1
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Tatla HK, Ismail S, Khan MA, Dhar BR, Gupta R. Coupling hydrothermal liquefaction and anaerobic digestion for waste biomass valorization: A review in context of circular economy. CHEMOSPHERE 2024; 361:142419. [PMID: 38789051 DOI: 10.1016/j.chemosphere.2024.142419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 05/09/2024] [Accepted: 05/22/2024] [Indexed: 05/26/2024]
Abstract
In light of the substantial global production of biomass waste, effective waste management and energy recovery solutions are of paramount importance. Hydrothermal liquefaction (HTL) and anaerobic digestion (AD) have emerged as innovative techniques for converting biomass waste into valuable resources. Their integration creates a synergistic framework that mitigates inherent limitations, leading to improved efficiency, enhanced product quality, and the comprehensive utilization of biomass. This review paper investigates the integration of HTL and AD, highlighting its significance and potential benefits as well as the optimal sequencing (HTL followed by AD and AD followed by HTL). The review encompasses experimental procedures, factors influencing both sequencing options, energy recovery characterizations, final product outcomes, as well as toxicological assessments and discussions on reduction. Additionally, it delves into the transition towards a circular bioeconomy and discusses the challenges and opportunities intrinsic to these processes. The findings presented in this review offer valuable insights to shape future research in this evolving field.
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Affiliation(s)
- Harveen Kaur Tatla
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada
| | - Sherif Ismail
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, Canada
| | - Mohd Adnan Khan
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada.
| | - Bipro Ranjan Dhar
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, Canada.
| | - Rajender Gupta
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada.
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2
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Bharadwaj A, Holwerda EK, Regan JM, Lynd LR, Richard TL. Enhancing anaerobic digestion of lignocellulosic biomass by mechanical cotreatment. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:76. [PMID: 38831375 PMCID: PMC11149370 DOI: 10.1186/s13068-024-02521-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 05/16/2024] [Indexed: 06/05/2024]
Abstract
BACKGROUND The aim of this study was to increase the accessibility and accelerate the breakdown of lignocellulosic biomass to methane in an anaerobic fermentation system by mechanical cotreatment: milling during fermentation, as an alternative to conventional pretreatment prior to biological deconstruction. Effluent from a mesophilic anaerobic digester running with unpretreated senescent switchgrass as the predominant carbon source was collected and subjected to ball milling for 0.5, 2, 5 and 10 min. Following this, a batch fermentation test was conducted with this material in triplicate for an additional 18 days with unmilled effluent as the 'status quo' control. RESULTS The results indicate 0.5 - 10 min of cotreatment increased sugar solubilization by 5- 13% when compared to the unmilled control, with greater solubilization correlated with increased milling duration. Biogas concentrations ranged from 44% to 55.5% methane with the balance carbon dioxide. The total biogas production was statistically higher than the unmilled control for all treatments with 2 or more minutes of milling (α = 0.1). Cotreatment also decreased mean particle size. Energy consumption measurements of a lab-scale mill indicate that longer durations of milling offer diminishing benefits with respect to additional methane production. CONCLUSIONS Cotreatment in anaerobic digestion systems, as demonstrated in this study, provides an alternative approach to conventional pretreatments to increase biogas production from lignocellulosic grassy material.
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Affiliation(s)
- Anahita Bharadwaj
- The Department of Agricultural and Biological Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Evert K Holwerda
- Thayer School of Engineering, Dartmouth College, Hanover, NH, 03755, USA
| | - John M Regan
- The Department of Civil and Environmental Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Lee R Lynd
- Thayer School of Engineering, Dartmouth College, Hanover, NH, 03755, USA
| | - Tom L Richard
- The Department of Agricultural and Biological Engineering, The Pennsylvania State University, University Park, PA, 16802, USA.
