| There are large numbers of biomass wastes being arised in our country every year, and pyrolytic carbon will be generated as by-product when those wastes pyrolyze, so a question on the utilization of pyrolytic carbon has become the research hotspot. Pyrolytic carbon is a kind of polymer with high specific surface area, abundant pore structure and many oxygen-containing functional groups, so it can be used as adsorbents to remove pollutants from wastewater. Thus, it not only takes advantage of biomass, but also has a significant meaning for reducing environment problems and increasing economic benefits. In this research, modified pyrolytic carbon(MW-PC) was obtained by Ca Cl2-microwave method using pyrolytic carbon(PC) as raw material, then MW-PC was employed as adsorbent to study the adsorption capacity of dyes(malachite green, light green) and organics(aniline, 4-chloro phenol), respectively.The surface structure and surface functional group of PC and MW-PC was characterized using X-ray fluorescence(XRF), Fourier transform infrared spectrum(FT-IR), Scanning electron microscope(SEM), X-ray diffraction(XRD) and acidbase titration method, respectively. The results showed that the superficial porosity and alkalinity functional group on the surface of MW-PC increased.Several influence factors, such as adsorption time, solution p H, the dosage of adsorbent, salt concentration, temperature and initial concentration, were conducted to investigate the effect of MW-PC for the adsorption of malachite green(MG), light green(LG), aniline and 4-chloro phenol in single system, respectively. Then the experiment data was fitted by several isotherms and dynamics equations. In addition, the adsorption experiments of MW-PC for MG and aniline in binary system were also studied. The results were as follows:(1) The adsorption property of MG, LG, aniline and 4-chloro phenol by MW-PC in single system were carried out. The optimum p H of adsorption of MW-PC for MG LG, aniline and 4-chloro phenol was 8.47, 3.81, 2 and 2, respectively. The existence of salt had an inhibitory effect for adsorbing MG and 4-chloro phenol, while promoted the adsorption capacity of aniline, and the salt of low concentration(<0.06 mol/L) favored the adsorption of LG, and when the concentration of salt was higher(>0.06 mol/L), the adsorption of LG was restrained. Freundlich equation could be used to fit the equilibrium data of MG and LG, respectively. While the equilibrium data of adsorption of aniline by MW-PC followed Langmuir, Koble-Corrigan, Temkin equations, respectively. Langmuir and Temkin isotherm models better fitted the experiment data of 4-chloro phenol. Pseudo-second-order model could be well fitted the adsorption process of MW-PC for MG, LG, aniline and 4-chloro phenol, respectively. The saturated MW-PC with MG and aniline could be desorbed and regenerated by absolute ethyl alcohol, and 0.1 mol/L HNO3 could be used as a regenerator for LG, while the reproducing property of 4-chloro phenol was worse.(2) The adsorption property of MG and aniline in binary system on MW-PC were also studied. The total adsorption amounts of MW-PC for MG and aniline in binary system were more than that in single system. MW-PC had bigger affinity force for MG. Pseudo-second-order equation and Pseudo-first-order equation could be used to describe the adsorption process of MW-PC for MG and aniline in binary system and(MW-PC)-MG for aniline, respectively.In conclusion, not only the adsorption performance of MW-PC for MG, LG, aniline and 4-chloro phenol in single system was good, but also the adsorption property for MG and aniline in the binary system was also good. So MW-PC could become a kind of adsorbent with the property of high efficiency and low cost to be used for wastewater treatment. |
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