Enhancement of Anaerobic Digestion for Energy and Resource Recovery

A special issue of Water (ISSN 2073-4441). This special issue belongs to the section "Wastewater Treatment and Reuse".

Deadline for manuscript submissions: closed (30 September 2020) | Viewed by 78837

Special Issue Editors

School of Engineering, University of Guelph, Canada
Interests: anaerobic digestion; biological and thermal hydrolysis for anaerobic digestion enhancement; biological nutrient removal; EPS characterization and membrane fouling
Suez Water Technologies and Solutions
Interests: anaerobic treatment; digestate treatment; GHG reduction technology; resource recovery; cost reduction engineering; technology commercialization
Cranfield Water Science Institute, Cranfield University, UK
Interests: anaerobic MBR; dissolved methane recovery; biogas treatment with membranes; resource recovery; energy generation with hybrid membranes; water reuse; membrane crystallisation
1. School of Environmental Science and Engineering, Sun Yat-Sen University, China
2. Department of Systems Design Engineering, University of Waterloo, Canada
Interests: sludge treatment; sustainability analysis; anammox; MBR; mass transfer in porous media; data driven approach for process control

Special Issue Information

Dear Colleagues,

With an objective to provide a comprehensive review on the recent development in advanced anaerobic digestion research, we would like to call for submissions for a Special Issue from both Scientific communities and Industrial sectors for original research papers, short communications, research/industrial notes, and state-of-the-art literature review articles on various aspects of recent progresses of anaerobic digestion technologies.

The world economic model is currently undergoing a paradigm shift from linear, waste-producing, economies to circular, waste-repurposing economies. Anaerobic digestion (AD) processes that can recover water, usable methane gas and reduce GHG emssion is a crucial technology of waste-to-resource. The recent emphasis on energy and resource recovery has driven AD to achieve higher biogas production, enhanced degradation of organics, increased treatment capacity and beneficial use of digested biosolids. Technologies to enhance the energy and resource recovery of AD, such as thermophilic digestion, temperature-phased anaerobic digestion, dry anaerobic digestion, chemical, physical, biological pretreatment and bioelectrochemical anaerobic reactor have gained much attention in recent years. This Special Issue will cover research and development of anaerobic digestion pretreatment, advanced anaerobic digestion, and anaerobic digestion post-treatment on aspects that include process mechanisms and operation; optimization, modeling, and applications; energy balance and economic analysis; and treatment and management of anaerobic digestate. It is expected that this Species Issues will exert a significant impact on the future research development and applications of advanced anaerobic digestion technologies.

Dr. Sheng Chang
Mr. Youngseck Hong
Dr. Ewan McAdam
Dr. Chao Jin
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Water is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • anaerobic treatment
  • biological hydrolysis
  • theraml hydrolysis
  • checmico-physical pretremtent
  • digestate treatment
  • biosolids
  • co-digestion
  • economic analysis
  • GHG reduction
  • energy and resource recovery

