Search results for "Reactor"

Harvesting Energy from Wastewater Using an Innovative Anaerobic Membrane Bioreactor

2015

Relating ions concentration variations to conductivity variations in a sequencing batch reactor operated for enhanced biological phosphorus removal

2006

In this paper a deterministic relationship between ionic conductivity and phosphorus concentration variations in an enhanced biological phosphorus removal (EBPR) process is established. Conductivity shows a strong correlation with phosphorus in both anaerobic and aerobic stages, increasing or decreasing when phosphorus is released or taken up, respectively. Since the end of these processes can be detected by examining the conductivity profile in a cycle, useful information on the EBPR performance and stability is available. This information can be used for adjusting the length of the anaerobic and aerobic stages. Therefore, online process control based on inexpensive and easy to maintain se…

Uncertainty assessment of a membrane bioreactor model using the GLUE methodology

2010

A mathematical model for the simulation of physical-biological organic removal by means of a membrane bioreactor (MBR) has been previously developed and tested. This paper presents an analysis of the uncertainty of the MBR model. Particularly, the research explores the applicability of the Generalised Likelihood Uncertainty Estimation (GLUE) methodology that is one of the most widely used methods for investigating the uncertainties in the hydrology and that now on is spreading in other research field. For the application of the GLUE methodology, several Monte Carlo simulations have been run varying the all model influential parameters simultaneously. The model was applied to an MBR pilot pl…

Shedding light on biogas: a transparent reactor triggers the development of a biofilm dominated by Rhodopseudomonas faecalis that holds potential for…

2019

AbstractConventional anaerobic digesters intended for the production of biogas usually operate in complete darkness. Therefore, little is known about the effect of light on microbial communities operating in anaerobic digesters. In the present work, we have studied through 16S rRNA gene amplicon Nanopore sequencing and shotgun metagenomic sequencing the taxonomic and functional structure of the microbial community forming a biofilm on the inner wall of a lab-scale transparent anaerobic biodigester illuminated with natural sunlight. The biofilm was composed of microorganisms involved in the four metabolic processes needed for biogas production. The biofilm proved surprisingly rich in Rhodops…

Cubic boron nitride: A new prospective material for ultracold neutron application

2009

Abstract At the ultracold neutron (UCN) source of the TRIGA research reactor in Mainz, we have measured for the first time the material optical wall-potential of cubic boron nitride. The measurements were performed with a time-of-flight (TOF) spectrometer. The samples investigated had a wall-potential of ( 305 ± 15 ) neV . This value is in good agreement with the result extracted from neutron reflectometry data and theoretical expectations. Because of its high critical velocity for UCN and its good dielectric characteristics, cubic boron nitride coatings (isotopically enriched) will be useful for a number of applications in UCN experiments.

Physico-chemical characterization of passive films on 316L stainless steel grown in high temperature water

2014

Hydrodynamics of a three-phase fixed-bed reactor operating in the pulsing flow regime at an elevated pressure

2002

Abstract Results are presented for a three-phase reactor operating at an elevated pressure in the pulsing flow regime. For the system air–water and pressures of 0.1– 0.9 MPa lines are determined that define the change of the hydrodynamic model from the gas continuous flow regime (GCF) to the pulsing flow regime (PF). Also, parameters are found that characterize the pulsing flow of fluids, namely the velocity of pulses travelling along the bed, the frequency of pulsations and their structure, i.e., the length of the pulses and that of the liquid-rich zone.

Nanoparticle-Directed Metal–Organic Framework/Porous Organic Polymer Monolithic Supports for Flow-Based Applications

2017

A two-step nanoparticle-directed route for the preparation of macroporous polymer monoliths for which the pore surface is covered with a metal–organic framework (MOF) coating has been developed to facilitate the use of MOFs in flow-based applications. The flow-through monolithic matrix was prepared in a column format from a polymerization mixture containing ZnO-nanoparticles. These nanoparticles embedded in the precursor monolith were converted to MOF coatings via the dissolution–precipitation equilibrium after filling the pores of the monolith with a solution of the organic linker. Pore surface coverage with the microporous zeolitic imidazolate framework ZIF-8 resulted in an increase in su…

SBA-15/POSS-Imidazolium Hybrid as Catalytic Nanoreactor

2019

Supported imidazolium modified polyhedral oligomeric silsesquioxanes (POSS) on SBA-15 have been used as platform for Pd(II) species. The so-obtained material was firstly characterized by means of TGA, solid state NMR, TEM, XPS, SAXS, porosimetry and ICP-OES and it was successfully tested as pre-catalyst in C−C cross couplings, namely Suzuki-Miyaura and Heck reactions. In both cases, the solid proved to be highly efficient and easily recoverable from the reaction mixture. The recyclability was verified for up to seven cycles without showing any activity decrease. Interestingly, only Pd(II) was detected in the reused catalyst in the Heck reaction. Therefore, the versatility of the material w…

Effect of extended famine conditions on aerobic granular sludge stability in the treatment of brewery wastewater

2017

Results obtained from three aerobic granular sludge reactors treating brewery wastewater are presented. Reactors were operated for 60 d days in each of the two periods under different cycle duration: (Period I) short 6 h cycle, and (Period II) long 12 h cycle. Organic loading rates (OLR) varying from 0.7 kg COD m-3 d-1 to 4.1 kg COD m-3 d-1 were tested. During Period I, granules successfully developed in all reactors, however, results revealed that the feast and famine periods were not balanced and the granular structure deteriorated and became irregular. During Period II at decreased 12 h cycle time, granules were observed to develop again with superior structural stability compared to the…