title: Adsorption of Cd(II) from aqueous solutions by rape straw biochar derived from different modification processes.
abstract: In order to deal with cadmium (Cd(II)) pollution, three modified biochar materials: alkaline treatment of biochar (BC-NaOH), KMnO4impregnation of biochar (BC-MnOx) and FeCl3magnetic treatment of biochar (BC-FeOx), were investigated. Nitrogen adsorption-desorption isotherms, Fourier transform infrared spectroscopy (FTIR), Boehm titration, and scanning electron microscopy (SEM) were used to determine the characteristics of adsorbents and explore the main adsorption mechanism. The results show that manganese oxide particles are carried successfully within the biochar, contributing to micropore creation, boosting specific surface area and forming innersphere complexes with oxygen-containing groups, while also increasing the number of oxygen-containing groups. The adsorption sites created by the loaded manganese oxide, rather than specific surface areas, play the most important roles in cadmium adsorption. Batch adsorption experiments demonstrate a Langmuir model fit for Cd(II), and BC-MnOxprovided the highest sorption capacity (81.10 mg g-1). The sorption kinetics of Cd(II) on adsorbents follows pseudo-second-order kinetics and the adsorption rate of the BC-MnOxmaterial was the highest (14.46 g (mg·h)-1). Therefore, biochar modification methods involving KMnO4impregnation may provide effective ways of enhancing Cd(II) removal from aqueous solutions.
authors.affiliation: College of Resources, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Li
authors.affiliation: College of Resources, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Yang
authors.affiliation: College of Resources, Sichuan Agricultural University, Chengdu 611130, China. Electronic address: w.changquan@163.com.
authors.forename: Chang-Quan
authors.initials: CQ
authors.lastname: Wang
authors.affiliation: College of Resources, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Qing-Pei
authors.initials: QP
authors.lastname: Zhang
authors.affiliation: College of Resources, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Qing-Cheng
authors.initials: QC
authors.lastname: Liu
authors.affiliation: College of Resources, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Yi-Ding
authors.initials: YD
authors.lastname: Li
authors.affiliation: College of Resources, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Xiao
mesh_terms: D000327:Adsorption; D029741:Brassica rapa; D002104:Cadmium / Q000737:chemistry*; D002606:Charcoal; D002712:Chlorides / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D017895:Manganese Compounds / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010087:Oxides / Q000737:chemistry; D018547:Plant Stems; D011196:Potassium Permanganate / Q000737:chemistry; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D017186:Titrimetry; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D002712:Chlorides; D005290:Ferric Compounds; D017895:Manganese Compounds; D010087:Oxides; D012996:Solutions; D014874:Water Pollutants, Chemical; C540010:biochar; D002104:Cadmium; D011196:Potassium Permanganate; D002606:Charcoal; C027424:manganese oxide; C024555:ferric chloride
keywords: Adsorption; Biochar; Cd(II); Modification