Published Papers (14 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

14 pages, 1402 KiB  
Article
Treatment of Effluent of Upflow Anaerobic Sludge Blanket Bioreactor for Water Reuse
by Peter Innes, Sheng Chang and Md. Saifur Rahaman
Water 2021, 13(15), 2123; https://doi.org/10.3390/w13152123 - 01 Aug 2021
Cited by 2 | Viewed by 3206
Abstract
The low-pressure reverse osmosis (LPRO) process is a recent development of reverse osmosis (RO) technology for the reduction in RO energy consumption and operation cost. The goal of this study was to investigate the performance of LPRO processes for the treatment and reuse [...] Read more.
The low-pressure reverse osmosis (LPRO) process is a recent development of reverse osmosis (RO) technology for the reduction in RO energy consumption and operation cost. The goal of this study was to investigate the performance of LPRO processes for the treatment and reuse of effluent discharged from brewery upflow anaerobic sludge blanket bioreactors (UASB). In this study, three different commercially available LPRO membranes were tested to evaluate the water quality that can be achieved under different operational and pretreatment conditions. It was found that the filtration performance and the effluent quality of the LPRO membranes can be considerably affected by the operation conditions and the selection of the pretreatment processes. The ultrafiltration (UF) pretreatment and the control of the operation pressure were found to be essential for mitigating LPRO membrane fouling, which could be caused by Ca2+ associated precipitates and organic gelation, in the treatment of the brewery UASB effluent. Water quality analyses showed that an integrated process of the UASB + UF + LPRO could achieve an effluent quality characterized by concentrations of 10.4–12.5 mg/L of chemical oxygen demand (COD), 1.8–2.1 mg/L of total nitrogen (TN), 1.3–1.8 mg/L of ammonia nitrogen (NH3-N) and 0.8–1.2 mg/L of total phosphorus (TP). The effluent quality and the LPRO performance could be further improved by adding a granular activated carbon (GAC) adsorption process between the UF and LPRO processes, which reduced the concentration of COD to 7–10 mg/L and those of TN, TP, NH3-N to below 1 mg/L. For the treatment of the UASB effluent tested in this study, the UF, UF + GAC (retention time 4 hrs), UF + LPRO, and UF + GAC + LPRO, respectively, achieved overall COD removal efficiencies of 89.6–93.7%, 94.5–96.7%, 99.3–99.1% and 99.3–99.4%; TN removal efficiencies of 73.0–78.2%, 89.2–97.2%, 97.1–98.2% and 94.3–99.7%; and TP removal efficiencies of 29.3–46.2%, 77.0–95.4%, 95.9–97.6z% and 98.0–98.3%. This study showed that both UASB + UF + LPRO and UASB + UF + GAC + LPRO are effective treatment processes for treating brewery wastewater toward reuse water quality standards set by the United States Environmental Protection Agency (US EPA). Therefore, the results of this study would help to answer whether a LPRO can treat the brewery UASB effluent to meet the requirements of wastewater reuse standards. Full article
(This article belongs to the Special Issue Enhancement of Anaerobic Digestion for Energy and Resource Recovery)
Show Figures

Figure 1

14 pages, 2625 KiB  
Article
Demonstrating Commercial Hollow Fibre Membrane Contactor Performance at Industrial Scale for Biogas Upgrading at a Sewage Treatment Works
by Sam Houlker, Tony Rutherford, Daniel Herron, Adam Brookes, Andrew Moore, Peter Vale, Marc Pidou and Ewan McAdam
Water 2021, 13(2), 172; https://doi.org/10.3390/w13020172 - 13 Jan 2021
Cited by 2 | Viewed by 2393
Abstract
Hollow fibre membrane contactor (HFMC) technology has been developed for CO2 absorption primarily using synthetic gas, which neglects the critical impact that trace contaminants might have on separation efficiency and robustness in industrial gases. This study, therefore, commissioned a demonstration-scale HFMC for [...] Read more.
Hollow fibre membrane contactor (HFMC) technology has been developed for CO2 absorption primarily using synthetic gas, which neglects the critical impact that trace contaminants might have on separation efficiency and robustness in industrial gases. This study, therefore, commissioned a demonstration-scale HFMC for CO2 separation at a full-scale anaerobic digester facility to evaluate membrane integrity over six months of operation on real biogas. The CO2 capture efficiency identified using real biogas was benchmarked at comparable conditions on synthetic gas of an equivalent partial pressure, and an equivalent performance identified. Two HFMC were subsequently compared, one with and one without a pre-treatment stage that targeted particulates, volatile organic compounds (VOCs) and humidity. Similar CO2 separation efficiency was again demonstrated, indicating limited impact within the timescale evaluated. However, gas phase pre-treatment is advised in order to ensure robustness in the long term. Over longer-term operation, a decline in CO2 separation efficiency was observed. Membrane autopsy identified shell-side deposition, where the structural morphology and confirmation of amide I and II groups, indicated biofouling. Separation efficiency was reinstated via chemical cleaning, which demonstrated that proactive maintenance could minimise process risk. Full article
(This article belongs to the Special Issue Enhancement of Anaerobic Digestion for Energy and Resource Recovery)
Show Figures

