scholarly journals Swine effluent treatment using anaerobic digestion at different loading rates

2014 ◽  
Vol 34 (3) ◽  
pp. 567-576 ◽  
Author(s):  
André C. do Amaral ◽  
Airton Kunz ◽  
Ricardo L. R. Steinmetz ◽  
Fábio Cantelli ◽  
Lucas A. Scussiato ◽  
...  

The industrial swine production is characterized by generation of significant effluent amounts that require treatment. The most adopted practices by Brazilian swine farmers have been wastewater storage in lagoons and its subsequent use as a biofertilizer. Nutrient accumulation in soil and water creates the need for an effective management of these residues. The anaerobic digestion process is an important alternative and low-cost treatment for organic matter reduction. However, its efficiency is limited by the digester capacity of solid degradation, especially at low hydraulic retention times. Thus, the present study aimed to verify the behavior of an upflow anaerobic digester by increasing the organic loading rate. This was accomplished in three stages using, as a parameter, volatile solids at 0.5; 1.0 and 1.5 kgVS m-3 d-1, respectively. This digester model proved to be quite robust and effective in swine manure treatment, achieving high efficiency of volatile solid removal at all stages of the study (stage 1: 61.38%; stage 2: 55.18%; and stage 3: 43.18%). Biogas production was directly related to the increasing organic load, reaching 0.14, 0.85, and 0.86 Nm³ kgVS-1add., respectively, with no significant difference (p<0.05) of biogas methane concentration among the studied stages (73.7, 75.0, and 77.9%).

2013 ◽  
Vol 726-731 ◽  
pp. 2875-2880
Author(s):  
Wen Hao Liu ◽  
Shi Jie Tian ◽  
Shu Biao Wu ◽  
Xiao Qian Zhang ◽  
Chang Le Pang ◽  
...  

The possible exploitation of two-phase anaerobic digestion for swine manure was investigated in this study. One-phase and two-phase anaerobic digestion process were investigated in continuous stirred-tank reactor with hydraulic retention times 15 days (hydrolysis and acidification for 3 days and methanogenic12 days in two-phase). When the organic loading rates were equal to or less than 4 g VS/L day, the biogas yield and volumetric production of two processes were no significant difference. However, in the case of organic loading rates being equal to or higher than 5.0 g VS/L day, two-phase biogas yield and volumetric biogas production averaged 0.294 L CH4/g VS added and 2.218 L/L day, compared with one-phase averaged 0.255L CH4/g VS added and 2.168 L/L day, respectively. Significant advantages in saving cost of biogas project were indicated by the comparison of biogas production and COD degradation in the one-phase and two-phase processes.


2021 ◽  
Vol 9 ◽  
Author(s):  
Mónica Amado ◽  
Cristian Barca ◽  
Mario A. Hernández ◽  
Jean-Henry Ferrasse

This study provides the first overview in Colombia on energy recovery potential by anaerobic digestion (AD) and dark fermentation (DF) of three different residual biomasses: coffee mucilage (CFM), cocoa mucilage (CCM), and swine manure (SM). First, AD and DF models were developed based on the ADM1 model. Then, simulated biogas production yields were compared to experimental data to validate the models. The results of comparative simulations indicate that energy recovery potentials from biogas for the different Colombian departments range from 148 to 48,990 toe, according to the local production amounts of CFM, CCM, and SM in 2017. The study provides crucial information that can be used to assess the best design, operation mode, and locations of AD and DF plants in Colombia. The results indicate that biogas production performances and energy recovery yields improve by increasing CFM/SM and/or CCM/SM ratios of the feed, and by increasing organic load from 2 to 26 gCOD∙l−1.


Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 151
Author(s):  
Jaime Jaimes-Estévez ◽  
German Zafra ◽  
Jaime Martí-Herrero ◽  
Guillermo Pelaz ◽  
Antonio Morán ◽  
...  

