Preparation And Modification Of Biomass Hydrochar And Its Performance In Environmental Application

Biomass,such as crop stalks and organic waste,is the most widespread waste and need to be dealed.Hydrothermal carbonization(HTC)of biomass is a promising technique for synthesizing novel carbon-based adsorbents,which not only can reduce the amount of waste biomass and reduce the release of greenhouse gases,but also can realize recycling use of waste and realize the circulation economy.In this research,HTC process was choose to convert the biomass to carbon-based functional materials.The as-prepared materials have been used as an adsorbent to remove the pollutants in the wastewater.On the basis of a series of characterization methods,the removal mechanisms of pollutants were elucidated.The main contents and results of this thesis are as follows:1.The preparation of amino-functionalized hydrochar(AFHC)and its removal performance to lead(Pb):Pb is a ubiquitous heavy metal,and its removal and immobilization from the wastewater have attracted considerable concern.In this work,we prepared AFHC from waste biomass and investigated its adsorption and immobilization activity toward Pb.Results showed that AFHC exhibits high performance in Pb removal,achieving over 1000 mg g-1 removal capacity within the first 5 min of reaction,and high selectivity toward this metal ion.Notably,AFHC can efficiently remove the low concentrations of Pb in aqueous solution,suggesting it has potential utility in treatment of drinking water.Further investigations indicated that the robust performance of AFHC may be attributed to the formation of rod-like Pb5(PO4)3(OH)crystals on the surface of AFHC,where amino groups function as bridges and hydrolyze to provide basic groups.2.Preparation of magnetic activated saw dust hydrochar(M-SDHA)and its removal performance to tetracycline:Thet etracycline(TC)is the second widely-used antibiotics with applications in human therapy and veterinary pharmaceuticals.The release of pharmaceutical active ingredient and metabolites have arisen considerable concern.The main objective of this study is to prepare M-SDHA by avtivated and magnetization of hydrochr form a widely available lignocellulosic biomass saw dust,and demonstrate the adsorption performance toward TC.The maximum adsorption capacity of M-SDHA for TC was calculated from Langmuir model is 502.5 mg g '.The high TC removal capacity can be attributed to two aspects:1)the high surface area of M-SDHA;2)the existence of Fe on the surface of M-SDHA.Magnetization curve and XRD spectra show that the Fe in M-SDHA was exist as Fe3O4 and Fe0,which presents an excellent separability of M-SDHA.