Department of Civil, Geological and Environmental Engineering, University of Saskatchewan, Canada.
Department of Civil, Geological and Environmental Engineering, University of Saskatchewan, Canada.
Sci Total Environ. 2019 Jun 1;667:400-411. doi: 10.1016/j.scitotenv.2019.02.067. Epub 2019 Feb 10.
It has been increasingly reported that aerobic soil respiration activity (CO production and O consumption) is measurable in frozen cold-climate soils. This study modifies the Generalized Respiration (GRESP) model, a function of soil temperature (T) and unfrozen water content (M), to cover the frozen, partially frozen and unfrozen phases of successfully bioremediated, petroleum hydrocarbon-contaminated, sandy sub-Arctic soils. The Michaelis-Menten equation was modified to express the observable change in unfrozen water content near 0 °C, which is related to soil respiration activity during soil phase changes and at temperatures below the effective endpoint of detectable unfrozen water at -2 °C. The modified Michaelis-Menten equation was further combined with a Q temperature term, and was then incorporated into the GRESP equation to produce a new URESP model for the engineered soil bioremediation system at sub-zero temperatures. The URESP model was applied to published input data measured from the biostimulated site soils of a pilot-scale soil tank experiment conducted between -5 and 15 °C. The model fit well with the experimental data for CO production (R = 0.96) and O consumption (R = 0.92). A numerical soil thermal model (TEMP/W model) of the thawing biotreated soils in the tank was also used in this study to produce valid alternative (predictive) input T and M data for the URESP model. The URESP-derived respiration quotients (RQ; 0.695 to 0.698), or the ratios of CO production to O consumption, aligned with the experimental RQ values from the soil tank experiment (0.69) and fell within the theoretical RQ range for aerobic hydrocarbon degradation (0.63-0.80). The URESP model combined with the TEMP/W simulation approximated changes in soil respiration during thawing and characterized the computed soil respiration outputs as related to hydrocarbon utilization, based on their RQ values.
越来越多的报道表明，在寒冷气候的土壤中可以测量到有氧土壤呼吸活性（CO 产生和 O 消耗）。本研究修改了通用呼吸（GRESP）模型，该模型是土壤温度（T）和未冻结水含量（M）的函数，以涵盖成功生物修复的、受石油烃污染的、亚北极沙土的冻结、部分冻结和未冻结相。米氏方程被修改为表达 0°C 附近未冻结水含量的可观察变化，该变化与土壤相变过程中和检测到的未冻结水有效端点以下的温度下的土壤呼吸活性有关。修改后的米氏方程进一步与 Q 温度项结合，并被纳入 GRESP 方程中，为亚零温度下的工程土壤生物修复系统产生了新的 URESP 模型。URESP 模型应用于从 -5 到 15°C 进行的小型土壤罐实验的生物刺激现场土壤测量的已发表输入数据。该模型与 CO 产生（R = 0.96）和 O 消耗（R = 0.92）的实验数据拟合良好。本研究还使用了罐中解冻生物处理土壤的土壤热数值模型（TEMP/W 模型），为 URESP 模型生成有效的替代（预测）输入 T 和 M 数据。URESP 衍生的呼吸商（RQ；0.695 至 0.698），即 CO 产生与 O 消耗的比值，与土壤罐实验的实验 RQ 值（0.69）一致，并落在有氧烃降解的理论 RQ 范围内（0.63-0.80）。URESP 模型与 TEMP/W 模拟相结合，模拟了解冻过程中的土壤呼吸变化，并根据它们的 RQ 值将计算出的土壤呼吸输出特征化为与烃类利用相关。
