Abstract Acacia nilotica gum (NG) was blended with high hydrolyzed grade biodegradable poly (vinyl alcohol) ( M n ¯ 14,000) in different mass proportions to produce a green and efficient flocculant for separartion of a low concentration of kaolin particles (3 mass%) from its suspension. Flocculation efficacy (settling time and turbidity number) was optimized with respect to flocculant dose, PVA-NG blend composition and pH of the medium. Results showed that PVA-NG73 (70% PVA and 30% NG) was the best performing flocculant at 25 ppm dose when the pH of the medium was maintained at 2.6. Zeta potential (both before and after addition of flocculant), hydrodynamic size, isoelectric point and reduced viscosity number were measured to explain the sedimentation rate and turbidity numbers. The floc size was measured and was found to be comparative to the rate of sedimentation. The amount of water absorbed and lost during operation was found to be proportional with the floc size. Impact of inorganic salts on sedimentation was investigated at a neutral pH which showed a faster settling potential of both bivalent and trivalent salts at an optimized concentration (0.3 M), at the best flocculant dose (25 ppm).

中文翻译：

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使用聚乙烯醇 - Acacia nilotica 胶混合物的可生物降解絮凝剂系统絮凝水性高岭土悬浮液

摘要 将尼罗河金合欢胶（NG）与高水解级可生物降解聚乙烯醇（M n ¯ 14,000）按不同质量比例混合制备绿色高效絮凝剂，用于分离低浓度高岭土颗粒（3质量%）从它的暂停。絮凝效果（沉降时间和浊度数）根据絮凝剂剂量、PVA-NG 混合成分和介质的 pH 值进行了优化。结果表明，当培养基的 pH 值保持在 2.6 时，PVA-NG73（70% PVA 和 30% NG）在 25 ppm 剂量下是性能最好的絮凝剂。测量 Zeta 电位（添加絮凝剂前后）、流体动力学尺寸、等电点和比浓粘度数以解释沉降速率和浊度数。测量絮体大小并发现其与沉降速率相当。发现在操作过程中吸收和损失的水量与絮体大小成正比。在中性 pH 值下研究了无机盐对沉降的影响，这表明在最佳絮凝剂剂量 (25 ppm) 下，二价和三价盐在最佳浓度 (0.3 M) 下具有更快的沉降潜力。