Preparation Of Graphene Composite Materials And Study On Their Adsorption Performance Of Tetracyclin

Tetracyclines（TCs）,as one of the widely used antibiotics in medical,husbandry and aquaculture,are frequently detected in the water environment due to their stable structure and difficulty to be biodegraded,resulting in generation of drug-resistant bacteria and spread of resistant genes.This seriously endangers the security of ecological environment.In view of current tetracycline-related environmental pollution,herein,graphene oxide（GO）was prepared from flake graphite and different graphene composites（α-FeOOH/rGO and C-rGO）were subsequently prepared by oxidation-reduction and hydrothermal method.After systematic characterization,α-FeOOH/rGO and C-rGO were applied to TC adsorption removal.Specific research contents and results are as follows:α-FeOOH/rGO was prepared by the reduction of ferrous ion.The characterization results indicated thatα-FeOOH nanoparticle was rod-like and anchored on surface of graphene.α-FeOOH/rGO showed the adsorption capacity of TC with a value of 219mg·g^-1 when the preparation condition was adding 5 mmol ferrous sulfate and reacting24 h at 90℃.And the adsorption kinetic and isotherm experiments for TC ontoα-FeOOH/rGO illustrated that pseudo-second-order model and Freundlich model were more suitable for describing this adsorption process,indicating multilayer adsorption nature of this process.In order to enhance the TC adsorption capacity by graphene composites,C-rGO was prepared via in-situ formations of copper nanoparticle on the surface of rGO under hydrothermal method.Characterization results indicated that Cu nanoparticles and a small amount of cuprous oxide nanoparticles were formed on surface of rGO.The effect of preparation conditions on the TC adsorption performance of C-rGO was also investigated,demonstrating that the GO/Cu²⁺mass ratio of 1:0.5 at 80℃for 24 h exhibited better adsorption performance with a high value of 3070 mg·g^-1.Such high TC adsorption capacity of C-rGO was attributed to load Cu particle and abundant oxygen-containing function group on the surface of rGO.Experiment of adsorption kinetics and isotherms for TC onto C-rGO illustrated that pseudo-first order kinetic model and Langmuir model were more suitable for describing the adsorption process.Furthermore,liquid film diffusion was rate-controlling step of TC adsorption on C-rGO.In addition,the removal efficiency of C-rGO still kept relatively high level after being used for 4 cycles.And C-rGO showed excellent adsorption capacities for other antibiotics,such as oxytetracycline,chlortetracycline hydrochloride,ciprofloxacin,sulfamethoxazole and norfloxacin.The ultrahigh TC adsorption ability and excellent reusability highlighted its great application potential in the field of antibiotic-related wastewater treatment.