Search results for "Digest"
showing 10 items of 3038 documents
Struvite formation from the supernatants of an anaerobic digestion pilot plant
2009
This work studied the influence of the characteristics of the supernatants on the struvite precipitation process. Eighteen experiments with the supernatants generated in an anaerobic digestion pilot plant were performed in a stirred reactor. In order to obtain the pH control during the crystallization process, a Fuzzy Logic based controller was used. High phosphorus precipitation and recovery efficiencies were obtained. The composition of the supernatants was analyzed in order to study its influence on the solids formed from those solutions. The presence of calcium reduced the percentage of phosphorus precipitated as struvite leading to the formation of amorphous calcium phosphate (ACP), wh…
Optimisation of sludge line management to enhance phosphorus recovery in WWTP
2008
The management of the sludge treatment line can be optimized to reduce uncontrolled phosphorus precipitation in the anaerobic digester and to enhance phosphorus recovery in WWTP. In this paper, four operational strategies, which are based on the handling of the prefermented primary sludge and the secondary sludge from an EBPR process, have been tested in a pilot plant. The separated or mixed sludge thickening, the use of a stirred contact tank and the elutriation of the thickened sludge are the main strategies studied. Both the reduction of phosphorus precipitation in the digester and the supernatant suitability for a struvite crystallization process were assessed in each configuration. The…
Producing high-strength liquor from mesophilic batch acidification of chicken manure.
2015
This report describes the results from anaerobic batch acidification of chicken manure as a mono-substrate studied under mesophilic conditions. The manure was diluted with tap water to prevent methane formation during acidification and to improve mixing conditions by reducing fluid viscosity; no anaerobic digester sludge has been added as an inoculum. Highest acidification rates were measured at concentrations of 10 gVS L−1 and 20 gVS L−1; the pH value remained high (pH 6.9–7.9) throughout the test duration and unexpected fast methane formation was observed in every single batch. At substrate concentrations of 10 gVS L−1 there was a remarkable methane formation representing a value of 82% …
Removal of DEHP in composting and aeration of sewage sludge.
2003
The potential of composting and aeration to remove bis(2-ethylhexyl) phthalate (DEHP) from municipal sewage sludge was studied with two dewatered sludges: raw sludge and anaerobically digested sludge. Composting removed 58% of the DEHP content of the raw sludge and 34% of that of the anaerobically digested sludge during 85 days stabilisation in compost bins. A similar removal for the anaerobically digested sludge was achieved in a rotary drum in 28 days. Less than 1% of DEHP was removed with the compost leachate. Although DEHP removal was greater from raw sludge compost than anaerobically digested sludge compost, the total and volatile solids removals were on the same level in the two compo…
Co-digestion of sewage sludge and sterilized solid slaughterhouse waste: Methane production efficiency and process limitations
2012
The rendering product of Category 2 and 3 Animal By-Products is known as sterilized mass (SM) and it is mainly composed of fat and proteins, making it interesting substrate for anaerobic digestion. Batch and semi-continuous laboratory experiments were carried out to investigate the effect of SM addition in co-digestion with sewage sludge on methane production and possible process limitations. Results showed that SM addition in the feed mixture up to 5% (w/w), corresponding to 68.1% of the organic loading, increased methane production 5.7 times, without any indication of process inhibition. Further increase of SM addition at 7.5% (w/w) caused methane production decrease and volatile solids r…
Co-digestion of energy crops and industrial confectionery by-products with cow manure: batch-scale and farm-scale evaluation.
2002
The possible co-digestion of energy crops and industrial confectionery by-products with cow manure was evaluated firstly, through long-term batch experiments and secondly, in a farm-scale digester. In batch assays, digestion with mesophilically digested cow manure as inoculum resulted in specific methane yields (m3 kg−1 VSadded waste) of 0.35 for grass hay (particle size <1.0 cm); 0.26 for oats (0.5 cm) and 0.21 for clover (2.0 cm) harvested at vegetative stage and 0.14 (2.0 cm) for clover harvested at flowering stage. Specific methane yields (m3 kg−1 VSadded waste) for confectionery by-products were 0.37 for chocolate, 0.39 for black candy and 0.32 for confectionery raw material. Ou…
The role of intact oleosin for stabilization and function of oleosomes.
2013
Lipid storage in plants is achieved among all plant species by formation of oleosomes, enclosing oil (triacylglycerides) in small subcellular droplets. Seeds are rich in this pre-emulsified oil to provide a sufficient energy reservoir for growing. The triacylglyceride core of the oleosomes is surrounded by a phospholipid monolayer containing densely packed proteins called oleosins. They are anchored in the triacylglycerides core with a hydrophobic domain, while the hydrophilic termini remain on the surface. These specialized proteins are expressed during seed development and maturation. Particularly, they play a major role in the stabilization and function of oleosomes. To better understand…
Degradation of diols and formation of ethylene glycol by different yeast species
1989
Die mikrobielle Bildung von Ethylenglykol sowie der Abbau von Diolen durch Hefestamme verschiedener Gattungen wurde im synthetischen Medium und in Traubensaft untersucht. Diole (aber nicht Diethylenglykol) wurden von Arlen wieHansenula, Candida, Pichia undRhodotorula abgebaut. Von 40 uberpruften Hefen produzierten einzelne Stamme vonZygosaccharomyces bailii, Torulopsis ernobii undKluyveromyces veronae unter aeroben Bedingungen 70 bis 210 mg/l Ethylenglykol bei Zusatz von 400 mg/l Ethanolamin zum synthetischen Medium. Ohne Ethanolamin erzeugtenZ. bailii undT. ernobii im synthetischen Medium oder Traubensaft zwischen 7 bis 30 mg/l Ethylenglykol. Die Bildung von Ethylenglykol war bei aeroben K…
Ligninolytic potential of Curvularia kusanoi L7 laccases for animal production
2020
The present research was conducted with the objective of evaluating the ligninolytic potential of Curvularia kusanoi L7 laccases in improving the nutritional quality of fibrous substrates for animal feed. Laccase production was obtained from C. kusanoi L7 under native conditions by solid submerged fermentation of wheat bran and by biological interactions with Trichoderma viride M5-2 and Trichoderma pleuroticola. The enzymes were purified from the culture broths by triphasic partition. The degradative potential of native and induced laccases where evaluated by determining foliar lignololytic capacity, raw wheat (Triticum aestivum) straw delignification and the effect of enzyme pretreatment o…
Elevated serum eotaxin levels in patients with inflammatory bowel disease.
2002
OBJECTIVE: Eotaxin is a recently characterized chemokine with potent and selective chemotactic activity for eosinophils. Previous studies indicating that eosinophils accumulate and become activated in inflammatory bowel disease (IBD) led us to hypothesize that eotaxin is potentially involved in the pathophysiology of IBD and, therefore, that eotaxin would be increased in the serum of patients with IBD. The objective of this study was to test those assumptions. METHODS: We investigated 72 patients with IBD, 35 with ulcerative colitis, and 37 with Crohn’s disease. A total of 27 patients had active and 45 inactive disease; 26 were receiving corticosteroids. Eotaxin serum levels were determined…