过硫酸盐-石灰苏打处理印染反渗透浓水研究

The treatment of reverse osmosis concentrate from textile and dyeing industry with persulfate sulfate oxidation and lime-soda softening

本文通过热活化过硫酸盐(PS)氧化印染反渗透浓水(ROC)中的难降解有机物,并辅以石灰苏打软水技术降低其硬度,以期实现印染ROC的回用.PS氧化研究表明,酸性条件相对于中性和碱性条件更有利于反应的进行,适宜的初始PS浓度为1000 mg·L^(-1),经济有效的活化温度为75℃.PS氧化降解ROC中难降解有机物的过程符合一级降解动力学模型.经PS氧化处理后,ROC中SO2-4浓度由9600 mg·L^(-1)上升到10350 mg·L^(-1),节省了回用时印染助剂的投加;TOC浓度<1.0 mg·L^(-1),表明ROC中难降解有机物已基本矿化.石灰苏打脱除印染ROC中硬度的研究表明,150 mg·L^(-1)的石灰和800 mg·L^(-1)的苏打投加量是降低硬度的最为适宜的药剂组合方式.PS-石灰苏打处理印染ROC可稳定实现出水COD<21.5 mg·L^(-1),硬度<17.5 mg·L^(-1),满足印染废水回用要求.

For total recycling of reverse osmosis concentrate（ROC） in textile and dyeing industry, the refractory organics were oxidized by heat activated persulfate（PS）, and was softened by lime-soda. It is shown that the oxidation process of ROC favored acidic condition than neutral and alkaline conditions, and the initial PS concentration at 100 mg·L-1 and 75 ℃ would be most effective and economic. Simultaneously, refractory organics degradation of ROC well fitted by using the pseudo-first-order model. In addition, the sodium sulfate concentration could increase from 9600 to 10350mg·L-1to save the supplementation in dyeing procedure, and total organic carbon decreased from 34.6 mg·L-1 to 1.0 mg·L-1 or less. The appropriate lime and soda dosage were determined to be 150 mg·L-1and 800 mg·L-1for softening, respectively. The results show that the after proper treatment, the effluent was satisfied for reuse（COD 〈21.5 mg·L-1, total hardness〈 17.5 mg·L-1） in the dyeing process.