scholarly journals Effects of Lipase Addition, Hydrothermal Processing, Their Combination, and Co-Digestion with Crude Glycerol on Food Waste Anaerobic Digestion

Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 284
Author(s):  
Xiaojue Li ◽  
Naoto Shimizu
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Methane Production ◽  
Crude Glycerol ◽  
Anaerobic Fermentation ◽  
Gompertz Model ◽  
Volatile Solids ◽  
Methane Potential ◽  
Better Than ◽  
Modified Gompertz Model

To enhance anaerobic fermentation during food waste (FW) digestion, pretreatments can be applied or the FW can be co-digested with other waste. In this study, lipase addition (LA), hydrothermal pretreatment (HTP), and a combination of both methods (HL) were applied to hydrolyze organic matter in FW. Furthermore, the effects of crude glycerol (CG), which provided 5%, 10%, and 15% of the volatile solids (VS) as co-substrate (denoted as CG5, CG10, and CG15, respectively), on the anaerobic digestion of FW were assessed. With an increasing proportion of CG in the co-digestion experiment, CG10 showed higher methane production, while CG15 negatively affected the anaerobic digestion (AD) performance owing to propionic acid accumulation acidifying the reactors and inhibiting methanogen growth. As the pretreatments partially decomposed hard-to-degrade substances in advance, pretreated FW showed a stronger methane production ability compared with raw FW, especially using the HL method, which was significantly better than co-digestion. HL pretreatment was shown to be a promising option for enhancing the methane potential value (1.773 NL CH4/g VS) according to the modified Gompertz model.

Anaerobic Co-Digestion of Food Waste and Thermal Pretreated Waste Activated Sludge: Synergetic Effect and Energy Assessment

2021 ◽  
Author(s):  
Jian Zhang ◽  
Peng Gan ◽  
Ru-yi Wang ◽  
Tian Xie ◽  
Yang Liu ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Food Waste ◽  
Methane Production ◽  
Synergetic Effect ◽  
Gompertz Model ◽  
Waste Activated Sludge ◽  
Thermal Pretreatment ◽  
Energy Assessment ◽  
Modified Gompertz Model

Abstract Thermal pretreatment was an effective method to improve the anaerobic digestion of waste activated sludge. However its application in China was still hindered by the high energy demand. In order to balance the energy consumption of sludge thermal pretreatment integrated with anaerobic digestion, food waste was introduced as co-substrate to achieve an energy self-sustainable sludge treatment system. Anaerobic biodegradability test was performed using thermal pretreated sludge and food waste in order to clarify the kinetics and mechanism of co-digestion, especially the synergetic effect on specific methane yield. The prominent synergetic effect was an initial acceleration of cumulative methane production by 20.7- 23.8% observed during the first 15 days, and the cumulative methane production of feedstock can be calculated proportionately from its composition. Between the evaluated models, modified Gompertz model presented a better agreement of the experimental results and it was able to describe the synergetic effect, assessed by the relative deviation between theoretical estimation and the experimental results of co-digestion tests. This feature made modified Gompertz model a suitable tool for methane production prediction of mono- and co-digestion. Energy assessment shown that co-digestion with food waste was a sustainable solution to maintain the integration of thermal pretreatment and anaerobic digestion energy neutral or even positive. Besides, the performance of sludge dewatering was a crucial factor for the energy balance.

scholarly journals Batch Anaerobic Co-Digestion and Biochemical Methane Potential Analysis of Goat Manure and Food Waste

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1952
Author(s):  
Ayobami Orangun ◽  
Harjinder Kaur ◽  
Raghava R. Kommalapati
Keyword(s):  
Food Waste ◽  
Gompertz Model ◽  
Water Displacement ◽  
Biochemical Methane Potential ◽  
Greenhouse Gasses ◽  
Nonlinear Regression Models ◽  
The Us ◽  
Methane Potential ◽  
Goat Manure ◽  
Modified Gompertz Model

