scholarly journals Two-phase thermophilic anaerobic digestion process for biohythane production treating biowaste: preliminary results

2011 ◽  
Vol 64 (3) ◽  
pp. 715-721 ◽  
Author(s):  
C. Cavinato ◽  
D. Bolzonella ◽  
F. Fatone ◽  
A. Giuliano ◽  
P. Pavan
Keyword(s):  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Biogas Production ◽  
Pilot Scale ◽  
Organic Loading Rate ◽  
Gas Composition ◽  
Two Phase ◽  
Thermophilic Anaerobic Digestion ◽  
Working Volume ◽  
And Control

This paper deals with the optimization of a two-phase anaerobic process treating biowaste for hydrogen and methane production. Neither physical nor chemical pre-treatments were used to optimize the process. The work was carried out at pilot scale, using two CSTRs (200 and 380 L working volume respectively) both maintained at thermophilic temperature (55 °C) and fed semi-continuously with biowaste. The experiment was divided into three periods; during the first two periods the organic loading rate was maintained at 20 kg TVS/m3 d and the hydraulic retention time was changed from 6.6 to 3.3 days, while in the last period the digestate of the second reactor was recirculated to the first reactor in order to buffer the system and control pH at levels around 5. The HRT was maintained at 3.3 days and the OLR was decreased at 16.5 kg TVS/m3 d. The best yield was obtained in the last period where a specific hydrogen production of 50.9 L/kg VSfed was reached, with a H2 content in biogas from the first reactor of 36%. The methanogenic stage after the hydrogen conversion reached a specific biogas production of 0.62 m3/kg VSfed and an overall organic removal above 70%, without any stability problem. The overall biogas production was some 1.5 m3 per day with a gas composition of 10% H2 and 50% CH4.

Biomass dewaterability, filterability and settleability in a membrane bioreactor operated with different sludge ages

2007 ◽  
Vol 2 (1) ◽  
Author(s):  
P. Pavan ◽  
C. Cavinato ◽  
D. Bolzonella ◽  
F. Fatone ◽  
F. Cecchi
Keyword(s):  
Activated Sludge ◽  
Single Phase ◽  
Loading Rate ◽  
Pilot Scale ◽  
Critical Conditions ◽  
Organic Loading Rate ◽  
Two Phase ◽  
Anaerobic Digesters ◽  
Working Volume ◽  
The Stability

The results of 2 years experiments on thermophilic single and two-phase anaerobic co-digestion process on activated sludge and agro-wastes are presented. Solid agro-waste (mainly fruit and vegetable residuals from markets) and waste activated sludge were used as substrates. A pilot scale CSTR of 200 l working volume was used for single phase test, while an 0.8 m3 digester was added to study two-phase experiments. Treating only wasted sludge, the initial organic loading rate (OLR) was 0.7kgTVS/m3 d; then it was increased up to 2, 4 and 6 kgTVS/m3 d by OFMSW addition. Following OFMSW increase in the feed, it was found out the increase of GPR from 0.12 to 3.12 m3/m3 d and SGP from 0.16 to 0.51 m3/kgTVS in single phase. The stability of the process was showed also in the most critical operative conditions. Two phase experiments didn't show important differences to the single phase test in the range of OLRs studied up to now (up to 4 kgTVS/m3 d), clearly showing that these are not critical conditions for the process, that can be carried out in single phase in all the range studied. Considering the option of retrofitting the anaerobic digesters of the existing sludge line in WWTPs, the obtained data give important indications about process feasibility.

scholarly journals Effect of Hydraulic Retention Time on Biogas Production from Cow Dung in A Semi Continuous Anaerobic Digester

2018 ◽  
Vol 7 (2) ◽  
pp. 93-100 ◽  
Author(s):  
Agus Haryanto ◽  
Sugeng Triyono ◽  
Nugroho Hargo Wicaksono
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Biogas Production ◽  
Stable Condition ◽  
Anaerobic Digester ◽  
Organic Loading Rate ◽  
Cow Dung ◽  
Biogas Yield ◽  
Average Analysis

