Swine manure biogas production improvement using pre-treatment strategies: lab-scale studies and full-scale application

We tested at full-scale the innovative Focused Pulsed (FP) technology for pre-treating waste sludge in order to improve methane gas production and biosolids reduction in sludge digestion, but without incurring problems of odors, toxicity, and high costs for chemical or energy consumption. FP pre-treatment of a mixture of primary and secondary sludge increased the soluble COD by 160% and DOC 120% over the control. FP pre-treatment of 63% of the input waste sludge increased biogas production by over 40% and reduced biosolids requiring disposal by 30% when compared to the plant baseline. FP pre-treatment also correlated with a shift of the bacterial and archaeal communities. The most significant change was that the acetate-cleaving Methanosaeta became the dominant methanogen. Full FP pre-treatment should increase biogas production and biosolids removal by 60% and 40%, respectively. Full FP pre-treatment should generate energy benefits of at least 2.7 times and as high as 18 times the FP energy input, depending on heat recovery from FP treatment. For a plant treating 76,000 m3/d of wastewater (380 m3-sludge/d), FP treatment should generate an annual economic benefit of approximately $540,000 net of electricity and other operating and maintenance costs. This represents a payback period of three years or less.

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Integrated biological and electro-chemical treatment of swine manure

Water Science & Technology ◽

10.2166/wst.2004.0784 ◽

2004 ◽

Vol 49 (5-6) ◽

pp. 427-434 ◽

Cited By ~ 7

Author(s):

K.J. Chae ◽

S.K. Yim ◽

K.H. Choi ◽

S.K. Kim ◽

W.K. Park

Keyword(s):

Electrochemical Oxidation ◽

Chemical Treatment ◽

Biogas Production ◽

Swine Manure ◽

Chemical Oxidation ◽

Ammonia Nitrogen ◽

Full Scale ◽

Experimental Conditions ◽

Potential Capacity ◽

Simultaneous Elimination

A full-scale biogas plant was applied to the processing of 10m3/d of swine manure. The plant consisted of an anaerobic digester and an engine-generator. The digester operation resulted in an 81% of COD removal, a 55% of VS reduction, and methane-rich biogas production that is used to generate electrical and thermal energies. To further treat the digested manure, for compliance with discharge limits, an electro-chemical oxidation with a dimensionally sable anode was investigated for the simultaneous elimination of both the remaining COD and ammonia nitrogen. It was able to reduce NH4+-N levels from as high as 1552 down to 25 mg/L in 160 min, and the COD from 1542 to 0.21 mg/L under the experimental conditions of 8 V, 30 A and 20000 μS/cm. The amount of electricity required for a 90% removal of the residual COD and ammonia in 1 m3 of filtered digester manure, via electrochemical oxidation, were approximately 153 and 151 kWh, respectively. These values exceed the maximum potential capacity of the biogas-originated electricity through the digestion of swine manure containing normal VS content. However, approximately 50% of the required electricity for the electrochemical oxidation could be supplied from the engine-generator.

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Full-stream and part-stream ultrasound treatment effect on sludge anaerobic digestion

Water Science & Technology ◽

10.2166/wst.2010.893 ◽

2010 ◽

Vol 61 (6) ◽

pp. 1363-1372 ◽

Cited By ~ 23

Author(s):

S. I. Pérez-Elvira ◽

L. C. Ferreira ◽

A. Donoso-Bravo ◽

M. Fdz-Polanco ◽

F. Fdz-Polanco

Keyword(s):

Anaerobic Digestion ◽

Biogas Production ◽

Full Scale ◽

Optimum Process ◽

Capillary Suction ◽

Biogas Yield ◽

Batch Tests ◽

Secondary Sludge ◽

Pre Treatment ◽

The Relationship

The use of ultrasound as pre-treatment to improve anaerobic digestion of secondary sludge has been established as a promising technology. There are great differences between lab scale and full-scale devices, regarding the relationship between the disintegration achieved and the energy supplied. Based on economic aspects, most of the full-scale plants use partial-stream instead of the full-stream sonication, which affects biogas production and digestate dewatering characteristics. A laboratory scale operation combining ultrasound and anaerobic digestion (batch tests) has been performed, determining the relationship between the ratio of sonicated sludge fed and the methane production, SCOD removal and capillary suction time after 20-day anaerobic biodegradation, in order to check the possible benefits of part-stream versus full-stream sonication. Additional incubation was also evaluated, searching for an optimum process combining ultrasound and 24-h incubation pretreatment. Results showed that by sonicating fresh WAS at 25,700 kJ/kg TS biogas yield increased linearly with the percentage of sonicated WAS in the substrate, from 248 (control reactor) to 349 mL CH4/g VS (41% increase in full-stream sonication). By incubation (24 h, 55°C), 325 mL CH4/g VS were obtained (31% increase), but the digestion of the soluble compounds generated during incubation of sonicated sludge appeared to be less degradable compared to those solubilised by ultrasound or incubation alone, which showed no benefit in combining both treatments. Post-digestion dewatering deteriorated for both part-stream and full-stream sonication, and CST values were constant (74% higher than the control digestate) from 30% to 100% sonicated sludge.

