Search results for "Reactor"

The role of fouling mechanisms in a submerged membrane bioreactor during the start-up

2006

Metabolic shift of polyphosphate-accumulating organisms with different levels of polyphosphate storage

2012

Previous studies have shown that polyphosphate-accumulating organisms (PAOs) are able to behave as glycogen-accumulating organisms (GAOs) under different conditions. In this study we investigated the behavior of a culture enriched with Accumulibacter at different levels of polyphosphate (poly-P) storage. The results of stoichiometric ratios Gly degraded/HAc uptake, PHB synthesized/HAc uptake, PHV synthesized/HAc uptake and P release/HAc uptake confirmed a metabolic shift from PAO metabolism to GAO metabolism: PAOs with high poly-P content used the poly-P to obtain adenosine tri-phosphate (ATP), and glycogen (Gly) to obtain nicotinamide adenine dinucleotide (NADH) and some ATP. In a test whe…

Electrochemical Processes and Apparatuses for the Abatement of Acid Orange 7 in Water

2014

We have studied the electrochemical treatment of aqu eous solutions contaminated by Acid Orange 7 (AO7) by electro-Fenton process (EF). The main object ive was to evaluate how the electrochemical route affects the performances of the d egradation process. EF process was carried out in a number of very different reactors: conventional bench scale electrochem ical cell, microfluidic electrochemical reactor, microbial fuel cell and stack for reverse electrodialysis processes. The utilisation of micro devices allowed to work without the addition of a supporting elec trolyte and improved the performances of EF. Microbial fuel cell did not need the supply of electric energy bu t our device requir…

Removal of algae from biological cultures: a challenge for electrocoagulation?

2014

BACKGROUND In the search for novel technologies for the treatment of urban wastewater, combined anaerobic–algae membrane bioreactors have become a very interesting choice. Recovery of algae produced in these reactors has become the key point to obtain a good economic efficiency with this technology. In this work, electrocoagulation is studied as an alternative for the coarse removal of algae from a biological culture. RESULTS Results demonstrate that the electrochemical technology is a suitable technology for this purpose allowing the removal of more than 90% of the algae without modifying significantly the pH and with an operating cost below 0.04 € m−3. The same general trends are observed…

Microbial communities involved in biogas production exhibit high resilience to heat shocks

2017

We report here the impact of heat-shock treatments (55 and 70 °C) on the biogas production within the acidification stage of a two-stage reactor system for anaerobic digestion and biomethanation of grass. The microbiome proved both taxonomically and functionally very robust, since heat shocks caused minor community shifts compared to the controls, and biogas yield was not decreased. The strongest impact on the microbial profile was observed with a combination of heat shock and low pH. Since no transient reduction of microbial diversity occured after the shock, biogas keyplayers, but also potential pathogens, survived the treatment. All along the experiment, the heat-resistant bacterial prof…

Active surfaces engineered by immobilizing protein-polymer nanoreactors for selectively detecting sugar alcohols.

2016

We introduce active surfaces generated by immobilizing protein-polymer nanoreactors on a solid support for sensitive sugar alcohols detection. First, such selective nanoreactors were engineered in solution by simultaneous encapsulation of specific enzymes in copolymer polymersomes, and insertion of membrane proteins for selective conduct of sugar alcohols. Despite the artificial surroundings, and the thickness of the copolymer membrane, functionality of reconstituted Escherichia coli glycerol facilitator (GlpF) was preserved, and allowed selective diffusion of sugar alcohols to the inner cavity of the polymersome, where encapsulated ribitol dehydrogenase (RDH) enzymes served as biosensing e…

PLLA Scaffold with Gradient pore size in microphysiological tissue system bioreactor for Osteochondral regeneration

2015

Cartilage and bone tissues in the joints are intimately linked and form the osteochondral unit. A better understanding of both disease and regenerative processes of bone and cartilage requires the study of both tissues together, as part of the osteochondral unit to account for their mutual interactions. However, the production of scaffolds for osteochondral tissue regeneration is a challenging task, since scaffolds must mimic the differents morphologies of cartilage and bone. Thermally Induced Phase Separation (TIPS) is one of the most adaptable techniques to produce porous scaffold for Tissue Engineering applications. A wide range of morphologies in terms of both pore size and distribution…

Effect of ambient temperature variations on an indigenous microalgae-nitrifying bacteria culture dominated by Chlorella

2019

[EN] Two outdoor photobioreactors were operated to evaluate the effect of variable ambient temperature on an indigenous microalgae-nitrifying bacteria culture dominated by Chlorella. Four experiments were carried out in different seasons, maintaining the temperature-controlled PBR at around 25¿°C (by either heating or cooling), while the temperature in the non-temperature-controlled PBR was allowed to vary with the ambient conditions. Temperatures in the range of 15¿30¿°C had no significant effect on the microalgae cultivation performance. However, when the temperature rose to 30¿35¿°C microalgae viability was significantly reduced. Sudden temperature rises triggered AOB growth in the indig…

Electrochemical Abatement of Organic Pollutants in Continuous-Reaction Systems through the Assembly of Microfluidic Cells in Series

2015

The electrochemical treatment of wastewater contaminated by organic pollutants was performed under a continuous mode by using, for the first time, various micro-electrochemical cells in series. A synthetic solution of acid orange 7 (AO7), a largely used azoic dye, was chosen as model wastewater. Both the electro-Fenton (EF) method with a cheap compact graphite cathode and electrochemical oxidation (EO) at a boron-doped diamond (BDD) anode were used. EO gave higher abatement of total organic carbon (TOC), but drastically higher energetic consumptions than EF. It is worth mentioning that very different operating conditions were set for EF and EO to optimize their performances. The utilization…

Removal of acetone from air emissions by biotrickling filters: providing solutions from laboratory to full-scale

2018

A full-scale biotrickling filter (BTF) treating acetone air emissions of wood-coating activities showed difficulties to achieve outlet concentrations lower than 125 mg C m-3, especially for high inlet concentrations and oscillating emissions. To solve this problem, a laboratory investigation on acetone removal was carried out simulating typical industrial conditions: discontinuous and variable inlet concentrations and intermittent spraying. The results were evaluated in terms of removal efficiency and outlet gas emission pattern. Industrial emissions and operational protocols were simulated: inlet load up to 70 g C m-3 h-1 during 2 cycles of 4 h per day and intermittent trickling of 15 min …