Prepartion Of Typha Based Biochar Material And Treatment Of Antibiotics And Heavy Metals In Aquatic Environment

In recent years,with the rapid development of industry and the extensive use of chemistry,heavy metals and antibiotic pollutants in water bodies exceed the standard seriously,which have adverse effects on the environment and human health.There is an urgent need to find scientific and effective solutions.In this thesis,TYPHA biomass was used as raw materials and a series of modified TYPHA biochar materials with low cost and high removal efficiency were developed for antibiotic and heavy metal wastewater treatment.（1）In this study,an integrated optimized method was used to prepare a biochar adsorbent（TBI_K）with large specific surface area and rich functional groups,by using typha rich in N and S elements as raw materials.The obtained TBI_Kshowed a high surface area of 1376.24 m~2/g and have more hydroxyl,pyridyl and mercapto groups on its surface.The experimental results showed that a rapid equilibrium has been detected within 20 min with a 99.95%removal rate towards a simulated mixed antibiotics residues.Meanwhile,coexisting anions and humic acid conditions had been designed to prove its brilliant environmental stability.The adsorption mechanism of TBI_Kwas studied by characterization methods such as BET and XPS.It was concluded that the microporous properties and retained functional groups were the determinants of biochar adsorption performance.In addition,this study analyzed the one-step carbonization and activation process and evaluated the energy consumption of the preparation method.It is found that the method saves 32.80%energy consumption compared with the traditional two-step carbonization and activation preparation method.（2）For complex wastewater containing both antibiotics and heavy metal Cr（VI）,TBI_Kadsorbent was modified to achieve selective enrichment and recovery of Cr（VI）in wastewater with complex composition in this study.The biochar adsorbent TBI_Znwas prepared from typha by Zn Cl₂activation.Through comparative experiments,TBI_Znshowed excellent adsorption effect for Cr（VI）,and can achieve selective adsorption in the mixed solution of antibiotics and Cr（VI）.At the same time,the adsorption effect of Cr（VI）may be related to the functional groups containing N and S elements.In addition,the fitting results of kinetic shows that the adsorption of Cr（VI）is mainly chemical adsorption.Langmuir model shows that the adsorption of Cr（VI）was dominated by monolayer adsorption.Finally,the selective enrichment and recovery of Cr（VI）in wastewater has been realized by adjusting p H.（3）This study verified the excellent adsorption performance of typha biochar for Cr（VI）,but it was difficult to completely remove Cr（VI）after adsorption.In order to solve this problem,photocatalytic technology was introduced.Typha biochar was used as the supporting material and Fe Cl₃was added to form a double REDOX system through thermal activation of sodium sulfate coupled with formic acid technology,then a series of highly active photocatalytic materials TBSP-Fe were prepared.Experiments showed that 0.5TBSP-Fe has the obvious removal effect on Cr（VI）,and the removal rate is greater than 99.5%within 40 min of photocatalysis.Besides,the reaction rate constant is higher than other materials.In addition,it is proved to have good stability by cycle test.At the same time,the active species capture experiment verified that e^-is the main active species for photocatalytic reduction of Cr（VI）by 0.5TBSP-Fe.The synergistic process and possible mechanism of adsorption-photocatalytic reduction are proposed by means of characterization.It provides a new idea for the removal and fixation of Cr（VI）in wastewater.