Showing 2 results for Montmorillonite
S. M. A. Zomorodian, M. Khoshkoo,
Volume 16, Issue 61 (10-2012)
Abstract
Internal erosion is the second major reason for earth dam's failure after overtopping. One of the effective factors in internal erosion in earth dams is the clay minerals used in dams as well as the effects of compaction efforts on soil in sample preparation. In this research, internal erosion and the effect of clay minerals and compaction effort on internal erosion were investigated. For this purpose, Kaolin clay and Na Montmorillonite (Bentonite) separately and with different percentages of mixture were used to investigate the effect of different percentages of Bentonite on internal erosion. Two hammers of standard compaction and modified compaction test were also used to investigate different compaction efforts in internal erosion. The results showed that as compaction effort increased in constant water content, erodibility also increased to about 3%. In addition, it is found that erodibility of kaolin clay is more than bentonite, which reaches 65%. Finally, by adding 12% bentonite to kaolinite, erodibility decreased to a great extent.
S. Farahi, M. Hamidpour, H. Shirani, H. Dashti, M. Heshmati,
Volume 17, Issue 66 (2-2014)
Abstract
This research was conducted to study the effect of natural and polyacrylamide-modified montmorillonite on the sorption of Cd from aqueous solutions. The sorption of Cd on the sorbents was studied as a function of pH (Cd concentration: 10 mg L-1) in the range of 4-8.5, and as a function of metal concentration (Cd concentration in the range of 1-10 mgL-1) using a 24h batch equilibration. Experimental and modeling data from equilibrium investigations revealed that the Koble–Corrigan sorption model describes the interaction between Cd and the two sorbents better than the Freundlich and Langmuir models. The values of KF constant of Freundlich and KL constant of Langmuir models were higher for sorption of Cd onto the modified montmorillonite than for those of natural montmorillonite. Maximum sorption capacity calculated from the Langmuir model was 0.6 and 0.7 mg g-1 for natural and modified montmorillonite, respectively. These values are indications of high sorption affinity of Cd to montmorillonite in the presence of polyacrylamide. The amount of Cd sorbed by modified montmorillonite decreased by increasing solution pH while Cd sorption by natural montmorillonite increased by increasing the solution pH.
