Claire Heary

How does duckweed and other plants effect the levels of dissolved nitrates in tap water in Pittsburgh?

Started Apr. 11, 2022

Abstract or project description

Artificial Wetlands: Introduction/Overview: Currently, Pittsburgh’s river water is being treated entirely with a process that begins with Coagulation (use of chemicals: Ferric Chloride, Potassium Permanganate, Carbon, Catatonic Polymer), followed by sedimentation and filtration, then disinfection (Sodium Hypochlorite), followed by Corrosion control (orthophosphate to reduce lead levels), and finished with fluoride (Hydrofluosilicic acid). Ceratophyllum demersum (coontail, hornwort), Elodea canadensis (American elodea, Canadian pondweed), or Lemna minor (common duckweed) significantly reduced the concentration of Metolachlor (MET) that remained in treated water. All three of these plants are abundant in North America and native to Western Pennsylvania, and although they might be considered weeds, they can be used to further cleanse and purify water.

Hypothesis: How might artificial wetlands promote the health of drinking water for Pittsburgh’s citizens? Water that is purified with plants will have lower nitrate levels than water that is not purified with plants.

Experiment to test Hypothesis: Over these next few weeks, the proposed experiment is to measure the nitrate levels in tap water (treated water from the Alleghney river) using water test strips, and the nitrate levels in tap water that is additionally treated with the following plants: Ceratophyllum demersum, Elodea canadensis, and Lemna minor.

General Methods for Proposed Experiments: The general methods for the proposed experiment will include having separate testing cups for tap water, plant treated water, and river water. Using a water test, we can reveal the amount of nitrates that are in the water, and therefore determine how healthy the water will be.

Details about the number of samples, replicates, or other considerations about experimental design: Each time there should be two samples collected from each cup, and there will be three replicates of each cup. The experiment will be conducted over a ___ week time period. Starting june 27, start trial experiment testing bin size, plants, growing location, and sampling methods Might be useful to measure water volume over the trial period to see how it might affect the experiment

Anticipated Results: The anticipated results are that the water that is purified with the plants will have significantly less nitrates in the water than the water fresh from the tap.