Most biogas plants in the world run under psychrophilic conditions and are operated by small and medium farmers. There is a gap of knowledge on the performance of these systems after several years of operation. The aim of this research is to provide a complete evaluation of a psychrophilic, low-cost, tubular digester operated for eight years. The thermal performance was monitored for 50 days, and parameters such as pH, total volatile fatty acid (tVFA), chemical oxygen demand (COD) and volatile solids (VS) were measured every week for the influent and effluent. The digester operated at a stabilized slurry temperature of around 17.7 °C, with a mean organic load rate (OLR) equal to 0.52 kg VS/m3digester *d and an estimated hydraulic retention time (HRT) of 25 days. The VS reduction in the digester was around 77.58% and the COD reduction was 67 ± 3%, with a mean value for the effluent of 3.31 ± 1.20 g COD/Lt, while the tVFA decreased by 83.6 ± 15.5% and the presence of coliforms decreased 10.5%. A BioMethane potential test (BMP) for the influent and effluent showed that the digester reached a specific methane production of 0.40 Nm3CH4/kg VS and a 0.21 Nm3CH4/m3digester d with 63.1% CH4 in the biogas. These results, together with a microbiological analysis, show stabilized anaerobic digestion and a biogas production that was higher than expected for the psychrophilic range and the short HRT; this may have been due to the presence of an anaerobic digestion microorganism consortium which was extremely well-adapted to psychrophilic conditions over the eight-year study period.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4936
Author(s):  
Ahmed Tawfik ◽  
Shou-Qing Ni ◽  
Hanem. M. Awad ◽  
Sherif Ismail ◽  
Vinay Kumar Tyagi ◽  
...  

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.


2019 ◽  
Vol 79 (11) ◽  
pp. 2145-2155 ◽  
Author(s):  
K. Yanuka-Golub ◽  
K. Baransi-Karkaby ◽  
A. Szczupak ◽  
L. Reshef ◽  
J. Rishpon ◽  
...  

Abstract Biogas is a sustainable, renewable energy source generated from organic waste degradation during anaerobic digestion (AD). AD is applied for treating different types of wastewater, mostly containing high organic load. However, AD practice is still limited due to the low quality of the produced biogas. Upgrading biogas to natural gas quality (&gt;90% CH4) is essential for broad applications. Here, an innovative bio-electrochemically assisted AD process was developed, combining wastewater treatment and biogas upgrading. This process was based on a microbial electrolysis cell (MEC) that produced hydrogen from wastewater at a relatively high efficiency, followed by high-rate anaerobic systems for completing biodegradation of organic matter and an in situ bio-methanation process. Results showed that CH4 production yield was substantially improved upon coupling of the MEC with the AD system. Interestingly, CH4 production yield increase was most notable once circulation between AD and MEC was applied, while current density was not markedly affected by the circulation rates. The microbial community analysis confirmed that the MEC enhanced hydrogen production, leading to the enrichment of hydrogenotrophic methanogens. Thus, directing soluble hydrogen from the MEC to AD is plausible, and has great potential for biogas upgrading, avoiding the need for direct hydrogen harvesting.


Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2392 ◽  
Author(s):  
Marcin Dębowski ◽  
Marcin Zieliński ◽  
Marta Kisielewska ◽  
Joanna Kazimierowicz

The aim of this study was the performance evaluation of anaerobic digestion of dairy wastewater in a multi-section horizontal flow reactor (HFAR) equipped with microwave and ultrasonic generators to stimulate biochemical processes. The effects of increasing organic loading rate (OLR) ranging from 1.0 g chemical oxygen demand (COD)/L·d to 4.0 g COD/L·d on treatment performance, biogas production, and percentage of methane yield were determined. The highest organic compounds removals (about 85% as COD and total organic carbon—TOC) were obtained at OLR of 1.0–2.0 g COD/L·d. The highest biogas yield of 0.33 ± 0.03 L/g COD removed and methane content in biogas of 68.1 ± 5.8% were recorded at OLR of 1.0 g COD/L·d, while at OLR of 2.0 g COD/L·d it was 0.31 ± 0.02 L/COD removed and 66.3 ± 5.7%, respectively. Increasing of the OLR led to a reduction in biogas productivity as well as a decrease in methane content in biogas. The best technological effects were recorded in series with an operating mode of ultrasonic generators of 2 min work/28 min break. More intensive sonication reduced the efficiency of anaerobic digestion of dairy wastewater as well as biogas production. A low nutrient removal efficiency was observed in all tested series of the experiment, which ranged from 2.04 ± 0.38 to 4.59 ± 0.68% for phosphorus and from 9.67 ± 3.36 to 20.36 ± 0.32% for nitrogen. The effects obtained in the study (referring to the efficiency of wastewater treatment, biogas production, as well as to the results of economic analysis) proved that the HFAR can be competitive to existing industrial technologies for food wastewater treatment.


