Study On The Adsorption Of P-aminophenol And P-aminophenol In Wasterwater On The Modified Gasification Coal Slime

The gasification coal slime was modified with the hydrochloric acid (HCl),sodium hydroxide solution (NaOH) and hexadecyl trimethyl ammonium bromidesolution (CTMAB), respectively. Adsorption of p-aminophenol (PAP) in wastewaterusing different modified gasfication coal slime was studied. Results showed that,NaOH-treated coal slime (CS-OH) had a greater sorption capacity than that ofHCl-treated coal slime (CS-H), CTMAB-treated coal slime (CS-OH-CTMAB) anduntreated coal slime (CS-R). The optimal conditions for preparation of CS-OH was asfollowing, the temperature was100℃, the modified time was24h, liquid to solid ratioby weight was10:1and concentration of NaOH was2mol/L. The content of PAP inwastewater treated by CS-OH could reach the national industrial wastewater dischargestandard. Mechanism of PAP adsorption may be molecular adsorption, andelectrostatic force may play a key role in adsorption of PAP using CS-OH.Redlich-Peterson adsorption isotherm model can be used to describe the adsorptionprocess of CS-OH on PAP. The themodynamic calculations results indicated that theadsorption of CS-OH onto PAP is a physical and spontaneous process.Then, The gasification coal slime was modified with the hydrochloric acid (HCl),sodium hydroxide solution (NaOH) and aluminium nitrate Al(NO3)3. Adsorption ofp-aminophenol (PNP) in wastewater using different modified gasification coal slimewas studied. Results showed that, Al(NO3)3-treated coal slime (CS-Al) had a greatersorption capacity than that of HCl-treated coal slime (CS-H), NaOH-treated coalslime (CS-OH) and untreated coal slime (CS-R). Under the conditions of pH=6,liquid to solid ratio of200:1, CPNP=150mg/L, the maximum adsorption capacity ofCS-Al is29.1mg/g. The optimal conditions for preparation of CS-Al was asfollowing: the temperature was25℃, the modified time was12h, liquid to solid ratioby weight was10:1and concentration of Al(NO3)3was0.1mol/L. Electrostatic forcemay play a key role in adsorption of PAP when using CS-Al. Langmuir, Freundlichadsorption isotherm model can be used to describe the adsorption process of CS-Al onPNP. The themodynamic calculations results indicated that the adsorption of CS-Alonto PNP is physical adsorption and a spontaneous process.