关键词: 壳聚糖, 甘草水提液, z电位, 絮凝, 沉降速度, 模型

Abstract: Chitosan was used to flocculate the licore water-leaching solution. The effects of pH value, the concentration of flocculant on flocculation rate, Zeta potential and settling velocity were examined. The results show that under the same pH condition, with the increase of flocculant dosage, the absolute value of Zeta potential first decreases and then increases, and the flocculation rate first increases and then decreases. In the range of effective flocculation, settling velocity increases with the increase of flocculant dosage. The optimal flocculant dosage is 0.347 g/L. The resulting solution has the highest clarity, flocculating rate can reach 93.58%, Zeta potential of 2.94 mV, the maximum subsidence velocity is 18 mm/min. Under the same condition of flocculant dosage, with the increase of pH value, the absolute value of Zeta potential first decreases and then increases, and the flocculation rate first increases and then decreases, settling velocity increases with the increase of pH value, the optimum pH value is 5, whereas the highest clarity of solution occurs, flocculation rate can reach 94.53%, Zeta potential is 2.04 mV, the maximum sedimentation velocity 15 mm/min. The closer the Zeta potential of experimental system to the isoelectric point, the more advantageous the flocculation of water leaching solution of traditional Chinese medicine. A settling velocity model was established through regression analysis on experimental data, and its rationality explained by the particle sedimentation theory in solid-liquid separation.

Key words: chitosan, licore water-leaching solution, Zeta potential, flocculation, settling velocity, model