Hydrazine-containing wastewater treatment method

Abstract

The invention discloses a hydrazine-containing wastewater treatment method, which is implemented through adding a sulfuric acid aqueous solution with a mass percent concentration of 30% into hydrazine-containing wastewater, and stirring for carrying out a neutralization reaction with hydrazine at a rotating speed of 100-150 r / min, so that a hydrazine sulfate solution is obtained; then, carrying out nanofiltration separation on the hydrazine sulfate solution so as to obtain an aqueous solution and a high-concentration hydrazine sulfate aqueous solution; adding sodium hydroxide into the high-concentration hydrazine sulfate aqueous solution to carry out a neutralization reaction, so that the pH value of the solution is controlled at 7.5-8.0, thereby obtaining an aqueous solution of hydrazine and sodium sulfate; carrying out nanofiltration separation on the aqueous solution of hydrazine and sodium sulfate, so that an aqueous solution of hydrazine and an aqueous solution of sodium sulfate are obtained; and carrying out evaporation concentration on the aqueous solution of sodium sulfate so as to obtain solid sodium sulfate, and recycling the aqueous solution of hydrazine. According to the treatment method disclosed by the invention, hydrazine and water in hydrazine-containing wastewater are respectively reutilized, thereby achieving the effect of changing waste material into things of value, and reducing the environmental pollution.

Description

technical field [0001] The invention relates to a treatment method for hydrazine-containing wastewater. technical background [0002] Nanofiltration is a membrane separation technology between ultrafiltration and reverse osmosis, and its molecular weight cut-off is in the range of 80-1000. Therefore, water (water molecular weight is 18) and molecular weight ratio water Much larger substances are easily separated by membranes. Because the molecular weight of hydrazine is 32, if hydrazine does not form a salt with sulfuric acid, hydrazine cannot be well intercepted by the membrane, and it can pass through the membrane as easily as water. In order to make the membrane well intercept hydrazine, hydrazine and sulfuric acid are reacted Hydrazine sulfate, the molecular weight of hydrazine sulfate is 130, so hydrazine sulfate is easily intercepted by nanofiltration membrane and separated by water. Hydrazine is an alkaline compound. When neutralizing with sulfuric acid to form a sa...

AI Technical Summary

Problems solved by technology

[0004] At present, most of the hydrazine treatment methods use the flocculation and sedimentation method. The COD of the hydrazine-containing wastewater treated by this method is generally 30-50ppm, which is far from meeting the discharge requirements.