【作者】 张健；

【导师】 贺高红；

【作者基本信息】 大连理工大学 ， 化学工程， 2006， 硕士

【摘要】 本无机高分子絮凝剂聚合氯化铝（PAC）中的Al_b形态含量是衡量其絮凝活性的主要指标。因此,如何有效地制备Al_b含量高的PAC产品已成为研究的重点。目前,现有的PAC制备方法如一次加碱法、微量加碱法等,可控性不强,连续性较差,且产品中Al_b的含量不高。 本文基于中空纤维膜表面具有大量的微米级的微孔这一特点,采用中空纤维膜反应器作为碱液分布器制备PAC,实现了碱液微量连续可控地加入到AlCl₃溶液中,从而显著提高了产品中的Al_b含量,并且实验成本低,无污染。 本研究采用双循环回路,碱液在膜的管程流动,AlCl₃溶液在膜的壳程流动,以内压法使碱液加入到AlCl₃溶液中,与AlCl₃反应制备PAC,并采用Al-Ferron逐时络合比色法对最终PAC产品的Al_b含量进行检测。 实验考察了碱化度B、原料液流动路径、AlCl₃溶液流速和浓度、NaOH溶液浓度、碱原料液碱性、膜反应器截留分子量和有效长度等对PAC产品中铝水解聚合形态的影响,观测了产品的微观形态,优化了反应条件,并用膜法制备的PAC产品进行了处理染料模拟废水的应用研究。 在实验研究范围内,碱化度B为2.0、碱液（NaOH）采用内压法、浓度为0.2 mol·L^-1、AlCl₃溶液浓度为0.5 mol·L^-1、流速为28.58 ml·S^-1、低截留分子量的短膜反应器有利于制备高Al_b含量的PAC产品。对100ppm的染料模拟废水,染料溶液pH值为4.1时,处理效果最佳。实验结果表明:膜法制备的聚合氯化铝Al_b含量可达90.18%,远高于其它方法制备的产品,其对染料模拟废水的絮凝效果远好于工业化产品。更多还原

【Abstract】 The content of Al_b in poly-aluminum chloride （PAC） is the most important index which decides the flocculation capacity of PAC. Therefore, researches have focused on how to prepare the PAC with high quantity of Alb. By far, the methods of PAC preparation, such as instantaneous-injection of base and micro-injection of base and so on, have many disadvantages involving the prepare process lack of continuous operation, uncontrollability and weak continuity of the addition of lye and then lead to low quantity of Al_b of PAC.In this paper, we use hollow fiber membrane reactor to prepare PAC owing to the large numbers of tiny pores on the membrane. This preparation method can operate continuously and add lye slightly and equably. Furthermore, it has a little cost without pollution.In the research, the double circulation is adopted, the lye flows in the monitor and the AlCl₃ solution flows in the lamella. The lye is added into aluminum chloride solution in a slight, well-proportioned and controllable way under the pressure difference, and then takes neutral reaction with aluminum chloride solution to prepare PAC. The final content of Al_b in PAC products is measured by Al-Ferron timed colorimetric method. The effects of various factors on the content of Alb in PAC products are studied thoroughly, such as B, the flow path of material solution, the flow velocity and concentration of AlCl₃ solution, the concentration of NaOH solution, the alkalescence of alkali material solution, the MWCO and the valid length of membrane reactor and so on. Furthermore, the micro-configuration of PAC is observed by STM and the conditions of preparing PAC are optimized. Finally, the PAC prepared by hollow fiber membrane is used to treat the model dye waste waters.By the experiment, we have obtained the optimal conditions of preparing PAC: the B is 2.0, the concentrations of NaOH solution and AlCl₃ solution are 0.2mol·L^-1 and 0.5mol·L^-1 respectively, and NaOH solution flows inside the membrane and the flow rate of AlCl₃ solution is 28.58ml·s^-1. In addition, the low MWCO of membrane reactor and short valid length of membrane reactor benefit to increase the quality of Alb. For the 100ppm dye solution, the flocculation effect reaches the best when the pH of the dye solution is 4.1. The result of experiment shows that the content of Al_b in PAC prepared by hollow fiber membrane reactor, which determines the flocculation of PAC, can reach as high as 90.18%. It is much higher than that prepared by other methods.更多还原