Novel process for desalinizing and comprehensively utilizing seawater

Abstract

The invention relates to a novel process for desalinizing and comprehensively utilizing seawater. The novel process comprises the steps: a manure extraction process, a pretreatment and filtration process, a flocculation and coagulation process, a nanofiltration process, a reverse osmosis process and a multiple-effect evaporation process. The maximum desalination of seawater and comprehensive utilization of seawater resources are realized by a process combination and the novel process, and a product such as an efficient slow-release fertilizer (magnesium phosphate), industrial fresh water, drinking water and edible salts are produced by using seawater. By using the novel process, zero sewage discharge resulted from seawater desalinization can be realized, the desalinization cost can also begreatly reduced by comprehensive utilization of the seawater resources, and therefore, the novel process is a novel technology for desalinizing and comprehensively utilizing seawater, which has popularization and application values, realizes zero sewage discharge and is low in cost.

Description

technical field [0001] The invention belongs to the field of inorganic chemical industry, in particular to a new process for seawater desalination and comprehensive utilization. Background technique [0002] Water is the foundation of human survival. Currently, global fresh water resources are being depleted, which has become the biggest threat to human survival. China's per capita water resources are less than 1 / 3 of the world's, and China is listed by the United Nations as one of the 13 water-poor countries. According to a survey, more than 420 of the 661 cities in the country are short of water, and the water shortage is about 7 billion cubic meters. The vast ocean accounts for about 71% of the earth's surface area, and is a huge treasure house with huge potential for development. The utilization of seawater water resources and the utilization of seawater chemical resources have very broad prospects. [0003] Seawater is an inexhaustible resource. The total volume of s...

AI Technical Summary

Problems solved by technology

However, the patented seawater is subjected to reverse osmosis first, and then decalcified. Although antiscalants are added to the seawater, fouling of the reverse osmosis membrane cannot be avoided, and long-term operation cannot be guaranteed.

Moreover, the patent uses low-temperature multi-effect evaporation + sun-dried salt to treat the concentrated seawater. The recovery rate of fresh water is low, and the salt obtained can only be coarse salt with low price.

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