Equilibrium, Kinetic, and Thermodynamic Analysis of Cd(II) Sorption from Aqueous Solutions using Polymeric Microcapsules containing an Acidic Organophosphonic Extractant

Adsorption of Pollutant Ions From Residual Aqueous Solutions Onto Nano-Structured Calcium Silicate

“…Cairns et al have proposed that the calcium silicate would contain 1.5 % of hydroxil groups meaning that approximately 8% of silicon atoms present are silanol groups allowing metallic ions like Cu(II) and Zn(II) to form the respective hydroxides on the surface of the silicates, which would act as nucleation site 33) . Measurements of porosimetry analysis using the N 2 sorptometer, indicated for the obtained nano-structured compounds an average surface area of 333.0 m 2 /g, value much higher than the surface area shown by other sorbents prepared in our laboratory 22,23,34) . The mean pore diameter varied between 15.8-23.6 nm and the pore volume between 0.7853-1.5441 cm 3 /g for calcium silicates synthesized at 6000 min -1 and 2000 min -1 , respectively.…”

“…During the past years a number of sorbents have been used successfully to treat industrial and mining wastewaters, natural surface and ground waters as well as acidic mine drainages (AMD), which are highly polluted with heavy metals ions and anions 10,11) . Examples of natural and synthetic adsorbents are among others activated carbon 12) , zeolites 13,14) , various clays 15) , kaolinites 16) , metal oxides 17) , and organic compounds like chitosan 18) , sawdust 19) , and allophones 20) , solvent impregnated resins (SIR) 21) and polymeric matrices that encapsulate organic extractants in their porous structure 22,23) . Many of the adsorbents have quite distinct and different properties and adsorbent activity, which make them interesting to study.…”