Improving the energy efficiency of a pilot-scale UASB-digester for low temperature domestic wastewater treatment

Xu, Shengnan; Zhang, Lei; Huang, Shengle; Zeeman, G.; Rijnaarts, H.H.M.; Liu, Yang

doi:10.1016/j.bej.2018.04.003

Cited by 32 publications

(7 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Yuan et al [37] also demonstrated that a combination of electrochemical and sodium hypochlorite pretreatments significantly enhanced the biogas yields by about 1.83-fold the sludge anaerobic digestion and shortened the stabilization period. According to Li et al [38] and Chong et al [13], the anaerobic UASB reactor is the most robust digester for the sludge treatment. Indeed, this type of reactor contains microorganisms that form granules through which, in an upward movement, the distributed effluent passes through the base of the reactor [39].…”

Section: Discussionmentioning

confidence: 99%

High-Rate Anaerobic Digestion of Waste Activated Sludge by Integration of Electro-Fenton Process

et al. 2020

View full text Add to dashboard Cite

Anaerobic digestion (AD), being the most effective treatment method of waste activated sludge (WAS), allows for safe disposal. The present study deals with the electro-Fenton (EF) pretreatment for enhancing the WAS biogas potential with low-cost iron electrodes. The effect of pretreatment on the physicochemical characteristics of sludge was assessed. Following EF pretreatment, the pH, conductivity, soluble chemical oxygen demand (SCOD), and volatile fatty acids (VFA) increased to 7.5, 13.72 mS/cm, 4.1 g/L, and 925 mg/L, respectively. Capillary suction time (CST) analysis highlighted the dewaterability effect of EF on WAS, as demonstrated by the decrease in CST from 429 to 180 s following 30 min of pretreatment. Batch digestion assays presented an increase in the biogas yield to 0.135 L/g volatile solids (VS) after 60 min of EF pretreatment in comparison to raw sludge (0.08 L/g VS). Production of biogas was also found to improve during semi-continuous fermentation of EF-pretreated sludge conducted in a lab-scale reactor. In comparison to raw sludge, EF-pretreated sludge produced the highest biogas yield (0.81 L biogas/g VS) with a high COD removal rate, reaching 96.6% at an organic loading rate (OLR) of 2.5 g VS/L. d. Results revealed that the EF process could be an effective WAS disintegration method with maximum recovery of bioenergy during AD.

show abstract

Section: Discussionmentioning

confidence: 99%

High-Rate Anaerobic Digestion of Waste Activated Sludge by Integration of Electro-Fenton Process

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Primary septic tank presence allows to reduce the required UASB start-up time [ 114 ]. A more complex scheme for raw municipal wastewater treatment, including a UASB reactor followed by a settler (having HRT of 3 h, where sludge was concentrated) and a digester, was proposed in the work in [ 115 ] to improve global energy efficiency of the system. The integrated process had total HRT of 6 h, achieving a mean COD removal of 49.2% [ 115 ].…”

Section: Uasb Treatment Of Municipal Wastewatermentioning

confidence: 99%

“…A more complex scheme for raw municipal wastewater treatment, including a UASB reactor followed by a settler (having HRT of 3 h, where sludge was concentrated) and a digester, was proposed in the work in [ 115 ] to improve global energy efficiency of the system. The integrated process had total HRT of 6 h, achieving a mean COD removal of 49.2% [ 115 ]. Compared to single UASB reactor, the combined UASB-settler-digester system had similar COD abatement and methane production applying a reduced sludge recirculation rate, leading to 50% energy saving [ 115 ].…”

Section: Uasb Treatment Of Municipal Wastewatermentioning

confidence: 99%

See 1 more Smart Citation

Up-Flow Anaerobic Sludge Blanket (UASB) Technology for Energy Recovery: A Review on State-of-the-Art and Recent Technological Advances