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3
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Palansooriya KN, Dissanayake PD, Igalavithana AD, Tang R, Cai Y, Chang SX. Converting food waste into soil amendments for improving soil sustainability and crop productivity: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 881:163311. [PMID: 37044338 DOI: 10.1016/j.scitotenv.2023.163311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 03/29/2023] [Accepted: 04/01/2023] [Indexed: 04/14/2023]
Abstract
One-third of the annual food produced globally is wasted and much of the food waste (FW) is unutilized; however, FW can be valorized into value-added industrial products such as biofuel, chemicals, and biomaterials. Converting FW into soil amendments such as compost, vermicompost, anaerobic digestate, biofertilizer, biochar, and engineered biochar is one of the best nutrient recovery and FW reuse approaches. The soil application of FW-based amendments can improve soil fertility, increase crop production, and reduce contaminants by altering soil's chemical, physical, microbial, and faunal properties. However, the efficiency of the amendment for improving ecosystem sustainability depends on the type of FW, conversion method, application rate, soil type, and crop type. Engineered biochar/biochar composite materials produced using FW have been identified as promising amendments for soil remediation, reducing commercial fertilizer usage, and increasing soil nutrient use efficiency. The development of quality standards and implementation of policies and regulations at all stages of the food supply chain are necessary to manage (reduce and re-use) FW.
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Affiliation(s)
| | | | | | - Ronggui Tang
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China
| | - Yanjiang Cai
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China
| | - Scott X Chang
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China; Department of Renewable Resources, University of Alberta, Edmonton T6G 2E3, Canada.
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4
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Nyang'au JO, Møller HB, Sørensen P. Effects of electrokinetic and ultrasonication pre-treatment and two-step anaerobic digestion of biowastes on the nitrogen fertiliser value by injection or surface banding to cereal crops. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 326:116699. [PMID: 36395644 DOI: 10.1016/j.jenvman.2022.116699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/29/2022] [Accepted: 11/01/2022] [Indexed: 06/16/2023]
Abstract
Biogas production from anaerobic digestion (AD) of biowastes is restricted by the recalcitrant nature of many substrates, and this may also reduce the fertiliser value of the produced digestate. The degradability of substrates can potentially be enhanced by physico-chemical pre-treatments before AD, and/or the degradation can be increased by a longer digestion time. In this study, we evaluated the effects of electrokinetic (high voltage) and ultrasonication pre-treatments of biowastes in a two-step AD process on nitrogen fertiliser replacement value (NFRV) of digestates obtained from two biogas plants with contrasting hydraulic retention time (HRT) in the primary AD step. The fertiliser value was tested by direct injection to spring barley and surface-banding to winter wheat, and the ammonium N was 15N-labelled to evaluate ammonia losses. The electrokinetic pre-treatment step significantly (p < 0.05) increased the NH4+-N/total N in the digestates before the second AD step but had an insignificant effect on the fertiliser value in winter wheat and spring barley. Ultrasonication pre-treatment had also no significant effect on the fertiliser value. The two-step AD significantly (p < 0.001) increased 15N recoveries and mineral fertiliser equivalence of labelled ammonium-N in winter wheat and reduced ammonia losses, with a significant effect (p < 0.001) observed in digestates sourced from a shorter HRT biogas reactor. The fertiliser equivalence of labelled ammonium-N in the digestates was 80-88% after injection, indicating relatively low N immobilisation with all the digestates. NFRV in the crops was mainly explained by the NH4+-N/total N ratio, C/N ratio and dry matter content of the digestates. The findings suggest that electrokinetic and ultrasonication pre-treatments combined with a second AD step have no considerable impact on the fertiliser value of digestates, whereas a second AD step significantly reduced ammonia losses after application by surface-banding in winter wheat.
