| 原水性质对新型含Ca2+复合混凝剂混凝过程的影响 |
| 摘要点击 1538 全文点击 487 投稿时间：2018-02-09 修订日期：2018-07-03 |
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| 中文关键词 混凝 复合药剂 Ca2+ 余铝 絮体性质 |
| 英文关键词 coagulation composite coagulant Ca2+ residual aluminum floc characteristics |
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| 中文摘要 |
| 为了提高水处理效率，保证出水水质，需要开发新型高效混凝剂.本实验采用经过Ca2+改性的混凝剂针对不同水样进行混凝实验，考察了浊度、有机物去除、余铝和形成絮体性质.结果表明在纯颗粒物体系中，PACl（聚合氯化铝）和AlCl3中加入的Ca2+对于浊度去除率无明显影响，在低投加量下能够有效降低沉后水中余铝浓度，AlCl3做混凝剂，投加量0.10mmol·L-1时，沉后水余铝浓度从0.15mg·L-1降低到0.10mg·L-1.在腐殖酸体系中，混凝剂中的钙离子可明显降低腐殖酸分子的负电荷，降低沉后水余铝浓度以及增大絮体粒径.对于腐殖酸与蛋白质体系，当投加量为0.16mmol·L-1时，使用含有Ca2+的PACl做混凝剂时，钙离子的存在使得平衡时絮体粒径增加了大约50 μm，可明显改善絮体的沉降性.碱性条件（pH=8.5）下改性混凝剂沉后水中DOC浓度降低0.2~0.6mg·L-1，余铝降低0.4~0.7mg·L-1.酸性条件（pH=5.5）下改性混凝剂沉后水DOC、余铝浓度无明显变化. |
| 英文摘要 |
| To improve the coagulation performances, new composite coagulants were used to treat different water samples. The results indicate that Ca2+ has no significant effects on the removal efficiency for turbidity in the kaolin system. The residual aluminum decreased from 0.15 mg·L-1 to 0.10 mg·L-1 (AlCl3 was used as coagulant and the coagulant dosage was 0.10 mmol·L-1). The presence of Ca2+ led to the decrease of the amount of negative charges in the HA system and the residual aluminum decreased due to the decrease of the complexation between the HA molecules and Al-based coagulants. When the raw water contained BSA molecules and the coagulant dosage was 0.16 mmol·L-1, the flocs formed by PACl with Ca2+ were larger (~50 μm) than the flocs generated by PACl and the settleability also improved. Under alkaline conditions (pH=8.5), the DOC concentration decreased after coagulation process by~0.2-0.6 mg·L-1 and the residual aluminum decreased by~0.4-0.7 mg·L-1 using composite coagulants. Under acidic conditions (pH=5.5), the concentrations of DOC and residual aluminum did not significantly differ. |
