Removal Of Ciprofloxacin In Water By Ti-Al-SBA15 Modified Mesoporous Molecular

Ciprofloxacin is a widely used fluoroquinolone antibiotic that has been frequently detected in water environments in recent years.The chronic ecotoxic effects and drug resistance caused by it seriously threaten the balance of the ecological environment and human health,and have attracted people's attention.Conventional water treatment processes are more difficult because of their low concentration levels in the water source and high biological toxicity.Adsorption method is favored by people because of its low cost,direct effect and easy operation.Therefore,it is particularly important to develop a low-cost and efficient removal of trace amounts of ciprofloxacin in water.In this paper,a modified mesoporous molecular sieve adsorbent capable of efficiently removing trace ciprofloxacin contamination in water was prepared from ciprofloxacin antibiotics in the main needle water by metal doping method,and passed SEM,TEM,XRD,TGA,FT-IR.BET,BET,ZETA potential analysis and other characterization methods to analyze the physicochemical properties of the adsorbent in detail,and study the adsorption efficiency,process and mechanism of the ciprofloxacin in water and the photocatalytic regeneration efficiency?Achieve the direct adsorption of ciprofloxacin in water,low adsorption dosage(short adsorption equilibrium time),and realize the recycling of adsorbent by means of regeneration,providing theoretical guidance for the application of adsorbent in practical engineering(1)Firstly,a metal-modified mesoporous molecular sieve adsorbent was synthesized by doping with Al,Fe,Mn,La,Cu,etc.The adsorption efficiency was best after A1 doping,and the optimum doping ratio was Al:Si=10%.(Atomic ratio).The Al-SBA15 has a specific surface area of 499.04 cm2/g,an average pore diameter of 11.09 nm,and an average pore volume of 1.25cm3/g.The adsorbent is a mesoporous material containing a large number of uniform mesopores.When the concentration of ciprofloxacin is 100?g/L,pH=7,20?,the dosage of Al-SBA15 is 0.02g/L.After 60min adsorption,the removal rate of ciprofloxacin is above 90%,compared with the removal of ciprofloxacin other adsorbents,which require less dosage and the shorter balance time.The kinetics are in accordance with the quasi-second-order kinetic model,and the isotherm conforms to the Langmuir model,demonstrating that the adsorption process is a single-layer chemical complexation reaction.The adsorption rate of sorbent to ciprofloxacin was 0.02(mg·g-1·min-1),the adsorption capacity was 59.524 mg/g,and the Langmuir's constant was k2=6.133 L/mg.Adsorption is spontaneous,endothermic,and elevated temperatures increase the adsorption capacity of the adsorbent for ciprofloxacin.The pH of the solution significantly affects the adsorption of ciprofloxacin by the adsorbent.The optimum pH is 5.0-7.0,and the adsorption removal rate decreases significantly under acidic or alkaline conditions.The anion and cation have certain influence on the adsorption,especially the effect of cation on the removal of ciprofloxacin by the adsorbent.The presence of humic acid has an inhibitory effect on the adsorption and removal of ciprofloxacin.The higher the concentration,the greater the inhibition.The effects of different initial concentrations indicate that the lower the concentration of ciprofloxacin in water,the more difficult it is to remove.The adsorption mechanism was judged to be that surface Al and ciprofloxacin functional groups formed a strong surface complexation and were affected by electrostatic interaction.(2)A co-doped modified mesoporous molecular sieve adsorbent with photocatalytic regenerability was synthesized by co-doping of Ti and Al metals.The optimum element doping ratio was Al:Ti:Si=1:3:10(atomic ratio).The Ti-Al modified mesoporous molecular sieve has a 101 crystal plane,and the material has ultraviolet photocatalytic ability to photocatalytic regeneration of the material after adsorption.Ti-Al modified mesoporous molecular sieves have a certain degree of decrease in pore size and specific surface area compared with SBA15.The specific surface area is 407.08 cm2/g,the average pore diameter is 7.36 nm,and the average pore volume is 0.75 cm3/g.However,the adsorbent is still a mesoporous material containing a large amount of mesoporous pores,and has good adsorption efficiency.When the concentration of ciprofloxacin is 100?g/L,pH=7,the dosage of Ti-Al-SBA15 is 0.02g/L.After half an hour of adsorption,ciprofloxacin can be completely removed within 15 minutes of UV light.The pH of the solution affects the adsorption of the sorbent on the ciprofloxacin.The optimum pH is 5.0-7.0.Anion and cation ions have certain effects on the photocatalytic regeneration of modified mesoporous molecular sieves,and the effect of Fe3+ is most obvious.Photocatalytic regeneration causes ciprofloxacin to remove functional groups,split into small molecules,lose complexation,and regenerate the material.Modified mesoporous molecular sieves can effectively degrade pollutants with a degree of mineralization of 78%.The co-doped modified mesoporous molecular sieve has good ultraviolet photocatalytic regeneration performance.After 4 cycles of adsorption-catalytic regeneration,the adsorption removal rate of ciprofloxacin can still reach 82.8%.