Functionalization of sewage sludge char by partial oxidation with molecular oxygen to enhance its adsorptive properties

JOURNAL OF CLEANER PRODUCTION

卷:290

Article

Atienza-Martinez, Maria^1,4  Suraini, Nurull Nadia Binti¹  Abrego, Javier¹  Fonts, Isabel^1,2  Lazaro, Luisa¹  Carstensen, Hans-Heinrich^1,3  Gea, Gloria¹ 

[1] Univ Zaragoza, Aragon Inst Engn Res I3A, Thermochem Proc Grp GPT, Zaragoza, Spain

[2] Ctr Univ Def CUD Zaragoza, Acad Gen Mil, Area Quim & Medio Ambiente, Zaragoza 50090, Spain

[3] Fdn Agencia Aragonesa Invest & Desarrollo ARAID, Zaragoza, Spain

[4] Univ Publ Navarra, Grp Reactores Quim & Proc Valorizac Recursos Reno, Dept Ciencias, Edificio Acebos,Campus Arrosadia, E-31006 Pamplona, Spain

关键词: Sewage sludge;    Char;    Oxygen activation;    Oxygenated functional groups;    Ammonium adsorption;   

DOI  :  10.1016/j.jclepro.2020.125201

来源: Elsevier

【 摘 要 】

This study investigates the activation of sewage sludge char through partial oxidation with molecular oxygen with the goal to increase the concentration of oxygen-containing surface functional groups and to enhance its ammonium adsorption capacity. The effects of oxidation temperature (200-350 degrees C), oxygen concentration (5-21 vol %) and oxidation time (30-120 min) on the degree of char oxidation are analyzed. The results obtained by thermogravimetric and elemental analysis, and Fourier Transform Infrared and X-ray Photoelectron spectroscopy corroborate the incorporation of oxygenated functional groups on the surface of sewage sludge char either at low temperature (200 degrees C) using air or at higher temperature (350 degrees C) using 5% O-2 for 30 min. The oxidation of sewage sludge char hardly increases its specific surface area. The operating conditions during oxidation must be carefully controlled to avoid runaway reactions that lead to total oxidation of char. The evolution of CO and CO2 during oxidation is a good indicator of the advance of the oxidation/burn-off reactions. The ammonium adsorption capacity of sewage sludge char increases after oxidation under mild operating conditions, providing support to the idea of onsite utilization of sewage sludge as ammonium adsorbent in waste water treatment plants. This would provide a step forward towards the implementation of a circular economy. (C) 2020 Elsevier Ltd. All rights reserved.

【 授权许可】

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