Abstract:

The influence of sodium aluminate adding quantity and the reaction pH on the removal efficiency of silicon dioxide was researched, the Ca²⁺ and Mg²⁺ removal efficiency was also investigated. It showed that the best effect of silicon dioxide removal by sodium aluminate appeared when the pH was controlled at 8.5. At the same time, if the additive mass ratio of sodium aluminate and silicon dioxide was controlled at 2:1, silicon dioxide concentration in the wastewater could be reduced to below 5 mg/L, and the removal rate of silicon dioxide was more than 95%. The residual amount of aluminum ion was just 0.47 mg/L in treated water, which would not cause a significant increase in aluminum ion content. In the process of silicon dioxide removal, calcium ions have no change while the magnesium ions reduced 15%.

Key words: silicon dioxide, sodium aluminate, high salt wastewater, zero discharge

摘要：

研究了偏铝酸钠的投加比、pH对二氧化硅去除效果的影响，同时考察了偏铝酸钠除硅时对Ca²⁺、Mg²⁺的去除效果。研究表明，当pH控制在8.5时对二氧化硅的去除效果最佳，同时偏铝酸钠与二氧化硅的投加质量比在2：1时即可将废水中的二氧化硅降至5 mg/L以下，去除率达到95%以上。除硅后产水中残留铝离子仅有0.47 mg/L，不会造成铝离子含量的明显上升；在偏铝酸钠除硅过程中对钙离子几乎没有去除作用，而对镁离子有15%的去除率。

关键词: 二氧化硅, 偏铝酸钠, 高盐废水, 零排放

CLC Number: 

• X703.5