Study on Cadmium Adsorption Characteristics of a Dark Septate Endophytes

PurposeTo study the adsorption characteristics of cadmium (Cd) for dark septate endophytes (DSE), providing theoretical basis for using DSE adsorption to remove Cd pollution.

MethodUsing a DSE (Exophiala pisciphila ACCC32496) as a research material to explore the influence factor (pH value, initial Cd mass concentration and adsorption time) of the mycelium adsorption Cd.

ResultsThe optimal pH value for Cd adsorption by E. pisciphila was 5, and as the initial Cd mass concentration increased, the adsorption amount increased until it reached the saturation state, and the maximum adsorption amount was 14.14 mg/g. The adsorption process was divided into a fast reaction and a slow reaction stage. The Cd adsorption amount in 60 min was 11.37 mg/g. The adsorption process conformed to Langmuir adsorption isothermal model, and adsorption dynamics conformed to the quasi-secondary rate equation. Infrared spectrum analysis showed that E. pisciphila adsorption Cd involved amino, amido, carboxyl, hydroxyl, and phosphoryl groups. The analysis test showed that HNO₃ and Na₂EDTA had the strongest ability to desorb Cd from the E. pisciphila.

ConclusionsDSE E. pisciphila ACCC32496 has a good adsorption effect on Cd, mainly relying on the amino, amido, carboxyl, hydroxyl, and phosphoryl groups on the cell wall.