Method for treating wastewater from industry of spinning acrylics thrugh two steps wet processes by using sodium thiocyanate as solvent

Abstract

A two-step process using sodium thiocyanate as solvent for treating the sewage generated by west spinning of acrylic fibres includes microelectrolyzing to degrade oligomer, adding flocculant, coagulating while depositing, separation, mixing the polymerized sewage with cyanogen contained sewage, homogenizing, hydrolyzing, acidifying, carbonifying, nitrating, denitrating, post-aerating, and separating the deposit mud from supernatant. Its advantage is high treating effect.

Description

technical field [0001] The invention relates to a treatment method for industrial wastewater, in particular to an industrial wastewater treatment method using sodium thiocyanate as a solvent for an acrylic fiber wet spinning process. Background technique [0002] The acrylic fiber wet spinning process using sodium thiocyanate as a solvent is currently the most commonly used in the industrial production of acrylic fiber. This wet acrylic fiber spinning process will produce a large amount of industrial wastewater. Especially in the two-step wet acrylic spinning process, there are more nitrogen-containing substances such as nitrile organic matter and sodium thiocyanate in the industrial wastewater produced, and these nitrogen-containing substances will be transformed during the biochemical treatment process. Ammonia nitrogen component. In recent years, the emission targets of ammonia nitrogen and total nitrogen have become increasingly strict in various countries, and the indu...

AI Technical Summary

Problems solved by technology

Another characteristic of the industrial wastewater produced by the two-step acrylic fiber wet spinning process is that there are high levels of organic additives and oligomers that are difficult to biodegrade, so its biodegradability is better than that of the industrial wastewater produced by the one-step process. Worse and more difficult to handle

In the prior art, the industrial wastewater produced by the two-step acrylic fiber wet spinning process is usually treated in the same way as the industrial wastewater produced by the one-step acrylic fiber wet spinning process. The indicators of the effluent are poor, and the COD Cr Generally around 100mg / l, ammonia nitrogen is generally around 15mg / l, and total nitrogen is generally around 30mg / l, and total nitrogen is not even used as a control index