scholarly journals Increase of biogas production through co-digestion of lipids and sewage sludge

2013 ◽  
Vol 14 (2) ◽  
pp. 133-140
Keyword(s):  
Sewage Sludge ◽  
Biogas Production ◽  
Daily Basis ◽  
Lag Phase ◽  
Digested Sludge ◽  
Anaerobic Digesters ◽  
Experimental Systems ◽  
Start Up ◽  
Acetogenic Bacteria ◽  
Time Required

The aim of this study was to assess the feasibility of co-digesting lipids originated from domestic wastewater along with sewage sludge. Three lab-scale single stage mesophilic anaerobic digesters were operated under a constant hydraulic retention time (15 days). One system (C) was fed on a daily basis with sewage sludge and served as the control system and its operation was compared with two experimental systems (E1 and E2). Both experimental systems received mixtures of sludge and lipids with different lipids content (20 % for system E1 and 60 % for system E2 on a VS basis), whereas organic loadings were 2 KgVS m-3 d-1 and 3,5 KgVS m-3 d-1 for systems E1 and E2, respectively. According to the results it can be stated that the addition of lipids to sewage sludge up to 60 % on a VS basis resulted in a significant increase of biogas production without producing any severe effects on the properties of the digested sludge. More specifically biogas production of reactor E1 was 18 % greater than that of reactor C, whereas biogas produced in reactor E2 was even greater (50 % higher than that of reactor C). Finally it is interesting that during start-up a lag phase was recorded at reactor E2 before biogas production initiated, which should be attributed to the time required for growth of acetogenic bacteria capable to degrade LCFA.

scholarly journals Comparison of Household and Communal Biogas Digester Performance to Treat Kitchen Waste, Case Study: Bandung City, Indonesia

2018 ◽  
Vol 73 ◽  
pp. 01019
Author(s):  
Elisabeth Rianawati ◽  
Enri Damanhuri ◽  
Marisa Handajani ◽  
Tri Padmi
Keyword(s):  
Organic Waste ◽  
Open Space ◽  
Biogas Production ◽  
Daily Basis ◽  
Kitchen Waste ◽  
Anaerobic Digesters ◽  
Disposal Area ◽  
Input And Output ◽  
Biogas Productivity

Bandung City is one of the big cities in Indonesia that grappled with waste problem. There is 1,500 ton of waste produced daily, of which 65% is organic. In addition, the water content of the waste could reach 80% during rainy season, given that the waste is commonly collected in open space before transported to the final disposal area. In order to tackle this issue, the municipality of Bandung has started to implement anaerobic digesters to treat kitchen waste since 2013 in an attempt to reduce organic waste. There are three scales of bio-digesters that have been implemented: city 2 ton, communal (20-1000 kg) and household scale (20 kg), which comprise of 1 unit, 15 units and 100 units respectively. This study evaluate the efficiency and biogas productivity of each bio-digesters type. We analyzed 30 unit and 14 unit of household and communal biodigesters respectively. The waste input, slurry output and biogas production were estimated based on average of daily basis. Both the input and output of the biodigesters were characterized (TS, VS, COD) to gain further understanding. This study provide facts and figures to improve the further implementation of household bio-digesters in Bandung City.

scholarly journals MBR-Assisted VFAs Production from Excess Sewage Sludge and Food Waste Slurry for Sustainable Wastewater Treatment

2020 ◽  
Vol 10 (8) ◽  
pp. 2921 ◽  
Author(s):  
Mohsen Parchami ◽  
Steven Wainaina ◽  
Amir Mahboubi ◽  
David I’Ons ◽  
Mohammad J. Taherzadeh
Keyword(s):  
Wastewater Treatment ◽  
Sewage Sludge ◽  
Food Waste ◽  
Volatile Fatty Acids ◽  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Economic Assessment ◽  
Ph Control ◽  
Daily Basis ◽  
Solids Concentration