The efficiency of biogas production in semi-continuous anaerobic digester is influenced by several factors, among other is loading rate. This research aimed at determining the effect of hydraulic retention time (HRT) on the biogas yield. Experiment was conducted using lab scale self-designed anaerobic digester of 36-L capacity with substrate of a mixture of fresh cow dung and water at a ratio of 1:1. Experiment was run with substrate initial amount of 25 L and five treatment variations of HRT, namely 1.31 gVS/L/d (P1), 2.47 gVS/L/d (P2), 3.82 gVS/L/d (P3), 5.35 gVS/L/d (P4) and 6.67 gVS/L/d (P5). Digester performance including pH, temperature, and biogas yield was measured every day. After stable condition was achieved, biogas composition was analyzed using a gas chromatograph. A 10-day moving average analysis of biogas production was performed to compare biogas yield of each treatment. Results showed that digesters run quite well with average pH of 6.8-7.0 and average daily temperature 28.7-29.1. The best biogas productivity (77.32 L/kg VSremoval) was found in P1 treatment (organic loading rate of 1.31 g/L/d) with biogas yield of 7.23 L/d. With methane content of 57.23% treatment P1 also produce the highest methane yield. Biogas production showed a stable rate after the day of 44. Modified Gompertz kinetic equation is suitable to model daily biogas yield as a function of digestion time.Article History: Received March 24th 2018; Received in revised form June 2nd 2018; Accepted June 16th 2018; Available onlineHow to Cite This Article: Haryanto, A., Triyono, S., and Wicaksono, N.H. (2018) Effect of Loading Rate on Biogas Production from Cow Dung in A Semi Continuous Anaerobic Digester. Int. Journal of Renewable Energy Development, 7(2), 93-100.https://doi.org/10.14710/ijred.7.2.93-100

scholarly journals The feasibility of trace element supplementation for stable operation of wheat stillage-fed biogas tank reactors

2011 ◽  
Vol 64 (2) ◽  
pp. 320-325 ◽  
Author(s):  
J. Gustavsson ◽  
B. H. Svensson ◽  
A. Karlsson
Keyword(s):  
Trace Element ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Biogas Production ◽  
Organic Loading Rate ◽  
Stable Operation ◽  
Organic Loading ◽  
Process Stability ◽  
Volatile Solids ◽  
High Sulfate

The aim of this study was to investigate the effect of trace element supplementation on operation of wheat stillage-fed biogas tank reactors. The stillage used was a residue from bio-ethanol production, containing high levels of sulfate. In biogas production, high sulfate content has been associated with poor process stability in terms of low methane production and accumulation of process intermediates. However, the results of the present study show that this problem can be overcome by trace element supplementations. Four lab-scale wheat stillage-fed biogas tank reactors were operated for 345 days at a hydraulic retention time of 20 days (37 °C). It was concluded that daily supplementation with Co (0.5 mg L−1), Ni (0.2 mg L−1) and Fe (0.5 g L−1) were required for maintaining process stability at the organic loading rate of 4.0 g volatile solids L−1 day−1.

Anaerobic treatment of a medium strength industrial wastewater at low-temperature and short hydraulic retention time: a pilot-scale experience

2011 ◽  
Vol 64 (8) ◽  
pp. 1629-1635 ◽  
Author(s):  
M. Esparza Soto ◽  
C. Solís Morelos ◽  
J. J. Hernández Torres
Keyword(s):  
Low Temperature ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Pilot Scale ◽  
Anaerobic Treatment ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Processing Industry ◽  
Industry Wastewater

The aim of this work was to evaluate the performance of a pilot-scale upflow anaerobic sludge blanket (UASB) reactor during the treatment of cereal-processing industry wastewater under low-temperature conditions (17 °C) for more than 300 days. The applied organic loading rate (OLRappl) was gradually increased from 4 to 6 and 8 kg CODsol/m3d by increasing the influent soluble chemical oxygen demand (CODsol), while keeping the hydraulic retention time constant (5.2 h). The removal efficiency was high (82 to 92%) and slightly decreased after increasing the influent CODsol and the OLRappl. The highest removed organic loading rate (OLRrem) was reached when the UASB reactor was operated at 8 kg CODsol/m3d and it was two times higher than that obtained for an OLRappl of 4 kg CODsol/m3d. Some disturbances were observed during the experimentation. The formation of biogas pockets in the sludge bed significantly complicated the biogas production quantification, but did not affect the reactor performance. The volatile fatty acids in the effluent were low, but increased as the OLRappl increased, which caused an increment of the effluent CODsol. Anaerobic treatment at low temperature was a good option for the biological pre-treatment of cereal processing industry wastewater.

scholarly journals Efficient high strength petrochemical wastewater treatment in a hybrid vertical anaerobic biofilm (HyVAB) reactor: a pilot study

2017 ◽  
Vol 12 (3) ◽  
pp. 501-513 ◽  
Author(s):  
Shuai. Wang ◽  
Nirmal. Ghimire ◽  
Gang. Xin ◽  
Eshetu. Janka ◽  
Rune. Bakke
Keyword(s):  
Wastewater Treatment ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
High Strength ◽  
Pilot Scale ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Organic Loading ◽  
Petrochemical Wastewater ◽  
Step Flow

