Search results for "digestio"
showing 10 items of 358 documents
Biomethane production from maize and liquid cow manure – Effect of share of maize, post-methanation potential and digestate characteristics
2013
Abstract This study investigates the co-digestion of liquid cow manure and maize with different share of maize in continuously stirred tank reactors (CSTRs). The objective was to determine the methane yield of reactor and the post-methanation potential of the digestate from different reactor trials. The highest specific methane yield (259 Nl CH 4 /kg volatile solids (VSs)) was obtained when the share of maize in the feedstock was 40% (VS) and the second highest specific methane yield was when the proportion of maize was 60% (VS) (234 Nl CH 4 /kg VS). The post-methanation potential of the digestate was determined in batch assays. The minimum value (maize 40%, 75 ± 1 Nl CH 4 /kg VS feed ) occ…
Long-term thermophilic mono-digestion of rendering wastes and co-digestion with potato pulp
2014
In this study, mono-digestion of rendering wastes and co-digestion of rendering wastes with potato pulp were studied for the first time in continuous stirred tank reactor (CSTR) experiments at 55°C. Rendering wastes have high protein and lipid contents and are considered good substrates for methane production. However, accumulation of digestion intermediate products viz., volatile fatty acids (VFAs), long chain fatty acids (LCFAs) and ammonia nitrogen (NH4-N and/or free NH3) can cause process imbalance during the digestion. Mono-digestion of rendering wastes at an organic loading rate (OLR) of 1.5 kg volatile solids (VS)/m(3)d and hydraulic retention time (HRT) of 50 d was unstable and resu…
Co-production of Hydrogen and Methane From the Organic Fraction of Municipal Solid Waste in a Pilot Scale Dark Fermenter and Methanogenic Biofilm Rea…
2018
The co-production of biohydrogen and methane from the organic fraction of municipal solid waste was investigated using a two-stage AD system, composed of a pilot scale dark fermenter (DF) and a continuous methanogenic biofilm reactor. From the DF process, a biohydrogen yield of 41.7 (± 2.3) ml H2/gVSadded was achieved. The liquid DF effluent (DFE) was rich in short chain volatile fatty acids, i.e., mainly acetic and butyric acid. The DFE was valorized by producing methane in the methanogenic biofilm reactor. Two methanogenic biofilm reactors were used to assess the biotic and abiotic role of the DFE on the performance of the reactors. Regardless of the different DFE feeding (i.e., biotic an…
Stability of different mesoporous silica particles during an in vitro digestion
2016
Mesoporous silica materials have the ability to entrap drugs, nutrients and functional biomolecules and can be able to act as smart delivery systems capable to control and target the release of their cargo in a particular part of the gastrointestinal tract when administrated orally. However, the aptness of these encapsulation supports in in vivo oral controlled release relies on their chemical stability through the digestive tube. In this context, we have evaluated the stability of four different mesoporous silica particles, frequently used as encapsulating supports, during an in vitro digestion process comprising buccal, stomach and intestinal phases. Results showed that after 4 h of diges…
Resource recovery from sulphate-rich sewage through an innovative anaerobic-based water resource recovery facility (WRRF)
2018
[EN] This research work proposes an innovative water resource recovery facility (WRRF) for the recovery of energy, nutrients and reclaimed water from sewage, which represents a promising approach towards enhanced circular economy scenarios. To this aim, anaerobic technology, microalgae cultivation, and membrane technology were combined in a dedicated platform. The proposed platform produces a high-quality solid- and coliform-free effluent that can be directly discharged to receiving water bodies identified as sensitive areas. Specifically, the content of organic matter, nitrogen and phosphorus in the effluent was 45 mg COD.L-1 , 14.9 mg N.L-1 and 0.5 mg P.L-1 , respectively. Harvested solar…
Factors that affect the permeability of commercial hollow-fibre membranes in a submerged anaerobic MBR (HF-SAnMBR) system
2013
A demonstration plant with two commercial HF ultrafiltration membrane modules (PURON (R), Koch Membrane Systems, PUR-PSH31) was operated with urban wastewater. The effect of the main operating variables on membrane performance at sub-critical and supracritical filtration conditions was tested. The physical operating variables that affected membrane performance most were gas sparging intensity and back-flush (BF) frequency. Indeed, low gas sparging intensities (around 0.23 Nm(3) h(-1) m(-2)) and low BF frequencies (30s back-flush for every 10 basic filtration relaxation cycles) were enough to enable membranes to be operated sub-critically even when levels of mixed liquor total solids were hi…
Wastewater nutrient removal in a mixed microalgae-bacteria culture: effect of light and temperature on the microalgae-bacteria competition.
2018
[EN] The aim of this study was to evaluate the effect of light intensity and temperature on nutrient removal and biomass productivity in a microalgae¿bacteria culture and their effects on the microalgae¿bacteria competition. Three experiments were carried out at constant temperature and various light intensities: 40, 85 and 125¿µE¿m¿2¿s¿1. Other two experiments were carried out at variable temperatures: 23¿±¿2°C and 28¿±¿2°C at light intensity of 85 and 125¿µE¿m¿2¿s¿1, respectively. The photobioreactor was fed by the effluent from an anaerobic membrane bioreactor. High nitrogen and phosphorus removal efficiencies (about 99%) were achieved under the following operating conditions: 85¿125¿µE¿…
Proteolytic processing of Bacillus thuringiensis Vip3A proteins by two Spodoptera species
2014
Abstract Vip3 proteins have been described to be secreted by Bacillus thuringiensis during the vegetative growth phase and to display a broad insecticidal spectrum against lepidopteran larvae. Vip3Aa protoxin has been reported to be significantly more toxic to Spodoptera frugiperda than to Spodoptera exigua and differences in the midgut processing have been proposed to be responsible. In contrast, we have found that Vip3Ae is essentially equally toxic against these two species. Proteolysis experiments were performed to study the stability of Vip3A proteins to peptidase digestion and to see whether the differences found could explain differences in toxicity against these two Spodoptera speci…
Uptake and bioavailability of persistant organic pollutants by plants grown in contaminated soil
2005
This paper assesses the uptake of persistent organic pollutants (POP's) into plants. In particular, uptake of alpha-endosulfan, beta-endosulfan and endosulfan sulfate from lettuce. The lettuce plants were grown on compost that had previously been contaminated at 10 and 50 microg g(-1) per POP. The soil was slurry spiked by adding the appropriate amount of POP in acetone in an approximate ratio of 1 ratio 2, w/v soil ratio solvent. The solvent was left to evaporate at ambient temperature for 24 hours. Lettuce plants were grown under artificial daylight for 12 hours a day. The influence of soil ageing on the recovery of POP's from spiked soil samples was also assessed. The average recovery of…
A phase-II study of low-dose cyclophosphamide and recombinant human interleukin-2 in metastatic renal cell carcinoma and malignant melanoma.
1989
Recent preclinical and clinical studies that have demonstrated antitumor activity of high-dose recombinant interleukin-2 (rIL-2), and animal models that demonstrated a synergistic effect of low-dose cyclophosphamide, led us to study rIL-2 (Cetus Corp., Emeryville, Calif) in a phase II clinical trial in combination with low-dose cyclophosphamide in 32 patients, 18 with malignant melanoma and 14 with renal cell carcinoma. rIL-2 was given once daily at 3 x 10(6) U/m2, as a 30-min infusion for 14 days in cycle I and for 2 x 5 days in cycles II and III respectively; if tolerated, the dose was increased to a maximum of 6 x 10(6) U m-2 day-1; the cycles, separated by 1 week treatment-free interval…