The significant amount of excess sewage sludge (ESS) generated on a daily basis by wastewater treatment plants (WWTPs) is mainly subjected to biogas production, as for other organic waste streams such as food waste slurry (FWS). However, these organic wastes can be further valorized by production of volatile fatty acids (VFAs) that have various applications such as the application as an external carbon source for the denitrification stage at a WWTP. In this study, an immersed membrane bioreactor set-up was proposed for the stable production and in situ recovery of clarified VFAs from ESS and FWS. The VFAs yields from ESS and FWS reached 0.38 and 0.34 gVFA/gVSadded, respectively, during a three-month operation period without pH control. The average flux during the stable VFAs production phase with the ESS was 5.53 L/m2/h while 16.18 L/m2/h was attained with FWS. Moreover, minimal flux deterioration was observed even during operation at maximum suspended solids concentration of 32 g/L, implying that the membrane bioreactors could potentially guarantee the required volumetric productivities. In addition, the techno-economic assessment of retrofitting the membrane-assisted VFAs production process in an actual WWTP estimated savings of up to 140 €/h for replacing 300 kg/h of methanol with VFAs.

Evaluation of Two Upflow Anaerobic Digesters Purifying Industrial Wastewaters High in Organic Matter

1994 ◽  
Vol 29 (9) ◽  
pp. 225-229 ◽  
Author(s):  
Alan R. Howgrave-Graham ◽  
Helen A. Isherwood ◽  
F. Mike Wallis
Keyword(s):  
Pollutant Removal ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Feed Composition ◽  
Anaerobic Digesters ◽  
Start Up ◽  
Acetogenic Bacteria ◽  
Uasb Granules ◽  
Anaerobic Sludge Blanket ◽  
Microbial Morphotypes

Two full-scale anaerobic digesters, one a clarigester purifying a maize processing wastewater and the other with an upflow anaerobic sludge blanket (UASB) configuration treating brewery effluent, contained well settling, granular sludges efficient in pollutant removal. Due to differences in both digester design and feed composition, the sludges differed in activity and microbial population. The clarigester granules contained a diverse population with a multiformity of hydrolytic, acidogenic and acetogenic bacteria while the predominant methanogens, in order of significance, were Methanothrix and Methanosarcina. These granules did not reconstitute on re-start up following digester shutdown and possible reasons for this are discussed. The UASB granules contained a more uniform population with three major microbial morphotypes, the predominant methanogens being Methanothrix and, possibly, Methanobacterium. In this paper the differences in digester design, feed composition, sludge microbiology and process performance are discussed.

scholarly journals Effect of Solids Concentration on the Kinetic of Biogas Production from Goat Droppings

2020 ◽  
pp. 25-33
Author(s):  
K. Eden Luboya ◽  
Mélissa Kusisakana ◽  
W. Gaston Luhata ◽  
K. Balthazar Mukuna ◽  
M. Justine Monga ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Laboratory Scale ◽  
Anaerobic Digesters ◽  
Average Temperature ◽  
Solids Concentration ◽  
C 30 ◽  
Time Required ◽  
The Relationship ◽  
Plastic Containers

This experiment was conducted at the Bioenergy laboratory of Groupe de Génies Congolais (GGC) at the Université Loyola du Congo in Kinshasa, D.R.Congo. The experiment started on May 23, 2019 and ended on July 17, 2019. The study focused on the relationship between solids concentration and the kinetic of anaerobic digestion of goat droppings in the methanation process. The feedstock consisted of goat droppings waste made into slurry of four solids concentration (SC); A=50%, B=38%, C=30% and D=25%. Each SC was repeated three times. Feedstocks were inserted in laboratory scale anaerobic digesters constructed from 5L plastic containers. The results revealed clearly that the time required for the production of biogas depends on SCs. The ratio D (1/3), i.g. 75% of water and 25% of biomass produced the biogas in 3 weeks (±22 days) and the ratio A (1/1), 50% of water and 50% of biomass, in 7 weeks and a few days (±53 days). The ratio C (1/2), 66.6% of water in the mixture, provided the biogas in ± 26 days (approximately 4 weeks) and finally, it took ±30 days (4 weeks and a few days) for ratio B to produce biogas rich in CH4 (<50%). The equation f(x)= 1.1x + 1 can be used to predict the approximative number of days to produce a biogas containing more than 50% of CH4. The average temperature inside the reactors was found to be 28.5 ± 0.8°C during the combustion testing process implying that the reactors designed at the GGC were operating in a mesophilic regime. Finally, the pH of the digestates obtained from reactors had an average of 9.0 ± 0.2.