Performance of a pilot scale Hybrid Vertical Anaerobic Biofilm (HyVAB) reactor treating petrochemical refinery wastewater is presented here. The reactor is an integration of a bottom anaerobic sludge bed and a top aerobic biofilm stage and was operated continuously for 92 days at 21 ± 2 °C. Wastewater was fed continuously to the reactor with step flow increases reducing hydraulic retention time from 55 to 12 hours, increasing organic loading rate from 3 to 33 kg-COD/m3·d. The HyVAB removed on average 91% and 86% of the soluble and total feed COD, respectively, at steady state and loads up to 23 kg-COD/m3·d, of which 98% of the soluble COD removal occurred in the anaerobic stage. Methane yield ranged from 0.29 to 0.51 L/g-COD removed, including conversion of settled aerobic sludge to methane. Sludge production was low (0.04 kg-VSS/kg-COD removed) and biogas methane content high (84 ± 2%). The results demonstrated that HyVAB is an efficient, low footprint alternative for high strength wastewater treatment.

scholarly journals Enzymatic Pretreatment of Byproducts from Soapstock Splitting and Glycerol Processing for Improvement of Biogas Production

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6782
Author(s):  
Sebastian Borowski ◽  
Weronika Cieciura-Włoch
Keyword(s):  
Loading Rate ◽  
Biogas Production ◽  
Organic Loading Rate ◽  
Sulfide Concentration ◽  
Organic Loading ◽  
High Concentration ◽  
Enzymatic Pretreatment ◽  
Thermophilic Anaerobic Digestion ◽  
Commercial Enzymes ◽  
Wet Weight

This study investigated acid splitting wastewater (ASW) and interphase (IF) from soapstock splitting, as well as matter organic non glycerol (MONG) from glycerol processing, as potential substrates for biogas production. Batch and semicontinuous thermophilic anaerobic digestion experiments were conducted, and the substrates were preliminary treated using commercial enzymes kindly delivered by Novozymes A/C. The greatest enhancement in the batch digestion efficiency was achieved when three preparations; EversaTransform, NovoShape, and Lecitase were applied in the hydrolysis stage, which resulted in the maximum methane yields of 937 NL/kg VS and 915 NL/kg VS obtained from IF and MONG, respectively. The co-digestion of 68% ASW, 16% IF, and 16% MONG (wet weight basis) performed at an organic loading rate (OLR) of 1.5 kg VS/m3/day provided an average methane yield of 515 NLCH4/kg VSadded and a volatile solid reduction of nearly 95%. A relatively high concentration of sulfates in the feed did not significantly affect the digestion performance but resulted in an increased hydrogen sulfide concentration in the biogas with the peak of 4000 ppm.

scholarly journals Effect of Hydraulic Retention Time (HRT) and Organic Loading Rate (OLR) to the Nata de coco Anaerobic Treatment Eficiency and its Wastewater Characteristics

2018 ◽  
Vol 38 (2) ◽  
pp. 160 ◽  
Author(s):  
Istna Nafi Azzahrani ◽  
Fanny Arivia Davanti ◽  
Ria Millati ◽  
Muhammad Nur Cahyanto
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Anaerobic Treatment ◽  
Organic Content ◽  
Anaerobic Digester ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Working Volume ◽  
Standard Rate

In this study, experiments were conducted to investigate the effect of hydraulic retention time (HRT) and organic loading rate (OLR) on process stability of nata de coco wastewater anaerobic treatment using semi-continuous digester. The standard-rate anaerobic digester with working volume of 8.5 L was used to investigate the effect of three different hydraulic retention times (15, 20, and 25 days), and a standard-rate anaerobic digester with working volume of 9.1 L was operated at different organic loading rates of 0.5, 1, and 1.5 g/L/day. The findings revealed that minimum HRT for nata de coco wastewater anaerobic treatment using semi-continuous digester was achieved at HRT 20 days. Based on data from this study, the reduction of organic content in nata de coco wastewater increased when OLR increased until 1 g/L/day. But then those parameters value decreased when OLR being increased further to 1.5 g/L/day. It showed that at 1.5 g/L/day the amount of substrate fed to the system was exceeding the total degradation capacity of methanogenic microorganisms, hence the organic overload happened and decreased the efficiency of organic content reduction in anaerobic treatment of nata de coco wastewater.

scholarly journals Effect of Semi-Continuous Anaerobic Digestion on the Substrate Solubilisation of Lignin-Rich Steam-Exploded Ludwigia grandiflora

2021 ◽  
Vol 11 (10) ◽  
pp. 4452
Author(s):  
Pranshu Bhatia ◽  
Masaaki Fujiwara ◽  
Maria Cecilia D. Salangsang ◽  
Jun Qian ◽  
Xin Liu ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Steam Explosion ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Biogas Production ◽  
Organic Loading Rate ◽  
Biogas Yield ◽  
Steam Explosion Pretreatment ◽  
The Stability ◽  
Ludwigia Grandiflora

