摘要
南海深海沉积物除了包含常规的岩源物质,还有丰富生物来源的海相化石.有孔虫壳体作为南海沉积物最重要的组分之一,其在重金属吸附方面的应用潜力还未可知.本研究以南海深海海域表层沉积物为研究对象,通过吸附动力学、热力学和吸附等温实验探究了其对重金属Cu(Ⅱ)的吸附特性以及pH、有机质对吸附过程的影响.结果表明,Cu(Ⅱ)在沉积物上的吸附过程符合伪二级动力学模型,主要为化学吸附,且吸附速率受到非均相扩散和内扩散两方面的控制.南海深海沉积物对Cu(Ⅱ)的最大吸附量可达到361.49 mg·g^(-1),且该吸附过程能很好的符合Langmuir等温吸附模型,是自发进行的放热反应.pH对吸附过程的影响显著,在2.0~5.0的pH值范围内随pH升高而增加,沉积物中有机物对吸附的贡献率为17.40%.通过XPS、FTIR、XRD、SEM-EDS等技术分析表明,沉积物表面或层间的部分Ca(Ⅱ)与溶液中的Cu(Ⅱ)发生了离子交换作用,碳酸盐矿物在Cu(Ⅱ)的吸附中发挥了重要作用.吸附在沉积物表面的Cu同时以Cu(Ⅱ)和Cu(Ⅰ)的形式存在,-OH和OH-在吸附过程中通过促进Cu(OH)2形成来将Cu吸附在沉积物表面.吸附后,沉积物表面形成了蓝铜矾和水胆矾的新矿相.
The sediments from the South China Sea contain not only conventional rock-derived materials but also marine fossils with rich biological sources.As one of the most important components of sediments,foraminifera shell is not known for its potential in heavy metal adsorption.In this study,Cu(Ⅱ)adsorption characteristics and influencing factors by deep-sea sediment from the South China Sea were investigated.The results showed that the adsorption process of Cu(Ⅱ)was well fitted by pseudo-second-order kinetic model and a Langmuir isothermal adsorption model.Chemical adsorption acted the main roles in Cu(Ⅱ)adsorption,whilst the adsorption rate was controlled by heterogeneous and internal diffusion.The maximum adsorption capacity of Cu(Ⅱ)by the sediments reached 361.49 mg·g^(-1).pH had a positive effect on Cu(Ⅱ)adsorption within a pH range of 2.0~5.0.Meanwhile,the contribution rate of organic matter to Cu(Ⅱ)adsorption was 17.40%.Results of XPS,FTIR,XRD and SEM-EDS analyses showed that partial Ca(Ⅱ)ions on the surface or between the layers of the sediments could exchange Cu(Ⅱ)in the solution,and carbonate minerals played an important role in Cu(Ⅱ)adsorption.The adsorbed Cu on the surface of the sediments existed in the form of Cu(Ⅱ)and Cu(Ⅰ).Hydroxyl and hydroxide radicals promoted the formation of Cu(OH)_(2) and new Cu-contained minerals including langite and brochantite formed during the adsorption process.
作者
钱子妍
曾娟
张立刚
雷湘
李义伟
QIAN Ziyan;ZENG Juan;ZHANG Ligang;LEI Xiang;LI Yiwei(Changsha Research Institute of Mining and Metallurgy Co.,LTD,Changsha 430000)
出处
《环境科学学报》
CAS
CSCD
北大核心
2023年第9期152-163,共12页
Acta Scientiae Circumstantiae
基金
国家重点研发计划项目(No.2022YFC2804002)。
关键词
深海沉积物
铜离子
重金属吸附
吸附特性
deep-sea sediments
Cu(Ⅱ)
heavy metal adsorption
adsorption property
