Influence of the phase separator design on the performance of the UASB reactor and on excess sludge production

Abstract The efficiency of the phase separator in UASB reactors can be increased by placing additional parallel plates above the conventional device, thus forming a high rate settler. From settling theory it can be deducted the performance of the plates improves when the height of the zone with parallel plates increases or the distance between plates and the angle of the plates decreases. In practice the height is limited by the construction cost of the reactor. The distance between the plates must be sufficient for maintenance and the angle to allow the retained sludge to slide readily back into the digestion zone. The experimental data show that indeed the digested COD fraction is greatly increased by adding parallel plates to a UASB reactor. As a consequence, the improved separator opens the possibility of a considerable increase of the applied load to the UASB reactor: Parallel plates used in a pilot scale (1500 l) UASB reactor led to an increase of the treatment capacity by a factor 2. The experimental data also showed that the fundamental operational variable to describe the behaviour of the UASB reactor is in fact the sludge age: at any particular temperature the effluent quality and the quality and quantity of excess sludge will be equal in two UASB reactors, if the sludge age in these is the same

LC-MS/MS Method for the determination of carbamathione in human plasma

Liquid chromatography-tandem mass spectrometry methodology is described for the determination of S-(N,N-diethylcarbamoyl)glutathione (carbamathione) in human plasma samples. Sample preparation consisted of a straightforward perchloric acid medicated protein precipitation, with the resulting supernatant containing the carbamathione (recovery ∼98%). For optimized chromatography/mass spec detection a carbamathione analog, S-(N,N-di-i-propylcarbamoyl)glutathione, was synthesized and used as the internal standard. Carbamathione was found to be stable over the pH 1-8 region over the timeframe necessary for the various operations of the analytical method. Separation was accomplished via reversed-phase gradient elution chromatography with analyte elution and re-equilibration accomplished within 8 minutes. Calibration was established and validated over the concentration range of 0.5-50 nM, which is adequate to support clinical investigations. Intra- and inter-day accuracy and precision determined and found to be < 4% and < 10%, respectively. The methodology was utilized to demonstrate the carbamathione plasma-time profile of a human volunteer dosed with disulfiram (250 mg/d). Interestingly, an unknown but apparently related metabolite was observed with each human plasma sample analyzed

Determinação do potencial de produção biológica de ácido caproico.

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Biomethanation potential of biological and other wastes

Anaerobic technology has been traditionally applied for the treatment of carbon rich wastewater and organic residues. Anaerobic processes can be fully integrated in the biobased economy concept for resource recovery. After a brief introduction about applications of anaerobic processes to industrial wastewater treatment, agriculture feedstock and organic fraction of municipal solid waste, the position of anaerobic processes in biorefinery concepts is presented. Integration of anaerobic digestion with these processes can help in the maximisation of the economic value of the biomass used, while reducing the waste streams produced and mitigating greenhouse gases emissions. Besides the integration of biogas in the existing full-scale bioethanol and biodiesel production processes, the potential applications of biogas in the second generation lignocellulosic, algae and syngas-based biorefinery platforms are discussed.(undefined