壬基酚聚氧乙烯醚在印染废水处理工艺中的去除研究

Elimination of nonylphenol ethoxylates and its biodegrading products from dyeing wastewater

为减少印染助剂壬基酚聚氧乙烯醚(nonylphenol ethoxylates,NPEO)及其降解产物壬基酚(nonylphenol,NP)随印染废水进入水体造成的不利环境影响,对2种常规印染废水处理净水工艺处理含NPEO的模拟印染废水效率开展了研究。研究发现,结合厌氧水解和曝气氧化的生物处理工艺能迅速地将废水中NPEO去除,去除率达到90%以上,但排水中残余一定含量的NP、短链NPEO和短链壬基酚聚氧乙烯醚酸酯(nonylphenol polyethoxycarboxylate,NPEC),在减少排水中NP、短链NPEO和短链NPEC浓度方面,接触氧化法比活性污泥法效果更好。排水中的NP和短链NPEO来自厌氧水解阶段长链NPEO的降解;减少排水中NP、短链NPEO需要减少厌氧水解阶段产生的短链NPEO。

The elimination of nonylphenol ethoxylates(NPEOs) and its biodegrading products from simulating dyeing wastewater during two typical treatment methods was studied. It was found that NPEOs could be removed from the influent with a removal rate above 90% in both methods. The method combined with the contact oxidation unit achieved more efficient results than that combined with aerobic active sludge unit. Fewer products of nonylphenol(NP),NPEOs and nonylphenol polyethoxycarboxylates( NPECs) binding 1 to 3 ethylene oxide molecule were found in the effluent from former method. NP and NPEOs of low molecule weight mainly came from the anaerobic hydrolysis units before the aerobic tanks. To lower their concentration in the final effluent,NP and NPEOs produced in the anaerobic unit should be lowered.