Study On The Adsorption Performance Of Citronella Leaf Biochar On Quinolone Antibiotics In Aqueous Solutio

Quinolone antibiotics have become one of the most widely used antibiotics in the world because of their good antibacterial effect.Because of its high toxicity,strong bioaccumulation and poor hydrolytic stability,the remediation of quinolone antibiotics in polluted water has become a hot research issue at present.In the exploration of antibiotic removal technology in aqueous solution,adsorption method is popular because of its advantages of simple process,low cost,low energy consumption,high removal rate,and no toxic intermediates.At present,activated carbon is the most widely used adsorbent.However,due to the increasing shortage of raw materials for the preparation of activated carbon,such as coal mines,forests and other natural resources,the preparation cost of activated carbon is getting higher and higher.Therefore,looking for green,efficient and low-cost adsorbent has become the focus of people’s research.Biochar has become the focus of research because of its low cost of raw materials and similar physical and chemical properties to activated carbon.In this paper,lemongrass leaf biochar was prepared from cheap agricultural waste lemongrass leaf as adsorbent,and the adsorption properties and mechanism of norfloxacin and ciprofloxacin,two typical quinolone antibiotics,were studied.In this paper,low-cost agricultural waste citronella grass leaves were used as raw materials to prepare biochar BC from citronella grass leaves by slow pyrolysis method and to prepare biochar CBC-1,CBC-2 and CBC-3 from citronella grass leaves by phosphoric acid modification with different concentrations(45%,65%and 85%by mass fraction).The structure and morphology of BC,CBC-1,CBC-2 and CBC-3 were characterized by Transmission electron microscopy(TEM),specific surface area analysis(BET),Fourier transform infrared spectroscopy(FT-IR)and X-ray diffraction(XRD).The results show that BC,CBC-1,CBC-2 and CBC-3 are all amorphous structures.Compared with BC,CBC-1,CBC-2 and CBC-3 all contain a large number of mesoporous structures,and their specific surface areas are 133.76 m~2/g,266.26 m~2/g and 372.68 m~2/g,respectively.The adsorption properties of citronella leaf biochar for norfloxacin and ciprofloxacin in aqueous solution and their influencing factors were studied in this paper.The results showed that BC could reach adsorption equilibrium in 60 min,CBC-1,CBC-2 and CBC-3 could all achieve rapid adsorption of norfloxacin and ciprofloxacin in aqueous solution,and adsorption equilibrium could be reached in 30min.When the p H value was less than 7.0,the adsorption capacity of Antibiotics for CBC-1,CBC-2 and CBC-3 increased with the increase of the initial p H value of the solution.When the p H value was greater than 7.0,the adsorption capacity of antibiotics decreased with the increase of the initial p H value of the solution.The adsorption process of citronella leaf biochar for antibiotics conforms to quasi-quadratic kinetics,the adsorption rate is linear with the dosage of citronella leaf biochar and the initial concentration of antibiotics,and the adsorption conforms to Langmuir adsorption isotherm equation.Compared with BC,CBC-1,CBC-2 and CBC-3 have better adsorption performance,and their removal rate is more than 97%after adsorption equilibrium,and they have better regeneration performance.