高盐水条件下亚硫酸盐氧化特性实验研究

在“水十条”背景下，脱硫废水零排放已是大势所趋，利用烟气余热浓缩脱硫废水将脱硫废水减量化引起业内关注。在烟气预浓缩过程中有较少的SO₂转移至液相，产生SO₃ ^2-、HSO₃ ^-、SO₄ ^2-。其中亚硫酸盐性质不稳定，会影响后续处理。为探究此过程中高盐水条件下亚硫酸盐的氧化特性，通过氧化还原电位（ORP） 和溶解氧联合监控，对亚硫酸盐的氧化特性进行研究。研究发现：烟气含氧量促进亚硫酸盐氧化；脱硫废水浓缩倍率同ORP值呈正相关，有利于亚硫酸盐的氧化；烟气预浓缩过程中亚硫酸盐氧化情况较好，氧化率可达94.7%，不需要进行强制氧化。此研究对烟气浓缩过程中控制结垢及减少对后续处理的不良影响具有重要的价值。

Experimental study on oxidation characteristics of sulfite under high salt water condition

Under the background of “Water pollution control action plan”, zero discharge of desulfurization wastewater has become the development trend of the era. The use of flue gas waste heat concentrated desulfurization wastewater to reduce desulfurization wastewater has attracted industry attention. During the pre-concentration of the flue gas, less SO₂ is transferred to the liquid phase to produce SO₃ ^2-, HSO₃ ^-, SO₄ ^2-. The sulfite nature is unstable and subsequent treatment will be affected. To explore the oxidation characteristics of sulfite under high salt water conditions in this process, the oxidation characteristics of sulfites were studied by oxidation-reduction potential(ORP) and dissolved oxygen. The study found that flue gas oxygen content promoted sulfite oxidation. The concentration ratio of desulfurization wastewater is positively correlated with the ORP value, which is beneficial to the oxidation of sulfite. Better sulfite oxidation during pre-concentration of flue gas, the oxidation rate can reach 94.7%, and no forced oxidation is required. This study is of great significance for controlling fouling during flue gas enrichment and reducing adverse effects on subsequent treatment.