Enhancing polycyclic aromatic hydrocarbon soil remediation in cold climates using immobilized low-temperature-resistant mixed microorganisms.

ABSTRACT

Polycyclic aromatic hydrocarbons (PAHs), widespread organic pollutants, significantly impact human health and environmental integrity. Recent approaches to ameliorate PAH-contaminated soils, particularly in cold environments, have been insufficient. This study investigates the use of immobilized low-temperature-resistant mixed microorganisms (LTRMM) for enhancing the degradation of PAHs in soils from coke plants and the Shenfu irrigation area. Our results demonstrate that treatment with immobilized mixed microorganisms (MC-HS) is more effective than treatments with free bacteria (H-S) and control (CK). Specifically, the degradation rates in the MC-HS1 treatment were 10.10 %-41.13 % higher than those in the coking plant soil treated with CK1 and H-S1. Similarly, in the Shenfu irrigation area soil, MC-HS2 showed improvements of 6.00 % to 52.56 % over CK2 and H-S2. A kinetic model was used to analyze the enhanced degradation capabilities, revealing that the half-life of PAHs under the immobilized mixed microorganism treatment (T3) was significantly shorter compared to the free bacteria (T2) and control treatments (T1). These findings suggest that employing immobilized LTRMM could significantly improve the remediation efficiency of PAH-contaminated soils in cold climates.