2018 ◽  
Vol 65 ◽  
pp. 05025 ◽  
Author(s):  
Sagor Kumar Pramanik ◽  
Fatihah Binti Suja ◽  
Biplob Kumar Pramanik ◽  
Shahrom Bindi Md Zain

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.


Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1487
Author(s):  
Vicky De Groof ◽  
Marta Coma ◽  
Tom C. Arnot ◽  
David J. Leak ◽  
Ana B. Lanham

Production of medium chain carboxylic acids (MCCA) as renewable feedstock bio-chemicals, from food waste (FW), requires complicated reactor configurations and supplementation of chemicals to achieve product selectivity. This study evaluated the manipulation of organic loading rate in an un-supplemented, single stage stirred tank reactor to steer an anaerobic digestion (AD) microbiome towards acidogenic fermentation (AF), and thence to chain elongation. Increasing substrate availability by switching to a FW feedstock with a higher COD stimulated chain elongation. The MCCA species n-caproic (10.1 ± 1.7 g L−1) and n-caprylic (2.9 ± 0.8 g L−1) acid were produced at concentrations comparable to more complex reactor set-ups. As a result, of the adjusted operating strategy, a more specialised microbiome developed containing several MCCA-producing bacteria, lactic acid-producing Olsenella spp. and hydrogenotrophic methanogens. By contrast, in an AD reactor that was operated in parallel to produce biogas, the retention times had to be doubled when fed with the high-COD FW to maintain biogas production. The AD microbiome comprised a diverse mixture of hydrolytic and acidogenic bacteria, and acetoclastic methanogens. The results suggest that manipulation of organic loading rate and food-to-microorganism ratio may be used as an operating strategy to direct an AD microbiome towards AF, and to stimulate chain elongation in FW fermentation, using a simple, un-supplemented stirred tank set-up. This outcome provides the opportunity to repurpose existing AD assets operating on food waste for biogas production, to produce potentially higher value MCCA products, via simple manipulation of the feeding strategy.


2018 ◽  
Vol 36 (11) ◽  
pp. 1106-1112 ◽  
Author(s):  
Xiaohui Guo ◽  
Kang Kang ◽  
Gaoyuan Shang ◽  
Xiunan Yu ◽  
Ling Qiu ◽  
...  

The mesophilic reactor (MR) exhibited advantages in biogas production and performance stability over thermophilic reactor (TR) during the long-term anaerobic digestion (AD) of food waste (FW) with stepwise organic loading rate elevating. It was interesting to explore the mechanism causing the divergences in performances between these two reactors. The microbial activity was compared on day 110 when TR began to deteriorate. The results show that MR had significantly higher specific acetoclastic methanogenic activities (SAMA) and specific propionate and butyrate oxidative activities (SPOA and SBOA) than TR. The SAMA, SPOA and SBOA in TR were only 50.3%, 18.6% and 46.4% of those values in MR, respectively. Remarkably, the specific hydrogenotrophic methanogenic activity of 15.5±2.1, 15.7±4.6 mmol CH4·L−1 original slurry·d−1 in MR and TR was comparative with insignificant difference, which indicates that the microbial activity in TR had been inhibited widely apart from the hydrogenotrophic methanogenesis. Additionally, many particles with the diameters of 1–2 mm were observed to form in MR and identified as complexes of calcium and long chain fatty acids (LCFAs). The formation of calcium crystallization might alleviate the inhibition of LCFAs during AD of FW, which further supports the better performance in MR than TR.


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