Removal of Salmonella, Streptococci and Coliforms in Pig Breeding Effluent by Anaerobic Mesophilic Digestion

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2169-2172 ◽  
Author(s):  
E. A. Duarte ◽  
B. Mendes ◽  
J. S. Oliveira
Keyword(s):  
Pollution Control ◽  
Biogas Production ◽  
Organic Load ◽  
Load Reduction ◽  
Faecal Coliforms ◽  
Efficient Treatment ◽  
Stirred Reactor ◽  
Thermophilic Conditions ◽  
Mesophilic Digestion ◽  
Pathogens Removal

Removal of bacteria has been followed in a continuously stirred reactor working at 37 °C and 54.9 °C on pig breeding effluents. The reduction of total and faecal coliforms, total and faecal Streptococci and Salmonella was extremely important, especially under thermophilic conditions. Biomethanisation may be considered as an efficient treatment for organic load reduction and biogas production, and also for nutrients recovery and for pathogens removal, being an important contribution for a global and integrated scheme of pollution control and environmental protection.

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.

scholarly journals Influence of the Heating Method on the Efficiency of Biomethane Production from Expired Food Products

Fermentation ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 12
Author(s):  
Joanna Kazimierowicz ◽  
Marcin Zieliński ◽  
Marcin Dębowski
Keyword(s):  
Biogas Production ◽  
Food Products ◽  
Organic Load ◽  
Organic Substrates ◽  
Methane Fermentation ◽  
Anaerobic Reactors ◽  
Convection Heating ◽  
Load Rate ◽  
Biomethane Production ◽  
Positive Effect

The aim of the study was to determine the effect of heating with microwave electromagnetic radiation (EMR) on the efficiency of the methane fermentation (MF) of expired food products (EFP). The research was inspired by the positive effect of EMR on the production of biogas and methane from different organic substrates. The experiment was carried out on a laboratory scale in fully mixed, semi-continuous anaerobic reactors. The technological conditions were as follows: temperature, 35 ± 1 °C; organic load rate (OLR), 2.0 kgVS·m−3∙d−1; and hydraulic retention time (HRT), 40 days. The source of the EMR was a magnetron (electric power, 300 W). There was no statistically significant influence of the use of EMR on the achieved technological effects of MF. The efficiency of biogas production was 710 ± 35 dm3·kgVS−1 in the variant with EMR and 679 ± 26 dm3·kgVS−1 in the variant with convection heating (CH). The methane contents were 63.5 ± 2.4% (EMR) and 62.4 ± 4.0% (CH), and the cumulative methane production after 40 days was 271.2 and 288.6 dm3CH4, respectively.

Methanol conversion in high-rate anaerobic reactors

2001 ◽  
Vol 44 (8) ◽  
pp. 7-14 ◽  
Author(s):  
J. Weijma ◽  
A.J.M. Stams
Keyword(s):  
Carbon Dioxide ◽  
Methanol Conversion ◽  
High Rate ◽  
Sulfate Reducing ◽  
Anaerobic Reactors ◽  
Substrate Level ◽  
Thermophilic Conditions ◽  
Mesophilic Digestion ◽  
Reducing Bacteria ◽  
Microbiological Aspects

An overview on methanol conversion in high-rate anaerobic reactors is presented, with the focus on technological as well as microbiological aspects. The simple C1-compound methanol can be degraded anaerobically in a complex way, in which methanogens, sulfate reducing bacteria and homoacetogens interact cooperatively or competitively at substrate level. This interaction has large technological implications as it determines the final product of methanol mineralization, methane or carbon dioxide. The degradation route of methanol may be entirely different when environmental conditions change. Direct methanogenesis from methanol seems the predominant mineralization route under mesophilic conditions both in the absence and the presence of sulfate. Under thermophilic conditions methanol oxidation to carbon dioxide and hydrogen appears to play an important role. The UASB technology for mesophilic digestion of methanolic waste has presently reached full-scale maturity. The potential of methanol as feedstock for anaerobic processes is discussed.