2020

View full text Add to dashboard Cite

Up-flow anaerobic sludge blanket (UASB) reactor belongs to high-rate systems, able to perform anaerobic reaction at reduced hydraulic retention time, if compared to traditional digesters. In this review, the most recent advances in UASB reactor applications are critically summarized and discussed, with outline on the most critical aspects for further possible future developments. Beside traditional anaerobic treatment of soluble and biodegradable substrates, research is actually focusing on the treatment of refractory and slowly degradable matrices, thanks to an improved understanding of microbial community composition and reactor hydrodynamics, together with utilization of powerful modeling tools. Innovative approaches include the use of UASB reactor for nitrogen removal, as well as for hydrogen and volatile fatty acid production. Co-digestion of complementary substrates available in the same territory is being extensively studied to increase biogas yield and provide smooth continuous operations in a circular economy perspective. Particular importance is being given to decentralized treatment, able to provide electricity and heat to local users with possible integration with other renewable energies. Proper pre-treatment application increases biogas yield, while a successive post-treatment is needed to meet required effluent standards, also from a toxicological perspective. An increased full-scale application of UASB technology is desirable to achieve circular economy and sustainability scopes, with efficient biogas exploitation, fulfilling renewable energy targets and green-house gases emission reduction, in particular in tropical countries, where limited reactor heating is required.

show abstract

“…Increased methane production potential and COD (chemical oxygen demand) removal efficiency using anaerobic membrane bioreactors (AnMBR) for sewer mining may be studied to optimize the environmental performance of sustainable community-based systems [50], however, upflow anaerobic sludge blanket (UASB) technology may have a better environmental performance, due to the associated environmental impacts of AnMBR membrane fouling [51]. Various other technologies based on circular economy thinking may be modelled to further improve the environmental performance of sanitation options, such as nutrient recovery [52,53], biogas production from urban organic waste [54,55] and blackwater [17,[56][57][58], and water reuse from source-diverted greywater [59].…”

Section: Other Resource Recovery and Future Technologiesmentioning

confidence: 99%

Life Cycle Assessment of Community-Based Sewer Mining: Integrated Heat Recovery and Fit-For-Purpose Water Reuse

et al. 2020

Self Cite

View full text Add to dashboard Cite

Municipal sewage contains significant embedded resources in the form of chemical and thermal energy. Recent developments in sustainable technology have pushed for the integration of resource recovery from household wastewater to achieve net zero energy consumption and carbon-neutral communities. Sewage heat recovery and fit-for-purpose water reuse are options to optimize the resource recovery potential of municipal wastewater. This study presents a comparative life cycle assessment (LCA) focused on global warming potential (GWP), eutrophication potential (EUP), and human health carcinogenic potential (HHCP) of an integrated sewage heat recovery and water reuse system for a hypothetical community of 30,000 people. Conventional space and water heating components generally demonstrated the highest GWP contribution between the different system components evaluated. Sewage-heat-recovery-based district heating offered better environmental performance overall. Lower impact contributions were demonstrated by scenarios with a membrane bioreactor (MBR) and chlorination prior to water reuse applications compared to scenarios that use more traditional water and wastewater treatment technologies and discharge. The LCA findings show that integrating MBR wastewater treatment and water reuse into a district heating schema could provide additional environmental savings at a community scale.

show abstract

Improving the energy efficiency of a pilot-scale UASB-digester for low temperature domestic wastewater treatment

Cited by 32 publications

References 22 publications

High-Rate Anaerobic Digestion of Waste Activated Sludge by Integration of Electro-Fenton Process

High-Rate Anaerobic Digestion of Waste Activated Sludge by Integration of Electro-Fenton Process

Up-Flow Anaerobic Sludge Blanket (UASB) Technology for Energy Recovery: A Review on State-of-the-Art and Recent Technological Advances

Life Cycle Assessment of Community-Based Sewer Mining: Integrated Heat Recovery and Fit-For-Purpose Water Reuse

Contact Info

Product

Resources

About