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HIGH SCHOOL

Chemistry

Concept Videos

Analytical Chemistry

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Introduction to Separation Methods

Wastewater Cleanup by Coagulation

Description

Coagulation helps remove colloidal particles from wastewater. Colloids are tiny solid particles suspended in a liquid. They are usually negatively charged, so they attract a compact first layer of positive ions. More counterions gather around them and form an electrical double layer. This charge barrier keeps the particles a...

Transcript

凝固是指胶体颗粒聚集形成较大聚集体的过程。

该技术用于净化含有悬浮胶体固体的废水,这些悬浮胶体固体通常带负电荷,并被吸附离子形成的双电层所包围。

静电排斥作用可防止颗粒发生碰撞,从而稳定胶体。

当加入铝盐或铁盐等金属混凝剂时,它们会与废水中的碳酸氢盐反应,生成相应的氢氧化物。

这些高电荷的反离子可被悬浮固体吸附,从而中和其表面电荷。

快速混合促进悬浮固体之间的碰撞,使其聚结。

此时,颗粒聚集在一起,形成稍大一些但仍为微观的颗粒,称为微絮体。

当微絮体达到最佳尺寸并形成宏絮体时,可通过沉淀或过滤去除,从而获得净化水。