Our Modeling
One of the local water treatment plants, the Timpanogos Special Service District, whose effluent goes directly into Utah Lake is our source for the proposed function/model of chlamy within the real world. With an influent phosphate concentration of 5.2 mg P/L and a daily average flow rate of 96.5 million liters, the Timpanogos Special Service District plant has approximately 504 kg of phosphate going through it daily. We found that the maximum uptake of phosphate for chlamy transformed with Psr1-nanoLuc was 3.75 x 10-9 mg P/cell/day. This means that we would need (5.04 x 1011 mg P) / (3.75 x 10-9 mg P/cell/day) = 1.35 x 1017 cells of chlamy to remove all of the phosphate passing through the wastewater treatment plant in a given day. We have been able to grow chlamy at a density of 3 x 109 cells/L without experiencing significant cell death, which is a higher density than that needed to remove the phosphate from the water, given current flow rates and phosphate concentrations (1.35 x 1017 cells/96.5 x 106 L = 1.4 x 109 cells/L). The values in our calculations were taken from the detailed facility report on the EPA ECHO database.
Assumptions in our model:
- Within the waste water treatment plant, our transformed chlamy will be able to achieve the maximum rate of P uptake as observed in our experiments.
- Flow rates through the treatment plant are slow enough for chlamy to have time to uptake phosphate.
- Our transformed chlamy will uptake P at a constant rate, regardless of the concentration of P in the effluent.
Conclusions:
- While our model simplifies the overall complexity of nutrient removal within the context of a wastewater treatment plant, it does show promise that this could a viable option for phosphate, and maybe even nitrate, in the future.
