Experimental Study Of Removal Of Cr In Water Using Furfural Residue

With the development of the industry, chromium and its compounds are more and more widely applied as the important raw materials in metallurgy, electroplating, leather and other industries. The chromium pollution in water environment is increasingly serious but the current process used for low concentration(< 10 mg/L) water has disadvantages such as complex operation, low efficiency. Adsorption has wide application prospect because of the advantages of simple operation but often high prices and the difficulty of regeneration makes its application is restricted. Therefore, the research and development of cheap adsorbent has important environmental, economic and social significance. This paper results select the furfural residue as adsorbent from agriculture and forestry wastes for good removal effect to achieve the purpose of using waste treat waste, for its ability to remove Cr( Ⅵ) in water experiment research, and the furfural slag modification, get the best modification condition.This paper first studied the effect of particle size, the quality of furfural residue, initial concentration of Cr(Ⅵ), initial p H, temperature and contacting time on removing Cr(Ⅵ). The applicationof the adsorption dynamics equation means to describe the adsorption process and the application of Langmuir and Freundlich means to simulate the adsorption isotherm and the SEM which is short for scanning electron microscope and the FTIR which is short for infrared spectra characterizes the surface features of furfural residue. To modify optimum conditions using epoxy chloropropane to improve removal capacity of Cr(Ⅵ) in water is determined and the results show that:(1) In the process of removing Cr(Ⅵ), p H is the main influence factors, changing the particle size and increase the furfural furfural slag slag dosage, the extension of adsorption time, improve the reaction temperature can also improve the adsorption quantity.(2) The process of removing Cr(Ⅵ) in water by furfural residue conforms to the dynamic model of the secondary and its isothermal adsorption behavior is described by Langmuir and Freundlich isothermal adsorption model. By fitting the parameters, the maximum saturated adsorption capacity is1.5mg/g, and n=3.46, n > 1 in Freundiich adsorption isotherm parameters shows that the adsorption is a preferential adsorption process.(3) The application of scanning electron microscopy(SEM) and infrared spectra(FTIR) characterizes the surface features of furfural residue. It can be seen from the SEM figure that surface is rough with porous microstructure and pages-like structure before the reaction while after the reaction the gaps on surface is filled and round section becomes angular. It can be seen in figure that obvious changes happened to the functional groups on the surface from the FTIR contrast.(4) Removal rate of Cr(Ⅵ) in water by the modified furfural residue can reach 98%. The optimum modification of furfural residue modified by epoxy chloropropane liquid-solid ratio is 4:1, epoxy chloropropane concentration 60%, reaction time 40 minutes.