Slightly acidic (pH 5.1) waste sludge with 4.7 % Total Solids (TS) was treated on a laboratory scale pined disc rotary generator of hydrodynamic cavitation (PD RGHC). Influence of four rotor discs with different number of cavitation generation units (CGUs) was investigated: 8-pins, 12-pins, 16-pins and 8-prism elements. The effect of hydrodynamic cavitation (HC) was investigated by analyzing rheological properties, surface tension, dewaterability, and particle size distribution. After subjecting the sludge to 30 cavitation passes, the dewatering ability of the sludge significantly decreased, resulting in a more than two-fold increase in Capillary Suction Time (CST). All regimes were successful in disintegrating particles to smaller sizes. A slight increase of sludge surface tension was measured post cavitation. Cavitated samples displayed a zero-shear viscosity, in contrast to the untreated sample, where viscosity noticeably increased as shear stress decreased. HC did not improve methane yield. Statistically significant correlations between physio-chemical properties and apparent viscosity at low shear stress were identified. Although there were no discernible statistical differences in sludge characteristics, some trends are visible among investigated CGU designs and warrant further research.

中文翻译：

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初步分析水力空化旋转发生器对废水污泥流变性和甲烷产率的影响


总固体量 (TS) 为 4.7% 的弱酸性（pH 5.1）废污泥在实验室规模的水动力空化针盘旋转发生器 (PD RGHC) 上进行处理。研究了具有不同数量的空化产生单元 (CGU) 的四个转子盘的影响：8 销、12 销、16 销和 8 棱柱元件。通过分析流变特性、表面张力、脱水性和粒度分布来研究水动力空化 (HC) 的影响。污泥经过30次空化后，污泥的脱水能力显着下降，导致毛细管吸入时间（CST）增加两倍以上。所有方案都成功地将颗粒分解成更小的尺寸。空化后测量到污泥表面张力略有增加。与未经处理的样品相比，空化样品表现出零剪切粘度，其中粘度随着剪切应力的降低而显着增加。 HC 没有提高甲烷产率。确定了物理化学性质和低剪切应力下表观粘度之间具有统计学意义的显着相关性。尽管污泥特性没有明显的统计差异，但在研究的 CGU 设计中可以看到一些趋势，值得进一步研究。