Remediation Technology Summit

Deirdre Mallyon
Deirdre Mallyon

Business Lead, Business Development

Deirdre holds a BSc in Earth Sciences from Dalhousie University (2014) and an MSc in Geophysics from the University of Alberta (2016). Currently, Deirdre co-leads business development at Eosense, and has been with the company for 2 years working on a number of projects related to the use of continuous monitoring to quantify greenhouse gas emissions in industrial settings. Leveraging her background in Earth Sciences, she has recently been developing strategies to measure the effectiveness of active remediation, and to quantify natural source zone depletion rates at hydrocarbon impacted sites using greenhouse gas fluxes.

Continuous Monitoring of Carbon Dioxide Effluxes Helps Eliminate Biases in Quantifying Contaminant Degradation Rates

Natural Source Zone Depletion (NSZD) has gained significant attention as a remediation method that provides low cost, in-situ management of Light Non-Aqueous Phase Liquids. Carbon dioxide (CO2) efflux is frequently used to quantify degradation rates at impacted sites. However, point sampling programs are problematic because soil respiration rates exhibit large temporal variability, potentially biasing measurements. This complicates interpretation and baseline correction of CO2 efflux data and tends to convolute spatial and temporal variability, reducing confidence in NSZD rates. Here we use model and field data to show that continuous monitoring of CO2 effluxes helps eliminate bias, allowing for accurate quantification of contaminant degradation. Using ecological models, we demonstrate the degree of natural or baseline variability in soil CO2 effluxes and highlight the biases introduced by point sampling. These results are compared to continuous and point measurements collected at hydrocarbon contaminated sites to illustrate how these biases manifest in the field.

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