Anaerobic co-digestion of winery waste and waste activated sludge: assessment of process feasibility

2013 ◽  
Vol 69 (2) ◽  
pp. 269-277 ◽  
Author(s):  
C. Da Ros ◽  
C. Cavinato ◽  
F. Cecchi ◽  
D. Bolzonella
Keyword(s):  
Activated Sludge ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Waste Activated Sludge ◽  
Organic Loading ◽  
Operational Conditions ◽  
Loading Rates ◽  
Thermophilic Conditions ◽  
Soluble Chemical Oxygen Demand

In this study the anaerobic co-digestion of wine lees together with waste activated sludge in mesophilic and thermophilic conditions was tested at pilot scale. Three organic loading rates (OLRs 2.8, 3.3 and 4.5 kgCOD/m3d) and hydraulic retention times (HRTs 21, 19 and 16 days) were applied to the reactors, in order to evaluate the best operational conditions for the maximization of the biogas yields. The addition of lee to sludge determined a higher biogas production: the best yield obtained was 0.40 Nm3biogas/kgCODfed. Because of the high presence of soluble chemical oxygen demand (COD) and polyphenols in wine lees, the best results in terms of yields and process stability were obtained when applying the lowest of the three organic loading rates tested together with mesophilic conditions.

scholarly journals Microwave Radiation Influence on Dairy Waste Anaerobic Digestion in a Multi-Section Hybrid Anaerobic Reactor (M-SHAR)

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1772
Author(s):  
Marcin Zieliński ◽  
Marcin Dębowski ◽  
Joanna Kazimierowicz
Keyword(s):  
Microwave Radiation ◽  
Food Industry ◽  
Biogas Production ◽  
Cod Removal ◽  
Organic Load ◽  
Radiation Heating ◽  
Methane Fermentation ◽  
Anaerobic Reactor ◽  
Dairy Waste ◽  
Acid Whey

Whey is a primary by-product of dairy plants, and one that is often difficult to manage. As whey processing units are costly and complicated, only 15–20% of whey is recycled for use in the food industry. The difficulties in managing waste whey are particularly pronounced for small, local dairy plants. One possible solution to this problem is to use advanced and efficient digesters. The aim of this study was to present an innovative multi-section hybrid anaerobic bioreactor (M-SHAR) design and to identify how microwave radiation heating (MRH) affects methane fermentation of liquid dairy waste (LDW) primarily composed of acid whey. The MRH reactor was found to perform better in terms of COD removal and biogas production compared with the convection-heated reactor. The heating method had a significant differentiating effect at higher organic load rates (OLRs). With OLRs ranging from 15 to 25 kgCOD∙m−3∙d−1, the M-SHAR with MRH ensured a 5% higher COD removal efficiency and 12–20% higher biogas yields.

Contribution for the Study of New Pathogenic Indicators Removal from W.S.P. in Portugal

1991 ◽  
Vol 24 (2) ◽  
pp. 381-386 ◽  
Author(s):  
M. J. Nascimento ◽  
J. S. Oliveira ◽  
L. Oliveira ◽  
J. T. Mexia
Keyword(s):  
Solar Radiation ◽  
Climatic Factor ◽  
Climatic Parameters ◽  
Faecal Coliforms ◽  
Different Types ◽  
Microbial Removal ◽  
Pathogens Removal ◽  
Faecal Streptococci

In the control of pathogens removal in W.S.P. in Portugal, other indicators than the classic ones were used to quantify die-off kinetics (Faecal coliforms, Faecal Streptococci, Clostridiumperfringens, Pseudomonasaeruginosa and Heterotrophies). The influence of climatic parameters (temperature, precipitation, solar radiation) in that kinetics was studied, different equations being tested to express relationships existing among climatic parameters and microbial removal in different types of ponds. The existence of significant correlations among these factors and parameters was concluded, as well as the dominance of certain models to quantify these relationships, differing according to the microorganisms considered, the type of lagoon and the climatic factor (θ) studied.