Figure 1

18 pages, 2576 KiB  
Article
Thermophilic Anaerobic Co-Digestion of Exhausted Sugar Beet Pulp with Cow Manure to Boost the Performance of the Process: The Effect of Manure Proportion
by Xiomara Gómez-Quiroga, Kaoutar Aboudi, Luis Alberto Fernández-Güelfo, Carlos José Álvarez-Gallego and Luis Isidoro Romero-García
Water 2021, 13(1), 67; https://doi.org/10.3390/w13010067 - 31 Dec 2020
Cited by 5 | Viewed by 2206
Abstract
Sugar beet by-products are a lignocellulosic waste generated from sugar beet industry during the sugar production process and stand out for their high carbon content. Moreover, cow manure (CM) is hugely produced in rural areas and livestock industry, which requires proper disposal. Anaerobic [...] Read more.
Sugar beet by-products are a lignocellulosic waste generated from sugar beet industry during the sugar production process and stand out for their high carbon content. Moreover, cow manure (CM) is hugely produced in rural areas and livestock industry, which requires proper disposal. Anaerobic digestion of such organic wastes has shown to be a suitable technology for these wastes valorization and bioenergy production. In this context, the biomethane production from the anaerobic co-digestion of exhausted sugar beet pulp (ESBP) and CM was investigated in this study. Four mixtures (0:100, 50:50, 75:25, and 90:10) of cow manure and sugar beet by-products were evaluated for methane generation by thermophilic batch anaerobic co-digestion assays. The results showed the highest methane production was observed in mixtures with 75% of CM (159.5 mL CH4/g VolatileSolids added). Nevertheless, the hydrolysis was inhibited by volatile fatty acids accumulation in the 0:100 mixture, which refers to the assay without CM addition. The modified Gompertz model was used to fit the experimental results of methane productions and the results of the modeling show a good fit between the estimated and the observed data. Full article
(This article belongs to the Special Issue Enhancement of Anaerobic Digestion for Energy and Resource Recovery)
Show Figures

Figure 1

13 pages, 2112 KiB  
Article
Impacts of Temperature and Solids Retention Time, and Possible Mechanisms of Biological Hydrolysis Pretreatment on Anaerobic Digestion
by Huihuang H. Ding, Polina Kotova, Christopher Shaw, Youngseck Hong and Sheng Chang
Water 2020, 12(11), 3166; https://doi.org/10.3390/w12113166 - 12 Nov 2020
Cited by 4 | Viewed by 2114
Abstract
Anaerobic digestion (AD) has benefits in sludge management, energy recovery, and pathogen reduction. In order to better understand the mechanisms of biological hydrolysis (BH) pretreatment on AD, biochemical methane potential (BMP) and continuous stirred-tank reactor (CSTR) tests were utilized to compare untreated municipal [...] Read more.
Anaerobic digestion (AD) has benefits in sludge management, energy recovery, and pathogen reduction. In order to better understand the mechanisms of biological hydrolysis (BH) pretreatment on AD, biochemical methane potential (BMP) and continuous stirred-tank reactor (CSTR) tests were utilized to compare untreated municipal combined sludge with pilot-scale BH pretreated sludge. During the BH process, there was 15%, 30%, and 33% (w/w) volatile solids (VS) reduction after BH at 42 °C (BH42) for 24, 48, and 72 h, respectively; under BH61 (42 °C for 36 h and 61 °C for 6 h), and there was 10% and 30% (w/w) overall VS reduction after 36-h and 42-h hydrolysis, respectively. BMP results showed that BH42-pretreated sludge had 22.6% enhancement of methane yield compared to untreated sludge, and BH61 pretreated sludge had 29.4% enhancement of methane yield. Both temperature and solids’ retention time (SRT) contributed to the enhanced AD performance within 36 h, while temperature played more important roles after 36-h BH pretreatment. CSTR tests confirmed the acceleration of anaerobic digestion by BH pretreatment, and higher enhancement was observed when SRT of anaerobic digestion was shorter than 16 days. Through a literature review of BH-related studies, the possible mechanisms were highlighted for further optimization on the scale-up systems in order to reduce carbon footprint and operating expenditure for wastewater treatment plants. Full article
(This article belongs to the Special Issue Enhancement of Anaerobic Digestion for Energy and Resource Recovery)
Show Figures