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Alkali pre-treatment of Sorghum Moench for biogas production

Chemical Papers ◽

10.2478/s11696-012-0298-0 ◽

2013 ◽

Vol 67 (9) ◽

Cited By ~ 12

Author(s):

Karina Michalska ◽

Stanisław Ledakowicz

Keyword(s):

Anaerobic Digestion ◽

Chemical Oxygen Demand ◽

Volatile Fatty Acids ◽

Biogas Production ◽

Oxygen Demand ◽

Total Phenolic ◽

Methane Generation ◽

Pre Treatment ◽

Alkali Hydrolysis ◽

Almost All

AbstractThis work studies the influence of the alkali pre-treatment of Sorghum Moench — a representative of energy crops used in biogas production. Solutions containing various concentrations of sodium hydroxide were used to achieve the highest degradation of lignocellulosic structures. The results obtained after chemical pre-treatment indicate that the use of NaOH leads to the removal of almost all lignin (over 99 % in the case of 5 mass % NaOH) from the biomass, which is a prerequisite for efficient anaerobic digestion. Several parameters, such as chemical oxygen demand, total organic carbon, total phenolic content, volatile fatty acids, and general nitrogen were determined in the hydrolysates thus obtained in order to define the most favourable conditions. The best results were obtained for the Sorghum treated with 5 mass % NaOH at 121°C for 30 min The hydrolysate thus achieved consisted of high total phenolic compounds concentration (ca. 4.7 g L−1) and chemical oxygen demand value (ca. 45 g L−1). Although single alkali hydrolysis causes total degradation of glucose, a combined chemical and enzymatic pre-treatment of Sorghum leads to the release of large amounts of this monosaccharide into the supernatant. This indicates that alkali pre-treatment does not lead to complete cellulose destruction. The high degradation of lignin structure in the first step of the pre-treatment rendered the remainder of the biomass available for enzymatic action. A comparison of the efficiency of biogas production from untreated Sorghum and Sorghum treated with the use of NaOH and enzymes shows that chemical hydrolysis improves the anaerobic digestion effectiveness and the combined pre-treatment could have great potential for methane generation.

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Enhanced biogas production and performance assessment of a full-scale anaerobic digester with acid phase digestion

International Biodeterioration & Biodegradation ◽

10.1016/j.ibiod.2017.04.001 ◽

2017 ◽

Vol 124 ◽

pp. 162-168 ◽

Cited By ~ 5

Author(s):

Long D. Nghiem ◽

Richard Wickham ◽

Dieudonne-Guy Ohandja

Keyword(s):

Performance Assessment ◽

Biogas Production ◽

Anaerobic Digester ◽

Full Scale ◽

And Performance

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Dynamic Behavior of Intermittent Buried Filters

Water Science & Technology ◽

10.2166/wst.1993.0213 ◽

1993 ◽

Vol 28 (10) ◽

pp. 99-107 ◽

Cited By ~ 22

Author(s):

M. Boiler ◽

A. Schwager ◽

J. Eugster ◽

V. Mottier

Keyword(s):

Filter Material ◽

Full Scale ◽

Septic Tank ◽

Retention Capacity ◽

Unsaturated Media ◽

Coarse Filter ◽

High Ammonia ◽

The Media ◽

Pre Treatment ◽

Optimized Conditions

Buried filters were investigated experimentally in pilot and full scale as typical on-site treatment for small wastewater flows. The filters were operated by intermittent flushing which causes the water and the pollutant transport through the unsaturated media to be of a highly dynamic nature. Water transport and tracer studies at low and high hydraulic flush loads revealed frequent flushing at low loads to be superior to less frequent flushing at high loads for treatment of the same daily amount of wastewater. These findings were confirmed in a full scale plant through monitoring of the dynamic washout of unoxidized matter in terms of COD and NH4+ after application of different hydraulic loads. The moisture retention capacity of the filter media correlated to the grain size distribution was found to be an important parameter. COD-removal and nitrification rates depend strongly on the oxygen supply to the media. In general, the oxygen diffusion into the media and the air exchange, induced by intermittent flushing, are sufficient. However, when applying relatively large hydraulic loads and coarse filter grains, especially in the range above 1 mm, buried filters tend to larger breakthroughs of unoxidized matter due to short retention times and instantaneous lack of oxygen. Experiments on average treatment performance were carried out and showed that under optimized conditions even wastewaters containing relatively high ammonia contents (150 gNH4+-N/m3) can be fully nitrified when limestone type filter material is used. Full scale operation revealed further that careful pre-treatment (e.g. septic tank) for the removal of most of the suspended solids is necessary to guarantee safe operation.

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