生物炭负载纳米零价铁对沉积物中十溴二苯乙烷去除效果及机制  

Removal Effect and Mechanism of DBDPE in Sediments by Biochar-loaded Nano-zero-valent Iron

作　　者：卢聪 LU Cong(Shanghai Textile Architecture Design Research Institute Co.,Ltd,Shanghai 200060,P.R.China;College of Resources and Environmental Engineering,East China University of Science and Technology,Shanghai 200237,P.R.China)

机构地区：[1]上海纺织建筑设计研究院有限公司,上海200060 [2]华东理工大学资源与环境工程学院,上海200237

出　　处：《生态环境学报》2024年第8期1279-1288,共10页Ecology and Environmental Sciences

基　　金：国家重点研发计划项目(2023YFC3707700)。

摘　　要：新型溴代阻燃剂十溴二苯乙烷(DBDPE)已经成为目前最常用的溴代阻燃剂。随着DBDPE在各种环境介质中被普遍检测到,其环境污染和治理正引起广泛的关注。迄今为止,生物炭负载零价铁材料(nZVI/BC)去除沉积物中DBDPE的应用尚未见报道。利用甘蔗渣通过液相还原法制备nZVI/BC,研究nZVI/BC去除沉积物体系里DBDPE的动力学过程,并探究其作用机制,为利用碳基零价铁去除沉积物中DBDPE提供了科学依据和技术支持。研究发现增加材料投加量、含水量、反应温度和降低底物初始质量分数,均能提高DBDPE的去除效率。高剂量的nZVI/BC能提供更多的吸附位点,并增大与DBDPE的接触面积,从而吸附更多的DBDPE分子。DBDPE质量分数的增加,将进一步增加DBDPE分子间的竞争反应,导致DBDPE分子与nZVI/BC颗粒的接触率降低。大量的水可以提供更多的活性H,从而提高与DBDPE反应的机会。温度升高,分子运动增强,提高了nZVI/BC与DBDPE的接触频率,也提高了n ZVI的反应活性。SEM表征结果显示,生物炭(BC)的加入使纳米零价铁(n ZVI)均匀分散在生物炭的表面,改善了n ZVI的分散程度,提高了n ZVI的反应活性。红外吸收光谱FTIR检测结果表明反应后nZVI/BC表面的-OH的伸缩振动和-CH_(2)-的弯曲强度均减弱,Fe-CO特征峰消失,并且出现了C=C的伸缩振动峰。nZVI/BC的微孔及介孔结构和表面的Fe-O、-OH、-CH_(2)-、C-O、C-H、C=O和-COOH等基团均能为DBDPE提供吸附位点,且DBDPE苯环结构上的π电子可能与nZVI/BC表面上的阳离子形成π-电荷相互作用。GC-ECNI-MS检测结果表明DBDPE被nZVI/BC降解过程中可能脱溴生成八溴二苯乙烷,ECOSAR (Ecological Structure Activity Relationships)软件预测nZVI/BC对DBDPE的降解降低了母体的生物毒性。Decabromodiphenyl ethane (DBDPE) is the most commonly used brominated flame-retardant.With the widespread detection of DBDPE in various environmental media,environmental pollution control has gained increasing attention.To date,there have been no reports on the application of biochar-loaded nano-zero-valent iron (nZVI/BC) to remove DBDPE from sediments.In this study,nZVI/BC was prepared from sugarcane bagasse by liquid-phase reduction.The kinetic process of nZVI/BC removal from sediment systems by DBDPE was studied,and the mechanism of action was explored,providing a scientific basis and technical support for the use of carbon-based zero-valent iron to remove DBDPE from sediment.It was found that increasing the dosage,moisture content,and reaction temperature,and reducing the initial mass fraction improved the DBDPE removal efficiency.High doses of nZVI/BC provide more adsorption sites and increase the contact area with DBDPE,thereby adsorbing more DBDPE molecules.As the mass fraction of DBDPE increased,the competition between the DBDPE molecules increased,resulting in a decrease in the contact rate between the DBDPE molecules and nZVI/BC particles.A large amount of water can provide more active H,thereby increasing the probability of reaction with DBDPE.The increase in temperature enhanced the molecular motion,contact frequency between nZVI/BC and DBDPE,and reactivity of nZVI.The SEM characterization results showed that the addition of biochar (BC) uniformly dispersed nano-zero-valent iron (nZVI) on the surface of biochar improved the dispersion degree of nZVI and enhanced the reaction activity of nZVI.The FTIR results showed that the stretching vibration of-OH and the bending intensity of-CH_(2)-on the surface of nZVI/BC decreased after the reaction,the characteristic peak of Fe-CO disappeared,and a stretching vibration peak of C=C appeared.The microporous and mesoporous structures of nZVI/BC,as well as the Fe-O,-OH,-CH_(2)-,C-O,C-H,C=O,and-COOH groups on the surface,can provide adsorption sites for DBDPE,and t

关 键 词：溴代阻燃剂 十溴二苯乙烷 生物炭 纳米零价铁 沉积物 去除机制 

分 类 号：X132[环境科学与工程—环境科学]