Figure 1

17 pages, 11127 KiB  
Article
Performance Analysis for the Anaerobic Membrane Bioreactor Combined with the Forward Osmosis Membrane Bioreactor: Process Conditions Optimization, Wastewater Treatment and Sludge Characteristics
by Yi Ding, Zhansheng Guo, Xuguang Hou, Junxue Mei, Zhenlin Liang, Zhipeng Li, Chunpeng Zhang and Chao Jin
Water 2020, 12(11), 2958; https://doi.org/10.3390/w12112958 - 22 Oct 2020
Cited by 4 | Viewed by 2178
Abstract
The anaerobic membrane bioreactors (AnMBR) were operated at 35 °C (H-AnMBR) and 25 °C (L-AnMBR) for long-term wastewater treatment. Two aerobic forward osmosis membrane bioreactors (FOMBRs) were utilized to treat the effluents of H-AnMBR and L-AnMBR, respectively. During the 180 days of operation, [...] Read more.
The anaerobic membrane bioreactors (AnMBR) were operated at 35 °C (H-AnMBR) and 25 °C (L-AnMBR) for long-term wastewater treatment. Two aerobic forward osmosis membrane bioreactors (FOMBRs) were utilized to treat the effluents of H-AnMBR and L-AnMBR, respectively. During the 180 days of operation, it is worth noting that the combined system was feasible, and the pollutant removal efficiency was higher. Though the permeate chemical oxygen demand (COD) of H-AnMBR (18.94 mg/L) was obviously lower than that of L-AnMBR (51.09 mg/L), the permeate CODs of the FOMBRs were almost the same with the average concentrations of 7.57 and 7.58 mg/L for the H-FOMBR and L-FOMBR, respectively. It was interesting that for both the AnMBRs, the permeate total nitrogen (TN) concentration was higher than that in bulk phase. However, the TN concentrations in the effluent remained stable with the values of 20.12 and 15.22 mg/L in the H-FOMBR and L-FOMBR effluents, respectively. For the two systems, the characteristics of activated sludge flocs were different for H-AnMBR-FOMBR sludge and L-AnMBR-FOMBR sludge. The viscosity of L-AnMBR-activated sludge (2.09 Pa·s) was higher compared to that of H-AnMBR (1.31 Pa·s), while the viscosity of activated sludge in L-FOMBR (1.44 Pa·s) was a little lower than that in H-FOMBR (1.48 Pa·s). The capillary water absorption time of L-AnMBR-activated sludge (69.6 s) was higher compared to that of H-AnMBR (49.5 s), while the capillary water absorption time of activated sludge in L-FOMBR (14.6 s) was little lower than that in H-FOMBR (15.6 s). The particle size of H-AnMBR-activated sludge (119.62 nm) was larger than that of L-AnMBR-activated sludge (84.92 nm), but the particle size of H-FOMBR-activated sludge (143.81 nm) was significantly smaller than that of L-FOMBR-activated sludge (293.38 nm). The observations of flocs indicated that the flocs of activated sludge in H-AnMBR were relatively loose, while the flocs of L-AnMBR were relatively tight. The fine sludge floc was less present in the L-FOMBR than in the H-FOMBR. Therefore, in the process of sewage treatment, the influent of each unit in the AnMBR-FOMBR system should have suitable organic content to maintain the particle sizes of sludge flocs. Full article
(This article belongs to the Special Issue Enhancement of Anaerobic Digestion for Energy and Resource Recovery)
Show Figures

Figure 1

10 pages, 1178 KiB  
Article
Impact of Organic Loading Rate on Performance and Methanogenic Microbial Communities of a Fixed-Bed Anaerobic Reactor at 4 °C
by Hongyan Zhao, Feifan Yan, Xue Li, Renzhe Piao, Weidong Wang and Zongjun Cui
Water 2020, 12(9), 2586; https://doi.org/10.3390/w12092586 - 16 Sep 2020
Cited by 2 | Viewed by 2149
Abstract
We investigated the feasibility of producing biogas in a fixed-bed anaerobic reactor at 4 °C with a gradual increase in organic loading rate (OLR). Reactor efficiency was highest when OLR was 4.33 kg/m3·d, whereas the reactor acidification occurred when OLR was [...] Read more.
We investigated the feasibility of producing biogas in a fixed-bed anaerobic reactor at 4 °C with a gradual increase in organic loading rate (OLR). Reactor efficiency was highest when OLR was 4.33 kg/m3·d, whereas the reactor acidification occurred when OLR was 4.67 kg/m3·d. The values of methane content, biogas production, chemical oxygen demand (COD) removal rate, biogas production rate, acetic acid content, and propionic acid content were 69.3%, 5.33 L, 59.8%, 1.03 L/OLR, 0.17 g/L, and 1.15 g/L, respectively. The pH was stable and ranged from 7.2 to 6.8 when the reactor was operating at 4 °C during OLR increase. The 16S rRNA gene analysis revealed that the dominant archaea were Methanosaetaceae at 30 °C. At 4 °C, the dominant archaea were Methanomicrobiales, which were more abundant in adhering sludge compared to settled sludge. In conclusion, operating a fixed-bed anaerobic reactor at psychrophilic temperatures is more suitable. Full article
(This article belongs to the Special Issue Enhancement of Anaerobic Digestion for Energy and Resource Recovery)
Show Figures

