国产纳滤膜在高氟苦咸水淡化脱氟中的应用研究

发布时间：2018-03-03 13:21

  本文选题：国产纳滤膜　切入点：脱氟　出处：《中国海洋大学》2015年硕士论文　论文类型：学位论文

【摘要】：当前我国部分地区存在饮用水水质问题,其中高氟苦咸水是较突出的问题之一。其严重影响了人们的生活质量,对人们的身体健康造成巨大威胁。因此,进行高氟苦咸水的淡化脱氟处理十分必要。目前,苦咸水处理技术主要有沉淀法、吸附法及膜技术等,各类方法的局限性限制了其广泛应用。纳滤技术作为一种新兴工艺,其特殊优势决定了纳滤技术的迅速发展,我国也积极发展纳滤技术,但是目前对国产纳滤膜的研究应用较少。针对以上问题,本实验选用国产纳滤膜,对处理高氟苦咸水的可行性进行研究分析,这项研究为国产纳滤膜处理高氟苦咸水的实际应用提供了技术数据,有利于国产纳滤膜的发展和完善。研究内容和结果主要包括以下三个方面：(1)国产纳滤膜处理高氟苦咸水的基础研究：实验选取三种国产纳滤膜NF1、NF2和NF3进行纳滤膜淡化高氟苦咸水的基础研究,考察操作压力、温度及进水pH对纳滤膜分离性能的影响,总结出纳滤膜工作的最佳实验条件,同时简单比较三种膜的性能。研究结果表明,纳滤膜处理高氟苦咸水的理想操作条件为：压力1.0-1.5 MPa,温度15～20℃,进水pH=7.0左右,在此条件下NF1纳滤膜的脱盐率为48%,脱氟率为53%,产水通量为96 L/(m2h)；NF2纳滤膜分别为71%,90%和43 L/(m2h)；NF3纳滤膜分别为65%,73%和61 L/(m2h)：对比三种国产纳滤膜的性能可知NF2的膜性能最优。并且测得NF2和NF3的Zeta电位分别为-22和-18 mV。(2)国产纳滤膜处理高氟高砷苦咸水的小试研究：选择NF2的膜元件在最佳的操作条件下,采用一级两段式纳滤系统进行小试实验。主要分析了进水氟浓度、砷浓度及盐浓度的变化对纳滤膜脱氟脱砷性能的影响,随进水氟砷浓度和总含盐量的增大,纳滤膜的脱氟、脱砷和脱盐率降低。研究发现,当原水的氟浓度低于7.5 mg/L,砷浓度低于1.25 mg/L,总含盐量低于2.5g/L时,本纳滤膜装置能够将苦咸水处理到满足国家饮用水标准。并且该纳滤装置长期运行72 h性能保持稳定。(3)硅藻土作为国产纳滤膜脱氟的前处理材料研究：研究表明纳滤技术是一种有效地处理高氟水的技术。但是,原水中氟浓度对对产出水水质影响较大,因此选用天然硅藻土作为原材料,用于纳滤脱氟水的前处理。硅藻土的特性通过SEM和XRD方法表征,其吸附氟离子的可能性通过XPS和FT-IR来证明。分析硅藻土添加量、原水pH、离子强度和阴离子等对吸附过程的影响。并且溶液中有机物HA的存在会影响吸附过程,在pH5时增强,pH5时削弱硅藻土吸附氟的性能。吸附过程符合Langmuir吸附等温方程和二级动力学方程。此外,对吸附过程和纳滤系统的联用也进行了初步分析,研究表明天然硅藻土作为纳滤膜脱氟的前处理材料是经济有效的。
[Abstract]:At present, there are drinking water quality problems in some areas of our country, among which high fluorine bitter salt water is one of the outstanding problems, which seriously affects people's quality of life and poses a great threat to people's health. The desalination and defluorination of brackish water with high fluorine content is very necessary. At present, the main technologies of brackish water treatment include precipitation, adsorption and membrane technology, etc. The limitations of various methods limit their wide application. Nanofiltration is a new technology. Its special advantages determine the rapid development of nanofiltration technology, and our country also actively develops nanofiltration technology, but at present, the research and application of domestic nanofiltration membrane is relatively few. In view of the above problems, this experiment chooses domestic nanofiltration membrane. The feasibility of treating brackish water with high fluorine was studied and analyzed. This study provided technical data for the practical application of domestic nanofiltration membrane in treating brackish water with high fluoride. The research contents and results mainly include the following three aspects: the basic research of domestic nanofiltration membrane treatment of high-fluorine brackish water: three kinds of domestic nanofiltration membrane NF1N _ 2 and NF3 were selected for nanofiltration membrane. Basic research on desalination of brackish water with high fluorine, The effects of operating pressure, temperature and influent pH on the separation performance of nanofiltration membrane were investigated. The ideal operating conditions for the treatment of brackish water with high fluorine by nanofiltration membrane are as follows: pressure 1.0-1.5 MPA, temperature 1520 鈩，

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