Elimination of organic water pollutants using adsorbents obtained from sewage sludge § M.Otero,F.Rozada,L.F.Calvo,A.I.Garcı ´ a,A.Mora´n* Natural Resources Institute. Department of Chemical Engineering. University of Leo ´n, Avda. de Portugal s/n, 24071, Leo ´n,Spain Received 27 September 2002; received in revised form 19 November 2002; accepted 6 January 2003 Abstract Sewagesludgevalorisationmustbethepreferredmanagementsolutionforaresiduewhichminimisingdoesnotkeep with a desirable improvement on wastewater treatment. This research work deals with the potential application of adsorbents produced from sewage sludge in organic pollutants removal. After chemical activation and pyrolysis treat- ment,sewagesludgeprovidesmaterialsofgreatporosityandhighsurfacearea.Thepropertiesofthistypeofmaterial was studied by liquid-phase adsorption using crystal violet, indigo carmine and phenol as adsorbates, experiments beingperformedfortwodifferentadsorbentparticlesizes.Firstly,singleadsorptionbatchexperimentswerecarriedout to obtain kinetic and equilibrium data. The adsorbate’s preferential adsorption was then investigated by studying adsorption from mixed solutions. The sludge-derived activated carbon produced could adsorb the three adsorbates considered with the time required to reach equilibrium and full adsorptive capacity varying between the adsorbates. Crystalvioletadsorptionhasbeenhigherandfasterthanindigocarmineorphenol.Itisproposedthatactivatedcarbons madefromsewagesludgeshowpromisefortheremovaloforganicpollutantsfromaqueousstreams. # 2003ElsevierScienceLtd.Allrightsreserved. Keywords: Adsorbents;Chemicalactivation;Liquid-phaseadsorption;Organicpollutants;Sewagesludge 1. Introduction Sewage sludges are by-products derived from the regular activities of wastewater treatment plants. It is estimated that an average production of40–60gdrymatter/inhabitant/dayistypicalfor urbansewageplants [1],towhichmustbeaddeda corresponding amount produced by industrial sewage plants. Production is expected to rise as investment in environmental management increa- ses and more municipal wastewater is treated to even higher standards [2]. The corresponding improvement in the environmental impact of water resources is likely to be countered by a marked increase in sludge volumes produced. In terms of high production volumes, both current and forecasted, the convenient management of sludges produced at sewage plants is a funda- mental requirement. Whilethereareseveralwaysofdisposingofsew- age sludge, considered use of this waste material 0143-7208/03/$ - see front matter # 2003 Elsevier Science Ltd. All rights reserved. doi:10.1016/S0143-7208(03)00005-6 Dyes and Pigments 57 (2003) 55–65 www.elsevier.com/locate/dyepig § The results were presented in the ‘‘Specialised Conference on Sludge Management: regulation, treatment, utilisation and disposal’’heldinAcapulco(Mexico),25–27October2001. * Corresponding author. Tel.: +34-987-291841; fax: +34- 987-291839. E-mail address: dfqamp@unileon.es(A.Mora´n).