Figure 1

14 pages, 1707 KiB  
Article
Biogas Generation from Sonicated Excess Sludge
by Iwona Zawieja, Renata Włodarczyk and Mariusz Kowalczyk
Water 2019, 11(10), 2127; https://doi.org/10.3390/w11102127 - 14 Oct 2019
Cited by 15 | Viewed by 2734
Abstract
The article presents an analysis of the possibilities of biogas production in the process of methane fermentation of sonicated excess sludge. The greater the percentage of methane in biogas, the higher its calorific value. In order to increase the intensity of biogas production [...] Read more.
The article presents an analysis of the possibilities of biogas production in the process of methane fermentation of sonicated excess sludge. The greater the percentage of methane in biogas, the higher its calorific value. In order to increase the intensity of biogas production containing approximately 70% of methane, sewage sludge is disintegrated. In particular, excess sludge formed as a result of advanced wastewater treatment by the activated sludge method shows low biodegradability. The study aim was to examine the effect of the ultrasonic field disintegration of excess sludge on biogas production. As a result of subjecting the sludge to disintegration by ultrasonic field, there was an increase in the digestion degree of sewage sludge. In the methane fermentation process of modified sludge, an increase of the biogas yield was noted, which confirmed the supportive action of ultrasonic field on the excess sludge biodegradation. In the case of disintegration of excess sludge by ultrasonic field, for the ultrasonic field intensity value of 4.3 W cm−2 and a sonication time equal to 300 s, the highest values of soluble chemical oxygen demand (SCOD), total organic carbon (TOC), and volatile fatty acids (VFAs) concentrations were obtained. In the process of conventional methane fermentation, biogas yield value was 0.303 L g VSS−1, while in the process of methane fermentation of sonicated excess sludge, the value 0.645 L g VSS−1. Full article
(This article belongs to the Special Issue Enhancement of Anaerobic Digestion for Energy and Resource Recovery)
Show Figures

Figure 1

16 pages, 1958 KiB  
Article
Metagenomics Response of Anaerobic Ammonium Oxidation (anammox) Bacteria to Bio-Refractory Humic Substances in Wastewater
by Yabing Meng, Li-Nan Huang and Fangang Meng
Water 2019, 11(2), 365; https://doi.org/10.3390/w11020365 - 21 Feb 2019
Cited by 20 | Viewed by 5268
Abstract
Anammox-based processes have been widely applied for the treatment of wastewater (e.g., wastewater irrigation systems and constructed wetland) which consists of bio-refractory humic substances. Nonetheless, the impacts of bio-refractory humic substances on anammox consortia are rarely reported. In the present study, three identical [...] Read more.
Anammox-based processes have been widely applied for the treatment of wastewater (e.g., wastewater irrigation systems and constructed wetland) which consists of bio-refractory humic substances. Nonetheless, the impacts of bio-refractory humic substances on anammox consortia are rarely reported. In the present study, three identical lab-scale anammox reactors (i.e., HS0, HS1 and HS10), two of which were dosed with humic substances at 1 and 10 mg·L−1, respectively, were operated for nearly one year. The long-term operation of the reactors showed that the presence of humic substances in influent had no significant influence on nitrogen removal rates. Despite this, comparative metagenomics showed changes in anammox microbiota structure during the exposure to humic substance; e.g., the relative abundance of Candidatus Kuenenia was lower in HS10 (18.5%) than that in HS0 (22.8%) and HS1 (21.7%). More specifically, a lower level of humic substances (1 mg·L−1) in influent led to an increase of genes responsible for signal transduction, likely due to the role of humic substances as electron shuttles. In contrast, a high level of humic substances (10 mg·L−1) resulted in a slight decrease of functional genes associated with anammox metabolism. This may partially be due to the biodegradation of the humic substances. In addition, the lower dosage of humic substances (1 mg·L−1) also stimulated the abundance of hzs and hdh, which encode two important enzymes in anammox reaction. Overall, this study indicated that the anammox system could work stably over a long period under humic substances, and that the process was feasible for leachate treatment. Full article
(This article belongs to the Special Issue Enhancement of Anaerobic Digestion for Energy and Resource Recovery)
Show Figures

