高浓度聚合氯化铝的合成及其形态分布与转化规律

以CaO为碱化剂采用一次加碱法合成了高浓度聚合氯化铝 (PAC) ,研究了其反应特性及产品的铝形态分布与转化规律 .结果表明 ,CaO特殊的水化反应可使PAC达到较高浓度和较高B值 ,PAC最高浓度可达 2 1mol/L ,B值为 2 1 .合成过程中无论高铝浓度体系还是低铝浓度体系 ,均存在一最佳B值 ,此B值下产品的Alb 含量最高 .最佳B值和最高Alb 含量均随总铝浓度的升高而降低 .B值小于最佳B值时 ,总反应主要表现为生成Alb;B值大于最佳B值时 ,总反应表现为生成Alc.

高浓度高Alb含量聚合氯化铝的制备及其水解行为研究

高浓度高Alb含量聚合氯化铝的制备及其相关性质研究一直是国内外学者研究的热点和前沿问题。本文首先采用化学法合成出AlT=0.2mol.L-1,Alb高于85%的低浓度高Alb含量的聚合氯化铝,并在热侧温度55℃,冷侧温度20℃条件下进行膜蒸馏浓缩,首次成功地制备出总铝浓度AlT=2.52mol.L-1,Alb含量高达88%的高浓度高Alb含量的聚合氯化铝溶液。其次,对两种高Alb含量的低浓度和高浓度的聚合氯化铝新产品进行了水解特性研究,分别考察了稀释倍数、pH和稀释时间等因素对溶液中聚铝形态分布的影响。结果表明,稀释刚一开始时,Alb下降比较明显,但随着稀释倍数的增大,Alb含量降低较为缓慢,但在整个稀释过程中Alb含量仍能保持在70%以上;溶液的pH在碱性范围内对聚铝形态有一定影响,在碱性范围内,随着pH的增加,Ala含量逐渐增加,Alb、Alc含量逐渐减少,在酸性和中性较宽的范围内能够保持较高的Alb含量和较低的Ala含量;稀释时间对铝形态的影响较小,Alb聚合形态能够保持较长时间的稳定性。实验结果表明我们所制备的高浓度高Alb含量聚合氯化铝具有相当的化学稳定性。

Study on Application of Novel Flocculating Agent in Treating Refinery Wastewater with High Concentration of Pollutants

After conducting a lot of screening experiments the appropriate flocculating formulations for treating high-concentration wastewater discharged from a certain refinery were selected. The oil removal rate and COD removal achieved by these flocculating formulations were better than that achieved by the conventional compound formulation consisting of polyaluminium chloride(PAC) and polyacrylamide(PAA) . Addition of an oil/water separating agent to the formulation could improve its oil removal performance to facilitate the oil/water separation of the oil-in-water emulsion in the high-concentration wastewater along with improved adaptability of the formulation to the wastewater containing high concentration of pollutants. This flocculating agent has promising prospects for commercial application.