硫氰酸根（SCN^-）普遍存在于HPF脱硫废液中,其含量高达90-140 g/L,对COD、色度等指标构成影响。首先对HPF脱硫废液做预处理,即以加酸的方法脱除其中的S2O2-3,然后利用氯酸根将废水中高浓度SCN^-氧化脱除,实验通过交替向废液中加入氯酸钠和浓硫酸,维持溶液pH值在1以下,使反应停留在轻度氧化阶段以使SCN^-定向转化为沉淀,处理后SCN^-的浓度由初始的69.76 g/L降至0.67 g/L,溶液COD由初始的98 600 mg/L降至2 400 mg/L。用较少的化学试剂将硫氰酸根基本脱除,达到了化学降解的目的。
High abundance of thiocyanate（ SCN^-） reserves in the HPF desulfurization waste solution.Generally,the concentration of this contaminant ranges from 90 to 140 g / L and it significantly influences COD and chromaticity. In this paper,a pretreatment by adding acid to remove thiosulphate in HPF desulfurization waste solution was firstly conducted. Subsequently,the concentrated thiocyanates were removed by chlorate oxidation. In this process,the concentrated sulfuric acid and sodium chlorate were added into the solutions alternately and the pH value of mixtures was kept below 1,which could maintain the reaction stay in the stage of mild oxidation so that the SCN^-could be directly transformed to precipitation. Experimental result showed that the concentration of SCN^-decreased from 69. 76 g / L to 0. 67 g / L and the original COD dropped from 98 600 mg / L to 2 400 mg / L. The removal of SCN^-was achieved by using a small quantity of chemical reagent to realize chemical degradation.
Techniques and Equipment for Environmental Pollution Control
desulfurization waste solution