Student Research Projects

Effectiveness of Amendments in Reducing the Release of Nutrients and Mercury from Green Roofs

Student Lan Tran
Faculty Mentor(s)
Department Earth and Environmental Sciences
Course EES 489: Research in the Natural Sciences


This study tests the effectiveness of two treatments, Phos Filter and Alum, on nitrogen and phosphorus release from green roofs. Rain samples were collected from the green roof experimental plots placed near Lake Taylor, from the Smithdeal green roof, and from the Miller green roof in Portsmouth, VA.

Phos Filter is a commercial product made to remove phosphorus from stormwater, and according to the findings of Maravich, Alum seemed to reduce phosphate load the most.

Phosphorus was analyzed spectrophotometrically with the ascorbic acid method, and nitrogen was analyzed with 2 point UV spectroscopy following persulfate digestion. In addition to nutrient runoff, samples will be analyzed for mercury levels using EPA Method 1631.

A significant decrease in nutrient release would suggest that the treatment(s) are effective at retaining phosphorous and/or nitrogen. On the other hand, if the water samples of treated replicates contain nearly equal or higher nutrient levels than the untreated green roofs, it would suggest that the treatment(s) are ineffective.