anaerobic digestion sludge Articles
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Application of dried anaerobic digested sewage sludge as phenol biosorbent
Untreated anaerobically digested sewage sludge was used for the first time as a biosorbent for removing phenol from aqueous solution. Results showed that adsorption capacity was influenced by the pH of the aqueous solution with an observed maximum phenol removal at pH around 6–8. The adsorption equilibrium of phenolic compounds was obtained after almost two hours with an adsorption of ...
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Nitrification of centrate from dewatering of anaerobically digested sludge
Nitrification of anaerobically digested sludge centrate was studied in bench-scale suspended growth and fixed film enhanced suspended growth systems at temperatures of 10.5-28.5°C and pH values of 6.0-9.1. Nitrification followed zero-order kinetics in both systems, and ammonia removals in excess of 99% were observed. The temperature dependency of the suspended growth nitrification rate ...
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Microwave and its combined processes: an effective way for enhancing anaerobic digestion and dewaterability of sewage sludge?
The enhancement for sludge anaerobic digestion and dewaterability were investigated in sludge pretreated by microwave (MW) and its combined processes. The results showed that microwave and its combined processes can efficiently release soluble organic matter and thus enhance anaerobic digestion of sludge. The cumulative methane production in the test of the MW-H2O2-OH (0.2) process was ...
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A novel technique for evaluating foam dynamics in anaerobic digesters
Foaming in anaerobic digesters has severe impacts on process efficiency and operational costs. In this study, we present an experimental method to determine foam behaviour and stability for various foaming solutions. This novel technique measured foam conductivity at different heights along a foam column allowing changes in foam composition to be monitored in time. We analysed foam stability ...
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Ferrrate(VI) and freeze-thaw treatment for oxidation of hormones and inactivation of fecal coliforms in sludge
This study examined the individual and combined effects of potassium ferrate(VI) additions and freeze-thaw conditioning for the treatment and dewatering of wastewater sludge in cold climates, with particular focus on the inactivation of fecal coliforms and oxidation of estrogens, androgens, and progestogens. The first phase of the study evaluated the effects of potassium ferrate(VI) ...
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H2 consumption by anaerobic non-methanogenic mixed cultures
The impact of H2 consumption, by homoacetogens, on the overall hydrogen yield in mixed culture fermentation is the focus of this study. Batch reactors were used to test the ability of anaerobic digested sludge, heat treated to eliminate methanogens, to produce and consume molecular hydrogen. The measured average hydrogen production rate from 4.2 g glucose/L was 44 ± 4 mmol H2/L sludge · d, while ...
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Degradation rate of anaerobically digested sewage sludge in soil
The objective of this study was to monitor the degradation and obtain the mineralization fraction of anaerobically digested sludge, also known as digestate, under field conditions, when applied to the surface or incorporated into the soil. Sludge was applied to a dystrophic Inceptisol at a dose of 500 kg ha–1 yr–1 of total nitrogen, where the monitoring period of the mineralization process ...
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Effect of daylight on regrowth of bacteria in anaerobically digested sludge
This study investigated the regrowth of total coliform, Salmonella, and Clostridium perfringens in anaerobically digested sludge after centrifuge dewatering in the presence and absence of daylight. Sludge cake and centrate samples were collected from a treatment plant, and half of the samples was stored in daylight and the other half was stored in dark for three weeks. The bacteria levels in the ...
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Preliminary evaluation of biosolids characteristics for anaerobic membrane reactors treating municipal wastewaters
This study assessed the characteristics of biosolids of a pilot-scale anaerobic membrane bioreactor (AnMBR) treating municipal wastewater. The production of total solids (TS) and volatile solids (VS) was comparable to that reported for the extended aeration system at solids residence time (SRT) longer than 40 days. The yields of TS and VS were reduced as SRT increased from 40 to 100 days and ...
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Behavior and fate of anthropogenic substances at a Swedish sewage treatment plant
The behavior and fate of anthropogenic substances during sewage treatment were investigated at a sewage treatment plant (STP) in Sweden which uses mechanical, chemical, and biological methods for sewage treatment and anaerobic digestion of sludge. Influent and effluent water, and sludge from two specific treatment sites were sampled. Mass balances were calculated from measured concentrations of ...
