Seawater desalination method

Abstract

The invention discloses a seawater desalination method. The seawater desalination method comprises the following steps: seawater pretreatment, ultrafiltration filtration, first-stage reverse osmosis membrane filtration, second-stage reverse osmosis membrane filtration and mineralization. The mineralization comprises the steps of introducing carbon dioxide gas into water of a desalination water tank, and adding a saturated limewater solution, wherein the adding proportion of carbon dioxide and saturated limewater is 2.5 to 1, and the contents of residual chlorine at a raw seawater inlet pipeline, a front filter, an ultrafiltration system, an ultrafiltration water producing pipeline and an ultrafiltration water tank are respectively 5ppm, 4ppm, 2ppm, 1ppm and 0.8ppm. The mineralization method is direct, simple, efficient, short in consumed time and stable in water quality; and a sodium hypochlorite adding site is arranged at a seawater extraction hole, and a reducing agent adding site and a non-oxidation sterilizing agent feeding point are arranged in front of a reverse osmosis membrane group, so that the sterilization effect of a full seawater desalination line can be guaranteed, the osmosis membrane is not damaged, meanwhile, the use amount of the non-oxidation sterilizing agent can be further reduced, and the cost is lowered.

Description

technical field [0001] The invention relates to the technical field of seawater desalination, in particular to a seawater desalination method. Background technique [0002] At present, the problem of insufficient fresh water resources in the world has emerged in more and more countries, and has also attracted the attention of all countries. At the same time, with the rapid economic development of coastal areas, the demand for fresh water is also increasing rapidly. The water supply capacity cannot meet the needs of its rapid development, and there is a large gap in fresh water supply. As an open-source incremental technology for water resources, seawater desalination has become one of the most important methods to solve water shortages in the world. Desalinated water is clean, high-purity, and stable in supply, and is a safe and reliable source of high-quality water. In the process of seawater desalination, the metal ions in the water are usually filtered out, making the wa...

AI Technical Summary

Problems solved by technology

In the process of seawater desalination, the metal ions in the water are usually filtered out, resulting in softer and more acidic water quality. On the one hand, it will affect the taste of desalinated water, and on the other hand, it will also cause certain corrosion to the water supply pipeline.

[0003] In the prior art, mineralized beds are usually used to mineralize water, but this method is inefficient and takes a long time, which greatly increases the cost of seawater desalination