Synthesis And Application Of Iron And Zinc Doped Biochar For Removal Of P-nitrophenol In Wastewater And Assessment Of The Influence Of Co-existed Pb(?)

With the development of industry and agriculture,a large amount of contaminants,such as the phenols and heavy metals,etc.was disgorged into the water environment.At present,the main way to relief the shortage of water resource was to purify sewage.And ascribing to the advantage of the biochar as an adsorbent,like the wide source,easy preparation,large specific surface area,abundant surface groups and great stability,it presented tremendous potential to apply biochar materials for water environment remediation.In this research,biochar materials doped with metal nanoparticles was proposed meant to improve their properties.And a kind of iron and zinc doped biochar(Fe/Zn-biochar)was prepared for PNP and Pb(?)removal in simulate wastewater sample.In contrast,three other modified biochar materials,iron doped biochar(Fe-biochar),zinc doped biochar(Zn-biochar),pristine biochar(P-biochar),was synthesized.Various characterization methods like SEM,nitrogen adsorption-desorption techniques,FTIR,XRD and XPS were utilized to analysis the physical and chemical properties of the adsorbents,and it indicated that the biochar materials were fully carbonized and crystal particles were evenly distributed on the surface of the modified biochar materials.Fe/Zn-biochar possessed large specific surface area(518.54 m/g),as well as favourable magnetism which was benefit for solid-liquid separation.In this study,the adsorption capability and optimized adsorption condition was detected about the biochar materials prepared above as an adsorbent for PNP removal.It showed that,Fe/Zn-biochar presented better adsorption performance for PNP compared with the others,and it was benefit for PNP adsorption under acidic condition than in an alkaline condition.The adsorption of PNP by Fe/Zn-biochar was a time-related process,and it took about 30 h to get balance.At room temperature and pH 3,the maximum adsorption capacity for PNP by Fe/Zn-biochar was about 158 mg/g.and it could be deduced the adsorption reaction of PNP by Fe/Zn-biochar was a endothermic and spontaneous process based on the experiment results under different reaction temperature.Meanwhile,the influence of coexist Pb(?)and PNP in solution on the adsorption of them respectively by Fe/Zn-biochar was detected in the study,and it showed a low concentration of PNP or Pb(?)could facilitate their adsorption respectively,while a high concentration suppressed their adsorption performance by Fe/Zn-biochar.Last,the possible adsorption pathways and mechanism in the binary system was also proposed.