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Wang X, Daigger G, Lee DJ, Liu J, Ren NQ, Qu J, Liu G, Butler D. Evolving wastewater infrastructure paradigm to enhance harmony with nature. SCIENCE ADVANCES 2018; 4:eaaq0210. [PMID: 30083599 PMCID: PMC6070318 DOI: 10.1126/sciadv.aaq0210] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 06/20/2018] [Indexed: 05/24/2023]
Abstract
Restoring and improving harmony between human activities and nature are essential to human well-being and survival. The role of wastewater infrastructure is evolving toward resource recovery to address this challenge. Yet, existing design approaches for wastewater systems focus merely on technological aspects of these systems. If system design could take advantage of natural ecological processes, it could ensure infrastructure development within ecological constraints and maximize other benefits. To test this hypothesis, we illustrate a data-driven, systems-level approach that couples natural ecosystems and the services they deliver to explore how sustainability principles could be embedded into the life phases of wastewater systems. We show that our design could produce outcomes vastly superior to those of conventional paradigms that focus on technologies alone, by enabling high-level recovery of both energy and materials and providing substantial benefits to offset a host of unintended environmental effects. This integrative study advances our understanding and suggests approaches for regaining a balance between satisfying human demands and maintaining ecosystems.
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Affiliation(s)
- Xu Wang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- Centre for Water Systems, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF, UK
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Glen Daigger
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Junxin Liu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Nan-Qi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Jiuhui Qu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Gang Liu
- Sanitary Engineering, Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, 2600 GA, Delft, Netherlands
| | - David Butler
- Centre for Water Systems, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF, UK
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Energy use and carbon footprints differ dramatically for diverse wastewater-derived carbonaceous substrates: An integrated exploration of biokinetics and life-cycle assessment. Sci Rep 2017; 7:243. [PMID: 28325897 PMCID: PMC5428015 DOI: 10.1038/s41598-017-00245-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 02/15/2017] [Indexed: 11/09/2022] Open
Abstract
Energy neutrality and reduction of carbon emissions are significant challenges to the enhanced sustainability of wastewater treatment plants (WWTPs). Harvesting energy from wastewater carbonaceous substrates can offset energy demands and enable net power generation; yet, there is limited research about how carbonaceous substrates influence energy and carbon implications of WWTPs with integrated energy recovery at systems-level. Consequently, this research uses biokinetics modelling and life cycle assessment philology to explore this notion, by tracing and assessing the quantitative flows of energy embodied or captured, and by exploring the carbon footprint throughout an energy-intensive activated sludge process with integrated energy recovery facilities. The results indicate that energy use and carbon footprint per cubic meter of wastewater treated, varies markedly with the carbon substrate. Compared with systems driven with proteins, carbohydrates or other short-chain fatty acids, systems fed with acetic acid realized energy neutrality with maximal net gain of power from methane combustion (0.198 kWh) and incineration of residual biosolids (0.153 kWh); and also achieved a negative carbon footprint (72.6 g CO2). The findings from this work help us to better understand and develop new technical schemes for improving the energy efficiency of WWTPs by repurposing the stream of carbon substrates across systems.
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Zaborowska E, Czerwionka K, Makinia J. Strategies for achieving energy neutrality in biological nutrient removal systems - a case study of the Slupsk WWTP (northern Poland). WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2017; 75:727-740. [PMID: 28192366 DOI: 10.2166/wst.2016.564] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The paper presents a model-based evaluation of technological upgrades on the energy and cost balance in a large biological nutrient removal (BNR) wastewater treatment plant (WWTP) in the city of Slupsk (northern Poland). The proposed upgrades include chemically enhanced primary sludge removal and reduction of the nitrogen load in the deammonification process employed for reject water treatment. Simulations enabled to estimate the increased biogas generation and decreased energy consumption for aeration. The proposed upgrades may lead the studied WWTP from the energy deficit to energy neutrality and positive cost balance, while still maintaining the required effluent standards for nitrogen. The operating cost balance depends on the type of applied coagulants/flocculants and specific costs of electric energy. The choice of the coagulant/flocculent was found as the main factor determining a positive cost balance.
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Affiliation(s)
- Ewa Zaborowska
- Faculty of Civil and Environmental Engineering, Gdansk University of Technology, Gdansk 80-233, Poland E-mail:
| | - Krzysztof Czerwionka
- Faculty of Civil and Environmental Engineering, Gdansk University of Technology, Gdansk 80-233, Poland E-mail:
| | - Jacek Makinia
- Faculty of Civil and Environmental Engineering, Gdansk University of Technology, Gdansk 80-233, Poland E-mail:
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Wang X, Li Y, Liu J, Ren NQ, Qu J. Augmentation of protein-derived acetic acid production by heat-alkaline-induced changes in protein structure and conformation. WATER RESEARCH 2016; 88:595-603. [PMID: 26562796 DOI: 10.1016/j.watres.2015.10.055] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 10/27/2015] [Accepted: 10/28/2015] [Indexed: 06/05/2023]
Abstract
Waste-derived acetic acid (HAc) is an attractive feedstock for microbe-mediated biofuel production. However, fermentative conversion of HAc from waste-activated sludge (WAS) has low yield because of the high concentration of proteins not readily utilizable by microorganisms without prior hydrolysis. We investigated a combined technology for HAc augmentation during sludge protein fermentation. The maximal HAc yield increased over two-fold, reaching 0.502 ± 0.021 g/g protein (0.36 ± 0.01 g COD/g COD, ∼52% of the total volatile fatty acids) when synthetic sludge protein was heated at 120 °C for 30 min, treated at pH 12 for 24 h, and fermented at pH 9 for 72 h. Comprehensive analysis illustrated that the heat-alkaline pretreatment significantly induced protein fragmentation, simultaneously increasing the efficiency of protein biohydrolysis (from 35.5% to 85.9%) by inducing conformational changes indicative of protein unfolding. Consequently, the native α-helix content was decreased from 67.3% to 32.5% by conversion to an unordered shape, whose content increased from 27.5% to 45.5%; disulfide bonds were cleaved, whereas the main S-S stretching pattern was altered from gauche-gauche-gauche to gauche-gauche-trans, consequently causing increased protein susceptibility to proteolytic hydrolysis (76.3% vs. 47.0%). Economic analysis indicated that anaerobic fermentation with appropriate heat-alkaline pretreatment is a cost-effective approach for waste conversion to energy sources such as HAc.
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Affiliation(s)
- Xu Wang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Yanbo Li
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Junxin Liu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Nan-Qi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Jiuhui Qu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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