Water Research 36 (2002) 2905–2909 Research note The application of membrane filtration for the removal of ammonium ions from potable water H. Kurama a, *, J. Poetzschke b , R. Haseneder b a Department of Mining Engineering, Osmangazi University, 26030 Bademlik-Eskisehir, Turkey b Lehrstuhl fuer Umweltverfahrenstechnik, TU-Bergakademie Freiberg, 09596 Freiberg, Germany Received 13 December 2000; accepted 21 November 2001 Abstract Itiswellrecognizedthatsolubleammoniaandnitriteindrinkingwaterhaschroniceffectsonhumans.Ammoniahas potential environmental health hazards, particularly to young children. European Union Standards limit the concentration of ammonia to 0.5mg/l in drinking water. In Eskisehir (Turkey) drinking and tap water are supplied fromawatertreatmentplant,consistingmainlyofscreening,sedimentation,filtrationandsterilizationunitsandhaving acapacityof80.000m 3 /d.Dependontheindustrialandclimaticeffectstheobservedhighammoniumconcentrationin treatedwatercausesundesirableeffectsofwaterquality.Therefore,peopleinEskisehirdonotwanttousetapwaterfor drinking.Theaimofthestudywastoevaluatetheperformanceofmembraneprocesses,i.e.Nanofiltrationandreverse osmosis to the removal of ammonium and Ca ions from plant effluent and recommend one of them for a subsequent pilot plant application. r 2002 Elsevier Science Ltd. All rights reserved. Keywords: Ammonium; Polluted potable water; Reverse osmosis; Nanofiltration; Water treatment 1. Introduction Most high-rate physico-chemical drinking water treatment processes are very efficient at removing of suspendedsolids,phosphorus,oilandheavymetals,but are unable to eliminate the soluble ammonium [1]. The presence of high ammonium content in drinking water, which is readily transformed into nitrate, is very toxic forhumanbeings.Nitrateuptakeisprimarilyexogenous by eating vegetables and drinking nitrate contaminated water;however,itcanalsobesynthesizedendogenously by various processes. Nitrite on the other hand can be usedinendogenoussynthesisoftheknowncarcinogenic N-nitrous compounds. Ammonium is adsorbed in the intestineandcanbeexcreteddirectlythoughthekidneys insmallquantities.Mostofthenitriteismetabolizedto urea in the liver, which can then easily be excreted through the kidney, as it is water-soluble [2]. Mascher andMarth[3]observedtheeffectofnitrateonthehealth ofmice.Nitratewasgiventomiceintheformofcalcium nitrateindrinkingwaterandmicewereobservedover18 months. After these period, it was found, that exposure to higher concentration of nitrate in drinking water alone led to the change in survival rate. The high ammonium concentration also can have a detrimental effect on disaffection of water supplies; it reacts with chlorine to form chloramines, which are still bacterial and they are slower acting and less effective [4]. As a consequence of these problems, reduction of ion concentration to o0.5mg/l is essential according to European Community and Turkish Standard [5,6]. Processes for the removal of ammonium ions from waste/potable water include nitrification–denitrification, air striping, ion exchange and membrane filtration. Although, the first two processes have found wide applicationareas,substantialreductionefficiencyoccurs attemperaturesbelow151C.Ionexchangeprocessescan beconsideredanattractivetreatmentmethodbecauseof *Corresponding author. Tel.: +90-222-230-3972; fax: +90- 222-221-3918. E-mail address: hkurama@ogu.edu.tr (H. Kurama). 0043-1354/02/$-see front matter r 2002 Elsevier Science Ltd. All rights reserved. PII:S0043-1354(01)00531-0