State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Chinese Academy of Science, Beijing, 100085, China; Sino-Danish Center for Education and Research (SDC), University of Chinese Academy of Sciences, Beijing, 100190, China.
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Chinese Academy of Science, Beijing, 100085, China; National Engineering Laboratory for Industrial Wastewater Treatment, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Sino-Danish Center for Education and Research (SDC), University of Chinese Academy of Sciences, Beijing, 100190, China.
Water Res. 2020 Apr 15;173:115517. doi: 10.1016/j.watres.2020.115517. Epub 2020 Jan 23.
Efficient removal of the non-biodegradable organics from the biological effluent of industrial wastewater is becoming more and more important with the increasing demand for stringent discharge regulation. In this study, a synchronized oxidation-adsorption (SOA) technology was proposed for the removal of hardly biodegradable COD (hard COD) from the biological effluent of coking wastewater, and its performance was verified in a full-scale coking industrial park wastewater treatment plant (Q = 5,000 m/d). The SOA was performed by coupling oxidation by hydroxyl radical (molar ratio of Fe to HO of 1:1 and pH = 5.0 ± 0.2) and adsorption by in-situ-formed nano hydrolyzed Fe particles (nano-FeOOH). The nano hydrolyzed Fe particles formed during the SOA exhibited a much higher specific surface area (22.83 m/g) than the particles (10.87 m/g) formed during the polyferric sulfate coagulation (PFSC). In comparison to PFSC, SOA performed better in terms of average COD removal (39% vs 18%) from the biological effluent. Wastewater fractionation result showed that SOA performed better in the removal of the hydrophobic acid matters, which was supported by the experiment using fulvic acid as the model organics. Mechanism studies using both biological effluent and fulvic acid solution showed that more carboxylic substances were adsorbed by the in-situ-formed nano-hydrolyzed Fe particles formed by SOA than by PFSC, which was likely due to the generation of carboxylic substances by hydroxyl radical oxidation. In the full-scale, the COD was reduced from 118.5-198.0 mg/L in the PFSC-pretreated effluent to 61.5-104.0 mg/L through SOA treatment. The SOA treatment characterized with a mild pH condition (pH 5) and low molar ratio of Fe to HO (1:1) is particularly suitable for the polishing purpose to remove limited amount of organic pollutants from wastewater before discharge.
从工业废水的生物废水中高效去除不可生物降解的有机物变得越来越重要，因为对严格排放标准的需求不断增加。在这项研究中，提出了一种同步氧化-吸附（SOA）技术，用于去除焦化废水生物出水中的难生物降解 COD（难 COD），并在一个全规模的焦化工业公园污水处理厂（Q=5000m/d）中验证了其性能。SOA 通过耦合羟基自由基氧化（Fe 与 HO 的摩尔比为 1:1，pH=5.0±0.2）和原位形成的纳米水解铁颗粒（纳米-FeOOH）吸附来进行。SOA 过程中形成的纳米水解铁颗粒比聚硫酸铁混凝（PFSC）过程中形成的颗粒（10.87m/g）具有更高的比表面积（22.83m/g）。与 PFSC 相比，SOA 在去除生物出水中的平均 COD 方面表现更好（39%对 18%）。废水分级结果表明，SOA 在去除疏水性酸物质方面表现更好，这得到了使用富里酸作为模型有机物的实验的支持。使用生物废水和富里酸溶液进行的机制研究表明，SOA 形成的原位纳米水解铁颗粒比 PFSC 吸附了更多的羧酸物质，这可能是由于羟基自由基氧化生成了羧酸物质。在全规模中，通过 SOA 处理，将 PFSC 预处理出水的 COD 从 118.5-198.0mg/L 降低到 61.5-104.0mg/L。SOA 处理具有温和的 pH 条件（pH5）和低的 Fe 与 HO 的摩尔比（1:1），特别适合在排放前从废水中去除有限量的有机污染物的抛光目的。
