以某电镀厂水回用系统产生的高盐有机废水为对象,对比研究了Fenton、UV-Fenton等工艺去除COD性能,考察了初始p H、H_2O_2投加量、Fe2+与H_2O_2摩尔比、反应时间等参数对处理效果的影响。结果表明:UV-Fenton工艺的最佳条件为初始p H=3.0,H_2O_2的投加量3 mmol/L,RFe2+∶H_2O_2=1∶1,反应时间30 min;在此条件下,COD去除率可达到60%以上,分别较Fenton和UV-H_2O_2工艺提高23.0%和39.3%。UV-Fenton工艺中,Fenton与UV表现出良好的协同效果,其处理效果较单独Fenton和单独UV处理效果之和高14.7%。UV的引入促进Fe(II)/Fe(Ⅲ)循环,可以提高·OH生成量以及Fe2+与H_2O_2利用率。UV-Fenton是处理高盐有机废水的可行工艺之一。
This study focused on the high-salinity organic wastewater from the recycling system of an electroplating factory and compared the chemical oxygen demand( COD) removal efficiency among various treatment processes including Fenton and UV-Fenton technologies. The effects of initial p H,hydrogen peroxide( H_2O_2) dosage,the molar ratios of iron( Fe2 +) /H_2O_2( RFe2 +∶ H_2O_2),and reaction time on COD removal were investigated,and results indicated that the UV-Fenton process achieved the optimum COD removal of above 60% at an initial p H of3. 0,H_2O_2 dose of 3 mmol / L,and RFe2 +∶ H_2O_2 of 1 ∶ 1 after a 30 min contact time. These results were 23. 0% and39. 3% higher than those achieved by Fenton and UV-H_2O_2 processes,respectively. Moreover,UV and Fenton show synergistic effects towards COD removal,and the removal efficiency was 14. 7% higher than the summative value achieved by UV and Fenton processes,respectively. Meanwhile,UV promotes hydroxide( ·OH) production and the utilization of Fe2 +and H_2O_2,owing to the accelerated transformation cycles between Fe( II) and Fe( Ⅲ) species. The UV-Fenton process is particularly valuable in the treatment of high-salinity organic wastewater.