Advanced enzymatic elimination of phenolic contaminants in wastewater: a nano approach at field scale

The removal of recalcitrant chemicals in wastewater treatment systems is an increasingly relevant issue in industrialized countries. The elimination of persistent xenobiotics such as endocrine-disrupting chemicals (EDCs) emitted by municipal and industrial sewage treatment plants remains an unsolved challenge. The existing efficacious physico-chemical methods, such as advanced oxidation processes, are resource-intensive technologies. In this work, we investigated the possibility to remove phenolic EDCs [i.e., bisphenol A (BPA)] by means of a less energy and chemical consuming technology. To that end, cheap and resistant oxidative enzymes, i.e., laccases, were immobilized onto silica nanoparticles. The resulting nanobiocatalyst produced at kilogram scale was demonstrated to possess a broad substrate spectrum regarding the degradation of recalcitrant pollutants. This nanobiocatalyst was applied in a membrane reactor at technical scale for tertiary wastewater treatment. The system efficiently removed BPA and the results of long-term field tests illustrated the potential of fumed silica nanoparticles/laccase composites for advanced biological wastewater treatment

Performance of an anaerobic membrane bioreactor for pharmaceutical wastewater treatment

Anaerobic treatment of wastewater and waste organic solvents originating from the pharmaceutical and chemical industries was tested in a pilot anaerobic membrane bioreactor, which was operated for 580 days under different operational conditions. The goal was to test the long-term treatment efficiency and identify inhibitory factors. The highest COD removal of up to 97% was observed when the influent concentration was increased by the addition of methanol (up to 25 g L−1 as COD). Varying and generally lower COD removal efficiency (around 78%) was observed when the anaerobic membrane bioreactor was operated with incoming pharmaceutical wastewater as sole carbon source. The addition of waste organic solvents (>2.5 g L−1 as COD) to the influent led to low COD removal efficiency or even to the breakdown of anaerobic digestion. Changes in the anaerobic population (e.g., proliferation of the genus Methanosarcina) resulting from the composition of influent were observed

Simulación en CFD de un BioReactor de Membrana Anaeróbico para tratamiento de aguas residuales industriales

A Computational Fluid Dynamics (CFD) model has been developed for an Anaerobic Membrane BioReactor (AnMBR) to treat industrial wastewater. Two models were created; (i) reactor and (ii) membrane. Different cases were conducted for each model, so the surroundings temperature and the total suspended solids (TSS) concentration were looked upon. For the reactor the most important aspects to consider were the dead zones and the mixing, while for the ceramic membrane was the shear stresses over the membrane surface. Results show that the reactor had an adequate mixing process and that the membrane presents higher shear stresses in the ‘triangular’ channel.  Una simulación en dinámica de fluidos computacional (CFD) fue desarrollada para un Biorreactor de Membrana anaeróbico (AnMBR) para el tratamiento de las aguasresiduales industriales. Debido a que el proceso consta del reactor y de la membrana separados, se crearon dos simulaciones:(i) reactor y (ii) membrana; se consideraron diferentes temperaturas del ambiente y concentraciones de sólidos suspendidos totales (SST). Para el reactor, los aspectos más importantes a analizar fueron las zonas muertas y el mezclado, mientras que para la membrana fueron las tensiones de cizallamiento sobre su superficie. Los resultados muestran que el reactor tenía un proceso de mezcladoadecuado y en la membrana se presentan las mayores tensiones de cizallamiento en el canal ‘triangular’