Ecotechnology: basis of a new immission concept in water pollution control

2005 ◽  
Vol 52 (5) ◽  
pp. 17-24 ◽  
Author(s):  
J. Benndorf
Keyword(s):  
Water Pollution ◽  
Pollution Control ◽  
Control Measures ◽  
Ecosystem Structure ◽  
Load Reduction ◽  
Optimum Structure ◽  
Stream Morphology ◽  
Water Pollution Control ◽  
Internal Mechanism ◽  
Predatory Fishes

Beyond the traditional load reduction also an ecosystem-internal mechanism can be used to minimise the effects of water pollution. The control of the internal mechanisms is achieved through the optimisation of the ecosystem structure. This ecotechnology principle is based on the idea to reduce as much as possible the gap between the current (suboptimal) structural status and the optimum structure by intentional manipulations. The spectrum of such manipulations is very broad. A few examples are demonstrated. They comprise physical (e.g. stream morphology), chemical (e.g. enhancing the redox potential at the sediment–water interface) and biological (e.g. enhancing stocks of predatory fishes) control measures. It can be supposed that a new immission concept including the ecotechnology principle could be much more adequate to the demand of modern water pollution control than the traditional emission and imission concepts.

Ammonia influence in anaerobic digestion of OFMSW

2009 ◽  
Vol 59 (6) ◽  
pp. 1153-1158 ◽  
Author(s):  
T. Benabdallah El Hadj ◽  
S. Astals ◽  
A. Galí ◽  
S. Mace ◽  
J. Mata-Álvarez
Keyword(s):  
Anaerobic Digestion ◽  
Competitive Inhibition ◽  
Biogas Production ◽  
Gompertz Model ◽  
Ammonia Concentration ◽  
Ion Concentration ◽  
Ammonium Ion ◽  
Municipal Solid Wastes ◽  
Methane Generation ◽  
Thermophilic Conditions

The anaerobic digestion of the organic fraction of municipal solid wastes is taking increasing importance in the recent years. The main problem of some anaerobic digestion process is the large quantity of ammonia that is released, especially when high solid digestion is implemented. A fraction of the supernatant is treated and the remaining is recirculated to maintain the reactor in the optimum solids concentration. The question arising is if this recirculation stream should also be treated to improve biogas production. However, when doing the latter the quantity of ammonia inside the reactor increases too which could lead to inhibit the reactor operation. In this paper it appears that not only free ammonia affects the methanogenic fermentation but also ammonium ion concentration. Biogas production profiles are estimated using the Gompertz model. On the other hand, inhibition constants are fitted using a non-competitive inhibition model equation Thus, 50% inhibition of biomethane production was observed at level of 215 and 468 mg NH3_N/L under mesophilic and thermophilic conditions. However, the methane generation under mesophilic and thermophilic conditions was reduced by 50% when ammonium ion reach concentrations of 3,860 and 5,600 mg NH4+_N/L respectively. Under mesophilic conditions, pH higher than 7 impacted the methanogens bacteria negatively. This threshold pH limit, is variable under thermophilic conditions, depending on the total ammonia concentration.

scholarly journals Limiting factors for anaerobic digestion of olive mill wastewater blends under mesophilic and thermophilic conditions

2018 ◽  
Vol 49 (2) ◽  
pp. 130-137
Author(s):  
Demetrio Antonio Zema ◽  
Giovanni Zappia ◽  
Souraya Benalia ◽  
Giuseppe Zimbalatti ◽  
Enzo Perri ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Anaerobic Digestion ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Olive Mill Wastewater ◽  
Limiting Factors ◽  
Citrus Peel ◽  
Thermophilic Conditions ◽  
High Concentrations ◽  
Olive Mill

Experimental trials of anaerobic digestion of olive mill wastewater (OMW) blended with other agro-industrial by-products were carried out to evaluate biogas production and sensitivity of the process to inhibiting compounds. Blends containing different percentages of OMW, digested liquid manure, and citrus peel were subjected to a batch anaerobic digestion process under both mesophilic and thermophilic conditions. The results showed that blends with percentages of OMW higher than 20% (v/v) had low methane yields due high concentrations of polyphenols (PPs) and/or volatile fatty acids (concentrations above 0.8 g kg–1 and 2.4 g L–1, respectively). The addition of other substrates such as citrus peel may have induced synergic inhibiting effects of PPs and essential oils (EO) on microbial growth. Thermophilic processes were more sensitive to these inhibiting compounds than mesophilic processes. The results of this study suggest that reducing PPs and EO concentrations in blends subject to anaerobic digestion below the inhibiting concentrations of 0.6 g L–1 and 0.5 g kg–1, respectively, is suitable. Additionally, it is advisable to maintain the volatile fatty acids content below 2 g L–1 to avoid its evident toxic effects on the growth of microorganisms in biochemical processes.

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