PDF下载

[1]孙志涛,李军,王秀杰,等.吸附架桥机理主导下APAM的多级絮凝效能[J].中国给水排水,2022,38(1):31-39.
　SUN Zhi-tao,LI Jun,WANG Xiu-jie,et al.Multi?stage Flocculation Efficiency of APAM Led by Adsorption and Bridging Mechanism[J].China Water & Wastewater,2022,38(1):31-39.

点击复制

吸附架桥机理主导下APAM的多级絮凝效能

中国给水排水[ISSN:1000-4062/CN:12-1073/TU] 卷: 第38卷期数: 2022年第1期页码: 31-39 栏目: 出版日期: 2022-01-01

Title:: Multi?stage Flocculation Efficiency of APAM Led by Adsorption and Bridging Mechanism

作者:: 孙志涛，李军，王秀杰，杜鹏，张阳，裴晗博; （北京工业大学建筑工程学院水质科学与水环境恢复工程北京市重点实验室，北京 100124）

Author(s):: SUN Zhi-tao， LI Jun， WANG Xiu-jie， DU Peng， ZHANG-Yang， PEI Han-bo; （Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering， College of Architecture and Civil Engineering， Beijing University of Technology， Beijing 100124， China）

关键词:: 多级絮凝; 阴离子聚丙烯酰胺; 吸附架桥; 絮体特性; 再絮凝; 污泥脱水

Keywords:: multi-stage flocculation; anionic polyacrylamide; adsorption and bridging; floccharacteristics; re-flocculation; sludge dewatering

摘要:: 对吸附架桥机理主导下阴离子聚丙烯酰胺（APAM）的絮凝过程进行了研究，通过改变絮凝剂投加工况，对比分析常规絮凝与多级絮凝在污染物去除效果、絮体性能、絮体生长动力学与污泥调理能耗等方面的差异。结果表明，相同投药量下，两级絮凝的出水浊度低于三级絮凝和常规絮凝，两级絮凝在最少的APAM投加量（2 mg/L）下达到最低的出水浊度（19.53 NTU）；与常规絮凝相比，两级絮凝的絮体成长速率、平均粒径和沉降速率分别增加12.67%、30 μm、36.74%。两级絮凝在投加间隔为240 s、投配比为1∶1条件下絮凝效能最优，出水浊度为15.34 NTU，絮体沉降速率为1.1 NTU/s，絮体密度达到1.123 4 g/cm³。絮体破碎再絮凝过程中，两级絮凝与常规絮凝破碎后均能恢复至破碎前水平，但破碎后均出现不可逆的絮体结构破损，粒径在0~100 μm的絮体颗粒增多，粒径>400 μm的絮体减少，破碎后两级絮凝的絮体强度因子（68.15%）高于常规絮凝（41.63%），两级絮凝的絮体强度和抗破碎剪切能力更高。在剩余污泥调理方面，两级絮凝产生的污泥只需要投加40 mg/L的APAM就可以达到最低的滤饼含水率（75.5%）。因此，两级絮凝可以显著提升除浊效能与絮体性能，是强化絮凝的发展方向。

Abstract:: Flocculation process of anionic polyacrylamide (APAM) led by adsorption and bridging mechanism was explored. The differences between conventional flocculation and multi-stage flocculation in pollutants removal, flocculation performance, flocculation growth kinetics and sludge conditioning energy consumption were compared and analyzed by changing flocculant dosing conditions. Under the same dosage, the effluent turbidity of the two-stage flocculation was the lowest, followed by the three-stage flocculation and the conventional flocculation. The two-stage flocculation achieved the lowest turbidity of 19.53 NTU in the effluent at the minimum dosage of APAM (2 mg/L). Compared with conventional flocculation, the growth rate of floc, average particle size and sedimentation velocity of two-stage flocculation increased by 12.67%, 30 μm and 36.74%, respectively. The best flocculation performance of the two-stage flocculation was obtained under the condition of dosing interval of 240 s and dosage ratio of 1∶1, and the effluent turbidity was 15.34 NTU, the floc sedimentation velocity was 1.1 NTU/s and the floc density reached 1.123 4 g/cm³. In the process of floc breakage and re?growth, both the two-stage flocculation and the conventional flocculation could recover to the level before breakage. However, irreversible damage of the floc structure occurred after breakage. Proportion of flocs with sizes of 0-100 μm increased, and proportion of flocs with sizes more than 400 μm decreased. In addition, the strength factor of the two-stage flocculation (68.15%) after breaking was higher than that of the conventional flocculation (41.63%), and flocs produced by the two-stage flocculation had higher strength and stronger shear resistance. In terms of excess sludge conditioning, the lowest water content of filter cake (75.5%) could be achieved by only adding 40 mg/L APAM for the sludge produced by two?stage flocculation. Therefore, two?stage flocculation can significantly improve the turbidity removal efficiency and flocculation performance, which is a promising direction of enhanced flocculation.

更新日期/Last Update: 2022-01-01