RECOVERY OF p-AMINOPHENOL (PAP) FROM AQUEOUS SOLUTION BY HYPER-CROSS-LINKED RESIN AND ITS USE FOR WASTEWATER TREATMENT

p-Aminophenol （PAP）, a typical amphoteric compound, has been widely used as raw chemical material and important interrnediate in various fields. To study on the recovery of PAP, an experimental comparison of the adsorption and desorption properties of PAP onto three types of hyper-cross-linked resins in aqueous solutions was performed. This paper focuses on the static equilibrium adsorption and desorption behaviors, the adsorption thermodynamics, the column dynamic adsorption and desorption, and other influencing factors of adsorption, such as temperature and pH values. All the isothermal data fit well to the Freundlich model. The capacity of equilibrium adsorption for PAP on NG-10 is the highest within the temperature range 288K-318K, which may greatly contribute to the advantage in specific surface area, especially the micropore area, of the adsorbent. While in the desorption experiments, NG-9 achieved relative well regeneration efficiency whether by ethanol or by 4% hydrochloric acid. Furthermore, the results of column tests and field applications were also proved that NG-9 was an effective sorbent for the reclamation PAP from wastewater.

Facile synthesis of graphene-based hyper-crosslinked porous carbon composite with superior adsorption capability for chlorophenols

In this work,we proposed a green and cost-effective method to prepare a graphene-based hyper-cross-linked porous carbon composite(GN/HCPC)by one-pot carbonization of hyper-cross-linked polymer(HCP)and glucose.The composite combined the advantages of graphene(GN)and hyper-cross-linked porous carbon(HCPC),leading to high specific surface area(396.93 m^2/g)and large total pore volume(0.413 cm^3/g).The resulting GN/HCPC composite was applied as an adsorbent to remove 2,4-dichlorophenol(2,4-DCP)from aqueous solutions.The influence of different solution conditions including pH,ionic strength,contact time,system temperature and concentration of humic acid was determined.The maximum adsorption capacity of GN/HCPC composite(calculated by the Langmuir model)could reach 348.43 mg/g,which represented increases of 43.6%and 13.6%over those of the as-prepared pure GN and HCPC,respectively.The Langmuir model and pseudo-second-order kinetic model were found to fit well with the adsorption process.Thermodynamic experiments suggested that the adsorption proceeded spontaneously and endothermically.In addition,the GN/HCPC composite showed high adsorption performance toward other organic contaminants including tetracycline,bisphenol A and phenol.Measurement of the adsorption capability of GN/HCPC in secondary effluent revealed a slight decrease over that in pure water solution.This study demonstrated that the GN/HCPC composite can be utilized as a practical and efficient adsorbent for the removal of organic contaminants in wastewater.