Assessing Ecological Impacts Of Land-Applied Municipal Biosolids : Effects Of Run-Off And Tile Drainage On The Aquatic Organisms Daphnia Magna, Hyalella Azteca And Lemna Minor
thesisposted on 22.05.2021, 16:50 by Sonja Gebert
The effect of municipal land applied biosolids run-off and tile drainage on aquatic organisms Daphnia magna, Hyalella azteca and Lemna minor was analyzed through a series of standardized eco-toxicological tests. Treatments included reference soil, reference soil amended with Guelph biosolids and reference soil amended with Kitchener biosolids. The assessment was done on biosolids elutriate collected after the simulated rainfall off the ramps on day 1 after the application of biosolids, and day 40 planted versus unplanted soil. Respiration rates, behavioural analysis and survivorship were tested on the two invertebrates, while 7-day Growth Inhibition test was performed on the plant. Although there were some significant differences between the reference soil and soil amended with biosolids elutriate, they were mostly on day 1 and in concentrations that are not likely to happen in nature. The plant Lemna minor showed eutrophication potential in elutriate from Day 1. The results are showing that although there are potential toxic constituents in the municipal biosolids that can adversely affect the aquatic life in the receiving waters, they largely very temporary and for the most part in concentrations that are environmentally irrelevant. To be able to understand the potential of using biosolids on agricultural fields in Ontario, more analytical and eco-toxicological studies should be performed that are relevant to Ontario's laws and topography.