State Key Laboratory of Clean Energy Utilization, National Environmental Protection Coal-fired Air Pollution Control Engineering Technology Center, Zhejiang University, Hangzhou, 310027, China.
Zhongyou Ruisi Technology Development Co., Ltd, Tianjin, China.
Environ Sci Pollut Res Int. 2019 Sep;26(26):27494-27504. doi: 10.1007/s11356-019-05297-6. Epub 2019 Jul 22.
The reduction of wet desulfurization wastewater is one of the important tasks of coal-fired power plants, and it is important for achieving "zero emissions." Evaporation and concentration (E&C) with waste heat is an effective way to reduce wastewater. Here, two typical types of industrial desulfurization wastewater are used to study the change rule of pH and total dissolved solids during wastewater concentration in a circulating evaporation tower. The results indicate that with the increase of concentration ratio, the pH of desulfurization wastewater is decreased rapidly and then is gradually stabilized at 2-3 when SO or SO is contained in flue gas, and the increase in conductivity is less for wastewater with higher SO content. The characteristics of various ions are also analyzed, and the composition and microscopic morphology of the precipitates are characterized during concentration. The growth pattern of Ca concentration is dependent on the ratio of Ca and SO in raw wastewater. When the concentration ratio is 7.21, the insoluble and slightly soluble substances undergo precipitation and the solid content is approximately 20%, which can help realize the concentration and reduction of desulfurization wastewater.
减少湿式脱硫废水是火电厂的重要任务之一，对于实现“零排放”至关重要。利用余热蒸发浓缩（E&C）是减少废水的有效方法。本文采用两种典型的工业脱硫废水，研究了在循环蒸发塔中废水浓缩过程中 pH 值和总溶解固体的变化规律。结果表明，在浓缩比增加的情况下，当烟道气中含有 SO 或 SO 时，脱硫废水的 pH 值迅速降低，然后逐渐稳定在 2-3，而 SO 含量较高的废水中电导率的增加较小。还分析了各种离子的特性，并在浓缩过程中对沉淀物的组成和微观形貌进行了表征。Ca 浓度的增长模式取决于原废水的 Ca 和 SO 比值。当浓缩比为 7.21 时，不溶性和微溶性物质发生沉淀，固体含量约为 20%，有助于实现脱硫废水的浓缩和减少。
