title: Nickel oxide grafted andic soil for efficient cesium removal from aqueous solution: adsorption behavior and mechanisms.
abstract: An andic soil, akadama clay, was modified with nickel oxide and tested for its potential application in the removal of cesium from aqueous solution. Scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), and powder X-ray diffraction (XRD) results revealed the nickel oxide was successfully grafted into akadama clay. N2 adsorption-desorption isotherms indicated the surface area decreased remarkably after modification while the portion of mesopores increased greatly. Thermogravimetric-differential thermal analysis (TG-DTA) showed the modified akadama clay had better thermostability than the pristine akadama clay. Decreases in cation exchange capacity (CEC) and ζ-potential were also detected after the modification. Adsorption kinetic and isotherm studies indicated the adsorption of Cs+ on the modified akadama clay was a monolayer adsorption process. Adsorption capacity was greatly enhanced for the modified akadama clay probably due to the increase in negative surface charge caused by the modification. The adsorption of Cs+ on the modified akadama clay was dominated by an electrostatic adsorption process. Results of this work are of great significance for the application of akadama clay as a promising adsorbent material for cesium removal from aqueous solutions.
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
authors.forename: Dahu
authors.initials: D
authors.lastname: Ding
authors.forename: Zhongfang
authors.initials: Z
authors.lastname: Lei
authors.forename: Yingnan
authors.initials: Y
authors.lastname: Yang
authors.forename: Chuanping
authors.initials: C
authors.lastname: Feng
authors.forename: Zhenya
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000327:Adsorption; D002586:Cesium / Q000737:chemistry*; D002588:Cesium Radioisotopes / Q000737:chemistry; D007700:Kinetics; D009532:Nickel / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D055672:Static Electricity; D014867:Water / Q000737:chemistry*; D014875:Water Pollutants, Radioactive / Q000737:chemistry
chemical_list: D002588:Cesium Radioisotopes; D012987:Soil; D014875:Water Pollutants, Radioactive; D014867:Water; D002586:Cesium; D009532:Nickel; C028007:nickel monoxide