The improper management of goat manure from concentrated goat feeding operations and food waste leads to the emission of greenhouse gasses and water pollution in the US. The wastes were collected from the International Goat Research Center and a dining facility at Prairie View A&M University. The biochemical methane potential of these two substrates in mono and co-digestion at varied proportions was determined in triplicates and processes were evaluated using two nonlinear regression models. The experiments were conducted at 36 ± 1 °C with an inoculum to substrate ratio of 2.0. The biomethane was measured by water displacement method (pH 10:30), absorbing carbon dioxide. The cumulative yields in goat manure and food waste mono-digestions were 169.7 and 206.0 mL/gVS, respectively. Among co-digestion, 60% goat manure achieved the highest biomethane yields of 380.5 mL/gVS. The biodegradabilities of 33.5 and 65.7% were observed in goat manure and food waste mono-digestions, while 97.4% were observed in the co-digestion having 60% goat manure. The modified Gompertz model is an excellent fit in simulating the anaerobic digestion of food waste and goat manure substrates. These findings provide useful insights into the co-digestion of these substrates.

Evaluation by Kinetic Models of Anaerobe Digestion Performances for Various Substrates and Co-substrates

2017 ◽  
Vol 68 (11) ◽  
pp. 2614-2617
Author(s):  
Adrian Eugen Cioabla ◽  
Gabriela Alina Dumitrel ◽  
Ioana Ionel
Keyword(s):  
Anaerobic Digestion ◽  
Kinetic Models ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Gompertz Model ◽  
Water Treatment Plant ◽  
Waste Water Treatment Plant ◽  
Complex Process ◽  
Methane Potential ◽  
Modified Gompertz Model

Anaerobic digestion is a complex process that allows the conversion of organic wastes into biogas with minimal costs and benefits for the environment. The goal of this study is to evaluate the anaerobic digestion potential of two common agricultural biomass wastes (degraded corn and degraded wheat) used as single substrates or as co-substrates together with wastewater from a waste water treatment plant. The results reveal that the co-digestion is an improved solution, both in terms of biogas amount produced and its methane concentration. Two kinetic models (modified Gompertz model and logistical growth model) were applied to study the methane production. For each case, the kinetic parameters were estimated. One demonstrates that the modified Gompertz model fitted very well the measured methane potential, for all studied cases.

Thermophilic anaerobic fermentation of olive pulp for hydrogen and methane production: modelling of the anaerobic digestion process

2006 ◽  
Vol 53 (8) ◽  
pp. 271-279 ◽  
Author(s):  
H.N. Gavala ◽  
I.V. Skiadas ◽  
B.K. Ahring ◽  
G. Lyberatos
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Anaerobic Fermentation ◽  
Anaerobic Treatment ◽  
Two Phase ◽  
Production Of Hydrogen ◽  
Subsequent Step ◽  
Methane Potential ◽  
Olive Pulp ◽  
Semi Solid

The present study investigates the thermophilic biohydrogen and methane production from olive pulp, which is the semi-solid residue coming from the two-phase processing of olives. It focussed on: a) production of methane from the raw olive pulp; b) anaerobic bio-production of hydrogen from the olive pulp; c) subsequent anaerobic treatment of the hydrogen-effluent with the simultaneous production of methane; and d) development of a mathematical model able to describe the anaerobic digestion of the olive pulp and the effluent of hydrogen producing process. Both continuous and batch experiments were performed. The hydrogen potential of the olive pulp amounted to 1.6 mmole H2 per g TS. The methane potential of the raw olive pulp and hydrogen-effluent was as high as 19 mmole CH4 per g TS suggesting that: a) olive pulp is a suitable substrate for methane production; and b) biohydrogen production can be very efficiently coupled with a subsequent step for methane production.

scholarly journals Impact of Attrition Ball-Mill on Characteristics and Biochemical Methane Potential of Food Waste

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2085
Author(s):  
Yang Mo Gu ◽  
Seon Young Park ◽  
Ji Yeon Park ◽  
Byoung-In Sang ◽  
Byoung Seong Jeon ◽  
...  
Keyword(s):  
Particle Size ◽  
Anaerobic Digestion ◽  
Food Waste ◽  
Methane Production ◽  
Ball Mill ◽  
Volatile Fatty Acids ◽  
Milling Time ◽  
Biochemical Methane Potential ◽  
Methane Potential ◽  
The Impact