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Affiliation(s)
| | - Henrik Bjarne Møller
- Department of Biological and Chemical Engineering, Aarhus University, Blichers Allé 20, 8830, Tjele, Denmark
| | - Peter Sørensen
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830, Tjele, Denmark
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5
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Palakodeti A, Rupani PF, Azman S, Dewil R, Appels L. Novel approach to ammonia recovery from anaerobic digestion via side-stream stripping at multiple pH levels. BIORESOURCE TECHNOLOGY 2022; 361:127685. [PMID: 35878773 DOI: 10.1016/j.biortech.2022.127685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/14/2022] [Accepted: 07/19/2022] [Indexed: 06/15/2023]
Abstract
Ammonia recovery from anaerobic digesters via side-stream stripping is a technique to recover nitrogen from manure wastes. This study demonstrated a novel approach to determining ammonia recovery to maintain total ammonia concentrations in the digester in the range of 1.7-2.1 gN/L. Increasing the pH during stripping from 8, 8.5 to 9.5 did not affect the stability of the digester. Methane yields of 60-80 mL/(gVS.d) and volatile fatty acid concentrations of 0-500 mg/L were reported throughout its operation. The low solubilisation increase upon recirculation of the digestate explained the lack of change in methane yields due to side-stream stripping. Increasing the pH during stripping also did not affect the digester's operating pH, which was attributed to the neutralising effect of biogas as stripping gas. Therefore, total ammonia concentrations in the digester can be controlled by determining the extent of ammonia recovery, and the pH during stripping can be increased without compromising the digester's stability.
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Affiliation(s)
- Advait Palakodeti
- KU Leuven, Department of Chemical Engineering, Process and Environmental Technology Lab, J. De Nayerlaan 5, B-2860 Sint-Katelijne-Waver, Belgium.
| | - Parveen Fatemeh Rupani
- KU Leuven, Department of Chemical Engineering, Process and Environmental Technology Lab, J. De Nayerlaan 5, B-2860 Sint-Katelijne-Waver, Belgium.
| | - Samet Azman
- Avans University of Applied Sciences, Academy of Life Sciences and Technology, Lovensdijkstraat 61, 4818 AJ, Breda, Netherlands
| | - Raf Dewil
- KU Leuven, Department of Chemical Engineering, Process and Environmental Technology Lab, J. De Nayerlaan 5, B-2860 Sint-Katelijne-Waver, Belgium; University of Oxford, Department of Engineering Science, Parks Road, Oxford OX1 3PJ, United Kingdom.
| | - Lise Appels
- KU Leuven, Department of Chemical Engineering, Process and Environmental Technology Lab, J. De Nayerlaan 5, B-2860 Sint-Katelijne-Waver, Belgium.
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6
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Romio C, Vedel Wegener Kofoed M, Bjarne Møller H. Effect of ultrasonic and electrokinetic post-treatments on methane yield and viscosity of agricultural digestate. BIORESOURCE TECHNOLOGY 2022; 358:127388. [PMID: 35644450 DOI: 10.1016/j.biortech.2022.127388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/21/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
The impact of post-treatment of digestate prior to its recirculation to the digester has been evaluated with industrial-scale ultrasonication and electrokinetic treatment units. Residual methane yields of untreated digestate samples from four biogas plants varied between 99 and 134 ml/g of volatile solids (after 97 days of digestion). At the tested conditions (1.90-7.60 kWh/t for ultrasonication and 4.37-6.06 kWh/t for electrokinetic disintegration), no significant increase in methane yields were obtained. Increases in maximum methane production rates of up to 42% were observed in samples from one of the biogas plants, resulting in net energy gains between 1.06 and 7.04 kWh/t (after 26 and 66 days of digestion). Both treatments significantly reduced digestate viscosities, especially of highly viscous samples. Lower viscosities could reduce the energy demand for pumping and stirring in the digester, enabling the potential for increased organic loading and increased methane production.
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Affiliation(s)
- Cristiane Romio
- Department of Biological and Chemical Engineering, Aarhus University, Hangøvej 2, 8200 Aarhus N, Denmark.
| | | | - Henrik Bjarne Møller
- Department of Biological and Chemical Engineering, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
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7
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Ultrasonic Processing of Food Waste to Generate Value-Added Products. Foods 2022; 11:foods11142035. [PMID: 35885279 PMCID: PMC9319240 DOI: 10.3390/foods11142035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/04/2022] [Accepted: 07/06/2022] [Indexed: 02/04/2023] Open
Abstract
Ultrasonic processing has a great potential to transform waste from the food and agriculture industry into value-added products. In this review article, we discuss the use of ultrasound for the valorisation of food and agricultural waste. Ultrasonic processing is considered a green technology as compared to the conventional chemical extraction/processing methods. The influence of ultrasound pre-treatment on the soluble chemical oxygen demand (SCOD), particle size, and cell wall content of food waste is first discussed. The use of ultrasonic processing to produce/extract bioactives such as oil, polyphenolic, polysaccharides, fatty acids, organic acids, protein, lipids, and enzymes is highlighted. Moreover, ultrasonic processing in bioenergy production from food waste such as green methane, hydrogen, biodiesel, and ethanol through anaerobic digestion is also reviewed. The conversion of waste oils into biofuels with the use of ultrasound is presented. The latest developments and future prospective on the use of ultrasound in developing energy-efficient methods to convert food and agricultural waste into value-added products are summarised.
