Low-concentration Ammonium Removal by Commercial Natural Zeolites
Ammonium-nitrate is a main component in blasting agents and dissolved ammonium residues may be discharged with mine water.The European Union aims to reach a good state of the water quality and recommends ammonium content below 0.5 mg/L for drinking water.Natural zeolites adsorb ammonium from water.In this work,the removal of low-concentration ammonium by commercial natural zeolites was studied in continuous tests.Natural zeolites made up between 83% and 95% of the mineral composition.The major zeolite minerals were chabazite and clinoptiolites and minor amounts of erionite and mordenite were as well present.The five natural zeolite samples,500～710 μm,were conditioned to obtain zeolites in the Na-form.Ammonium adsorption onto natural zeolites depends mainly on the zeolite mineral type.The chabazite containing zeolite was superior over the four clinoptiolite samples for the removal of low concentrations of ammonium from water (pH of 7.5,flow 5 mL/min,room temperature).The adsorption capacity of chabazite was 48.3 mg NH4+/g zeolites,i.e.73% of the theoretical exchange capacity 69 mg NH4+/g,during duration over 107 days and almost 6700 bed volumes exchanged.The four tested clinoptiolites had an adsorption capacity of 15.7mg to 25.0 mg NH4+/g zeolites.The natural zeolites were rapidly regenerated by an alkaline sodium chloride solution fed to the columns.
Adsorption Ammonium Chabazite Clinoptiolite Mineralogy Zeolites
J.Langwaldt
Geological Survey of Finland,Mineral Processing,Finland
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
3888-3893
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）