The impact of attrition ball-mill pretreatment on food waste particle size, soluble chemical oxygen demand (SCOD), biochemical methane potential, and microbial community during anaerobic digestion was investigated based on milling speed and time. The uniformity of particle size improved with increasing milling speed and time. The SCOD of the pretreated samples increased to 4%, 7%, and 17% at the speeds of 150, 225, and 300 rpm, respectively, compared to the control. Milling time did not significantly change the SCOD. The cumulative methane productions of 430, 440, and 490 mL/g-VS were observed at the speeds of 150, 225, and 300 rpm, respectively, while the untreated sample exhibited the cumulative methane production of 390 mL/g-VS. Extended milling time did not improve methane production much. When the milling times of 10, 20, and 30 min were applied with the milling speed fixed at 300 rpm, the methane productions of 490, 510, and 500 mL/g-VS were observed respectively. Ball-mill pretreatment also increased the total volatile fatty acids. During the anaerobic digestion (AD) of ball-mill treated food waste, acetoclastic methanogens predominated, with a relative abundance of 48–49%. Interestingly, hydrogenotrophic methanogens were 1.6 times higher in the pretreated samples than those in the control. These results showed the potential of attrition ball milling as a food waste pretreatment for improving methane production.

scholarly journals Assessment of the biochemical methane potential of mono- and co-digested dairy farm wastes

2019 ◽  
Vol 38 (1) ◽  
pp. 88-99 ◽  
Author(s):  
Mohamad Adghim ◽  
Mohamed Abdallah ◽  
Suhair Saad ◽  
Abdallah Shanableh ◽  
Majid Sartaj
Keyword(s):  
Methane Production ◽  
Dairy Farm ◽  
Gompertz Model ◽  
Maximum Error ◽  
Methane Yield ◽  
Cow Manure ◽  
Biochemical Methane Potential ◽  
Volatile Solids ◽  
Waste Milk ◽  
Methane Potential

This study aimed to evaluate the methane potential of mono- and co-digested dairy farm wastes. The tested substrates included manure from lactating, dry, and young cows, as well as waste milk and feed waste. The highest methane yield was achieved from the lactating cow manure, which produced an average of 412 L of CH4 kg−1 volatile solids, followed by young and dry cow manures (332 and 273 L of CH4 kg−1 volatile solids, respectively). Feed and milk yielded an average of 325 and 212 L of CH4 kg−1 volatile solids, respectively. Co-digesting the manures from lactating and young cows with feed improved methane production by 7%. However, co-digesting the dry cow manure with feed achieved only 85% of the calculated methane yield. Co-digesting manure and milk at a ratio of 70:30 enhanced the methane potential from lactating, dry, and young cow manures by 19, 30, and 37%, respectively. Moreover, co-digesting lactating, dry, and young cow manures with milk at a ratio of 30:70 enhanced the methane yield by 60, 30, and 88%, respectively. The cumulative methane production of all samples was accurately described using the Gompertz model with a maximum error of 10%. Carbohydrates contributed the most to methane potential, while proteins and lipids were limiting.

scholarly journals Performance and Kinetic Model of a Single-Stage Anaerobic Digestion System Operated at Different Successive Operating Stages for the Treatment of Food Waste

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 600 ◽  
Author(s):  
Sagor Kumar Pramanik ◽  
Fatihah Binti Suja ◽  
Mojtaba Porhemmat ◽  
Biplob Kumar Pramanik
Keyword(s):  
Experimental Data ◽  
Anaerobic Digestion ◽  
Kinetic Model ◽  
Removal Efficiency ◽  
Food Waste ◽  
Biogas Production ◽  
Gompertz Model ◽  
Methane Yield ◽  
Biogas Yield ◽  
Modified Gompertz Model

