Thesis Details

Thesis Title: An analysis of the effects of selected variables on the ADMI method of effluent color measurement
Thesis Author: William C. McKinney, Jr.
Abstract: 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.