Preparation Of Organicbentonites And Its Adsorption Wastewater Thiocyante Ions

Coking wastewater contains large amounts of organic and inorganic pollutants, inorganic sulfur content of more cyanide ions, such substances in the aquatic environment and soil have done great harm to the human body, and thus how to remove coking wastewater thiocyanate ions has a very important significance. Bentonite because of its rich resources, special layered structure and physical properties, which can be used as an inexpensive adsorbent material in wastewater treatment has great potential. However, the effect of anionic pollutants present in the wastewater is poor. The modified bentonite interlayer spacing becomes large, the surface charge change can effectively adsorbs organic and inorganic contaminants. In this paper, using a variety of surfactants on bentonite modified to study the adsorption of thiocyanate ions removal behavior.Mixing method used in this thesis, the variety of typical surfactants (OTAC, HDBAC, TMPAC, BTMAB, CTMAB) to obtain a series of organic modified bentonite sodium bentonite (Na-Bent) and then labeled OTA+-Bent, HDBA+-Bent, TMPA+-Bent, BTMA+-Bent, CTMA+-Bent. With XRD, BET, FTIR means to characterize the physical and chemical properties, and to study the adsorption behavior of thiocyanate ions under the same conditions. Then organicbentonites were used for adsorption of thiocyanate ions.CTMAB-Bent was used for adsorption of thiocyanate ions of initial concentration of50mg·L-1. The modified quantity of CTMAB、additive amount of modified bentonite and adsorption time on the influence of adsorption rate were detailed discussed. The results showed that the amount of CTMAB modified for1.0CEC (Na-Bent cation exchange capacity), adsorption time was60min, adsorbent dosage15g·L-1, the adsorption rate of thiocyanate ions up to91.63%, the Langmuir isotherm model, with a quasi-one quasi-two model dynamics analysis, regression results show that the quasi-two model more accurately reflects the adsorption power, but is a simple physical adsorption. Calculate the thermodynamic parameters obtained△G=-2～-5kJ·mol-1, indicates CTMA+-Bent adsorption of thiocyanate ions is spontaneous;△H--24.42kJ·mol-1, described the adsorption is an exothermic process.CTMA+-TMA+-Bent for thiocyanate ions adsorbed mass concentration of SOmg·L-1, the detailed discussion of the CTMA+-TMA+-Bent affect the amount of modification, the dosage of modified soil and adsorption time on the adsorption rate. The results showed that the amount of modifier is1.0CEC CTMAB and0.4CEC TMAC, adsorption time is60min, adsorbent dosage15g·L-1, the adsorption rate of thiocyanate ions up to97.05%, the Langmuir isotherm model, with associate a quasi-two model dynamics analysis, regression results show that the quasi-one model more accurately reflects the adsorption power. Calculate the thermodynamic parameters obtained△G=-7～-8kJ·mol-1, indicates CTMA+-Bent adsorption of thiocyanate ions is spontaneous;△H=-21.54kJ·mol-1, described the adsorption is an exothermic process.