A large quantity of food waste (FW) is generated annually across the world and results in environmental pollution and degradation. This study investigated the performance of a 160 L anaerobic biofilm single-stage reactor in treating FW. The reactor was operated at different hydraulic retention times (HRTs) of 124, 62, and 35 days under mesophilic conditions. The maximum biogas and methane yield achieved was 0.934 L/g VSadded and 0.607 L CH4/g VSadded, respectively, at an HRT of 124 days. When HRT decreased to 62 days, the volatile fatty acid (VFA) and ammonia accumulation increased rapidly whereas pH, methane yield, and biogas yield decreased continuously. The decline in biogas production was likely due to shock loading, which resulted in scum accumulation in the reactor. A negative correlation between biogas yield and volatile solid (VS) removal efficiency was also observed, owing to the floating scum carrying and urging the sludge toward the upper portion of the reactor. The highest VS (79%) and chemical oxygen demand (COD) removal efficiency (80%) were achieved at an HRT of 35 days. Three kinetic models—the first-order kinetic model, the modified Gompertz model, and the logistic function model—were used to fit the cumulative biogas production experimental data. The kinetic study showed that the modified Gompertz model had the best fit with the experimental data out of the three models. This study demonstrates that the stability and performance of the anaerobic digestion (AD) process, namely biogas production rate, methane yield, intermediate metabolism, and removal efficiency, were significantly affected by HRTs.

scholarly journals Effects of Salt on Anaerobic Digestion of Food Waste with Different Component Characteristics and Fermentation Concentrations

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3571 ◽  
Author(s):  
Li ◽  
Huang ◽  
Liu ◽  
Huang ◽  
Maurer ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Food Processing ◽  
Biogas Production ◽  
Gompertz Model ◽  
Salt Addition ◽  
Vs Removal ◽  
Processing Effects ◽  
Kinetics Of ◽  
Modified Gompertz Model

Effects of salt on anaerobic digestion are dosage-dependent. As salt is a widely used condiment in food processing, effects of salt are bound to be considered when food waste is digested. In this study, salt addition effects (0, 2, 4, 6, 9, 12 g∙L−1) on biogas and methane yields and kinetics of biogas production were researched. Meanwhile, component characteristics (food waste featured in carbohydrate, protein and fat, respectively) and fermentation concentrations (5 and 8 gVS∙L−1) were also taken into consideration. Results showed that 2–4 g∙L−1 salt addition was the optimal addition dosage for AD systems as they not only have the maximum biogas and methane yields, but also the maximum vs. removal in most cases. Also, according to the results of a modified Gompertz model, which is used to predict biogas and methane production rates, suitable salt addition can accelerate biogas production, improving the maximum biogas production rate (Rmax). Factorial design (2 × 2) proved that interaction of salt and fermentation concentrations was significant for food waste featured with carbohydrate and with protein (p <0.05). High salt addition and fermentation concentration can break the AD system when the feeding material was food waste featured with carbohydrate, but for food waste featured with protein, interaction of fermentation concentrations and salt addition can alleviate inhibition degrees.

scholarly journals Thermophilic Anaerobic Digestion: Enhanced and Sustainable Methane Production from Co-Digestion of Food and Lignocellulosic Wastes

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2058 ◽  
Author(s):  
Aditi David ◽  
Tanvi Govil ◽  
Abhilash Tripathi ◽  
Julie McGeary ◽  
Kylie Farrar ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Synergistic Effects ◽  
C:N Ratio ◽  
Lignocellulosic Wastes ◽  
Thermophilic Anaerobic Digestion ◽  
Volatile Solids ◽  
Prairie Cordgrass

This article aims to study the codigestion of food waste (FW) and three different lignocellulosic wastes (LW) (Corn stover (CS), Prairie cordgrass (PCG), and Unbleached paper (UBP)) for thermophilic anaerobic digestion to overcome the limitations of digesting food waste alone (volatile fatty acids accumulation and low C:N ratio). Using an enriched thermophilic methanogenic consortium, all the food and lignocellulosic waste mixtures showed positive synergistic effects of codigestion. After 30 days of incubation at 60 °C (100 rpm), the highest methane yield of 305.45 L·kg−1 volatile solids (VS) was achieved with a combination of FW-PCG-CS followed by 279.31 L·kg−1 VS with a mixture of FW-PCG. The corresponding volatile solids reduction for these two co-digestion mixtures was 68% and 58%, respectively. This study demonstrated a reduced hydraulic retention time for methane production using FW and LW.

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