Selective removal of mercury ions by functionalized Ti-Zr bimetallic coordination polymers

摘要

In order to effectively treat mercury pollution, a bimetallic coordination polymer (Ti/Zr-TA) was successfully synthesized by doping Ti metal for mercury removal in wastewater. The optimum pH (5.0), maximum adsorption capacity (298-318 K: 583.5, 615.4 and 654.4 mg/g), and thermodynamic behavior (endothermic) of Ti/Zr-TA was obtained by batch experiments. The adsorption process conforms to pseudo-second-order kinetic model and Hill isotherm model. Selectivity experiments confirmed that Ti/Zr-TA had a strong interaction with Hg(II), which was more easily adsorbed than interfering ions. Adsorption-desorption experiments indicated that Ti/ZrTA had excellent reusability, and the removal rate decreased by only 15.2 % after four cycles. In addition, the adsorption mechanism was revealed, mercury ions were adsorbated by electrostatic interaction and chelation, in which the chelation between the functional groups containing O, S and Hg(II) was dominant.

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