Derakhshan Mahmood, Fazeli Mojtaba
Faculty of Civil, Water and Environmental Engineering, Shahid Beheshti University A.C, Abbaspour Boulevard, Hakimieh, Tehranpars, Tehran, 17765-1719 Iran.
J Biol Eng. 2018 Jun 20;12:10. doi: 10.1186/s13036-018-0104-9. eCollection 2018.
Petrochemical wastewaters are highly polluting due to having various destructive materials such as aromatic hydrocarbons and heavy metal ions. Therefore, they need to be treated before disposal to the environment. However, due to low biodegradability, applying common treatment methods such as activated sludge is not feasible for these wastewaters.
Photo-Fenton is an advanced oxidation process which was applied to promote the biodegradability of hardly-decomposable petrochemical wastewaters. The wastewater samples were provided by Maroon and Karoon petrochemical plants, located in Mahshahr, Iran. To design the experiments and analyze the experimental results, response surface method with four variables (input COD and TDS concentrations and injected a dosage of H2O2 and Fe2+) and four fixed parameters (temperature, pH, retention time, and UV power) were used.
The ranges of input COD, H2O2, Fe2+ and TDS were 1000 to 2500 mg L- 1, 1000 to 4000 mg L- 1, 500 to 3000 mg L- 1, and 4500 to 11,500 mg L- 1, respectively. Average input BOD5/COD ratio was 0.09. These ranges and values were determined according to the quality of the raw wastewater and experimental design. Output BOD5/COD ratio was varying between 0.3 and 0.6, which declined with an increase of input COD. The results showed that the biodegradability of the industrial wastewater was promoted upon application of higher H2O2 and Fe2+ concentrations. Meanwhile, TDS concentration had no significant effect on biodegradability of this wastewater. The following optimum conditions were resulted by evaluating the maximum efficiency of the reactor in enhancing the biodegradability of the wastewater: 1000 mg L- 1 input COD, 2668 mg L- 1 H2O2, 1655 mg L- 1 Fe2+, 8000 mg L- 1 TDS, 0.6 output BOD5/COD, 852 mg L- 1 output BOD5 and 939 mg L- 1 output COD.
Photo-Fenton method is highly efficient for increasing the biodegradability of petrochemical wastewaters before applying biological wastewater treatment.
石化废水由于含有芳烃和重金属离子等多种有害物质而具有高度污染性。因此，在排放到环境之前需要对其进行处理。然而，由于生物降解性低，采用活性污泥等常规处理方法处理这些废水并不可行。
光芬顿法是一种高级氧化工艺，用于提高难降解石化废水的生物降解性。废水样本由位于伊朗马赫沙尔的栗色和卡伦石化厂提供。为了设计实验并分析实验结果，采用了具有四个变量（输入化学需氧量和总溶解固体浓度以及过氧化氢和亚铁离子的注入剂量）和四个固定参数（温度、pH值、停留时间和紫外线功率）的响应面法。
输入化学需氧量、过氧化氢、亚铁离子和总溶解固体的范围分别为1000至2500mg/L、1000至4000mg/L、500至3000mg/L和4500至11500mg/L。平均输入生化需氧量与化学需氧量之比为0.09。这些范围和数值是根据原废水的质量和实验设计确定的。输出生化需氧量与化学需氧量之比在0.3至0.6之间变化，并随输入化学需氧量的增加而下降。结果表明，采用较高浓度的过氧化氢和亚铁离子可提高工业废水的生物降解性。同时，总溶解固体浓度对该废水的生物降解性没有显著影响。通过评估反应器提高废水生物降解性的最大效率得出以下最佳条件：输入化学需氧量1000mg/L、过氧化氢2668mg/L、亚铁离子1655mg/L、总溶解固体8000mg/L、输出生化需氧量与化学需氧量之比0.6、输出生化需氧量852mg/L和输出化学需氧量939mg/L。
在应用生物废水处理之前，光芬顿法对于提高石化废水的生物降解性非常有效。
