Abstract

• Phytoremediation is an emerging technology that uses various plants to degrade contaminants including metals, and pesticides from soil and water. The aim of this research is to determine the insecticide residue and enzyme activity during phytoremediation with Sinngo and Hngetdaw-ni myet. In this study, the physicochemical properties of the soil samples were determined by conventional techniques, and EDXRF and AAS were used to determine metals before and after remediation (January 2023 to March 2023) in cold season. Phytoremediation was used to remediate cypermethrin-contaminated soil in the concentration range of 1-100 µg kg-1. In addition, the potential phytoremediation efficiency of two plant species, Sinngo (Eleusine indica (L.) Gaertn.) and Hngetdaw-ni myet (Axonopus compressus (Swartz.) P. Beauv.) was evaluated. The residual insecticide and its metabolite, 3-phenoxybenzoic acid (3-PBA), extracted from the soil samples of the experimental plot were examined using a UV-Vis spectrophotometer. The highest phytoremediation efficiency was demonstrated by Sinngo and Hngetdaw-ni myet (89.6 and 87.4 % of PBA removal) in a 10-week period. The activities of urease and dehydrogenase enzymes were determined by the phenol-hypochlorite colourimetric and the Triphenyl Tetrazolium Chloride (TTC) assay methods. The urease enzyme activities (mg NH4+-N g-1 soil h-1) in soils treated with Sinngo myet (5.46 ± 0.0206) and Hngetdaw-ni myet (4.45 ± 0.0113) were found to be higher the uncultivated soil (S0) (1.34 ± 0.01419), and the dehydrogenase enzyme activities (µg TPF g-1 soil h-1) in soils treated with Sinngo myet (0.0033 ± 0.0042) and Hngetdaw-ni myet (0.0026 ± 0.0000) were also increased the uncultivated soil S0 (0.00011 ± 0.00046) in the field experiment. The results clearly demonstrated that Sinngo and Hngetdaw-ni myet showed great promising potential as phytoremediating agents for the further clean-up of insecticide contaminated soil.