In this study, semi-continuous anaerobic digestion of lignin-rich steam-exploded Ludwigia grandiflora (Lignin = 25.22% ± 4.6% total solids) was performed to understand better the effect of steam explosion on the substrate solubilisation and inhibitors formation during the process. Steam explosion pretreatment was performed at 180 °C for 30 min at a severity factor of 3.8 to enhance the biogas yield of the lignocellulosic biomass. The semi-continuous anaerobic digestion was performed in a continuously stirred tank reactor for 98 days at an initial hydraulic retention time of 30 days and an organic loading rate of 0.9 g-VS L−1day−1. The performed steam explosion pretreatment caused biomass solubilisation, resulting in enhanced biogas production during the process. During the anaerobic digestion process, the average biogas yield was 265 mL g-VS−1, and the pH throughout the operation was in the optimum range of 6.5–8.2. Due to fluctuations in the biogas yield, the hydraulic retention time and organic loading rate were changed on day 42 (50 days and 0.5 g-VS L−1day−1) and on day 49 (40 days and 0.7 g-VS L−1day−1), and 1 M of NaOH was added to the liquid fraction of the steam-exploded L. grandiflora during the latter part of the operation to maintain the stability in the reactor. Therefore, the steam explosion pretreatment helped in the degradation of L. grandiflora by breaking the lignocellulose structure. In addition, changes in the operating conditions of the anaerobic digestion led to an increase in the biogas production towards the end of the process, leading to the stability in the CSTR.

Enhanced Treatment of CSTR Anaerobic Digested Effluent from Poultry Wastewater by IC Reactor

2012 ◽  
Vol 433-440 ◽  
pp. 1239-1244
Author(s):  
Zhan Guang Liu ◽  
Xue Fei Zhou ◽  
Ya Lei Zhang ◽  
Hong Guang Zhu
Keyword(s):  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Biogas Production ◽  
Granular Sludge ◽  
Anaerobic Treatment ◽  
Controlling Factors ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Internal Circulation ◽  
Poultry Wastewater

The feasibility of applying internal circulation (IC) reactor anaerobic treatment for effluent from a CSTR plant treating poultry wastewater was examined and the key controlling factors were explored. A continuous-flow IC reactor of 12.3L capacity inoculated with anaerobic granular sludge was operated for 98 days at 35±1°C. With corresponding organic loading rate of 1.5-3.5 kgCOD/m3•d at hydraulic retention time of 1.5d, the maximum volumetric biogas production rate of 1.2 m3/m3•d and tCOD (total COD) removal efficiency in the range of 70-80% was achieved. Therefore, IC reactor is competent to treat CSTR effluent from poultry wastewater. The decrease of sCOD (soluble COD) relative to tCOD and ammonia inhibition may lead to deterioration of IC reactor anaerobic treatment.

scholarly journals EFFECT OF ORGANIC LOADING RATE ON THE PERFORMANCE OF ANAEROBIC CO-DIGESTION DIGESTER TREATING FOOD WASTE AND SLUDGE WASTE

2018 ◽  
Vol 56 (2A) ◽  
pp. 37-42
Author(s):  
Dinh Thi Nga
Keyword(s):  
Production Rate ◽  
Food Waste ◽  
Loading Rate ◽  
Biogas Production ◽  
Methane Yield ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Working Volume ◽  
Sludge Waste ◽  
Biogas Production Rate

This research was carried out to evaluate the effect of organic loading rate to the performance of anaerobic co-digestion digester treating organic fraction of food waste (FW) and sludge waste (SW) from wastewater treatment plant. The experiment was conducted in two runs: Run S50, substrate contained 50 % of FW and 50 % of SW in term of volatile solid (VS) concentration; Run S100 (control run) contained 100 % SW in the influent substrate. The experiment was performed in a 3L working volume reactor at ambient temperature with three levels of organic loading rate (OLR) as 2; 4; 6 kgVS/m3/day, the duration of experiment was 18 days for each level of OLR. As results, the average of biogas production rate (BPR) at OLR 2;4;6 kgVS/m3/day,in Run S50 and Run S100 was 390 – 520;  860 – 1220; 1140 - 2440 ml/day and 160 – 300; 560 – 640; 700 - 1400 ml/day, respectively. The maximum methane yield (mlCH4/gVSadded/day) of organic loading rate 2; 4; 6 kgVS/m3/day was 118.96; 326.49; 628.20 for Run S50 and; 58.28; 160.27; 255.54 for Run S100, respectively. In conclusion, Run S50 always produced higher biogas production rate and higher methane yield at all 3 OLR levels. The higer OLR could enhance BPR and methane yield but at OLR 6 kgVS/m3/day made unstable performance and high concentration of COD in the effluent. Therefore, in this experimental conditions it has better operation at OLR under 6 kgVS/m3/day for the stable performance of reactors.

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