Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, 266100, China; College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.
Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao, 266100, China; Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering (MEGE), Qingdao, 266100, China; College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.
Chemosphere. 2021 Sep;279:130520. doi: 10.1016/j.chemosphere.2021.130520. Epub 2021 Apr 8.
Hexabromocyclododecane (HBCD) is one of the priority persistent organic pollutants (POPs), yet a cost-effective technology has been lacking for the removal and degradation of HBCD. Zero-valent aluminum (ZVAl) is an excellent electron donor. However, the inert and hydrophilic surface oxide layer impedes the release of the electrons from the core metallic Al, resulting in poor reactivity towards HBCD. In this research, a new type of modified mZVAl particles (AC@mZVAl) were prepared through ball milling mZVAl in the presence of activated carbon (AC) and NaCl, and tested for adsorption and reductive degradation of HBCD in water. AC@mZVAl was characterized with a metallic Al core with newly created reactive surface coated with a thin layer of crushed carbon nanoparticles. AC@mZVAl was able to rapidly (within 1 h) adsorb HBCD (C = 2 mg L) and thus effectively enriched HBCD on the carbon surface of AC@mZVAl. The pre-enriched HBCD was subsequently degraded by the electrons from the core Al, and ∼63.44% of the pre-sorbed HBCD was completely debrominated after 62 h of the contact. A notable time lag (∼12 h) from the onset of the adsorption to the debromination was observed, signifying the importance of the solid-phase mass transfer from the initially adsorbed AC particles to the reactive Al-AC interface. Overall, AC@mZVAl synergizes the adsorptive properties of AC and the high reactivity of metallic Al, and enables a novel two-step adsorption and reductive degradation process for treating HBCD or likely other POPs.
六溴环十二烷（HBCD）是优先控制的持久性有机污染物（POPs）之一，但缺乏去除和降解 HBCD 的经济有效技术。零价铝（ZVAl）是一种极好的电子供体。然而，惰性和亲水的表面氧化层阻碍了核心金属 Al 中电子的释放，导致其对 HBCD 的反应性差。在这项研究中，通过在活性炭（AC）和 NaCl 的存在下球磨 mZVAl，制备了一种新型改性 mZVAl 颗粒（AC@mZVAl），并测试了其在水中对 HBCD 的吸附和还原降解性能。AC@mZVAl 具有金属 Al 核，表面新生成了反应性表面，表面覆盖有一层破碎的碳纳米颗粒。AC@mZVAl 能够快速（在 1 小时内）吸附 HBCD（C=2mg/L），从而有效地将 HBCD 富集在 AC@mZVAl 的碳表面上。预先富集的 HBCD 随后被核心 Al 中的电子降解，在接触 62 小时后，约 63.44%的预吸附 HBCD 完全脱溴。从吸附到脱溴的时间有显著的滞后（约 12 小时），这表明从最初吸附的 AC 颗粒到反应性 Al-AC 界面的固相质量传递的重要性。总的来说，AC@mZVAl 协同了 AC 的吸附性能和金属 Al 的高反应性，为处理 HBCD 或可能其他 POPs 提供了一种新的两步吸附和还原降解过程。
