Preparation And Study Adsorption Ability Of Graphene Oxide-carbon Nanotubes Composite Material Modified By Amino And Thiol Groups

The water pollution problems had became more and more serious in the process of modernization,especially heavy metal ions and phenol organic matters were the key pollutants in water.These pollutants mainly from electroplating and mining industries' wastewater discharge,unreasonable use of chemical fertilizers in agriculture.Heavy metal ions and phenol organic matters into the underground water and due to the bioconcentration caused a large number of accumulation in the human bodies,which caused seriously damage and even endangered the life of next generation.In recent years,many methods used to remove heavy metal ions and organic matters from wastewater have been reported,such as chemical precipitation,separation membrane,ion exchange,enrichment evaporation,etc.All of these methods play certain effect towards removing heavy metal ions and organic matters from wastewater.However,there exits disadvantages,for example high cost,complex preparation,cause secondary pollution,etc.But,adsorption method has attracted much attention owning to its extensive material sources,simple preparation process,fast adsorption and easy to recycle.In this paper,the better adsorption performance of graphene oxide?GO?and carbon nanotubes?MWCNTs?as the main raw material s,adopts the method of ultrasonic mixed to prepare the GO/MWCNTs composite material,then amino and thiol groups modified the composite material and the NH₂-SH-GO/MWCNTs composite material have been prepared.TEM,SEM,FT-IR,XRD,Nitrogen adsorption isotherms and other characterization methods were used to prove the morphology and groups load in the surface.According to the static adsorption experiment of lead,zinc ions and phenol in water,studies the NH₂-SH-GO/MWCNTs composite materials adsorpted heavy metal ions and phenol,the p H value,adsorption time and temperature were also studied which affect the static adsorption process.The experimental results show that when the p H is 5,composite materials for lead and zinc ion the maximum adsorption capacity is 126.5 and 99.7 mg/g,largest of phenol adsorption capacity of 2 5.1 mg/g.Under the p H of 5,studied the different adsorption time of lead,zinc ion and th e influence of the adsorption capacity of phenol,experiments show that when 60 min adsorption equilibrium and the adsorption capacity is 125.8,98.6 and 23.8 mg/g,respectively.According to initial adsorption rate formula,which can conclude that the initial adsorption rate of lead,zinc,phenol are 553.897 min-1,136.107 min-1,37.951 min-1,respectively.Thus can we illustrate the adsorption capacity of lead,zinc and phenol is increase sequentially.Through study on thermodynamics,the composite material of heavy metal ions and the phenol adsorption belongs to spontaneous endothermic process and physical adsorption,in addition,the intermolecular interaction is the main attraction in adsorption process;the dynamics of adsorption process show that the composite materials of heavy metal ions and phenol adsorption conforms to the dynamics equation of quasi secondary;according to adsorption isotherm adsorption process in accordance with the Freundlich model,belongs to the successive multilayer adsorption;through the recycling experiment showed that composite material has good stability.NH₂-SH-GO/MWCNTs composite material has good adsorption effect to heavy metal ions and phenol compare with the traditional adsorbent,which can be better to remove the trace metal ions in the water and phenol organic pollutants.Its have advantages which compared with the traditional adsorbents.This article provides a good method for water water treatment for trace poisonous and harmful substances.