Recent Approaches for the Production of High Value-Added Biofuels from Gelatinous Wastewater

Gelatin production is the most industry polluting process where huge amounts of raw organic materials and chemicals (HCl, NaOH, Ca2+) are utilized in the manufacturing accompanied by voluminous quantities of end-pipe effluent. The gelatinous wastewater (GWW) contains a large fraction of protein and lipids with biodegradability (BOD/COD ratio) exceeding 0.6. Thus, it represents a promising low-cost substrate for the generation of biofuels, i.e., H2 and CH4, by the anaerobic digestion process. This review comprehensively describes the anaerobic technologies employed for simultaneous treatment and energy recovery from GWW. The emphasis was afforded on factors affecting the biofuels productivity from anaerobic digestion of GWW, i.e., protein concentration, organic loading rate (OLR), hydraulic retention time (HRT), the substrate to inoculum (S0/X0) ratio, type of mixed culture anaerobes, carbohydrates concentration, volatile fatty acids (VFAs), ammonia and alkalinity/VFA ratio, and reactor configurations. Economic values and future perspectives that require more attention are also outlined to facilitate further advancement and achieve practicality in this domain.

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Volatile Fatty Acid Production from Organic Waste with the Emphasis on Membrane-Based Recovery

Fermentation ◽

10.3390/fermentation7030159 ◽

2021 ◽

Vol 7 (3) ◽

pp. 159

Author(s):

Prawat Sukphun ◽

Sureewan Sittijunda ◽

Alissara Reungsang

Keyword(s):

Organic Waste ◽

Volatile Fatty Acids ◽

Low Cost ◽

Cost Effective ◽

Future Research ◽

Fatty Acid Production ◽

Factors Affecting ◽

Acidogenic Fermentation ◽

Recovery Techniques ◽

Biotechnological Processes

In recent years, interest in the biorefinery concept has emerged in the utilization of volatile fatty acids (VFAs) produced by acidogenic fermentation as precursors for various biotechnological processes. This has attracted substantial attention to VFA production from low-cost substrates such as organic waste and membrane based VFA recovery techniques to achieve cost-effective and environmentally friendly processes. However, there are few reviews which emphasize the acidogenic fermentation of organic waste into VFAs, and VFA recovery. Therefore, this article comprehensively summarizes VFA production, the factors affecting VFA production, and VFA recovery strategies using membrane-based techniques. Additionally, the outlook for future research on VFA production is discussed.

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A VFA-based controller for anaerobic digestion of industrial winery wastewater

Water Science & Technology ◽

10.2166/wst.2018.367 ◽

2018 ◽

Vol 78 (9) ◽

pp. 1871-1878 ◽

Cited By ~ 1

Author(s):

Gustavo Vargas-Morales ◽

Rolando Chamy ◽

Santiago García-Gen

Keyword(s):

Anaerobic Digestion ◽

Volatile Fatty Acids ◽

Upflow Anaerobic Sludge Blanket ◽

Uasb Reactor ◽

Organic Loading Rate ◽

Anaerobic Sludge ◽

Variable Gain ◽

Winery Wastewater ◽

Empirical Function ◽

Anaerobic Sludge Blanket

Abstract A variable-gain controller for anaerobic digestion of industrial winery wastewater is presented. A control law using both volatile fatty acids (VFA) and methane production rate as controlled variables and organic loading rate (OLR) as manipulated variable is defined. The process state is quantitatively estimated by an empirical function comparing VFA measurements against a setpoint value; then, it is modified with a second empirical function that compares the methane flow rate with a maximum capacity reference, and finally it is adjusted with a third factor considering the actual hydraulic retention time. The variable-gain function determines the extent of the OLR change applied to the system. The controller was successfully validated in a 95 L upflow-anaerobic-sludge-blanket (UASB) reactor, treating industrial wine wastewater at OLR ranged between 2.0 and 39.2 g COD/L d for 120 days at mesophilic conditions. Higher performance was achieved contrasted with a conventional strategy carried out in a parallel UASB unit.

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Experimental and Artificial Neural Network Modeling of a Upflow Anaerobic Contactor (UAC) for Biogas Production from Vinasse

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2016-0025 ◽

2016 ◽

Vol 14 (6) ◽

pp. 1241-1254 ◽

Cited By ~ 8

Author(s):

Ousman R. Dibaba ◽

Sandip K. Lahiri ◽

Stephan T’Jonck ◽

Abhishek Dutta

Keyword(s):