Start-up of a multi-stage system for biogas production and solid waste treatment in low-tech countries

2003 ◽  
Vol 48 (4) ◽  
pp. 239-243 ◽  
Author(s):  
E.M. Biey ◽  
E.D. Musibono ◽  
W. Verstraete
Keyword(s):  
Solid Waste ◽  
Waste Treatment ◽  
Biogas Production ◽  
Daily Basis ◽  
Methanogenic Activity ◽  
Multi Stage ◽  
Start Up ◽  
Solid Waste Treatment ◽  
Stage System ◽  
Biowaste Treatment

Vegetable fruit garden wastes were treated anaerobically using a multistage Dranco system. The digesters were composed of three 50 L vessels kept in mesophilic conditions. They were operating at 14.5-17% TS. By controlling the pH in the system, the start-up for biogas production was shortened to 60 days. The pH correction was a buffering which enhanced methanogenic activity in the digesters. With a loading rate of 4.1 kg VS/m3reactor.day, the production of biogas was 5 m3/m3reactor.day, and 60-70% methane content. This allowed making a multisystem by starting every 3 weeks with new vessels in order to maintain biogas production, to be used in industries or in local communities in low-tech countries. The designed model was started in Kinshasa (Congo) where a project is expected to treat one ton of solid waste on a daily basis, for a production of 100 m3 biogas. This cost effectiveness of the system is demonstrated and presents the opportunity for biowaste treatment coupled with environmental protection and substantial energy recovery.

The use of ultrasound to accelerate the anaerobic digestion of sewage sludge

1997 ◽  
Vol 36 (11) ◽  
pp. 121-128 ◽  
Author(s):  
A. Tiehm ◽  
K. Nickel ◽  
U. Neis
Keyword(s):  
Sewage Sludge ◽  
Residence Time ◽  
Continuous Fermentation ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Residence Times ◽  
Anaerobic Digesters ◽  
Rate Limiting Step ◽  
Volatile Solids ◽  
Sludge Hydrolysis

The slow degradation rate of sewage sludge in anaerobic digesters is due to the rate limiting step of sludge hydrolysis. The effect of ultrasound pretreatment on sludge degradability was investigated using ultrasound at a frequency of 31 kHz and high acoustic intensities. Ultrasound treatment resulted in raw sludge disintegration as was demonstrated by increase of Chemical Oxygen Demand in the sludge supernatant and size reduction of sludge solids. Semi-continuous fermentation experiments with disintegrated and untreated sludge were done for four months on a half-technical scale. One fermenter was operated as a control with a conventional residence time of 22 days. Four fermenters were operated with disintegrated sludge and residence times of 22, 16, 12, and 8 days, respectively. In the fermenters operated with identical residence times of 22 days reduction of volatile solids was 45.8% for untreated sludge and 50.3% for disintegrated sludge. The fermentation of disintegrated sludge was stable even at the shortest residence time of 8 days with biogas production 2.2 times that of the control fermenter. Due to ultrasound disintegration a better degradability of raw sludge was achieved that permitted a substantial increase in throughput.

scholarly journals Modelling the Kinetics of Biogas Production from Mesophilic Anaerobic Co-Digestion of Cow Dung with Plantain Peels

