Batch adsorption study of ammonia removal from synthetic/real wastewater using ion exchange resins and zeolites

ABSTRACT

The presence of ammonia in wastewater from industry activities is an important environmental issue; therefore, an adsorption process is one viable alternative process that can be used to reduce concentrations, and accordingly, 10 resins and 6 zeolites were tested for the removal of ammonia from real wastewater (3.8 to 8 mg/L NH₃ − N) containing other cations. In subsequent tests, the performance of the most promising adsorbents (four resins & two zeolites) was further characterized using isotherms and kinetic experiments. Adsorbent equilibrium capacities in the range of 0.2 to 0.4 mg/g were determined for ammonia concentrations of approximately 1 mg/L.

KEYWORDS:

• Batch Adsorption
• Ammonia Removal
• Resins
• Zeolites
• Isotherms
• Kinetics

Nomenclature

$C_e$	=	NH3−N concentration in real wastewater at equilibrium (mg/L)
$C_o$	=	NH3−N concentration in synthetic/real wastewater at initial (mg/L)
$C_t$	=	NH3−N concentration in synthetic/real wastewater at time t (mg/L)
$k_1$	=	Rate constant of the pseudo-1st order kinetic equation (1/min)
$k_2$	=	Rate constant of the pseudo-2nd order kinetic equation (g/mg.min)
$k_f$	=	Freundlich constant of the adsorption capacity ((mg/g).(L/mg)1/n)
$k_L$	=	Langmuir constant of the free energy of adsorption (L/mg)
$m$	=	Mass of the adsorbent (g)
$n$	=	Freundlich constant of the desorption intensity (dimensionless)
$N$	=	Number of the experiment samples
$q_e$	=	Experimental adsorption capacity at equilibrium (mg/g)
$q_{eth}$	=	Theoretical adsorption capacity at equilibrium (mg/g)
$q_{max}$	=	Maximum adsorption capacity (mg/g)
$q_t$	=	Experimental adsorption capacity at time (mg/g)
$R_L$	=	Separation factor of the Langmuir isotherm (dimensionless)
$t$	=	Time (min)
$V$	=	Volume of the adsorbate (L)

Acknowledgements

The authors would like to acknowledge the Ministry of Higher Education, and Scientific Research, University of Technology in Baghdad – Iraq, and Natural Sciences and Engineering Research Council of Canada for their financial support.

Additional information

Funding

This work was supported by the Natural Sciences and Engineering Research Council of Canada; Ministry of Higher Education, and Scientific Research and University of Technology, Baghdad, Iraq.