Neural Network ◽

Artificial Neural Network ◽

Anaerobic Digestion ◽

Volatile Fatty Acids ◽

Biogas Production ◽

Oxygen Demand ◽

Pilot Scale ◽

Organic Loading Rate ◽

Neural Network Modeling ◽

Artificial Neural

Abstract A pilot scale Upflow Anaerobic Contactor (UAC), based on upflow sludge blanket principle, was designed to treat vinasse waste obtained from beet molasses fermentation. An assessment of the anaerobic digestion of vinasse was carried out for the production of biogas as a source of energy. Average Organic loading rate (OLR) was around 7.5 gCOD/m3/day in steady state, increasing upto 8.1 gCOD/m3/day. The anaerobic digestion was conducted at mesophilic (30–37 °C) temperature and a stable operating condition was achieved after 81 days with average production of 65 % methane which corresponded to a maximum biogas production of 85 l/day. The optimal performance of UAC was obtained at 87 % COD removal, which corresponded to a hydraulic retention time of 16.67 days. The biogas production increased gradually with OLR, corresponding to a maximum 6.54 gCOD/m3/day (7.4 % increase from initial target). A coupled Artificial Neural Network-Differential Evolution (ANN-DE) methodology was formulated to predict chemical oxygen demand (COD), total suspended solids (TSS) and volatile fatty acids (VFA) of the effluent along with the biogas production. The method incorporated a DE approach for the efficient tuning of ANN meta-parameters such as number of nodes in hidden layer, input and output activation function and learning rate. The model prediction indicated that it can learn the nonlinear complex relationship between the parameters and able to predict the output of the contactor with reasonable accuracy. The utilization of the coupled ANN-DE model provided significant improvement to the study and helps to study the parametric effect of influential parameters on the reactor output.

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Effect of Organic Loading Rate and Temperature on the Anaerobic Digestion of Municipal Solid Waste: Process Performance and Energy Recovery

Frontiers in Energy Research ◽

10.3389/fenrg.2020.00089 ◽

2020 ◽

Vol 8 ◽

Author(s):

Junfeng Jiang ◽

Shuibin He ◽

Xihui Kang ◽

Yongming Sun ◽

Zhenhong Yuan ◽

...

Keyword(s):

Anaerobic Digestion ◽

Municipal Solid Waste ◽

Solid Waste ◽

Energy Recovery ◽

Loading Rate ◽

Organic Loading Rate ◽

Process Performance ◽

Organic Loading

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Simultaneous treatment of sewage sludge and food waste by the unified high-rate anaerobic digestion system

Water Science & Technology ◽

10.2166/wst.2006.166 ◽

2006 ◽

Vol 53 (6) ◽

pp. 29-35 ◽

Cited By ~ 4

Author(s):

H.-W. Kim ◽

S.-K. Han ◽

H.-S. Shin

Keyword(s):

Anaerobic Digestion ◽

Sewage Sludge ◽

Production Rate ◽

Food Waste ◽

High Rate ◽

Organic Loading Rate ◽

Simultaneous Treatment ◽

Methanogenic Activity ◽

Ch4 Production ◽

Methane Production Rate

This study aimed to evaluate the performance of the unified high-rate anaerobic digestion (UHAD) system treating co-substrate of sewage sludge and food waste. A 24-hr operating sequence consisted of four steps including fill, react, settle, and draw. The effects of co-substrate and organic loading rate (OLR) on the performance were investigated to verify the system applicability. In each OLR, the UHAD system showed higher CH4 recovery (>70%), CH4 yield (0.3 L CH4/g VSadded) and CH4 production rate (0.6 L CH4/L/d) than the control system. In the specific methanogenic activity (SMA) tests on thermophilic biomass of the UHAD system, the average SMA of acetate (102 mL CH4/gVSS/d) was much higher than those of butyrate (85 mL CH4/g SS/d) and propionate (42 mL CH4/gVSS/d). It was demonstrated that the UHAD system for co-digestion resulted in higher methane yield and methane production rate due to sequencing batch operation, thermophilic digestion, and co-digestion. The enhanced performance could be attributed to longer retention time of active biomass, faster hydrolysis, higher CH4 conversion rate, and balanced nutrient conditions of co-substrate in the UHAD system. Consequently, this optimized unification could be a viable option for the simultaneous treatment of two types of OFMSW with high stability.

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Single-Stage and Two-Stage Anaerobic Digestion of Food Waste: Effect of the Organic Loading Rate on the Methane Production and Volatile Fatty Acids

Water Air & Soil Pollution ◽

10.1007/s11270-021-05064-9 ◽

2021 ◽

Vol 232 (3) ◽

Author(s):

Brayan Alexis Parra-Orobio ◽

Mariano Nicolas Cruz-Bournazou ◽

Patricia Torres-Lozada

Keyword(s):

Fatty Acids ◽

Anaerobic Digestion ◽

Food Waste ◽

Methane Production ◽

Volatile Fatty Acids ◽

Loading Rate ◽

Single Stage ◽

Organic Loading Rate ◽

Organic Loading ◽

Two Stage

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Review and perspectives of enhanced volatile fatty acids production from acidogenic fermentation of lignocellulosic biomass wastes

Bioresources and Bioprocessing ◽

10.1186/s40643-021-00420-3 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Jiachen Sun ◽

Le Zhang ◽

Kai-Chee Loh

Keyword(s):

