To address the co-contamination of phthalic acid esters (PAEs) and cadmium (Cd) in agricultural soils of Guangxi province, a novel approach using immobilized functional microbial agent has been proposed. A composite microbial consortium, composed of three functional bacterial strains including Gordonia sp., Rhodococcus sp., and Bacillus sp., was developed with the ability to tolerate Cd and degrade PAEs. The microbial agent was immobilized on a thiol-modified montmorillonite-biochar composite carrier with optimized preparation conditions to enhance their remediation capabilities. The synergistic remediation efficacy of the agent on PAEs-Cd co-contaminated soils and the underlying mechanisms were elucidated. The results demonstrated that the composite microbial consortium achieved a degradation rate of 92.7% for total PAEs within 5days, while the carrier material exhibited a Cd saturation adsorption capacity of 15.2mg/kg. The optimal immobilization conditions were determined to be 30℃, with a bacteria-to-carrier ratio of 1:20 (V/M) for 1day. Under these conditions, the immobilized microbial agent achieved a degradation rate of 95.4% for ΣPAEs within 5days. When applied at a dosage of 1% to PAEs-Cd co-contaminated soils, the immobilized microbial agent resulted in 54.14% PAEs elimination and 37.06% decrease of exchangeable Cd after 50days. The immobilized microbial agent exhibited favorable synergistic remediation efficacy for PAEs-Cd co-contamination. The research findings provided a theoretical basis for the remediation of PAEs-Cd co-contamination in farmland soil of Guangxi and filled the theoretical gap in the control and remediation of PAEs-Cd co-contamination.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |