scholarly journals Mild Thermal Pre-Treatment of Waste Activated Sludge to Increase Loading Capacity, Biogas Production, and Solids’ Degradation: A Pilot-Scale Study

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6059
Author(s):  
Adrian Gonzalez ◽  
Hongxiao Guo ◽  
Oscar Ortega-Ibáñez ◽  
Coert Petri ◽  
Jules B. van Lier ◽  
...  
Keyword(s):  
Extracellular Polymeric Substances ◽  
Biogas Production ◽  
Treatment Method ◽  
Pilot Scale ◽  
Organic Loading Rate ◽  
Wastewater Purification ◽  
Refractory Compounds ◽  
Volatile Solids ◽  
Methane Production Rate ◽  
Pre Treatment

Sludge pre-treatments are emerging as part of the disposal process of solid by-products of wastewater purification. One of their benefits is the increase in methane production rate and/or yield, along with higher loading capacities of existing digesters. In this study, we report the performance of a pilot-scale compartmentalized digester (volume of 18.6 m3) that utilized a mild thermal pre-treatment at 70 °C coupled with hydrogen peroxide dosing. Compared with a reference conventional anaerobic digester, this technique allowed an increased organic loading rate from 1.4 to 4.2 kg volatile solids (VS)/(m3d) and an increment in the solids degradation from 40 to 44%. To some extent, these improvements were promoted by the solubilization of the tightly-bound fraction of the extracellular polymeric substances to looser and more accessible fractions without the formation of refractory compounds. In sum, our results suggest that this pre-treatment method could increase the treatment capacity of existing digesters without significant retrofitting.

Enhanced sludge conditioning by enzyme pre-treatment: comparison of laboratory and pilot scale dewatering results

2006 ◽  
Vol 54 (5) ◽  
pp. 33-41 ◽  
Author(s):  
D. Dursun ◽  
M. Turkmen ◽  
M. Abu-Orf ◽  
S.K. Dentel
Keyword(s):  
Extracellular Polymeric Substances ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Solid Content ◽  
Filter Press ◽  
Treatment Comparison ◽  
Anaerobically Digested Sludge ◽  
Network Strength ◽  
Pre Treatment ◽  
Solids Content

The effect of enzyme pre-treatment on dewaterability of anaerobically digested sludge was investigated at both laboratory and pilot scale. Our results revealed a significant increase in cake solid content (27% cake solids compared to 18% without enzyme pre-treatment), using an enzyme dose of only 20 mg/L. In order to assess practical application, enzyme pre-treatment was applied at the Wilmington, Delaware (US) wastewater treatment plant, using a pilot-scale centrifuge. However, the efficiency reached in laboratory scale could not be obtained in pilot scale, where the final cake solids content did not exceed 20%. Centrifuge and belt filter press (simulated by Crown Press™) dewatering were compared in terms of the process efficiencies in the absence and presence of enzyme pre-treatment. Possible factors that might cause the differences were tested by experimental and statistical comparisons. Results indicated that the higher shear applied in centrifugation is responsible for the lack of improved cake solids. The network strength of sludge determined by rheological measurements revealed that enzymatic treatment weakens the gel structure of the sludge floc through the hydrolysis of extracellular polymeric substances; this allows improved dewatering by filtration processes, but leads to floc deterioration when subjected to high shear during centrifugation.

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.

scholarly journals Opportunity of Biogas Production from Solid Organic Wastes through Anaerobic Digestion

2018 ◽  
Vol 65 ◽  
pp. 05025 ◽  
Author(s):  
Sagor Kumar Pramanik ◽  
Fatihah Binti Suja ◽  
Biplob Kumar Pramanik ◽  
Shahrom Bindi Md Zain
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Nutrient Balance ◽  
Organic Wastes ◽  
Organic Loading Rate ◽  
Biogas Yield ◽  
Carbon And Nitrogen ◽  
Potential Risks ◽  
Nitrogen Ratio ◽  
Pre Treatment

Solid organic wastes create potential risks to environmental pollution and human health due to the uncontrolled discharge of huge quantities of hazardous wastes from numerous sources. Now-a-days, anaerobic digestion (AD) is considered as a verified and effective alternative compared to other techniques for treating solid organic waste. The paper reviewed the biological process and parameters involved in the AD along with the factors could enhance the AD process. Hydrolysis is considered as a rate-limiting phase in the complex AD process. The performance and stability of AD process is highly influenced by various operating parameters like temperature, pH, carbon and nitrogen ratio, retention time, and organic loading rate. Different pre-treatment (e.g. mechanical, chemical and biological) could enhance the AD process and the biogas yield. Co-digestion can also be used to provide suitable nutrient balance inside the digester. Challenges of the anaerobic digestion for biogas production are also discussed.

scholarly journals Improving Biomethanation of Chicken Manure by Co-Digestion with Ethanol Plant Effluent

