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Abstract:
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Protecting and conserving our natural resources is a primary focus of government agencies and private industry alike. One particular wastewater parameter the textile
industry is faced with is that of colored effluent. Textile
dyeing is the main source of color from the textile manufacturing plants and they may soon be required to
monitor and adjust the amount of color discharged into receiving streams. Today, a specified method for measuring
color in effluent is the American Dye Manufacturers Institute (ADMI) method. In the ADMI method, a pectrophotometer capable of transmission measurements is
used to measure the transmittance of colored solutions. The ADMI method is intended to provide an instrumental method of measuring the amount of color present in wastewater.
The primary objective of this thesis was to determine the effects of receiving water type, dye class, dye hue, and dye concentration on the ADMI color measurement method.
Other objectives of this thesis were to determine the amount of color (commercial dyestuff and treated effluent) that was necessary to cause a visible change in receiving water
having varying levels of natural color.
Results from this thesis indicate that receiving water did not significantly impact the filtered ADMI measurements.
However; receiving water did significantly influence
nonfiltered ADMI results. Natural turbidity and insoluble color in the receiving water did influence the measured color in nonfiltered samples. Highly soluble fiber reactive dyes generally exhibited higher ADMI values than did the slightly soluble disperse dyestuffs. Dye hue statistically
influenced both filtered and nonfiltered ADMI values. The yellow hue generally exhibited higher ADMI values for both the filtered and nonfiltered conditions. As dye
concentration increased, ADMI values increased proportionally at the low dye concentrations evaluated in
this thesis. ADMI values increased in smaller proportions at concentration levels above 0.1 gil.
In general, judges who viewed samples to determine noticeable color changes agreed only when viewing filtered
samples. The natural turbidity present in nonfiltered samples caused the judges' determinations to vary.
Receiving water did influence the judges' perception of color. The ten judges reported noticeable color shifts at higher ADMI levels for coastal receiving water (122) than
distilled (GG) or piedmont (34) receiving water. On average, the ten judges observed noticeable color
differences at higher filtered and nonfiltered ADM! values for disperse dyes (97 and 111) than fiber reactive dyes (51 and 87). All ten judges reported noticeable color shifts
for the yellow hue at a higher ADM! than the other hues evaluated. Judges reported color in red and green hues at
generally lower levels of ADM!.
To determine at what ADM! clarifier effluent becomes visible, judges were asked to evaluate actual treated
clarifier effluent diluted into different receiving water to
determine noticeable color levels for each condition. For both the filtered and nonfiltered conditions, judges who
performed the observations did not agree on the ADM! values where there was a noticeable color difference. Receiving water type and different clarifier effluents affected the
judges perception of noticeable color.
Further study of the ADM! method of effluent color measurement may produce and effluent color measurement
procedure which overcomes the disadvantages of the current
ADM! method.
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