Removal of recalcitrant organic compounds from stabilized landfill leachate usinga combination of ammonium stripping and GAC adsorption

摘要

Laboratory-scale experiments were conduced to study the combination performance of ammoniumstriping and granular activated carbon (GAC) adsorption for the treatment of landfill leachate. The effectsof Ph, temperature and air flow rate on the removal of NH3-N and COD were firstly investigated duringammonium stripping treatment alone. To improve the removal of recalcitrant organic compounds fromleachate, subsequent treatment was carried out using GAC adsorption with the surface of the adsorbentchemically oxidized by ozone. The removal of COD and/or NH3-N after ammonium stripping aloneand/or its combination with GAC adsorption treatment was evaluated and compared. The results werealso compared to those of other individual and/or combined treatments from other studies. Of the twodifferent treatments investigated, the combination of ammonium stripping and GAC adsorption usingozone-modified GAC demonstrated almost complete removal of COD (99.6%) and NH3-N (99.9%) withan initial COD concentration of 30,010 mg/L and NH3-N concentration of 2,546 mg/L, compared toammonium stripping alone (COD: 16%; NH3-N: 97%) at the same initial concentrations with thefollowing conditions: Ph 11, 60 Ml/min of flow rate and 28°C of temperature. With the COD level oftreated effluent at less than 200 mg/L, the results indicate that the combination of ammonium strippingand GAC adsorption was more effective than ammonium stripping alone for the removal of recalcitrantcompounds from stabilized leachate. Moreover, the application of the integrated process for leachatetreatment was able to meet the stringent NH3-N discharge standard of less than 5 mg/L, indicating that nofurther treatments would be required to comply with local environmental legislation.