分床电去离子（EDI）技术制备超纯水研究

【作者】 尚广浩；

【导师】 张贵清；

【作者基本信息】 中南大学 ， 有色金属冶金， 2008， 硕士

【摘要】 电去离子(EDI)技术是新一代超纯水制备技术,该技术是电渗析技术和离子交换技术的有效结合,能实现低浓度水溶液的深度脱盐。本文基于对EDI过程本质的分析,针对目前工业化广泛应用的混床EDI制备超纯水中存在的单位膜面积处理水量小、电流效率较低、弱电解质去除能力较弱的不足,提出采用分床EDI过程制备超纯水。论文设计了4种新型分床电去离子过程并通过试验对上述4种新型分床电去离子过程的脱盐能力进行了验证,同时还对新型双极膜分床电去离子制备超纯水进行了对比实验研究。研究结果表明,4种新型分床电去离子过程均能实现从低浓度水溶液进行深度脱盐,过程脱盐率达98%以上,其产水电阻率可达4MΩ·cm,证明了这4种新型分床EDI在技术上的可行性,但长期的运转表明,这4种新型分床EDI尚存在产水水质下降和膜堆电压升高的现象,而且其产水水质也尚未达到超纯水的水质要求,因此有待进一步的研究改进。而新型双极膜电去离子过程制备超纯水的运行试验表明,新型双极膜EDI能够克服普通双极膜分床EDI的不足,能够连续稳定地制取高品质产水,产水电阻率大于17.5MΩ·cm,脱盐率大于99.9%。为此进行了多单元新型双极膜EDI制取超纯水的运行,结果显示,多单元新型双极膜EDI能获得高品质产水,产水电阻率在18.0MΩ·cm左右,显示了新型双极膜EDI制取超纯水技术的良好产业化应用前景。更多还原

【Abstract】 Electrodeionization (EDI), known as a new technology for water purification, combines ion exchange and electrodialysis, which is to realize deeply desalting in low concentration solution. Based on the essential analysis of EDI, the separated bed EDI was put forward to overcome the shortages, such as low water throughput by unit memberane area, low current efficiency and low removal rate of weak electrolyte, which exist in traditional mixed-bed EDI on current.In this paper, four new styles of separated-bed EDI were schemed out, and the good results of desalting were achieved. In the same time, a new scheme of EDI with bipolar membrane process was contrasted experimentally.The feasibility of four new styles of separated-bed EDI process are proved. Result shows that the deeply desalting in low concentration solution can be realized in four new styles of separated-bed EDI process, the desalinization ratio up to 98% and the resistivity of product water can reach 4 MΩ·cm. But the long-term running indicated that the quality of product Water quality worsen and voltage of stack increased with the passage of time, the quality of water also can not reach the standard of the ultra-pure water. The further researches about new styles of separated-bed EDI should be done in the future. Then the experiment about EDI with bipolar membrane shows that the shotage of conventional EDI with bipolar membrane was conquered by the new scheme of EDI with bipolar membrane. The high quality water can be produced stably and continuously, the desalinization ratio up to 99.9% and the resistivity of product water can reach 17.5MΩ·cm. And then the experiment with multi-unit scheme of EDI with bipolar membrane was carried out and the resistivity of product water could reach over 18MΩ·cm, and the good prospect of EDI with bpolar membrane for industrial application was laid out.更多还原