Rapid Two Stage Anaerobic Digestion of Nejayote through Microaeration and Direct Interspecies Electron Transfer

Corn is one of the main food products in Mexico. The elaboration of corn-derived products generates wastewater with a high organic load (nejayote). Anaerobic digestion is an indicated treatment for wastewater with high organic loads. The results of this study show that the application of microaeration in the hydrolysis-fermentative reactor increased the percentage of volatile fatty acids (VFA) available in the medium by 62%. The addition of a conductive material, such as granulated activated carbon (GAC), promotes DIET (Direct interspecies electrons transfer) in the methanogenic UASB reactor increasing the methane yield by 55%. Likewise, a great diversity of exoelectrogenic bacteria, with the ability to donate electrons DIET mechanisms, were developed in the GAC biofilm, though interestingly, Peptoclostridium and Clostridium (17.3% and 12.75%, respectively) were detected with a great abundance in the GAC biofilm. Peptoclostridium has not been previously reported as a participant in DIET process.

Download Full-text

Robust Data-Driven Soft Sensors for Online Monitoring of Volatile Fatty Acids in Anaerobic Digestion Processes

Processes ◽

10.3390/pr8010067 ◽

2020 ◽

Vol 8 (1) ◽

pp. 67 ◽

Cited By ~ 3

Author(s):

Pezhman Kazemi ◽

Jean-Philippe Steyer ◽

Christophe Bengoa ◽

Josep Font ◽

Jaume Giralt

Keyword(s):

Fatty Acids ◽

Anaerobic Digestion ◽

Real Time ◽

Volatile Fatty Acids ◽

Synthetic Data ◽

Data Driven ◽

Organic Load ◽

Support Vector ◽

Soft Sensors ◽

Artificial Neural Network Ann

The concentration of volatile fatty acids (VFAs) is one of the most important measurements for evaluating the performance of anaerobic digestion (AD) processes. In real-time applications, VFAs can be measured by dedicated sensors, which are still currently expensive and very sensitive to harsh environmental conditions. Moreover, sensors usually have a delay that is undesirable for real-time monitoring. Due to these problems, data-driven soft sensors are very attractive alternatives. This study proposes different data-driven methods for estimating reliable VFA values. We evaluated random forest (RF), artificial neural network (ANN), extreme learning machine (ELM), support vector machine (SVM) and genetic programming (GP) based on synthetic data obtained from the international water association (IWA) Benchmark Simulation Model No. 2 (BSM2). The organic load to the AD in BSM2 was modified to simulate the behavior of an anaerobic co-digestion process. The prediction and generalization performances of the different models were also compared. This comparison showed that the GP soft sensor is more precise than the other soft sensors. In addition, the model robustness was assessed to determine the performance of each model under different process states. It is also shown that, in addition to their robustness, GP soft sensors are easy to implement and provide useful insights into the process by providing explicit equations.

Download Full-text

Study of two-phase anaerobic digestion of corn stover: Focusing on the conversion of volatile fatty acids and microbial characteristics in UASB reactor

Industrial Crops and Products ◽

10.1016/j.indcrop.2020.113097 ◽

2020 ◽

pp. 113097

Author(s):

Yan Li ◽

Haipeng Xu ◽

Xiaolu Yi ◽

Yuxiao Zhao ◽

Fuqiang Jin ◽

...

Keyword(s):

Fatty Acids ◽

Anaerobic Digestion ◽

Corn Stover ◽

Volatile Fatty Acids ◽

Uasb Reactor ◽

Two Phase ◽

Microbial Characteristics

Download Full-text

Conductive material engineered direct interspecies electron transfer (DIET) in anaerobic digestion: Mechanism and application

Environmental Technology & Innovation ◽

10.1016/j.eti.2020.101056 ◽

2020 ◽

Vol 20 ◽

pp. 101056

Author(s):

Pallavi Gahlot ◽

Banafsha Ahmed ◽

Satya Brat Tiwari ◽

Nabin Aryal ◽

Anwar Khursheed ◽

...

Keyword(s):

Electron Transfer ◽

Anaerobic Digestion ◽

Conductive Material ◽

Direct Interspecies Electron Transfer ◽

Interspecies Electron Transfer

Download Full-text

Influence of hydrothermal pretreatment conditions, typology of anaerobic digestion system, and microbial profile in the production of volatile fatty acids from olive mill solid waste

Journal of Environmental Chemical Engineering ◽

10.1016/j.jece.2021.105055 ◽

2021 ◽

Vol 9 (2) ◽

pp. 105055

Author(s):

Yasmim Arantes da Fonseca ◽

Nayara Clarisse Soares Silva ◽

Adonai Bruneli de Camargos ◽

Silvana de Queiroz Silva ◽

Hector Javier Luna Wandurraga ◽

...

Keyword(s):

Fatty Acids ◽

Anaerobic Digestion ◽

Solid Waste ◽

Volatile Fatty Acids ◽

Hydrothermal Pretreatment ◽

Microbial Profile ◽

Olive Mill Solid Waste ◽

Pretreatment Conditions ◽

Olive Mill

Download Full-text

Timing of biochar dosage for anaerobic digestion treating municipal leachate: Altered conversion pathways of volatile fatty acids

Bioresource Technology ◽

10.1016/j.biortech.2021.125283 ◽

2021 ◽

pp. 125283

Author(s):

To-Hung Tsui ◽

Le Zhang ◽

Ee Yang Lim ◽

Jonathan T.E. Lee ◽

Yen Wah Tong

Keyword(s):

Fatty Acids ◽

Anaerobic Digestion ◽

Volatile Fatty Acids

Download Full-text

Structure of Microbial Communities When Complementary Effluents Are Anaerobically Digested

Applied Sciences ◽

10.3390/app11031293 ◽

2021 ◽

Vol 11 (3) ◽

pp. 1293

Author(s):

Ana Eusébio ◽

André Neves ◽

Isabel Paula Marques

Keyword(s):

Anaerobic Digestion ◽

Microbial Communities ◽

Volatile Fatty Acids ◽

Olive Mill Wastewater ◽

Organic Load ◽

Rrna Gene ◽

Bacterial Populations ◽

Next Generation Sequencing Ngs ◽

Generation Sequencing ◽

Olive Mill

Olive oil and pig productions are important industries in Portugal that generate large volumes of wastewater with high organic load and toxicity, raising environmental concerns. The principal objective of this study is to energetically valorize these organic effluents—piggery effluent and olive mill wastewater—through the anaerobic digestion to the biogas/methane production, by means of the effluent complementarity concept. Several mixtures of piggery effluent were tested, with an increasing percentage of olive mill wastewater. The best performance was obtained for samples of piggery effluent alone and in admixture with 30% of OMW, which provided the same volume of biogas (0.8 L, 70% CH4), 63/75% COD removal, and 434/489 L CH4/kg SVin, respectively. The validation of the process was assessed by molecular evaluation through Next Generation Sequencing (NGS) of the 16S rRNA gene. The structure of the microbial communities for both samples, throughout the anaerobic process, was characterized by the predominance of bacterial populations belonging to the phylum Firmicutes, mainly Clostridiales, with Bacteroidetes being the subdominant populations. Archaea populations belonging to the genus Methanosarcina became predominant throughout anaerobic digestion, confirming the formation of methane mainly from acetate, in line with the greatest removal of volatile fatty acids (VFAs) in these samples.

Download Full-text