| With the rapid growth of pharmaceutical and chemical industries in the world,the disposal of pharmaceutical wastewater has attracted increasingly great concern.Traditional water treatment technology is difficult to effectively remove antibiotics from pharmaceutical wastewater,which leads to the residual antibiotic in surface water and drinking water all over the world increased year by year.The accumulation of residual antibiotics in the ecosystem seriously harms the balance of microecology and human health,and the phenomenon of microbial drug resistance is becoming more and more serious.For the effective removal of antibiotics from pharmaceutical wastewater,adsorption method is considered to be one of the most promising technologies due to its advantages of simplicity,low cost,no secondary pollution involved and strong feasibility.The research and development of effective adsorbents has become a hot-spot issue in recent years.In this paper,a series of boron nitride(BN)-based nanomaterials were synthesized by green mechanical ball milling technology and used in the adsorption and separation of typical antibiotics in pharmaceutical wastewater.The physical and chemical properties of the materials are characterized by XRD,FTIR,XPS,TEM,BET and other characterization methods.Through the optimization of adsorption conditions,adsorption kinetics and isotherm properties,the intrinsic relationship between structure and performance was studied to explore the adsorption mechanism,and the regeneration performances of series BN-based few-layered nanomaterials were investigated.1.A low-cost,green,simple and fast one-step ball milling process was developed for the preparation of few-layered graphene-like BN nano-absorbent material(BM-BN).The efficient stripping of commercial bulk BN was realized by the physical and mechanical force of ball milling.The graphene-like BM-BN prepared under the optimal ball milling conditions had about 3 layers,and the specific surface area and pore volume increased to 3.5 times and 3 times of the commercial BN respectively,and the removal efficiency of oxytetracycline(OTC)was significantly improved by 66%.Hydrophobic action,?-? action and electrostatic action are the main forces in the adsorption process.2.A new method for efficient preparation of Fe-doped graphene-like BN nano-absorbent material(Fe-BN)by ball milling was established by situ introduction of different molar ratios of metal iron sources.With the physical and mechanical force of ball milling,the efficient stripping of commercial bulk BN and the efficient doping of Fe based active metal center were realized.A series of Fe-BN adsorbents with different Fe molar contents were screened.The removal efficiency of antibiotics onto Fe(5%)-BN was the best.Compared with commercial BN,the removal efficiency of OTC onto Fe(5%)-BN was improved by 85%.3.A new method for the preparation of Cu-doped graphene-like BN nano-absorbent material(Cu-BN)by ball milling was established by situ introduction of copper sources with different molar ratios.A series of Cu-BN nano-materials with different Cu molar ratios were prepared by high-speed impact and shear force during ball milling process,and Cu based active metal center was highly dispersed and mixed into BN while commercial bulk BN was efficiently exfoliated.Structure characterization results showed that the active metal in material was mainly in the form of Cu(?),which demonstrated this metal was CuO nanoparticles.Compared with commercial BN,the adsorption performance of antibiotics onto Cu(5%)-BN was significantly improved and the removal efficiency of OTC was improved by 87%.Moreover,compared with Fe(5%)-BN,the adsorption rate was significantly accelerated.The adsorption mechanism might be ?-? interaction,cationic bridge interaction and electrostatic interaction. |
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