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This study compared two anammox sequencing batch reactors (SBR) for one year. SBR was kept at 30 °C while temperature in SBR was decreased step-wise from 30 °C to 20 °C and 15 °C followed by over 140 days at 12.5 °C and 10 °C. High retention of anammox bacteria (AnAOB) and minimization of competition with AnAOB were key. 5-L anoxic reactors with the same inoculum were fed synthetic influent containing 25.9 mg NH-N/L and 34.1 mg NO-N/L (no COD). Specific ammonium removal rates continuously increased in SBR, reaching 785 mg NH-N/gVSS/d, and were maintained in SBR, reaching 82.2 and 91.8 mg NH-N/gVSS/d at 12.5 and 10 °C respectively. AnAOB enrichment (increasing hzsA and 16S rDNA gene concentrations) and adaptation (shift from Ca. Brocadia to Ca. Kuenenia in SBR) contributed to these high rates. Rapidly settling granules developed, with average diameters of 1.2 (SBR) and 1.6 mm (SBR). Results reinforce the potential of anammox for mainstream applications.

La incorporación de materiales de desecho en el ciclo productivo es una alternativa de interés en la industria moderna que conduce tanto a un beneficio económico como a una considerable reducción del impacto sobre el medio ambiente. En este trabajo se comparan estudios realizados sobre la reutilización de diversos residuos: vidrio, aisladores eléctricos y cenizas volantes. Estos materiales fueron molidos y clasificados por tamaño de partículas para ser usados en la preparación de muestras representativas. Las diferentes etapas de tratamiento se establecieron según los procesos habituales de producción de la industria cerámica. Algunos de los polvos obtenidos se utilizaron sin aditivos, mientras que otros fueron mezclados en distintas proporciones con diversos componentes cerámicos con el fin de mejorar sus propiedades finales. Todos los compactos, obtenidos por prensado uniaxial de estos polvos, recibieron tratamientos térmicos adecuados a sus composiciones, para luego ser caracterizados por diversas técnicas entre las que se pueden mencionar: dilatometría, difracción de rayos X, porosidad, microdureza, microscopías óptica y electrónica de barrido y análisis por dispersión de energías. Del análisis de los resultados obtenidos en estos estudios, se concluyó que los materiales ensayados constituyen una potencial fuente de materia prima para la industria cerámica. Palabras clave: materiales cerámicos, materias primas, reciclado, residuos, densificación. Non traditional raw material in ceramic industryThe wastes incorporation to the production cycle is an interesting alternative in modern industry. This gives rise to not only an economical profit but to a considerable decrease in environmental impact. Studies made about recycling of several wastes: glass, electric insulators and fly ash are compared in this work. The materials were crushed and separated by particle size distribution in order to prepare representative samples. Different treatment steps were carried out as is usual in the process of ceramic industries. Some of the obtained powders were used without additives while other were mixed in different ratios with other ceramic components in order to improve their final properties. All the compacts, obtained by uniaxial pressing of the powders, received thermal treatments which were adequate to their compositions. They were then characterised by several techniques including dilatometry, X ray diffraction, porosity, microhardness, optical and scanning electron microscopy and energy dispersion analysis (SEM/EDX). From this investigation it was concluded that the studied materials constitute a potential source of raw materials for the ceramic industry.Key words: ceramic materials, raw material, recycling, wastes, densification. INTRODUCCIÓNComo productos secundarios en los procesos industriales y como consecuencia de las actividades humanas se genera una gran cantidad de residuos, cuyo control o tratamiento constituye uno de los problemas más importantes en la actualidad, principalmente en los países desarrollado...

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The utilization of residual materials in the fabrication of new products has a strong impact on the preservation of non-renewable natural resources, diminishes energetic consumption and avoids the costs and problems that imply the final disposal of them. The aim of this work is to investigate the recycling of waste foundry sand coming from the process of cast iron for use as aggregate in the manufacture of red clay bricks and tiles. The raw materials, waste foundry sand and clay soil were chemically and microstructural characterized and different samples were designed. Compact bodies were prepared with 10%, 20%, 30%, 40% and 50% (wt%) of waste. They were thermally treated in the range 950-1000ºC. The experimental conditions were established taking into account those used for commercial products. The characterization of raw materials and products was carried out using various techniques. The results allow one to conclude that it is feasible to incorporate important quantities of waste foundry sand into the manufacture process of clay bricks and tiles. The best properties were obtained in samples with 30 and 40 wt% of waste added, taking into account the characteristics required for commercial applications.