Graphical abstract

11 pages, 2949 KiB  
Article
Nitrogen Removal Characteristics and Comparison of the Microbial Community Structure in Different Anaerobic Ammonia Oxidation Reactors
by Liqiu Zhang, Wei Lv, Shugeng Li, Zhongxuan Geng and Hainan Yao
Water 2019, 11(2), 230; https://doi.org/10.3390/w11020230 - 29 Jan 2019
Cited by 10 | Viewed by 2940
Abstract
Nitrogen removal characteristics and the comparison of the microbial community structure were investigated in different anaerobic ammonia oxidation (Anammox) reactors: an anaerobic sequencing batch reactor (ASBR) and a biofilter reactor. The Anammox systems were inoculated with sludge from the second settling tank of [...] Read more.
Nitrogen removal characteristics and the comparison of the microbial community structure were investigated in different anaerobic ammonia oxidation (Anammox) reactors: an anaerobic sequencing batch reactor (ASBR) and a biofilter reactor. The Anammox systems were inoculated with sludge from the second settling tank of a wastewater treatment plant in Guangzhou, China. After successful start up of Anammox, the microbial community structure of different Anammox reactors were studied through high-throughput sequencing. The results showed that anaerobic ammonium oxidation in the ASBR reactor could successfully start up after 134 days, while Anammox in the biofilter could start up after 114 days. In both systems, total nitrogen removal was at 80% after more than 200 days of operation. The diversity of denitrifying microorganisms was high in both reactors, with Planctomycetes as the main taxa. Anammox bacteria belonging to the genera Candidatus Anammoxoglobus and Kuenenia, were dominant in the ASBR, while all three genera of Candidatus, Anammoxoglobus, Kuenenia, and Brocadia, could be detected in the biofilter reactor. Therefore, the biofilter starts up faster than the ASBR, and contains richer species, which makes it more suitable to domesticate Anammox bacteria. Full article
(This article belongs to the Special Issue Enhancement of Anaerobic Digestion for Energy and Resource Recovery)
Show Figures

Figure 1

16 pages, 2098 KiB  
Article
The Performance and Microbial Community Identification in Mesophilic and Atmospheric Anaerobic Membrane Bioreactor for Municipal Wastewater Treatment Associated with Different Hydraulic Retention Times
by Yi Ding, Zhenlin Liang, Zhansheng Guo, Zhipeng Li, Xuguang Hou and Chao Jin
Water 2019, 11(1), 160; https://doi.org/10.3390/w11010160 - 17 Jan 2019
Cited by 21 | Viewed by 4394
Abstract
The anaerobic membrane bioreactors (AnMBR) with ring membrane module were operated under mesophilic temperature (M-AnMBR) and atmospheric temperature (A-AnMBR). Compared to the M-AnMBR, the removal efficiency of the A-AnMBR was found to be lower and the faster membrane fouling occurred in the A-AnMBR [...] Read more.
The anaerobic membrane bioreactors (AnMBR) with ring membrane module were operated under mesophilic temperature (M-AnMBR) and atmospheric temperature (A-AnMBR). Compared to the M-AnMBR, the removal efficiency of the A-AnMBR was found to be lower and the faster membrane fouling occurred in the A-AnMBR under corresponding hydraulic retention time (HRT). The MiSeq high-throughput sequencing was applied to analyze the microbial community structure. The HRT change had different effects on the community richness and diversity of the cake and bulk sludge. The abundance of phylum Proteobacteria in the M-AnMBR was higher than that in the A-AnMBR, which should account for the higher removal of nutrients in the M-AnMBR. The faster membrane fouling would occur in the A-AnMBR due to the relatively high abundance of Bacteroidetes in the bulk sludge and cake sludge. Moreover, specific comparison down to the genus level showed that the dominant abundant bacterial genera were Candidate division OP8 norank and Anaerolineaceae uncultured in the cake sludge for M-AnMBR, and were VadinHA17 norank, WCHB1-69 norank, VadinBC27 wastewater-sludge group, and Synergistaceae uncultured in the cake sludge for A-AnMBR The different representative genera with the variation of the HRTs for the two bioreactors might indicate the different performance between the two AnMBRs. Full article
(This article belongs to the Special Issue Enhancement of Anaerobic Digestion for Energy and Resource Recovery)
Show Figures