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8
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Mozhiarasi V. Overview of pretreatment technologies on vegetable, fruit and flower market wastes disintegration and bioenergy potential: Indian scenario. CHEMOSPHERE 2022; 288:132604. [PMID: 34678338 DOI: 10.1016/j.chemosphere.2021.132604] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 10/11/2021] [Accepted: 10/16/2021] [Indexed: 06/13/2023]
Abstract
Disposal of segregated organic fractions of centralized wholesale market wastes (i.e. vegetable, fruit and flower markets waste) in dumpsites/landfills are not only a serious issue but also underutilizes the huge potency of these organic wastes. Anaerobic digestion (AD) is a promising technology for converting organic wastes into methane, as a carbon-neutral alternative to conventional fuels. The major challenges related to the AD process are poor biodegradation of wastes and buffering capacity within the anaerobic digester that lowers the biogas yield. To accelerate biodegradation and to enhance the process efficacy of anaerobic digestion, several pretreatment technologies (mechanical, thermal, biological, chemical and combined pre-treatments) for organic wastes prior to the AD process were developed. This review article presents a comprehensive analysis of research updates in pretreatment techniques for vegetable, fruit and flower markets wastes for enhancing biogas yields during the AD process. The technological aspects of the pretreatment process are described and their efficiency comparison with the resultant process yields and environmental benefits are also discussed. The challenges and technical issues associated with each pretreatment and future research directions for overcoming the field implementation issues are also proposed.
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Affiliation(s)
- Velusamy Mozhiarasi
- CLRI Regional Centre Jalandhar, CSIR-Central Leather Research Institute, Jalandhar, 144021, Punjab, India.
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9
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Assessment of the Possibilities for the Use of Selected Waste in Terms of Biogas Yield and Further Use of Its Digestate in Agriculture. MATERIALS 2022; 15:ma15030988. [PMID: 35160933 PMCID: PMC8839082 DOI: 10.3390/ma15030988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 12/17/2022]
Abstract
The utilization of municipal waste and sewage sludge as a source of energy is technically very difficult due to high variability of their physical and chemical properties. The aim of this study was to evaluate the efficiency of the conversion of biomass contained in the whitewater fraction of municipal waste and sewage sludge by means of methanogenesis. The second objective was to assess the chemical composition of the digestate in the context of its use for fertilizer purposes. The whitewater fraction of municipal waste and sewage sludge was subjected to methanogenesis under static experimental conditions, according to DIM DIN 38414 methodology. The methanogenesis of concentrated substrates used in agricultural biogas plants was taken as a reference to evaluate the efficiency of the process. The organic fraction of the municipal waste was characterized by approximately 30% lower value of the soluble COD, with a comparable level of total COD compared to other materials. The total biogas yield, i.e., 404 dm3 per 1 kg of dry weight of the batch, was measured in the facility with sewage sludge. In COD value, this is 0.232 dm3·g O2 COD. In the case of corn, these values were, respectively, 324 dm3 and 0.193, and for the organic sub-sieve fraction of municipal waste, 287 dm3·kg−1 dw or 0.178 dm3·g O2 COD, respectively. The type of fermented material did not affect the intensity of biogas production. The maximum level of biogas production occurred between the 13th and 15th day of the process. The digestate obtained in the process of methanogenesis of corn silage and the organic fraction of municipal waste was characterized by good parameters in terms of possible use for fertilization purposes.
