College of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215000, China.
College of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215000, China.
J Environ Manage. 2022 Nov 15;322:116077. doi: 10.1016/j.jenvman.2022.116077. Epub 2022 Aug 30.
To optimize the efficiency of general adsorption-Fenton oxidation treatment, iron-loaded granular activated carbon (Fe-GAC) was prepared, characterized, and used as a catalyst in the heterogeneous Fenton oxidation of tetracycline (TC). Characterization revealed that the Fe(II) was successfully introduced onto the original granular activated carbon (GAC) and diversified the materials' surface morphology and elemental compounds. Under an initial pH of 3.0, the Fe-GAC/Fenton system obtained a maximum removal rate of 92.6%, with hydrogen peroxide (HO) dosages of 9 mmol g. And the GAC/Fenton without iron supplementation was 89.5%, with HO dosages of 8 mmol g. Additionally, the Fe-GAC/Fenton system consumed a lower Fe(II) dosage than GAC/Fenton, with Fe(II)/HO molar ratios of 0.007:1 and 0.04:1, respectively. Analysis of total organic carbon demonstrated higher mineralization efficiency in the Fe-GAC/Fenton system (67.2%), which was approximately 1.3 times of GAC/Fenton. Desorption experiments showed that the adsorption and degradation accounted for 19.22% and 80.78% of the total TC removal by GAC/Fenton, and 10.58% and 89.42% in the Fe-GAC/Fenton system, respectively. Electron paramagnetic resonance (EPR) technique and quenching experiments demonstrated that the dominant reactive oxygen species (ROS) in synergistic treatments were hydroxyl (•OH) and hydroxy peroxyl (HO•) radicals. In addition, three potential degradation pathways for TC were proposed according to the detected fourteen intermediates. Catalyst regeneration treatments were evaluated over six cycles, and the regeneration was 6.5% higher with the iron-supplemented carbon granules. Overall, the Fe-GAC can be used as an efficient catalyst in practical water treatment, and this study demonstrated a promising method to develop adsorption-Fenton technology.
为了优化常规吸附-Fenton 氧化处理的效率，制备了负载铁的颗粒活性炭（Fe-GAC），并将其作为催化剂用于四环素（TC）的非均相 Fenton 氧化反应。表征结果表明，Fe(II)成功地负载到原始颗粒活性炭（GAC）上，改变了材料的表面形态和元素组成。在初始 pH 值为 3.0 时，Fe-GAC/Fenton 体系在 H2O2 用量为 9mmol g-1 时的去除率最高，达到 92.6%，而没有铁补充的 GAC/Fenton 体系的去除率为 89.5%，H2O2 用量为 8mmol g-1。此外，Fe-GAC/Fenton 体系比 GAC/Fenton 体系消耗更少的 Fe(II)，Fe(II)/H2O2 的摩尔比分别为 0.007:1 和 0.04:1。总有机碳分析表明，Fe-GAC/Fenton 体系具有更高的矿化效率（67.2%），约为 GAC/Fenton 的 1.3 倍。解吸实验表明，GAC/Fenton 体系中吸附和降解分别占总 TC 去除量的 19.22%和 80.78%，而在 Fe-GAC/Fenton 体系中分别占 10.58%和 89.42%。电子顺磁共振（EPR）技术和猝灭实验表明，协同处理中主要的活性氧物种（ROS）是羟基（•OH）和过羟基（HO•）自由基。此外，根据检测到的 14 种中间产物，提出了 TC 的三种潜在降解途径。对催化剂进行了六次循环再生处理，结果表明添加铁的碳颗粒的再生率提高了 6.5%。总的来说，Fe-GAC 可以作为一种有效的催化剂应用于实际水处理中，本研究为开发吸附-Fenton 技术提供了一种有前景的方法。