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Conversion of sewage sludge to commodity chemicals via syngas fermentation
Gasification of sewage sludge allows the recovery of energy, and produces a mix of CO, CO2 and H2 called synthesis gas (or syngas), which can be fermented by acetogenic bacteria to added-value products. This work presents the conversion of syngas to organic acids and alcohols using both pure and mixed cultures. Pure culture kinetic experiments with Clostridium carboxidivorans P7 resulted in the ...
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Microalgae growth for nutrient recovery from sludge liquor and production of renewable bioenergy
Proof-of-concept has been demonstrated for a process that will utilize nutrients from sludge liquor, natural light, and CO2 from biogas to grow microalgae at wastewater treatment plants. This process will reduce the impact of returning side-streams to the head of the plant. The produced algae will be fed to anaerobic digesters for increased biogas production. Dewatering of anaerobically digested ...
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Enhancement of the conventional anaerobic digestion of sludge: comparison of four different strategies
Anaerobic digestion (AD) is the preferred option to stabilize sludge. However, the rate limiting step of solids hydrolysis makes it worth modifing the conventional mesophilic AD in order to increase the performance of the digester. The main strategies are to introduce a hydrolysis pre-treatment, or to modify the digestion temperature. Among the different pre-treatment alternatives, the thermal ...
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Organic waste biodegradability test bio methane potential method
Management Summary The biogas production from a mixture of food waste, garden waste, paper, napkins, plastic, metals and glass and anaerobically digested sludge was monitored until gas production had ceased. The homogenised biowaste mixture was subjected to two pre-treatment methods prior to being fed to the BMP reactors, these were: pasteurisation at 70oC followed by anaerobic digestion ...
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Odour reduction strategies for biosolids produced from a Western Australian wastewater treatment plant: results from Phase I laboratory trials
This study investigated sources of odours from biosolids produced from a Western Australian wastewater treatment plant and examined possible strategies for odour reduction, specifically chemical additions and reduction of centrifuge speed on a laboratory scale. To identify the odorous compounds and assess the effectiveness of the odour reduction measures trialled in this study, headspace ...
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Dynamic modelling of nitrous oxide emissions from three Swedish sludge liquor treatment systems
The objective of this paper is to model the dynamics and validate the results of nitrous oxide (N2O) emissions from three Swedish nitrifying/denitrifying, nitritation and anammox systems treating real anaerobic digester sludge liquor. The Activated Sludge Model No. 1 is extended to describe N2O production by both heterotrophic and autotrophic denitrification. In addition, mass transfer ...
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How do you remove struvite?
The photographs above demonstrates what can happen if you don’t control or remove struvite. This is a 14” diameter line used to transfer sludge from an anaerobic digester to a sludge holding pond. Every year this agency would mechanically clean this transfer line. However, every year plant operation notice that it took longer to transfer equivalent amounts of liquid from the ...
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Static gas analyser at United Utilities case study
About the customer United Utilities, Lancaster, England Equipment GA3000 Location United Kingdom Customer United Utilities Requirement The customer required its own precise, detailed and accurate recording of the concentrations of methane (CH4), carbon dioxide (CO2) and hydrogen sulphode (H2S) that it sends to its two CHP engines. Dave Bega, Installation and Commissioning Manager for GCA ...
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Hygienization of sludge through anaerobic digestion at 35, 55 and 60 °C
Legislation in Sweden and the European Union concerning the use of sewage sludge in agriculture is under revision and future concentration limits for pathogens in treated sludge are likely to be expected. The aim of this study was to evaluate the hygienization of Salmonella, Escherichia coli, Enterococcus and Clostridium perfringens through continuous anaerobic digestion at 35, 55 or 60 ...
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Advantages of anaerobic digestion of sludge in microaerobic conditions
The paper reviews results and experience of microaerobic experiments at both high and low sulphide concentrations and evaluates advantages and drawbacks of the anaerobic digestion of sludge in microaerobic conditions as regards biogas quality, digested sludge quality, organic pollutants biodegradability and methanogenic activity of biomass. The innovative microaerobic modification of the ...
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