Optimization study of biopile ventilation system based on microbial respiration intensity

Abstract

[Objective] In order to address the challenges in the precise design of ventilation systems for biopile remediation of contaminated soil, [Methods] an innovative design framework based on microbial respiration dynamics was developed. Through pilot-scale data comparison, the theoretical model using the CO₂ production rate as an indicator(with a deviation of 10.7 times) was proved far superior to the traditional O₂ consumption model(with a deviation of 1 450 times), confirming the validity of CO₂ as a high-sensitivity dynamic monitoring indicator. [Results] The optimized “effective extraction flow rate”(406 m³·h^-1) was the core engineering parameter for maintaining an efficient degradation environment and avoiding metabolic inhibition. Throughout a two-week pilot remediation, the degradation efficiency of petroleum hydrocarbons(C₁₀-C₄₀) in the test group(area 1) using the optimized system reached 62.70%, which was significantly higher than that of 30.94% in the control group(area 2). Moreover, the effectiveness of the system was further verified at the microbial level by facilitating the enrichment of key degrading bacteria(Bacillus and Flavobacterium). [Conclusion] The established semi-empirical system of “theoretical calculation + comprehensive engineering coefficient(10.7)” realizes the direct coupling between microbial physiological characteristics and engineering parameters, offering a scientifically sound and practical approach for biopile ventilation design.

Keywords

biopile / petroleum hydrocarbon-contaminated soil / aeration system / soil respiration / biodegradation / microorganism / energy consumption