REMEDIATION OF SOIL CONTAMINATED WITH SALT, ZINC AND MANGANESE BY LANDSCAPE PLANTS AND MODIFIER

In order to provide a basis for the remediation of severely contaminated soil with salt, Zn and Mn, a pot experiment was conducted by adding combined modifier (TH-SM01) to the polluted soil and planting landscape plants. The salt, Zn and Mn tolerance capacity of plants, and the effect of TH-SM01 on the soil total salt content, Zn and Mn available contents were studied in the experiment. The results showed that bird of paradise flower (Strelitzia reginae Aiton) had strong salt, Zn and Mn tolerance, and could be used preferentially in the heavy salt, Zn and Mn contaminated soil. The salt tolerance of the four plants, redflowered loropetalum (Loropetalum chinense (R. Br.) Oliver var. rubrum Yieh), michelia figo (Michelia figo (Lour.) Spreng.), fragrant flower (Osmanthus fragrans (Thunb.) Loureiro), and bougainvillea glabra (Bougainvillea spectabilis Willd.) were inferior to that of birdofparadise flower, but they could still grow with TH-SM01 applying. In addition, michelia figo and bougainvillea glabra could hyperaccumulate Mn. Adding TH-SM01 into the soil could reduce the soil total salt content, and TH-SM01 could continue to play the role of desalination after being planted for three months. TH-SM01 could increase soil pH, but the increase trend was decreasing with the extension of applying time. At the same time, TH-SM01 could reduce the content of DTPA-Zn and DTPA-Mn in soil, especially DTPA-Mn content. The reduction rate of DTPA-Mn content was 94.45%~96.21% after being planted for three months. Therefore, the measure that applying TH-SM01 to reduce salt, DTPA-Zn, DTPA-Mn content in soil, and planting tolerant plants, to remediate severely contaminated soil with salt, Zn and Mn, was proved to be feasible.