Fatty Acids ◽

Anaerobic Digestion ◽

Lignocellulosic Biomass ◽

Volatile Fatty Acids ◽

Loading Rate ◽

Value Added ◽

High Loading ◽

Acidogenic Fermentation ◽

Electrochemical Technology ◽

High Loading Rate

AbstractLignocellulosic biomass wastes are abundant resources that are usually valorized for methane-rich biogas via anaerobic digestion. Conversion of lignocellulose into volatile fatty acids (VFA) rather than biogas is attracting attention due to the higher value-added products that come with VFA utilization. This review consolidated the latest studies associated with characteristics of lignocellulosic biomass, the effects of process parameters during acidogenic fermentation, and the intensification strategies to accumulate more VFA. The differences between anaerobic digestion technology and acidogenic fermentation technology were discussed. Performance-enhancing strategies surveyed included (1) alkaline fermentation; (2) co-digestion and high solid-state fermentation; (3) pretreatments; (4) use of high loading rate and short retention time; (5) integration with electrochemical technology, and (6) adoption of membrane bioreactors. The recommended operations include: mesophilic temperature (thermophilic for high loading rate fermentation), C/N ratio (20–40), OLR (< 12 g volatile solids (VS)/(L·d)), and the maximum HRT (8–12 days), alkaline fermentation, membrane technology or electrodialysis recovery. Lastly, perspectives were put into place based on critical analysis on status of acidogenic fermentation of lignocellulosic biomass wastes for VFA production.

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Impact of Organic Loading Rate in Volatile Fatty Acids Production and Population Dynamics Using Microalgae Biomass as Substrate

Scientific Reports ◽

10.1038/s41598-019-54914-4 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 11

Author(s):

Jose Antonio Magdalena ◽

Silvia Greses ◽

Cristina González-Fernández

Keyword(s):

Fatty Acids ◽

Population Dynamics ◽

Organic Matter ◽

Anaerobic Digestion ◽

Volatile Fatty Acids ◽

Building Blocks ◽

Biofuel Production ◽

Organic Loading Rate ◽

Organic Loading ◽

Wide Range

AbstractVolatile fatty acids (VFAs) are regarded as building blocks with a wide range of applications, including biofuel production. The traditional anaerobic digestion used for biogas production can be alternatively employed for VFAs production. The present study aimed at maximizing VFAs productions from Chlorella vulgaris through anaerobic digestion by assessing the effect of stepwise organic loading rates (OLR) increases (3, 6, 9, 12 and 15 g COD L−1 d−1). The biological system was proven to be robust as organic matter conversion efficiency into VFAs increased from 0.30 ± 0.02 COD-VFAs/CODin at 3 g COD L−1 d−1 to 0.37 ± 0.02 COD-VFAs/CODin at 12 g COD L−1d−1. Even though, the hydrolytic step was similar for all studied scenario sCOD/tCOD = 0.52–0.58), the highest OLR (15 g COD L−1 d−1) did not show any further increase in VFAs conversion (0.29 ± 0.01 COD-VFAs/CODin). This fact suggested acidogenesis inhibition at 15 g COD L−1d−1. Butyric (23–32%), acetic (19–26%) and propionic acids (11–17%) were the most abundant bioproducts. Population dynamics analysis revealed microbial specialization, with a high presence of Firmicutes followed by Bacteroidetes. In addition, this investigation showed the microbial adaptation of Euryarchaeota species at the highest OLR (15 g COD L−1d−1), evidencing one of the main challenges in VFAs production (out-competition of archaea community to avoid product consumption). Stepwise OLR increase can be regarded as a tool to promote VFAs productions. However, acidogenic inhibition was reported at the highest OLR instead of the traditional hydrolytic barriers. The operational conditions imposed together with the high VFAs and ammonium concentrations might have affected the system yields. The relative abundance of Firmicutes (74%) and Bacteroidetes (20%), as main phyla, together with the reduction of Euryarchaeota phylum (0.5%) were found the best combination to promote organic matter conversion into VFAs.

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A Review on the Fate of Nutrients and Enhancement of Energy Recovery from Rice Straw through Anaerobic Digestion

Applied Sciences ◽

10.3390/app10062047 ◽

2020 ◽

Vol 10 (6) ◽

pp. 2047 ◽

Cited By ~ 1

Author(s):

Furqan Muhayodin ◽

Albrecht Fritze ◽

Vera Susanne Rotter

Keyword(s):

Anaerobic Digestion ◽

Rice Straw ◽

Energy Recovery ◽

Loading Rate ◽

Effect Of Temperature ◽

Organic Loading Rate ◽

Organic Loading ◽

Environmental Threats ◽

Liquid Digestate ◽

Methane Potential

Open field burning and tilling the rice straw (RS) back into the fields causes environmental threats by contributing to the increased greenhouse gas emissions. Energy and nutrient recovery from RS through anaerobic digestion (AD) is an effective solution for its utilization. Although RS has good methane potential, its characteristics make it a difficult substrate for AD. This paper reviews the characteristics of RS, mass balance, and distribution of nutrients into liquid and solid digestate in the AD. The present review also discusses the effect of temperature, co-digestion, mixing, inoculum, organic loading rate, recycling liquid digestate, the addition of trace elements, and their bioavailability on the enhancement of biogas/methane yield in the AD of RS. In addition, the digestion of RS at various scales is also covered in the review.

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