Graphical abstract

13 pages, 2601 KiB  
Article
Influence of Temperature on Biogas Production Efficiency and Microbial Community in a Two-Phase Anaerobic Digestion System
by Shiwei Wang, Fang Ma, Weiwei Ma, Ping Wang, Guang Zhao and Xiaofei Lu
Water 2019, 11(1), 133; https://doi.org/10.3390/w11010133 - 12 Jan 2019
Cited by 79 | Viewed by 11112
Abstract
In this study, the influence of temperature on biogas production efficiency and the microbial community structure was investigated in a two-phase anaerobic digestion reactor for co-digestion of cow manure and corn straw. The results illustrated that the contents of solluted chemical oxygen demand [...] Read more.
In this study, the influence of temperature on biogas production efficiency and the microbial community structure was investigated in a two-phase anaerobic digestion reactor for co-digestion of cow manure and corn straw. The results illustrated that the contents of solluted chemical oxygen demand (SCOD) and volatile fatty acid (VFA) in the acidogenic phase and biogas production in the methanogenic phase maintained relatively higher levels at temperatures ranging from 35–25 °C. The methane content of biogas production could be maintained higher than 50% at temperatures above 25 °C. The microbial community structure analysis indicated that the dominant functional bacteria were Acinetobacter, Acetitomaculum, and Bacillus in the acidogenic phase and Cenarchaeum in the methanogenic phase at 35–25 °C. However, the performances of the acidogenic phase and the methanogenic phase could be significantly decreased at a lower temperature of 20 °C, and microbial activity was inhibited obviously. Accordingly, a low temperature was adverse for the performance of the acidogenic and methanogenic phases, while moderate temperatures above 25 °C were more conducive to high biogas production efficiency. Full article
(This article belongs to the Special Issue Enhancement of Anaerobic Digestion for Energy and Resource Recovery)
Show Figures

Figure 1

18 pages, 1570 KiB  
Article
Temperature-Phased Biological Hydrolysis and Thermal Hydrolysis Pretreatment for Anaerobic Digestion Performance Enhancement
by Beraki Bahre Mehari, Sheng Chang, Youngseck Hong and Han Chen
Water 2018, 10(12), 1812; https://doi.org/10.3390/w10121812 - 09 Dec 2018
Cited by 20 | Viewed by 5025
Abstract
Thermal hydrolysis (TH) and biological hydrolysis (BH) are two main and growing anaerobic digestion pretreatment technologies. In this study, municipal wastewater sludge samples were collected from the Guelph Wastewater Treatment Plant (WWTP) in Ontario, Canada. The effects of temperature on BH treatment, including [...] Read more.
Thermal hydrolysis (TH) and biological hydrolysis (BH) are two main and growing anaerobic digestion pretreatment technologies. In this study, municipal wastewater sludge samples were collected from the Guelph Wastewater Treatment Plant (WWTP) in Ontario, Canada. The effects of temperature on BH treatment, including BH at 42 °C (BH42), 42 °C followed by 55 °C (BH42+55), 55 °C followed by 42 °C (BH55+42), and 55 °C (BH55) were evaluated for anaerobic digestion performance enhancement and compared with TH treatment at 165 °C. The TH, BH42, BH42+55, BH55+42, and BH55 treatments caused the reduction of volatile suspended solids (VSS) by 22.6%, 17.5%, 24.6%, 23.1%, and 25.9%, respectively. The soluble chemical oxygen demand (sCOD) content of the sludge increased by 377.5%, 323.8%, 301.3%, 286.9%, and 221.7% by the TH, BH55, BH42+55, BH55+42, and BH42 treatments, respectively. Volatile fatty acids (VFA) constituted around 40% of the sCOD in the BH-treated sludge and 6% in the TH-treated sludge. The cumulative methane yields (NmLCH4/g COD fed) of sludge treated by BH55+42 and TH were respectively 23% and 20% higher than that of the untreated sludge. For BH pretreatment, sludge treated by BH55+42 produced more methane than those treated by BH42+55, BH55, and BH42. The methane yields of the combined sludge treated by the TH and BH55+42 treatments were in the ranges of 248.9 NmLCH4/g COD to 266.1 NmLCH4/g COD fed, and 255.3 NmLCH4/g COD to 282.2 NmLCH4/g COD fed, respectively. Full article
(This article belongs to the Special Issue Enhancement of Anaerobic Digestion for Energy and Resource Recovery)
Show Figures

