College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
Marine Engineering Environmental Supervision Technology Room, National Marine Environmental Monitoring Center, Dalian 116023, China.
Int J Environ Res Public Health. 2022 Apr 19;19(9):4944. doi: 10.3390/ijerph19094944.
biochar (BC) has been proposed as a potential absorbent in the marine environments. This study attempts to understand the process of active capping using BC to prevent the release of heavy metals (Pb and Cd) from contaminated marine dredged sediments. The capping efficiency was assessed with a series of lab-scale column experiments. Results showed that the BC exhibits rough pore structure and higher specific surface area, as well as more surface organic functional groups, which is favorable for its adsorption capacity and selectivity towards heavy metals. The capping thickness of 2 cm for BC was sufficient to prevent the release of heavy metals from sediments, with the capping efficiency of 47% for Pb and 62% for Cd. Kinetic studies showed that heavy metals released into the overlying water can be described by a three-parameter sigmoidal kinetic model. Importantly, the fractions of heavy metals in the dredged sediments below the capping layer were analyzed to reveal the capping remediation mechanism. The outcomes of the present study indicate that capping with BC is a promising method to regulate the water environment by preventing the release of heavy metals from the contaminated dredged sediments.
生物炭 (BC) 已被提议作为海洋环境中的一种潜在吸附剂。本研究试图通过使用 BC 来了解活性封盖的过程，以防止受污染的海洋疏浚沉积物中重金属（Pb 和 Cd）的释放。通过一系列实验室规模的柱实验评估了封盖效率。结果表明，BC 具有粗糙的孔隙结构和更高的比表面积，以及更多的表面有机官能团，这有利于其对重金属的吸附能力和选择性。BC 的 2 厘米封盖厚度足以防止重金属从沉积物中释放，对 Pb 的封盖效率为 47%，对 Cd 的封盖效率为 62%。动力学研究表明，进入上覆水中的重金属可以用三参数 S 型动力学模型来描述。重要的是，分析了封盖层下方疏浚沉积物中重金属的分数，以揭示封盖修复机制。本研究的结果表明，通过使用 BC 进行封盖是一种通过防止受污染疏浚沉积物中重金属释放来调节水环境的有前途的方法。