2019 ◽  
Vol 16 (24) ◽  
pp. 5023 ◽  
Author(s):  
Dae-Yeol Cheong ◽  
Jeffrey Todd Harvey ◽  
Jinsu Kim ◽  
Changsoo Lee
Keyword(s):  
Loading Rate ◽  
Chicken Manure ◽  
Continuous Reactor ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Methanogenic Activity ◽  
Volatile Solids ◽  
Methane Production Rate ◽  
Specific Methanogenic Activity ◽  
Ethanol Plant

As the global production of chicken manure has steadily increased, its proper management has become a challenging issue. This study examined process effluent from a bioethanol plant as a co-substrate for efficient anaerobic digestion of chicken manure. An anaerobic continuous reactor was operated in mono- and co-digestion modes by adding increasing amounts of the ethanol plant effluent (0%, 10%, and 20% (v/v) of chicken manure). Methanogenic performance improved significantly in terms of both methane production rate and yield (by up to 66% and 36%, respectively), with an increase in organic loading rate over the experimental phases. Correspondingly, the specific methanogenic activity was significantly higher in the co-digestion sludge than in the mono-digestion sludge. The reactor did not suffer any apparent process imbalance, ammonia inhibition, or nutrient limitation throughout the experiment, with the removal of volatile solids being stably maintained (56.3–58.9%). The amount of ethanol plant effluent appears to directly affect the rate of acidification, and its addition at ≥20% (v/v) to chicken manure needs to be avoided to maintain a stable pH. The overall results suggest that anerobic co-digestion with ethanol plant effluent may provide a practical means for the stable treatment and valorization of chicken manure.

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.

Ultrasound pre-treatment for anaerobic digestion improvement

2009 ◽  
Vol 60 (6) ◽  
pp. 1525-1532 ◽  
Author(s):  
S. Pérez-Elvira ◽  
M. Fdz-Polanco ◽  
F. I. Plaza ◽  
G. Garralón ◽  
F. Fdz-Polanco
Keyword(s):  
Anaerobic Digestion ◽  
Energy Balance ◽  
Specific Energy ◽  
Biogas Production ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Net Generation ◽  
Batch Reactors ◽  
Anaerobic Reactors ◽  
Pre Treatment

Prior research indicates that ultrasounds can be used in batch reactors as pre-treatment before anaerobic digestion, but the specific energy required at laboratory-scale is too high. This work evaluates both the continuous ultrasound device performance (efficiency and solubilisation) and the operation of anaerobic digesters continuously fed with sonicated sludge, and presents energy balance considerations. The results of sludge solubilisation after the sonication treatment indicate that, applying identical specific energy, it is better to increase the power than the residence time. Working with secondary sludge, batch biodegradability tests show that by applying 30 kWh/m3 of sludge, it is possible to increase biogas production by 42%. Data from continuous pilot-scale anaerobic reactors (V=100 L) indicate that operating with a conventional HRT = 20 d, a reactor fed with pre-treated sludge increases the volatile solids removal and the biogas production by 25 and 37% respectively. Operating with HRT = 15 d, the removal efficiency is similar to the obtained with a reactor fed with non-hydrolysed sludge at HTR = 20 d, although the specific biogas productivity per volume of reactor is higher for the pretreated sludge. Regarding the energy balance, although for laboratory-scale devices it is negative, full-scale suppliers state a net generation of 3–10 kW per kW of energy used.

Treatment of a chocolate industry wastewater in a pilot-scale low-temperature UASB reactor operated at short hydraulic and sludge retention time

2013 ◽  
Vol 67 (6) ◽  
pp. 1353-1361 ◽  
Author(s):  
M. Esparza-Soto ◽  
O. Arzate-Archundia ◽  
C. Solís-Morelos ◽  
C. Fall
Keyword(s):  
Low Temperature ◽  
Retention Time ◽  
Biogas Production ◽  
Pilot Scale ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Processing Industry ◽  
Sludge Retention Time ◽  
Industry Wastewater

The aim of this work was to evaluate the performance of a 244-L pilot-scale upflow anaerobic sludge blanket (UASB) reactor during the treatment of chocolate-processing industry wastewater under low-temperature conditions (18 ± 0.6 °C) for approximately 250 d. The applied organic loading rate (OLR) was varied between 4 and 7 kg/m3/d by varying the influent soluble chemical oxygen demand (CODsol), while keeping the hydraulic retention time constant (6.4 ± 0.3 h). The CODsol removal efficiency was low (59–78%). The measured biogas production increased from 240 ± 54 to 431 ± 61 L/d during the experiments. A significant linear correlation between the measured biogas production and removed OLR indicated that 81.69 L of biogas were produced per kg/m3 of CODsol removed. Low average reactor volatile suspended solids (VSS) (2,700–4,800 mg/L) and high effluent VSS (177–313 mg/L) were derived in a short sludge retention time (SRT) (4.9 d). The calculated SRT was shorter than those reported in the literature, but did not affect the reactor's performance. Average sludge yield was 0.20 kg-VSS/kg-CODsol. The low-temperature anaerobic treatment was a good option for the pre-treatment of chocolate-processing industry wastewater.

