Positive effects of composite material immobilized enzymes in 2,4,6-trichlorophenol degradation on soil properties and plant growth.

Abstract

2,4,6-Trichlorophenol (2,4,6-TCP) is recognized as a bio-toxic compound which is widely present in water and soil, and immobilized enzymes technology is widely used to degrade 2,4,6-TCP efficiently. However, previous studies have primarily focused on the degradation capability of immobilized enzymes towards 2,4,6-TCP, while the impacts on soil after degradation remain largely unexplored. In this study, sodium alginate/hydroxyapatite/chitosan microspheres immobilized with enzymes were used for 2,4,6-TCP degradation, and the impacts of degradation on soil properties and plant growth were explored. The results indicated that sodium alginate/hydroxyapatite/chitosan microsphere-immobilized enzymes achieved a removal rate of 94.72% for 160 mg L^-1 2,4,6-TCP over 24 h and 73.17% for 160 mg kg^-1 2,4,6-TCP contaminated soil over 72 h. Soil dehydrogenase and catalase activities were enhanced during degradation. The inhibitory effects of 2,4,6-TCP on wheat root and leaf elongation were mitigated by immobilized enzymes that degrade 2,4,6-TCP. Nutrients, such as fast-acting phosphorus and fast-acting potassium, were increased by immobilized enzymes that release nutrient elements. The changes of wheat growth observed in the soil after 2,4,6-TCP degradation by immobilized enzymes were driven by nutrients and degradation. These insights may facilitate the advancement of future applications of immobilized enzyme degradation technologies, contributing to sustainable soil management and ecological restoration.