本发明属于海水淡化和浓海水资源化利用领域,提供一种采用化学法-纳滤-反渗透-电渗析集成浓海水软化与浓缩工艺。本发明采用化学法-纳滤(NF)-反渗透(RO)-电渗析(ED)技术集成实现浓海水软化与浓缩工艺,用于海水淡化浓海水再利用的工艺流程,通过化学法脱除浓海水中Ca2+,纳滤实现浓海水中一、二价离子分离,有效降低浓缩过程中膜污染现象,延长膜寿命；将纳滤产水通入反渗透系统,初步浓缩,得到淡水；并采用电渗析对反渗透浓水深度浓缩,得到高浓盐水,可提浓作为液体盐为氯碱、纯碱等工业提供原料；同时,原料室溶液可循环回至反渗透进水储槽再进入浓缩系统循环。该方法能够实现浓海水综合利用,具有广阔的应用前景。

The invention belongs to the field of seawater desalination and resource utilization of concentrated seawater, and provides a process for integrating concentrated seawater softening and concentration using a chemical method-nanofiltration-reverse osmosis-electrodialysis. The present invention adopts chemical method-nanofiltration (NF)-reverse osmosis (RO)-electrodialysis (ED) technology integration to realize concentrated seawater softening and concentration process, and is used for the process flow of seawater desalination and reuse of concentrated seawater. The Ca²⁺ in the concentrated seawater is removed by chemical method, and the monovalent and divalent ions in the concentrated seawater are separated by using nanofiltration, which effectively reduces membrane fouling during the concentration process and prolongs the membrane life. The nanofiltration product water is passed into the reverse osmosis system to initially concentrate to obtain fresh water. The reverse osmosis concentrated water is deeply concentrated by using electrodialysis in order to obtain high-concentration brine, which can be concentrated as a liquid salt to provide raw materials for chlor-alkali, soda ash and other industries. At the same time, the raw material room solution can be recycled to the reverse osmosis water inlet storage tank and then enter the concentration system circulation. This method can realize the comprehensive utilization of concentrated seawater and thus has broad application prospects.