2015 ◽  
Vol 4 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Ganiyu Kayode Latinwo ◽  
Samuel Enahoro Agarry
Keyword(s):  
Biogas Production ◽  
Logistic Growth ◽  
Cow Dung ◽  
Anaerobic Digesters ◽  
Biogas Yield ◽  
Digestion Process ◽  
Start Up ◽  
Linear Plot ◽  
Logistic Growth Model ◽  
Kinetics Of

This work investigated the effect of plantain peels as co-substrate in the anaerobic digestion of cow dung for efficient and high biogas production. The biogas experiments were carried out in two different 5 L anaerobic digesters and incubated for 40 days at ambient mesophilic temperatures (28 oC to 34 °C). The results showed that co-digestion of cow dung with plantain peels as co-substrate reduced start-up time for biogas generation and increased biogas yield by 18% as compared to cow dung alone. Peak biogas production was obtained for both digesters at pH of 6.7 and 6.9 as well as temperature of 29 and 30oC, respectively. Modelling study revealed that exponential plot simulated better in both ascending and descending limb than the linear plot the biogas production rates in biogas production from cow dung co-digested with plantain peels and cow dung alone, respectively. Logistic growth model and modified Gompertz plot showed better correlation of cumulative biogas production than exponential rise to maximum plot. These results show that biogas production can be enhanced efficiently through co-digestion process.

Disintegration of excess activated sludge – evaluation and experience of full-scale applications

2006 ◽  
Vol 53 (12) ◽  
pp. 229-236 ◽  
Author(s):  
J. Zábranská ◽  
M. Dohányos ◽  
P. Jeníček ◽  
J. Kutil
Keyword(s):  
Organic Matter ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Activated Sludge ◽  
Biogas Production ◽  
Full Scale ◽  
Energy Yield ◽  
Operational Experience ◽  
Digested Sludge

Anaerobic digestion of sewage sludge can be improved by introducing a disintegration of excess activated sludge as a pretreatment process. The disintegration brings a deeper degradation of organic matter and less amount of output sludge for disposal, a higher production of biogas and consequently energy yield, in some cases suppression of digesters foaming and better dewaterability. The full-scale application of disintegration by a lysate-thickening centrifuge was monitored long term in three different WWTPs. The evaluation of contribution of disintegration to biogas production and digested sludge quality was assessed and operational experience is discussed. Increment of specific biogas production was evaluated in the range of 15–26%, organic matter in digested sludge significantly decreased to 48–49%. Results proved that the installation of a disintegrating centrifuge in WWTPs of different sizes and conditions would be useful and beneficial.

scholarly journals Thermal hydrolysis to enhance energetic potential of sewage sludge: A review

Paliva ◽  
2021 ◽  
pp. 59-68
Author(s):  
Anna Mágrová ◽  
Pavel Jeníček
Keyword(s):  
Sewage Sludge ◽  
Biogas Production ◽  
Treatment Plant ◽  
Multicriteria Analysis ◽  
Thermal Hydrolysis ◽  
Digested Sludge ◽  
Advantages And Disadvantages ◽  
Input Material ◽  
Hydrolysis Process

Sewage sludge biomass is a renewable energy source commonly produced by anaerobic digestion (AD). However, the limited biodegradability of sewage sludge causes a poor energy conversion of organic material into biogas and requires further enhancement. One possible solution is sludge disintegration by a thermal hydrolysis process (THP) that has already proven to enhance biogas production and improve the quality of digested sludge. This article reviews possible THP configurations, such as THP-AD, ITHP, and PAD-THP, together with different input materials and their impact on the energy balance of the wastewater treatment plant (WWTP). Data from full-scale THP demonstrate differences between the configurations and input material. Moreover, the general advantages and disadvantages of THP integration are summarized and presented as a multicriteria analysis that simplifies the decision-making whether the THP should be integrated in the WWTP.

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