The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou, 510006, People's Republic of China.
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.
Environ Sci Pollut Res Int. 2018 May;25(13):13118-13126. doi: 10.1007/s11356-018-1571-8. Epub 2018 Feb 27.
In this study, a sequential Fe/HO reaction and biological process was employed as a low-cost depth treatment method to remove recalcitrant compounds from coal-chemical engineering wastewater after regular biological treatment. First of all, a chemical oxygen demand (COD) and color removal efficiency of 66 and 63% was achieved at initial pH of 6.8, 25 mmol L of HO, and 2 g L of Fe in the Fe/HO reaction. According to the gas chromatography-mass spectrometer (GC-MS) and gas chromatography-flame ionization detector (GC-FID) analysis, the recalcitrant compounds were effectively decomposed into short-chain organic acids such as acetic, propionic, and butyric acids. Although these acids were resistant to the Fe/HO reaction, they were effectively eliminated in the sequential air lift reactor (ALR) at a hydraulic retention time (HRT) of 2 h, resulting in a further decrease of COD and color from 120 to 51 mg L and from 70 to 38 times, respectively. A low operational cost of 0.35 $ m was achieved because pH adjustment and iron-containing sludge disposal could be avoided since a total COD and color removal efficiency of 85 and 79% could be achieved at an original pH of 6.8 by the above sequential process with a ferric ion concentration below 0.8 mg L after the Fe/HO reaction. It indicated that the above sequential process is a promising and cost-effective method for the depth treatment of coal-chemical engineering wastewaters to satisfy discharge requirements.
在这项研究中，采用顺序的 Fe/HO 反应和生物过程作为一种低成本的深度处理方法，用于在常规生物处理后去除煤化工废水中的难降解化合物。首先，在初始 pH 值为 6.8、HO 浓度为 25 mmol/L 和 Fe 浓度为 2 g/L 的条件下，Fe/HO 反应实现了 66%的 COD 和 63%的色度去除效率。根据气相色谱-质谱联用仪（GC-MS）和气相色谱-火焰离子化检测器（GC-FID）分析，难降解化合物被有效地分解为短链有机酸，如乙酸、丙酸和丁酸。尽管这些酸对 Fe/HO 反应具有抗性，但它们在顺序式气升式反应器（ALR）中在 2 h 的水力停留时间（HRT）下被有效地去除，从而使 COD 和色度进一步从 120 降至 51 mg/L，从 70 降至 38 倍。由于可以避免 pH 值调节和含铁污泥的处理，因此操作成本低，仅为 0.35 美元/m，这是因为在 Fe/HO 反应后，铁离子浓度低于 0.8 mg/L 时，原始 pH 值为 6.8 的上述顺序过程可实现 85%的总 COD 和 79%的色度去除效率。这表明，上述顺序过程是一种有前途且具有成本效益的煤化工废水深度处理方法，可满足排放要求。
