机械破碎强度对絮体破碎再絮凝过程的影响

发布时间：2018-01-02 19:24

本文关键词：机械破碎强度对絮体破碎再絮凝过程的影响　出处：《中国给水排水》2016年17期 　论文类型：期刊论文

【摘要】：采用连续流混凝沉淀反应器,研究了絮凝过程中机械搅拌强度对絮体破碎再絮凝过程以及出水水质的影响。结果发现,絮体破碎再絮凝的平均粒径无法恢复至破碎前的水平,同时絮体内部结构发生了变化。当破碎阶段的搅拌转速为250 r/min时,破碎后的絮体再絮凝程度较高,絮凝结束阶段絮体平均粒径为72.9μm,接近破碎前的水平(76.1μm),同时几何分形维数由未破碎时的1.80降至1.75,说明絮体的内部结构变得更加紧实;近球态絮体的比例升至58.7%,长链态絮体比例则降至41.3%,说明机械破碎可以改变絮体形态;对于浊度为100 NTU的原水,沉淀出水浊度由未破碎时的6.69 NTU降至破碎再絮凝后的5.85 NTU,说明适当地进行机械破碎可以提高絮凝处理效果。
[Abstract]:By continuous coagulation reactor, study the flocculation process of mechanical stirring and crushing strength and flocculation process affecting the water quality of the floc. The results showed that the average particle flocculation floc breakage size can not be restored to the level before the break, and the internal structure of flocs changed. When the stirring and crushing stage the speed is 250 r/min, the broken floc flocculation degree is high, the end stage of flocculation floc average particle size of 72.9 m, close to the level before the break (76.1 m), while the geometric fractal dimension from 1.80 to 1.75 is not broken, the internal structure of the Ming said the flocs become more compact; in the sphere of floc ratio rose to 58.7%, the long chain state of floc proportion dropped to 41.3%, the mechanical crushing can change the shape of the flocs; for the raw water turbidity was 100 NTU, precipitation water turbidity decreased from 6.69 NTU without broken broken again after flocculation 5 .85 NTU, indicating that proper mechanical crushing can improve the effect of flocculation treatment.

【作者单位】：哈尔滨工业大学市政环境工程学院;
【分类号】：TU991.2
【正文快照】： 传统絮凝理论期望形成粒径较大、结构密实的絮体,并且尽量避免已形成的絮体发生破碎。因此,进行絮凝池设计时,应采用絮凝强度递减的水动力学条件[1]。但是,近年来很多研究发现,混凝沉淀过程中絮体的破碎是不可避免的,且破碎过程具有不可逆性[2~4]。但也有少数研究指出,对于特

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