Removal Of PPCPs Using Nanometal-graphene Modified Composites

With the rapid development of industry,the PPCPs pollution in water have become more and more critical.Due to their harmful effect on aquatic organism and human health,the study on removal of PPCPs in water is of important significance.The traditional materials are widely used for the adsorption of ciprofloxacin?CIP?from water but suffered from the narrow pH range,limited adsorption capacity and the problem of separation.The oxidation technologies are effective to degrade diclofenac?DCF?,however,more toxic intermediates and products,high cost and slow degradation process limited its application in wastewater treatment.Herein,we used graphene as the supporter to prepare nanometal-graphene modified composites under different reaction conditions.The synthesized products were characterized by X-ray diffraction?XRD?,field emission scanning electron microscopy?FE-SEM?and energy dispersive spectrometer?EDS?.Their properties for adsorption of CIP and degradation of DCF were also investigated.The principal obtained results are as following:?1?NZVI16-GO1?F16G1?,was successfully synthesized by reduction in solution,which exhibited excellent adsorption properties for CIP removal in water.NZVI particles were uniformly dispersed on GO which diameter was about 100nm.GO can alleviate NZVI's disadvantage,such as its aggregation effect.The adsorption of CIP onto F16G1may depend on electrostatic attraction.When the dosage of F16G1 was 0.5g/L,91.39%of CIP?50mg/L?could be adsorbed within 3 h.The effects of pH,reaction time,initial concentration,dosage on the removal of CIP were investigated.The pH had no obvious effect on the adsorption capacity in the range of 4 to 5.The maximum adsorption capacity of F16G1 was 656.66 mg/g,respectively.The Langmuir adsorption isotherm was used to fit the adsorption equilibrium process well.It's convenient to separate the composite because of the magnetism of NZVI after treatment.?2?We have successfully assembled on the surface of carbon fiber by electrochemical method.The material we synthesised exhibited excellent properties for DCF removal at H₂ atmosphere in water at room temperature.Pd-In bimetal was attached to the surface and interior of carbon fiber with a large amount.The individual In had no obvious effect in degrading DCF,but it can enhance the catalytic activity of Pd.When the dosage of catalyst was 0.5cm²,90%of DCF?30mg/L?could be degraded within 24 h.The degradation products were studied by using HPLC and LC-MS,then we can study the reaction mechanism of this catalytic process in detail.It was found that the degradation was a first-order exponential reation.The one main degradation product was obtaind by cleaving the carbon-halogen bond of DCF.After 3 times of recycling of materials we synthesized,the results showed that still 76.8%of DCF was dechlorinated.?3?We have successfully assembled on the surface of graphene by febiehydrothermal process.respectively.The material we synthesised exhibited more excellent properties than carbon fiber for DCF removal at H₂ atmosphere in water at room temperature.The nanoparticles were uniformly dispersed on the graphene.When the dosage of catalyst was 0.2g/L,93%of DCF?30mg/L?could be degraded within 15 h.The degradation products were studied by using HPLC and LC-MS,then we can study the reaction mechanism of this catalytic process in detail.It was found that the degradation was a second-order exponential reation.The two main degradation products were obtaind by cleaving the carbon-halogen bond of DCF and this made the degradation products more environmentally friendly.After 3 times of recycling of materials we synthesized,the results showed that still 74.4%of DCF was dechlorinated.