Title:
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Recovery of ammonia from domestic wastewater effluents as liquid fertilizers by integration of natural zeolites and hollow fibre membrane contactors
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Author:
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Sancho Lacalle, Irene; Licon Bernal, Edxon Eduardo; Valderrama Angel, César Alberto; de Arespacochaga, Nicolas; Lopez Palau, Silvia; Cortina Pallás, José Luís
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Other authors:
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Universitat Politècnica de Catalunya. Departament d'Enginyeria Química; Universitat Politècnica de Catalunya. SETRI - Grup de Tècniques de Separació i Tractament de Residus Industrials |
Abstract:
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The integration of up-concentration processes to increase the efficiency of primary sedimentation, as a solution to achieve energy neutral wastewater treatment plants, requires further post-treatment due to the missing ammonium removal stage. This study evaluated the use of zeolites as a post-treatment step, an alternative to the biological removal process. A natural granular clinoptilolite zeolite was evaluated as a sorbent media to remove low levels (up to 100 mg-N/L) of ammonium from treated wastewater using batch and fixed bed columns. After being activated to the Na-form (Z-Na), the granular zeolite shown an ammonium exchange capacity of 29 ± 0.8 mg N-NH4+/g in single ammonium solutions and 23 ± 0.8 mg N-NH4+/g in treated wastewater simulating up-concentration effluent at pH = 8. The equilibrium removal data were well described by the Langmuir isotherm. The ammonium adsorption into zeolites is a very fast process when compared with polymeric materials (zeolite particle diffusion coefficient around 3 × 10- 12 m2/s). Column experiments with solutions containing 100 mg N-NH4+/L provide effective sorption and elution rates with concentration factors between 20 and 30 in consecutive operation cycles. The loaded zeolite was regenerated using 2 g NaOH/L solution and the rich ammonium/ammonia concentrates 2–3 g/L in NaOH were used in a liquid-liquid membrane contactor system in a closed-loop configuration with nitric and phosphoric acid as stripping solutions. The ammonia recovery ratio exceeded 98%. Ammonia nitrate and di-ammonium phosphate concentrated solutions reached up to 2–5% wt. of N. |
Abstract:
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Peer Reviewed |
Subject(s):
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-Àrees temàtiques de la UPC::Enginyeria química -Sewage -Membranes (Technology) -Zeolites -Ammonia valorization -Ion-exchange -Natural clinoptilolite -Liquid-liquid membrane contactor -Nitric acid -Phosphoric acid -Liquid fertilizers -Aigües residuals -- Depuració -Membranes (Tecnologia) -Zeolites |
Rights:
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Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/ |
Document type:
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Article - Submitted version Article |
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