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Full-Text Articles in Physical Sciences and Mathematics

The Effect Of Azo Textile Dyes On Gross Primary Production And Community Respiration In An Artificial Environment, Theresa L. Petzoldt Jan 2014

The Effect Of Azo Textile Dyes On Gross Primary Production And Community Respiration In An Artificial Environment, Theresa L. Petzoldt

Honors Theses

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 …


The Impact Of Dams On Nitrogen Cycling In The Messalonskee Stream, Rebecca K. Forgrave Jan 2014

The Impact Of Dams On Nitrogen Cycling In The Messalonskee Stream, Rebecca K. Forgrave

Honors Theses

The Messalonskee Stream in central Maine has five hydroelectric dams on 16.6km. Each dam drastically changes the flow regime of the stream, dividing it into segments with different patterns of sediment settling and organic matter retention. I investigated how these disruptions impact nitrogen cycling, specifically nitrification rates above and below each dam. I expected higher nitrification rates above the dams, where levels of organic matter are higher, and lower rates below the dam where scouring removes organic matter and fine sediment from the streambed. I measured sediment nitrification rates with a nitrapyrin-inhibition assay and potential drivers of nitrification including sediment …