Adsorption Of Typical Organic Pollutants In Water By Modified Wheat Straw And Carbon Nanotubes

In order to remove the dyes and antibiotics in the wastewater,the wheat straw was modified by different methods and the experimental conditions were optimized.The material modified before and after were characterized by scanning electron microscopy?SEM??X-ray fluorescence analysis?XRF??Elemental analysis?infrared spectroscopy?FT-IR?and isoelectric point et al.The results showed that zirconium was successfully loaded onto the surface of wheat straw and analyzed dynamically.In addition,the paper also discussed static adsorption of methylene blue?MB?in wastewater on carboxylated carbon nanotubes?mCNTs?.In order to further discuss the reaction mechanism of the adsorption process,the adsorbent before and after adsorptiop was analysised by X-ray photoelectron spectroscopy?XPS?.The adsorption results of alizarin red?AR?and tetracycline hydrochloride?TCs?on the modified wheat straw?Zr-DWS,Zr-ClWS?were as follows:?1?:The maximum adsorption capacity of the adsorption of AR on Zr-DWS was 173 mg·g^-1,and the initial pH increase of the solution was not conducive to the adsorption process,while the effect of temperature was on the country.The pseudo second-order equation and the Elovich equation could be used to describe the adsorption process of AR on Zr-DWS,which indicated that this adsorption was mainly chemical adsorption.0.1 mol·L^-1 NaOH had the best desorption and regeneration effected on AR.The competitive adsorption of AR with acid chrome blue K?AK?indicated that Zr-DWS had preferential adsorption properties for AR.The results of dynamic adsorption:high column?high concentration?low flow rate were beneficial to the adsorption of AR on Zr-DWS;Yan model can well describe the dynamic adsorption behavior.?2?:The adsorption of TCs on Zr-ClWS:the salt had no effect on the adsorption of TCs on Zr-ClWS under weakly acidic conditions,indicating that the combination between the two relied mainly on complexation.Thermodynamic and kinetic fitting of the adsorption process showed that the adsorption of TCs on Zr-ClWS was multi-layer adsorption,and the adsorption process was chemical-based adsorption.The thermodynamic parameters indicated that the adsorption of TCs on Zr-ClWS was a physicochemical reaction of endothermic and entropy increase.The results of dynamic adsorption of TCs on Zr-ClWS were similar to those of AR on Zr-DWS.Adsorption of MB on mCNTs:compared with MWCNTs,the adsorption capacity of MB on mCNTs was significantly improved.The increase of pH was not conducive to the adsorption of MB on mCNTs.The adsorption amount of MB on mCNTs decreased with the increase of temperature with the range of experimental temperature,indicating that the adsorption of MB on mCNTs was exothermic.The adsorption of MB on mCNTs was consistent with the Langmuir equation,and the adsorption process conformed to the pseudo second-order equation,indicating that the adsorption was a multi-molecular layer reaction dominated by chemical adsorption.In order to make full use of the adsorbent,the paper adsorbed MB by mCNTs and then adsorbed congo red?CR?.The experimental results proved that the adsorption capacity of CR on MB-loaded mCNTs was much improved than that of mCNTs for CR,which once again proved that the mCNTs prepared in this paper could be used for many times and was environmentally friendly.