Date of Award


Document Type

Honors Thesis (Open Access)


Colby College. Environmental Studies Program


Denise Bruesewitz


Azo dyes are the largest category of textile dyes in production today, with over 100,000 tons of dye produced yearly in the United States. Ten to fifty percent of this dye is not fixed to the fabric during the textile production process, and is therefore discarded as effluent. Because dye waste is difficult to process in wastewater treatment facilities, it is important to understand how this waste affects aquatic systems using a whole ecosystem approach. This study used an artificial stream to model the effects of four azo dyes on benthic biofilm production and respiration. Dyes were found to have varying effects on primary production, respiration, and net ecosystem production, with Acid Red 1 being the most inhibitory of gross primary production. A pulse release of this dye monitored over time revealed the main factor influencing primary production to be light limitation, rather than acute toxicity. Because legislation surrounding dye effluent is based upon perceivable color, and therefore light limitation, it was concluded that current legislation regulates textile effluent in an appropriate manner.


textile waste, effects, laws, dyes, community, stream

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