The contribution of thermophilic anaerobic digestion to the stable operation of wastewater sludge treatment

2002 ◽  
Vol 46 (4-5) ◽  
pp. 447-453 ◽  
Author(s):  
J. Zábranská ◽  
M. Dohányos ◽  
P. Jeníček ◽  
P. Zaplatílková ◽  
J. Kutil
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Removal Rate ◽  
Wastewater Sludge ◽  
Anaerobic Sludge ◽  
Stable Operation ◽  
Sludge Treatment ◽  
Thermophilic Anaerobic Digestion ◽  
Mesophilic Digestion ◽  
Pathogens Removal

Thermophilic anaerobic digestion of sewage sludge has been successfully operated in full-scale tanks almost three years. The higher loading capacity and specific biogas production rate in comparison with mesophilic digestion was proved. Thermophilic anaerobic sludge is also more resistant against foaming problems. Biogas from thermophilic tanks contains less hydrogen sulphide and other malodorous substances. Pathogens removal rate is apparently more efficient in the thermophilic process.

Simulation of the Impact of Higher Ammonia Recycle Loads Caused by Upgrading Anaerobic Sludge Digesters

2005 ◽  
Vol 40 (4) ◽  
pp. 491-499 ◽  
Author(s):  
Jeremy T. Kraemer ◽  
David M. Bagley
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Treatment Plant ◽  
Anaerobic Sludge ◽  
Content Increase ◽  
Limited Information ◽  
Dynamic Simulations ◽  
Treatment Train ◽  
Temperature Liquid ◽  
The Impact

Abstract Upgrading conventional single-stage mesophilic anaerobic digestion to an advanced digestion technology can increase sludge stability, reduce pathogen content, increase biogas production, and also increase ammonia concentrations recycled back to the liquid treatment train. Limited information is available to assess whether the higher ammonia recycle loads from an anaerobic sludge digestion upgrade would lead to higher discharge effluent ammonia concentrations. Biowin, a commercially available wastewater treatment plant simulation package, was used to predict the effects of anaerobic digestion upgrades on the liquid train performance, especially effluent ammonia concentrations. A factorial analysis indicated that the influent total Kjeldahl nitrogen (TKN) and influent alkalinity each had a 50-fold larger influence on the effluent NH3 concentration than either the ambient temperature, liquid train SRT or anaerobic digestion efficiency. Dynamic simulations indicated that the diurnal variation in effluent NH3 concentration was 9 times higher than the increase due to higher digester VSR. Higher recycle NH3 loads caused by upgrades to advanced digestion techniques can likely be adequately managed by scheduling dewatering to coincide with periods of low influent TKN load and ensuring sufficient alkalinity for nitrification.

The use of microalgae and their culture medium for biogas production in an integrated cycle

2013 ◽  
Vol 69 (5) ◽  
pp. 941-946 ◽  
Author(s):  
E. L. Formagini ◽  
F. R. Marques ◽  
M. L. Serejo ◽  
P. L. Paulo ◽  
M. A. Boncz
Keyword(s):  
Anaerobic Digestion ◽  
Culture Medium ◽  
Biogas Production ◽  
Algal Growth ◽  
Culture Broth ◽  
Strong Tendency ◽  
Stable Operation ◽  
Microalgae Cultivation ◽  
Algae Cultivation ◽  
Batch Tests

Vinasse is a residue produced in large quantities as a sub-product of ethanol production. Anaerobic digestion of vinasse can yield large amounts of biogas, but often difficulties arise in maintaining stable operation, due to the acidity of the material (which has a pH between 3.5 and 5) and a strong tendency to further acidification. Anaerobically digested vinasse can be used as part of a culture medium for microalgae cultivation, for the production of biodiesel and other compounds, whilst the excess CO2 produced in the ethanol fermentation can be used to stimulate algal growth. During algae cultivation, the pH of the culture medium has a strong tendency to increase; therefore, recycling of the spent culture medium or the concentrated algae suspension to the anaerobic digester treating vinasse was considered an option for pH stabilization there. Batch tests, however, showed that alkalinity of the spent culture broth, in spite of its high pH, is too low (only 350 mgCaCO3L−1) to help stabilise the pH of vinasse digestion. Alkalinity of the algae suspension is higher and digestion of a mixture of vinasse and a suspension of algae results in efficient biogas production, but still the alkalinity is insufficient to stabilise the pH in a range suitable for methanogenic microorganisms; hence, the addition of additional alkalinity, for instance as sodium bicarbonate or urea, remains necessary.

