TY - GEN
T1 - Simulation of adsorption equilibrium of heavy metal cations on soils in circumneutral aqueous solution
T2 - 2011 International Conference on Advanced Engineering Materials and Technology, AEMT 2011
AU - Ryu, Yo
AU - Kobayashi, Takeshi
AU - Kameya, Takashi
AU - Takahashi, Yukari
AU - Ohashi, Yuko
PY - 2011/8/12
Y1 - 2011/8/12
N2 - Adsorption isotherms are often required for understanding mobility, fate and bioavailability of contaminants in soils. Those about Pb (II) and Cd (II) on Andosols and Kanto loam were investigated in this work. Results show that adsorption increased with cation equilibrium concentration (10-4 - 1 meq L-1) and solution pH (5 - 7), and also that most adsorption isotherms can be simulated precisely with the ion-exchange-based Urano model. The applicability of model in predicting adsorption equilibriums of cations on soils in circumneutral aqueous solution (pH 5 - 7) were experimentally confirmed. There is an exception as to the Pb (II) adsorption on Andosols with the solid-to-liquid phase ratio higher than 1:100, there adsorption isotherms at pH 5 and pH 7 crossed, and the measurement precision decreased. The Urano model equation becomes inapplicable. Further experiment where humus substances (HS) were added indicated that the abnormal phenomenon can be attributed to dissolved HS and their complexation with Pb (II). The dissolution of HS with solution pH has enhanced Pb (II) concentration in solution but hardly reduced the total amount of adsorption on soil.
AB - Adsorption isotherms are often required for understanding mobility, fate and bioavailability of contaminants in soils. Those about Pb (II) and Cd (II) on Andosols and Kanto loam were investigated in this work. Results show that adsorption increased with cation equilibrium concentration (10-4 - 1 meq L-1) and solution pH (5 - 7), and also that most adsorption isotherms can be simulated precisely with the ion-exchange-based Urano model. The applicability of model in predicting adsorption equilibriums of cations on soils in circumneutral aqueous solution (pH 5 - 7) were experimentally confirmed. There is an exception as to the Pb (II) adsorption on Andosols with the solid-to-liquid phase ratio higher than 1:100, there adsorption isotherms at pH 5 and pH 7 crossed, and the measurement precision decreased. The Urano model equation becomes inapplicable. Further experiment where humus substances (HS) were added indicated that the abnormal phenomenon can be attributed to dissolved HS and their complexation with Pb (II). The dissolution of HS with solution pH has enhanced Pb (II) concentration in solution but hardly reduced the total amount of adsorption on soil.
KW - Adsorption equilibrium
KW - Cation
KW - Humus substances
KW - Model simulation
KW - Soil
KW - Solution pH
UR - http://www.scopus.com/inward/record.url?scp=79961224651&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79961224651&partnerID=8YFLogxK
U2 - 10.4028/www.scientific.net/AMR.287-290.2822
DO - 10.4028/www.scientific.net/AMR.287-290.2822
M3 - Conference contribution
AN - SCOPUS:79961224651
SN - 9783037851920
T3 - Advanced Materials Research
SP - 2822
EP - 2825
BT - Applications of Engineering Materials
Y2 - 29 July 2011 through 31 July 2011
ER -