Figure 1

Review

Jump to: Research

29 pages, 1950 KiB  
Review
Biochemical Methane Potential (BMP) Assay Method for Anaerobic Digestion Research
by Jameson Filer, Huihuang H. Ding and Sheng Chang
Water 2019, 11(5), 921; https://doi.org/10.3390/w11050921 - 01 May 2019
Cited by 209 | Viewed by 23544
Abstract
Biochemical methane potential (BMP) tests are widely used for characterizing a substrate’s influence on the anaerobic digestion process. As of 2018, there continues to be a lack of standardization of units and techniques, which impacts the comparability and validity of BMP results. However, [...] Read more.
Biochemical methane potential (BMP) tests are widely used for characterizing a substrate’s influence on the anaerobic digestion process. As of 2018, there continues to be a lack of standardization of units and techniques, which impacts the comparability and validity of BMP results. However, BMP methods continue to evolve, and key aspects are studied to further eliminate systematic errors. This paper aims to update these key aspects with the latest research progress both to introduce the importance of each variable to those new to BMP measurements and to show the complexity required to design an accurate BMP test. Full article
(This article belongs to the Special Issue Enhancement of Anaerobic Digestion for Energy and Resource Recovery)
Show Figures

Figure 1

27 pages, 8346 KiB  
Review
Influence of Pre-Hydrolysis on Sewage Treatment in an Up-Flow Anaerobic Sludge BLANKET (UASB) Reactor: A Review
by Rajinikanth Rajagopal, Mahbuboor Rahman Choudhury, Nawrin Anwar, Bernard Goyette and Md. Saifur Rahaman
Water 2019, 11(2), 372; https://doi.org/10.3390/w11020372 - 21 Feb 2019
Cited by 25 | Viewed by 8203
Abstract
The up-flow anaerobic sludge blanket (UASB) process has emerged as a promising high-rate anaerobic digestion technology for the treatment of low- to high-strength soluble and complex wastewaters. Sewage, a complex wastewater, contains 30–70% particulate chemical oxygen demand (CODP). These particulate organics [...] Read more.
The up-flow anaerobic sludge blanket (UASB) process has emerged as a promising high-rate anaerobic digestion technology for the treatment of low- to high-strength soluble and complex wastewaters. Sewage, a complex wastewater, contains 30–70% particulate chemical oxygen demand (CODP). These particulate organics degrade at a slower rate than the soluble organics found in sewage. Accumulation of non-degraded suspended solids can lead to a reduction of active biomass in the reactor and hence a deterioration in its performance in terms of acid accumulation and poor biogas production. Hydrolysis of the CODP in sewage prior to UASB reactor will ensure an increased organic loading rate and better UASB performance. While single-stage UASB reactors have been studied extensively, the two-phase full-scale treatment approach (i.e., a hydrolysis unit followed by an UASB reactor) has still not yet been commercialized worldwide. The concept of treating sewage containing particulate organics via a two-phase approach involves first hydrolyzing and acidifying the volatile suspended solids without losing carbon (as methane) in the first reactor and then treating the soluble sewage in the UASB reactor. This work reviews the available literature to outline critical findings related to the treatment of sewage with and without hydrolysis before the UASB reactor. Full article
(This article belongs to the Special Issue Enhancement of Anaerobic Digestion for Energy and Resource Recovery)
Show Figures

Figure 1

Back to TopTop