Bentonite Modified Its Applied Research, Printing And Dyeing Wastewater Treatment

Bentonite is a clay mineral with expandable layer structures that is primary constituent of montmorillonite. It has the large surface proportion and good ion exchange capability resulting from its strueture characteristic, so it has been widely used as adsorbent in all walks of lives.In this paper, the sodium modified Bentonite is modified using cetyltrimethylammonium bromide (CTMAB), Acrylamide(AC) and Benzyltriethylammionium chloride(BTMAC)by the means of intercalation in a liquid solutions,and the three modified bentonites are characterized by XRD,FTIR and DSC techniques. The results show that ion of the surfactants had entered into the chip layer of the bentonite, and changed the hydrophilic environment of the chip layer into hydrophobic environment and increased the basal spacing values.In this thesis study, the adsorption thermodynamics and kinetics of two kinds of dyestuff onto bentonite modified by CTMAB,AC, BTMAC. The adsorption properties of different modified bentonite were compared. The result illustrates that the adsorption of Methyl Orange from aqueous solution onto modified bentonites is correlated with the Freundlich type isotherm equation. At 303K, The equilibrium adsorption capability of sodium modified Bentonite, CTMAB modified bentonite, AC modified bentonite and BTMAC modified bentonite is 8.458mg/g, 96.385 mg/g, 79.855 mg/g, 40.149 mg/g respectively. The adsorption kineties result illustrates that it fit the pseudo-seeond order equation and the adsorption is a spontaneous and exothermic process. The adsorption of Crystal Violet from aqueous solutions by modified bentonites follows the Freundlich type isotherm equation better, and The equilibrium adsorption capability of sodium modified Bentonite, CTMAB modified bentonite, AC modified bentonite and BTMAC modified bentonite is 55.542 mg/g, 204.362 mg/g, 144.932 mg/g, 117.012 mg/g, respectively at 303K. The adsorption kinetic curves agree with the pseudo-seeond order equation and the adsorption is a spontaneous and endothermic process.On the basis of the experimentation, the effective diffusion coefficient (Def) of the Methyl Orange in the CTMAB modified bentonite is got. The breakthrough of the adsorbent used in fixed-bed is researched by math model, which is according with the breakthrough got by the experiment. It shows that the math model can be used to forecast the experiment's result.