Effect of 2,4,6-trimercaptotriazine, trisodium salt, nonahydrate on heavy metals bioavailability in soils and accumulation in tobacco

Pot experiments were carried out to study the effects of a novel stabilizer of 2,4,6-trimercaptotriazine, trisodium salt, nonahydrate (TMT) on the bioavailability of heavy metals (Cu, Zn, As, Cd and Pb) in soils and heavy metals accumulation in tobacco. The results showed the optimal TMT dosage 200 mL/kg could effectively reduce the bioavailability of heavy metals in soils, and the bioavailability of Cu, Zn, As, Cd and Pb in soils was reduced simultaneously by up to 73.1, 63.2, 48.0, 68.9 and 57.2%, respectively. Application of TMT could significantly decrease Cu, Zn, As, Cd and Pb contents of all parts of tobacco. Furthermore, the contents of available Cu, Zn, As, Cd and Pb in soils were significantly positively correlated with Cu, Zn, As, Cd and Pb contents in upper, middle and lower leaves and stems of tobacco. There were no significant differences among plant height, number of leaves, stem girth, length and width of maximum leaves of tobacco under TMT treatments and that under control (P < 0.05), which showed that the TMT did not promote and inhibit the growth of tobacco.