Recovery process of dilute sulfuric acid in industrial wastewater

Abstract

The invention discloses a recovery process of dilute sulfuric acid in industrial wastewater. The process comprises the steps: adding a polyamino compound-containing toluene extract to the dilute sulfuric acid-containing industrial wastewater, performing stirring and still standing, separating the toluene extract, adding an aldehyde group-containing compound and deionized water to the separated toluene extract, performing stirring and still standing, performing separation so as to obtain a Schiff base compound-containing toluene solution and a sulfuric acid aqueous solution, and then recyclingintermediate products by using copper chloride, deionized water, sodium hydroxide and other substances. The recovery process has large universality for to-be-treated dilute sulfuric acid solutions andconcentrations of the to-be-treated dilute sulfuric acid solutions, and is suitable for general recovery of sulfuric acid in wastewater which contains dilute sulfuric acid with different concentrations; and the adopted reagents and the generated by-products in the entire process can be recycled basically, sulfuric acid is precipitated through a room-temperature reaction between the aldehyde group-containing compound and the polyamino compound-containing sulfate solution so that side effects caused by high-temperature reactions can be avoided, and no easy damage to equipment and high safety are achieved.

Description

technical field [0001] The invention relates to the field of environmental protection engineering, in particular to a recovery process of dilute sulfuric acid in industrial waste water. Background technique [0002] Sulfuric acid is widely used in the industrial field. The recovery of industrial wastewater after use is an extremely important technical requirement, the use of environmental protection, and the recycling of industrial wastewater. [0003] At present, the recovery and reuse of dilute sulfuric acid is mainly based on physical methods, such as: [0004] (1) Xiangyang Jinzhan Technology Development Co., Ltd. (application number 201910101001.8), mainly adopts the combination of membrane separation method and oxidation treatment method to recycle and reuse waste sulfuric acid. [0005] (2) Jiangsu Nostra Environmental Protection Technology Co., Ltd. (application number: 201811543181.7) uses hydrogen peroxide to oxidize some substances in sulfuric acid, and then deco...

AI Technical Summary

Problems solved by technology

[0008] (1) The precipitation rate of amino compounds to dilute sulfuric acid in wastewater needs to be improved;

[0009] (2) The temperature required for thermal decomposition is about 320°C, which is highly corrosive to equipment;

[0010] (3) During thermal decomposition, the recovery and reuse of the by-products generated by the decomposition is insufficient

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