Preparation And Application Of Coconut Shell Biochar

The problem of environmental pollutants discharge has been attracting people's attention.These pollutants release into natural environment may give rise to severe pollution of aquatic environment and air quality,and does serious harm to human by the bio-megascopic effect of biologic chains.As a new adsorbent biochar has raw material sources widely,low cost,large porosity,high specific surface area,strong adsorption characteristics and other advantages,arising more and more attention.In this thesis,biochar was prepared by raw material-coconut shell and used as adsorbent for removing environment pollutants,in the meantime,the effect of different factors on the adsorb ability of biochar was investigated.In the first chapter,a general introduction about biochar was made,including the basic concept,development status,raw material,preparation methods,etc.Then,the application of biochar in the removal of environmental pollutants and adsorption mechanism was introduced.The purpose and the main contents of this thesis had been pointed out also.In the second chapter,biochar was prepared from biomass renewable source-coconut shell,and BET specific surface area analyzer,X-Ray Diffraction(XRD),Fourier transformed infrared(FT-IR)and Scanning electron microscopy(SEM),and were used to characterize coconut shell biochar(CSBC).CSBC was used as adsorbent for adsorption removal of four kinds of fluoroquinolone antibiotics.The results showed that the BET surface area,pore volume and average pore diameter of CSBC were 1224m2/g,0.647cm3/g and 2.52nm,respectively.CSBC have good removal efficiency of ofloxacin,enrofloxacin,norfloxacin and ciprofloxacin,the maximum adsorption capacity were 345.6 mg/g,375.7 mg/g,408.5 mg/g and 385.7 mg/g,respectively.In the third chapter,coconut shell biochar(CSBC)was modified by iodine chloride at the first time,and the new product was named CSBC-ICl.Then,CSBC-ICl was used for the adsorptive removal of elemental mercury(Hg0)and mercury ion(Hg2+).The results showed that the removal efficiency of modification of CSBCs was better than unmodified,and CSBC-ICl has a better removal efficiency of Hg2+than other several kinds of adsorbent and the adsorption capacity of Hg2+ was 228.5mg/g.In the fourth chapter,amino modified coconut shell biochar(CSBC-NH2)was prepared and then used for adsorptive removal of anionic and cationic dyes in water.The results showed that CSBC-NH2 has good removal efficiency of Congo red(CR)and Crystal violet(CV)and the adsorption capacity were 228.1 mg/g and 215.8mg/g,respectively.The adsorption of CR and CV on the CSBC and CSBC-NH2 can be best described by the pseudo-second-order kinetic model.The adsorption process was taken place by chemical adsorption mechanism and electrostatic attraction,?-?interactions and van der Waals may be the main mechanisms for the adsorption of dye contaminants onto biochar.