Search results for "anaerobic"
showing 10 items of 456 documents
Anaerobic digestion of organic solid poultry slaughterhouse waste – a review
2002
This work reviews the potential of anaerobic digestion for material recovery and energy production from poultry slaughtering by-products and wastes. First, we describe and quantify organic solid by-products and wastes produced in poultry farming and poultry slaughterhouses and discuss their recovery and disposal options. Then we review certain fundamental aspects of anaerobic digestion considered important for the digestion of solid slaughterhouse wastes. Finally, we present an overview of the future potential and current experience of the anaerobic digestion treatment of these materials.
Sicilian potential biogas production
2013
This study is aimed at predicting the Sicilian potential biogas production, using the Organic Fraction of Municipal Solid Waste (OFMSW), animal manure and food industry by-products, in a region where only one biogas plant using MSW and one co-digestion plant are nowadays available. The statistical data about OFMSW, the number of animals bred in medium and large farms and the amounts of by-products of food processing industries were evaluated, in order to compute the Sicilian potential biogas and energy production. The OFMSW produced in Sicily, that is 0.8 million tons ca. per year (37% of MSW), could be used in a bio-reactor, together with other raw materials, for Anaerobic Digestion (AD) p…
A fuzzy-logic-based controller for methane production in anaerobic fixed-film reactors
2017
The main objective of this work was to develop a controller for biogas production in continuous anaerobic fixed-bed reactors, which used effluent total volatile fatty acids (VFA) concentration as control input in order to prevent process acidification at closed loop. To this aim, a fuzzy-logic-based control system was developed, tuned and validated in an anaerobic fixed-bed reactor at pilot scale that treated industrial winery wastewater. The proposed controller varied the flow rate of wastewater entering the system as a function of the gaseous outflow rate of methane and VFA concentration. Simulation results show that the proposed controller is capable to achieve great process stability ev…
Unveiling microbial structures during raw microalgae digestion and co-digestion with primary sludge to produce biogas using semi-continuous AnMBR sys…
2020
[EN] Methane production from microalgae can be enhanced through anaerobic co-digestion with carbon-rich substrates and thus mitigate the inhibition risk associated with its low C:N ratio. Acclimated microbial communities for microalgae disruption can be used as a source of natural enzymes in bioenergy production. However, co-substrates with a certain microbial diversity such as primary sludge might shift the microbial structure. Substrates were generated in a Water Resource Recovery Facility (WRRF) and combined as follows: Scenedesmus or Chlorella digestion and microalgae co-digestion with primary sludge. The study was performed using two lab-scale Anaerobic Membrane Bioreactors (AnMBR). Du…
Unveiling the distinctive role of titanium dioxide nanoparticles in aerobic sludge digestion.
2022
Abstract Aerobic digestion is considered to be a common process for the stabilization of waste activated sludge (WAS) in the small-sized wastewater treatment systems, while the broad application of titanium dioxide nanoparticles (TiO2 NPs) results in their unavoidable existence in WAS aerobic digestion, with its role in aerobic sludge digestion being never documented. This study set up a series of aerobic sludge digesters to evaluate the previously unknown role of TiO2 NPs on the performance of the digesters. The volatile solids (VS) degradation percentage increased from 21.9 ± 0.6% to 26.9 ± 0.1% − 30.0 ± 0.3% with the different contents of TiO2 NPs (0, 1, 20 and 50 mg/L). Similarly, the t…
Modelling the metabolic shift of polyphosphate-accumulating organisms
2014
Enhanced biological phosphorus removal (EBPR) is one of the most important methods of phosphorus removal in municipal wastewater treatment plants, having been described by different modelling approaches. In this process, the PAOs (polyphosphate accumulating organisms) and GAOs (glycogen accumulating organisms) compete for volatile fatty acids uptake under anaerobic conditions. Recent studies have revealed that the metabolic pathways used by PAOs in order to obtain the energy and the reducing power needed for polyhydroxyalkanoates synthesis could change depending on the amount of polyphosphate stored in the cells. The model presented in this paper extends beyond previously developed metaboli…
Dewaterability of CAS and MBR Sludge: Effect of Biological Stability and EPS Composition
2018
The dewaterability of sludge from two conventional activated sludge (CAS) and three membrane bioreactor (MBR)-based wastewater treatment plants is investigated prior to and after anaerobic digestion. The concentration and composition of extracellular polymeric substances (EPS) mostly affect the dewaterability of all raw sludge samples. Better sludge dewaterability is observed when the concentration of proteins, carbohydrates, uronic acids, and humic acids is below approximately 400, 250, 200, and 40 mg/L, respectively. In contrast, the specific resistance to filtration (SRF) increases in the sludge samples with a higher EPS concentration. The MBR results in a lower EPS production and a uron…
Fate of endocrine disruptor compounds in an anaerobic membrane bioreactor (AnMBR) coupled to an activated sludge reactor
2018
[EN] The occurrence and fate of three groups of micropollutants - alkylphenols, pentachlorophenol and hormones - were studied in a pilot plant consisting of an anaerobic membrane bioreactor (AnMBR) coupled to an activated sludge reactor (University of Cape Town configuration - UCT). Under anaerobic conditions, the octylphenol and technical-nonylphenol soluble concentrations increased producing negative degradation ratios (i.e., -175 and -118%, respectively). However, high 4-n-nonylphenol and bisphenol-A degradation ratios (92 and 59% for 4-n-nonylphenol and bisphenol-A, respectively) as well as complete pentachlorophenol, estrone, 17 beta-estradiol and 17 alpha-ethinylestradiol removal were…
A review on anaerobic membrane bioreactors (AnMBRs) focused on modelling and control aspects
2018
[EN] The use of anaerobic membrane bioreactor technology (AnMBR) is rapidly expanding. However, depending on the application, AnMBR design and operation is not fully mature, and needs further research to optimize process efficiency and enhance applicability. This paper reviews state-of-the-art of AnMBR focusing on modelling and control aspects. Quantitative environmental and economic evaluation has demonstrated substantial advantages in application of AnMBR to domestic wastewater treatment, but detailed modelling is less mature. While anaerobic process modelling is generally mature, more work is needed on integrated models which include coupling between membrane performance (including fouli…
Anaerobically digested poultry slaughterhouse wastes as fertiliser in agriculture
2001
Chemical and physical analysis, 27-d plant growth assays with carrot (Daucus carota) and Chinese cabbage (Brassica campestris var. chinensis), and 5-d phytotoxicity assays with Chinese cabbage and perennial ryegrass (Lolium perenne) were used to investigate the suitability of anaerobically digested poultry slaughterhouse waste for fertiliser in agriculture and the effect of aerobic post-treatment on the properties of the digested material. The digested material appeared to be rich in nitrogen. In 27-d assays with digested material as nitrogen source, carrots grew almost as well as those fertilised with a commercial mineral fertiliser used as reference, whereas, the growth of Chinese cabbage…