高含盐高硬度废水化学软化的预处理工程

Pretreatment of High Salinity and High Hardness Wastewater by Chemical Softening

针对某工业园区排放的经过超滤+反渗透工艺系统处理过的工业高含盐高硬度废水(总硬度为1 900~3 200 mg/L),采用高密池、液碱-纯碱法及V型滤池处理工艺进行化学软化的预处理。本文首先加入液碱调节废水的pH值至11.2,投加纯碱量为理论计算量的1.2倍;之后投加絮凝剂和助凝剂进行沉淀;沉淀后的出水加入硫酸调节pH值为8左右,然后经V型滤池过滤后出水总硬度可降至100 mg/L以下,浊度降至1.0以下,总硬度去除率达99%以上。

The treatment process of high density pool, liquid caustic-soda method and V type filter was used to treat the high salinity and high alkalinity wastewater from an industrial district after ultrafiltration and reverse osmosis treatment. Firstly, liquid caustic was added to adjust the wastewater pH value to 11.2, and the dosage of liquid caustic was 1.2 times that of theoretical calculation. Secondly, flocculant and coagulant were added to form the sediments. And then, sulphuric acid was added to adjust pH value to 8. Finally, the wastewater was filtered by V type filter. After the above process, the total hardness could decrease to 100 mg/L, the turbidity fell to less than 1.0, at the same time, the total hardness removal rate was over 99%.