microscopic count Modified Bailenger method,
and coliphages 5.2E03 9.0E08 1.2E08
per ml centrifuge (1000 g), compound microscope 5 38 23
58 IE(I) Journal–EN