脱硫废水Hg^(2+)-Cl^--SO_3^(2-)体系中汞配合物稳定性影响的研究

Experimental Study on the Stability of the Mercuric Complexes in the Hg^(2+)-Cl^--SO_3^(2-) System

湿法烟气脱硫设备作为可协同脱除烟气中汞污染物的技术得到了广泛应用。但是,脱硫废水排放可能会引起的二次污染却少有关注。本文通过搭建实验台架,根据脱硫废水性质模拟脱硫废水的Hg^(2+)-Cl^--SO_3^(2-)体系。并通过紫外可见光谱分析手段确定C1HgSO_3为脱硫废水中主要汞配合物。实验研究了废水温度、pH、氧化程度以及重金属含量等因素的变化对CIHgSO_3的稳定性的影响。发现废水性质的改变可以打破Hg^(2+)-Cl^--SO_3^(2-)体系的平衡,从而破坏了ClHgSO_3的稳定性。

Wet flue gas desulfurization （WFGD） technologies have been wildely applied in the power plants for their superior performance on co-controlling the acid gases and mercury. However, the secondary pollution which due to the Hg^0 re-emission from desulfnrization wastewater has not received significant attention. In this paper, a laboratory-scale bench reactor was setup to simulate the Hg^2＋-Cl^--SO3^2- system in the desulfurization wastewater. The experiment revealed that ClHgSO3^- was contained in the desulfurization wastewater. The effects of tempreature, pH level, wastewater oxidation degree and iron metal on the stability of the ClHgSO3^- were also investigated. The studies suggested that the change of waste water features could disturbe the steady-state system of Hg^2＋-Cl^--SO3^2- system which stimulated the decomposition of the C1HgSO3.