Synergy effect of ultrasonication and salt addition on settling behaviors of activated sludge
Synergy effect of ultrasonication and salt addition on settling behaviors of activated sludge
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DOI：
10.1016/j.seppur.2015.02.028
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发表时间：
2015-04
影响因子：
8.6
通讯作者：
E. Iritani;Masako Nishikawa;N. Katagiri;K. Kawasaki
中科院分区：
文献类型：
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作者：
E. Iritani;Masako Nishikawa;N. Katagiri;K. Kawasaki
对超声和氯化钠处理后的剩余活性污泥进行了批量沉降试验，考察了不同超声负荷功率、不同超声时间、不同氯化钠浓度对污泥沉降速度、污泥体积、上清液质量的影响。超声预处理在沉淀初期显著提高了沉淀速度，而在单纯加盐的预处理效果不明显的情况下，添加氯化钠也能显著促进效果。超声作用的效果随载荷功率和超声作用时间的增加而增强，并可通过比超声能量耗散到液体中来评价。预处理带来的沉降速度的增大是由于絮体粒径的增大引起的，基于Stokes定律，考虑絮体粒径和絮体密度的影响，沉降速度与絮体中位粒径有关。此外，与单独超声波和单独加盐的预处理相比，联合预处理显著减少了污泥体积。
The batch sedimentation tests were conducted for the excess activated sludge treated by ultrasonication and addition of sodium chloride, and the settling behaviors such as the sedimentation velocity, the sludge volume, and the quality of the supernatant were examined for different values of the load power of ultrasonication, the sonication time, and the sodium chloride concentration. The ultrasonication pretreatment significantly increased the sedimentation velocity in the initial stage of sedimentation, and the effect was dramatically facilitated by the addition of sodium chloride even when the effect was unnoticeable in the pretreatment of the salt addition alone. The effect of ultrasonication was increased with increasing load power and sonication time and found to be evaluated by the specific ultrasonic energy dissipated into a liquid. The increase in the sedimentation velocity brought about by the pretreatment was caused by the increase in the floc size, and the sedimentation velocity was related to the median diameter of flocs, based on the Stokes law considering the effect of both the floc size and floc density. Moreover, the combined pretreatment markedly reduced the sludge volume, as compared to the pretreatments of ultrasonication alone and salt addition alone.