Destruction of Faecal Bacteria, Enteroviruses and OVA of Parasites in Wastewater Sludge by Aerobic Thermophilic and Anaerobic Mesophilic Digestion

1991 ◽  
Vol 24 (2) ◽  
pp. 377-380 ◽  
Author(s):  
E. G. Carrington ◽  
E. B. Pike ◽  
D. Auty ◽  
R. Morris
Keyword(s):  
Sewage Treatment ◽  
Treatment Plant ◽  
Wastewater Sludge ◽  
Sludge Treatment ◽  
Volatile Solids ◽  
Working Volume ◽  
Thermotolerant Coliforms ◽  
Mesophilic Digestion ◽  
Faecal Bacteria ◽  
Faecal Streptococci

A new sludge treatment plant at Harrogate South Sewage Treatment Works is designed to handle up to 4 tonnes (dry solids) daily. Sludge is thickened continuously up to 8% (ds) and is then treated in parallel anaerobic mesophilic (AD) and thermophilic aerobic digestion (TAD) plants each with a maximum working volume of 530m3. Microbiological studies were carried out to compare the destruction of pathogens and faecal indicator bacteria. The AD plant operated with a mean retention of 26 days at 34 °C and achieved 49% reduction of volatile solids. The TAD plant operated with a mean retention of 28 days at 55 °C and reduced volatile solids by 35%. Operation was on a pump in-pump out cycle, guaranteeing 4h retention for all sludge. The disinfecting ability of TAD exceeded that of AD since it reduced counts of Enterobacteriaceae, thermotolerant coliforms and faecal streptococci to below 103/100ml, rendered cytopathic enteroviruses undetectable and destroyed viability of Ascaris suum ova within 4h. The AD process reduced bacterial counts by 90% and enteroviruses by 99%, but has no effect upon viability of Ascaris ova.

Sludge electrooxidation as pre-treatment for anaerobic digestion

2016 ◽  
Vol 75 (4) ◽  
pp. 775-781 ◽  
Author(s):  
J. A. Barrios ◽  
U. Duran ◽  
A. Cano ◽  
M. Cisneros-Ortiz ◽  
S. Hernández
Keyword(s):  
Anaerobic Digestion ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Wastewater Sludge ◽  
Boron Doped Diamond ◽  
Boron Doped ◽  
Treatment Conditions ◽  
Volatile Solids ◽  
Pre Treatment

Anaerobic digestion of wastewater sludge is the preferred method for sludge treatment as it produces energy in the form of biogas as well as a stabilised product that may be land applied. Different pre-treatments have been proposed to solubilise organic matter and increase biogas production. Sludge electrooxidation with boron-doped diamond electrodes was used as pre-treatment for waste activated sludge (WAS) and its effect on physicochemical properties and biomethane potential (BMP) was evaluated. WAS with 2 and 3% total solids (TS) achieved 2.1 and 2.8% solubilisation, respectively, with higher solids requiring more energy. After pre-treatment, biodegradable chemical oxygen demand values were close to the maximum theoretical BMP, which makes sludge suitable for energy production. Anaerobic digestion reduced volatile solids (VS) by more than 30% in pre-treated sludge with a food to microorganism ratio of 0.15 g VSfed g−1 VSbiomass. Volatile fatty acids were lower than those for sludge without pre-treatment. Best pre-treatment conditions were 3% TS and 28.6 mA cm−2.

Methanogenic Performance of Pulp and Paper Mill Sludge Using Anaerobic Digestion Process

2014 ◽  
Vol 675-677 ◽  
pp. 680-684
Author(s):  
Zhao Mei Du ◽  
Qin Wu ◽  
Xiao Qin Zhang
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Paper Mill ◽  
Pulp And Paper ◽  
Wastewater Sludge ◽  
Pulp And Paper Mill ◽  
Anaerobic Digestion Process ◽  
Digestion Process ◽  
Feeding Modes ◽  
Paper Mill Wastewater

The feasibility of pulp and paper mill wastewater sludge as substrates for biogas production was evaluated in labrotory scale. Also the influence of pre-acidification, feeding modes and sludge concentration on anaerobic digestion system were studied.

scholarly journals Addition of Different Biochars as Catalysts during the Mesophilic Anaerobic Digestion of Mixed Wastewater Sludge

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1094
Author(s):  
Marco Chiappero ◽  
Francesca Cillerai ◽  
Franco Berruti ◽  
Ondřej Mašek ◽  
Silvia Fiore
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Biogas Production ◽  
Chemical Properties ◽  
Principal Component ◽  
Gompertz Model ◽  
Wastewater Sludge ◽  
Total Carbon ◽  
Lag Phase ◽  
Working Volume

Biochar (BC) recently gained attention as an additive for anaerobic digestion (AD). This work aims at a critical analysis of the effect of six BCs, with different physical and chemical properties, on the AD of mixed wastewater sludge at 37 °C, comparing their influence on methane production and AD kinetics. AD batch tests were performed at the laboratory scale operating 48 reactors (0.25 L working volume) for 28 days with the addition of 10 g L−1 of BC. Most reactors supplemented with BCs exhibited higher (up to 22%) methane yields than the control reactors (0.15 Nm3 kgVS−1). The modified Gompertz model provided maximum methane production rate values, and in all reactors the lag-phase was equal to zero days, indicating a good adaptation of the inoculum to the substrate. The potential correlations between BCs’ properties and AD performance were assessed using principal component analysis (PCA). The PCA results showed a reasonable correlation between methane production and the BCs’ O–C and H–C molar ratios, and volatile matter, and between biogas production and BCs’ pore volume, specific surface area, and fixed and total carbon. In conclusion, the physic-chemical properties of BC (specifically, hydrophobicity and morphology) showed a key role in improving the AD of mixed wastewater sludge.

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