title: Adsorption behavior of lead on aquatic sediments contaminated with cerium dioxide nanoparticles.
abstract: Aquatic sediments serve as an important sink for engineered nanomaterials (ENMs), such as metal oxide nanoparticles (MeO NPs) and carbon nanotubes (CNTs). Owing to their remarkable properties, ENMs demonstrate significant potential to disturb the adsorption behavior of other contaminants in aquatic sediments, thereby altering the bioavailability and toxicity of these contaminants. Thus far, most studies have investigated the effect of CNTs on the adsorption of other contaminants on sediments. Cerium dioxide nanoparticles (CeO2NPs), as one of the important MeO NPs, are also inevitably discharged into aquatic sediments because of their widespread use. In this study, we investigated the adsorption behavior of Pb2+on sediments spiked with CeO2NPs at a weight ratio of 5.0%. The results showed that the adsorption rates at three stages occurring during adsorption clearly increase for sediments contaminated with CeO2NPs. Moreover, the results obtained from the adsorption isotherms indicated that the Langmuir isotherm model best fits the isotherm data for both sediments and those contaminated with CeO2NPs. After spiking the sediments with CeO2NPs, the theoretical maximum monolayer adsorption capacity (Qmax) for Pb2+increased from 4.433 to 4.995 mg/g and the Langmuir isotherm coefficient (KL) decreased from 8.813 to 7.730 L/g. The effects of CeO2NPs on the surface charge and pore surface properties of sediments were also studied as these properties affect the adsorption of several chemicals in sediments. The results showed that pHzpc, SBET, Sext, and average pore size of sediments clearly decrease for sediments contaminated with CeO2NPs. Hence, the strong adsorption capacity of CeO2NPs and the changes of sediment surface charge and pore surface properties caused by CeO2NPs are important factors affecting the adsorption behavior of Pb2+. The potential risk of Pb2+in aquatic environment may increase with CeO2NPs buried in sediments.
authors.affiliation: Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.affiliation: Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
authors.forename: Xiulei
authors.initials: X
authors.lastname: Fan
authors.affiliation: Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China. Electronic address: pfwang2005@hhu.edu.cn.
authors.forename: Peifang
authors.initials: P
authors.lastname: Wang
authors.affiliation: Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Hou
authors.affiliation: Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Ao
authors.affiliation: Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
authors.forename: Lingzhan
authors.initials: L
authors.lastname: Miao
mesh_terms: D000327:Adsorption; D002563:Cerium / Q000737:chemistry*; D019015:Geologic Sediments / Q000737:chemistry*; D007854:Lead / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D007854:Lead; D002563:Cerium; C030583:ceric oxide
keywords: Cerium dioxide nanoparticles; Pb(2+) adsorption; Pore surface property; Sediment; Surface charge