新型高浓度聚硅氯化铝水解形态与絮凝基础理论研究

Study on the aluminum species and coagulation efficiency of high concentration PASC in diluted solutions

以铝酸钠为碱化剂,采用缓慢滴碱法合成了高浓度(2.0mol·L-1左右)具有不同Si/Al摩尔比γ(Si/Al)的聚硫氯化铝,研究了铝的水解聚合形态和除浊效果.AlFerron和AlNMR分析结果表明,随着γ(Si/Al)的增加,Al13/Alb形态的含量逐渐减小,Al单体和Al高聚体形态含量逐渐增大.烧杯实验结果表明PASC浓度高、最佳投加量低,絮凝效果好,pH适用范围广,可显著降低处理成本.Al水解形态与絮凝效果的研究表明以铝酸钠为碱化剂制备的高浓度絮凝剂的絮凝效果不宜用Al13/Alb含量高低来表征.

High-concentration （about 2.0 mol·L^-1） flocculants -polyaluminum silicate chloride （PASC） with different Si/Al mole ratio γ （Si/Al） and polyaluminum chloride （PAC） were prepared using NaAl02 as basification agent. The chemical species distributions of PASC and PAC were compared, which were determined by Al-Ferron complexation timed spectrophotometric and 27Al-NMR methods respectively. Jar-test was applied to evaluate the coaguation efficiencies. The experimental results show that the species distribution and transformation of PASC are different from those of PAC, due to the interaction of polysilicic acid and hydrolyzed aluminum species. The Al13/Alb and Al other/Als concentration decreased while the monomer species Al mono/Al, concentration increased with the increasing of γ （Si/Al）. The result of the jar-test shows high concentration PASC, which has great advantage in water treatment owing to its low dosage, high coagulation efficiency and wide pH value adaptation. However, it is not appropriate to express coagulation efficiency of PASC and PAC using Al13/Alb concentration.