scholarly journals Biogas Production by Pilot-Scale Anaerobic Co-Digestion and Life Cycle Assessment Using a Real Scale Scenario: Independent Parameters and Co-Substrates Influence

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1875
Author(s):  
Jhessica Mosquera ◽  
Carol Rangel ◽  
Jogy Thomas ◽  
Angelica Santis ◽  
Paola Acevedo ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Biogas Production ◽  
Scale Up ◽  
Pilot Scale ◽  
Industrial Sector ◽  
Potential Effect ◽  
Organic Loading Rate ◽  
Environmentally Sustainable ◽  
Real Scale

This study evaluates the performance of different agricultural by-products to identify the potential effect of independent variables, using as the dependent variable the biogas production. A Box–Behnken experimental design was carried out in a pilot-scale plant of four stirred stainless-steel digesters under mesophilic semi-continuous digestion. The results obtained support the creation of a technical framework to scale up the process and further evaluation of the potential environmental impacts through life cycle assessment (LCA) methodology. A stable behaviour was achieved in 12 of the 13 experiments proposed. The highest value of daily biogas production was 2200.15 mL day−1 with a stabilization time of 14 days, an organic loading rate of 4 g VS feed daily, low C/N ratio and a 1:1 relation of nitrogen providers. The concentrations of CH4 remained stable after the production stabilization and an average biogas composition of 60.6% CH4, 40.1% CO2 and 0.3% O2 was obtained for the conditions mentioned above. Therefore, the real scale plant was estimated to manage 2.67 tonnes of residual biomass per day, generating 369.69 kWh day−1 of electricity. The LCA analysis confirms that the co-digestion process evaluated is a feasible and environmentally sustainable option for the diversification of the Colombian energy matrix and the development of the agro-industrial sector.

scholarly journals Bioreactor Cells as Waste Pre-Treatment Method

2017 ◽  
Author(s):  
Ruta Bendere ◽  
Ruslans Smigins ◽  
Dace Arina ◽  
Inara Teibe
Keyword(s):  
Biogas Production ◽  
Treatment Method ◽  
Baltic States ◽  
Treatment Technology ◽  
Sanitary Landfills ◽  
Pre Treatment ◽  
Waste Degradation

Bioreactor landfilling, with the acceptance of landfill Directive in EC in 1999, loosed its actuality in EC, but this method can still be used for acceleration of bio-waste degradation and biogas production as pre-treatment technology of waste. As large gas collection facilities are built and millions of EUR are invested for biogas treatment and production of electricity and heat in the new constructed sanitary landfills in Baltic States, the idea of usage of biogas production cells as bio-waste pre-treatment method is revised.

scholarly journals Enhanced biogas production potential of microalgae and swine wastewater using co-digestion and alkaline pretreatment

2018 ◽  
Vol 78 (1) ◽  
pp. 92-102 ◽  
Author(s):  
K. Panyaping ◽  
R. Khiewwijit ◽  
P. Wongpankamol
Keyword(s):  
Biogas Production ◽  
Oxygen Demand ◽  
Electrical Energy ◽  
Pilot Scale ◽  
Major Effect ◽  
Alkaline Pretreatment ◽  
Swine Wastewater ◽  
Biogas Yield ◽  
Volatile Solids ◽  
Vs Removal

Abstract Biogas yield obtained from anaerobic digestion of swine wastewater (SWW) needs to be increased to produce electrical energy. To enhance biogas and prevent pollution, use of mixed culture microalgae grown in wastewater (MWW) with SWW has attracted a lot of interest. This research was focused on the possibility of utilizing MWW. Six experiments using raw SWW and MWW, and their co-digestion were conducted on a laboratory scale in one-litre reactors with the ratio of inoculum and substrate of 70:30 under without and with alkaline pretreatment (using 3% NaOH for pH adjustment every 15 min at pH 11 for 3 h). The results showed that co-digestion had the major effect on increasing biogas and methane yields (0.735 and 0.326 m3/kg of volatile solids (VS) removed), and the highest chemical oxygen demand and VS removal (60.29% and 63.17%). For pretreatment, the effect of ammonia inhibition at a high pH of 11 had more influence on biodegradation than the effect of destruction of MWW's cell walls, resulting in a low biogas production of pretreated MWW and pretreated co-digestion. These findings affirm the potential of co-digestion, and the possibility of using both single and co-substrate MWW. Pretreatment could be improved at a lower alkaline pH condition. A pilot scale of co-digestion should be performed.

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