为高效处理染料中间体生产废水、优化工艺参数,针对染料中间体生产废水有机负荷高、生物抑制性强等特点,选用Fenton氧化处理过程,以实际生产废水为研究对象,基于Box-Behnken响应曲面法分别考察了反应时间、初始pH、n(H2 O2)/n(Fe2)、Fenton试剂投加频率等因素对Fenton法处理废水过程的单独影响及各因素间的交互作用,并建立以CODCr去除率为评价指标的数学模型进行全面分析.结果表明:各影响因子显著性顺序为初始pH >n(H2O2)/n(Fe2)> Fenton反应时间>投加频率,其中n(H2O2)/n(Fe2)与投加频率的交互作用最为显著(F=3.43);模型决定系数R2=0.917 9,说明模型可信度和精密度高;最佳反应条件组合为反应时间30 min、初始pH为3.46、n(H2O2)/n(Fe2)为6.12、投加频率为2次.预测最大CODCr去除率为56.53%,验证试验实测平均结果为55.17%,与预测值相比偏差为1.36%.经最优条件处理后废水的ρ(CODCr)由9 600 mg/L降至4 000 mg/L左右,ρ(BOD5)/ρ(CODCr)由0.07增至0.37,可生化性提高.研究显示,采用Fenton法预处理高浓度染料中间体废水可有效提高CODCr去除率及其可生化性.
In order to treat dye intermediate wastewater efficiently and optimize the process parameters,this study investigated actual production wastewater and characterized it by high organic loading and biological inhibition.Based on the Box-Behnken response surface method,the separate action and interaction effects of reaction time,initial pH,n(H2 O2)/n(Fe2+) and dosing frequency were eva luated,and an empirical mathematical model between CODcr removal rate and influencing factors was established by Fenton process.The significance of influencing factors followed the order:initial pH > n(H2O2)/n(Fe2 +) > reaction time > dosing frequency,and the most significant interaction occurred between n(H2 O2)/n(Fe2 +) and dosing frequency (F =3.43).Furthermore,the decision coefficient R2 =0.9179 showed that the model had high reliability and high precision.The optimal reaction conditions were determined to be reaction time 30 min,pH 3.46,n(H2O2)/n(Fe2+) 6.12,and dosing frequency twice.The predicted maximum CODCr removal was 56.53%,while the average result of verification test was 55.17%,with a deviation of 1.36%.Under optimal conditions,the ρ(CODCr) of the treated wastewater decreased from 9600 mg/L to about 4000 mg/L,ρ (BOD5)/ρ (CODCr) increased from 0.07 to 0.37,indicating that the biochemical properties were improved.Therefore,the Fenton process was successfully applied for the pretreatment of the high concentration dye intermediate wastewater with a favorable CODCr removal efficiency and could improve the biodegradability.