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10
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Nordell E, Björn A, Waern S, Shakeri Yekta S, Sundgren I, Moestedt J. Thermal post-treatment of digestate in order to increase biogas production with simultaneous pasteurization. J Biotechnol 2021; 344:32-39. [PMID: 34929206 DOI: 10.1016/j.jbiotec.2021.12.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 12/03/2021] [Accepted: 12/13/2021] [Indexed: 01/17/2023]
Abstract
Biogas production by anaerobic digestion (AD) of organic wastes is important for the transition to fossil free fuels in both the transport sector, industries and shipping. The aim of this study was to target the residual organic matter in the outgoing residue from the AD process, so called digestate, with different thermal treatment methods in order to improve digestate degradability and biogas potential upon post-digestion. The thermal treatment was performed at 55 °C in 24 h, 70 °C in 1 h and by thermal hydrolysis process (THP; 165 °C, 8 bar in 0.33 h), and were carefully selected to offer a simultaneous possibility for pasteurization of the digestate according to the regulations in Sweden. Digestates from ten full-scale biogas plants were collected, with different substrate profiles including wastewater treatment plant (WWTP), food waste digestion, agriculture digestion and manure digestion. The results showed that all thermal treatment methods caused increased dissolved organic carbon concentration (DOC). Four of the thermal treated digestates with the highest increase in DOC were subsequently tested for the bio-methane potential. Thermal treatments at 70 °C and THP, respectively, resulted in the highest increase in bio-methane potentials, with an increase of 15-39% for one WWTP, 38 - 40% for digestate from an agriculture digestion plant and 20 - 22% for digestate from a co-digestion plant treating food waste. Interestingly, the bio-methane potential from digestate treated with the energy-intense THP method, did not show any significant difference compared to thermal treatment at 70 °C for 1 h. The outcomes of this study suggest that placing a pasteurization unit between a main digester and a post digester, when applying two-step digestion allows for a combined pasteurization and increased biogas production.
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Affiliation(s)
- E Nordell
- Tekniska verken i Linköping AB, Department of Biogas R &D, Box 1500, Linköping SE-581 15, Sweden; Biogas Research Center, Linköping University, Linköping SE-581 83, Sweden
| | - A Björn
- Biogas Research Center, Linköping University, Linköping SE-581 83, Sweden; Department of Thematic Studies-Environmental Change, Linköping University, Linköping SE-581 83, Sweden
| | - S Waern
- Tekniska verken i Linköping AB, Department of Biogas R &D, Box 1500, Linköping SE-581 15, Sweden; Biogas Research Center, Linköping University, Linköping SE-581 83, Sweden
| | - S Shakeri Yekta
- Biogas Research Center, Linköping University, Linköping SE-581 83, Sweden; Department of Thematic Studies-Environmental Change, Linköping University, Linköping SE-581 83, Sweden
| | - I Sundgren
- Biogas Research Center, Linköping University, Linköping SE-581 83, Sweden; Department of Thematic Studies-Environmental Change, Linköping University, Linköping SE-581 83, Sweden
| | - J Moestedt
- Tekniska verken i Linköping AB, Department of Biogas R &D, Box 1500, Linköping SE-581 15, Sweden; Biogas Research Center, Linköping University, Linköping SE-581 83, Sweden; Department of Thematic Studies-Environmental Change, Linköping University, Linköping SE-581 83, Sweden.
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11
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Kundariya N, Mohanty SS, Varjani S, Hao Ngo H, W C Wong J, Taherzadeh MJ, Chang JS, Yong Ng H, Kim SH, Bui XT. A review on integrated approaches for municipal solid waste for environmental and economical relevance: Monitoring tools, technologies, and strategic innovations. BIORESOURCE TECHNOLOGY 2021; 342:125982. [PMID: 34592615 DOI: 10.1016/j.biortech.2021.125982] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 09/15/2021] [Accepted: 09/15/2021] [Indexed: 06/13/2023]
Abstract
Rapid population growth, combined with increased industrialization, has exacerbated the issue of solid waste management. Poor management of municipal solid waste (MSW) not only has detrimental environmental consequences but also puts public health at risk and introduces several other socioeconomic problems. Many developing countries are grappling with the problem of safe disposing of large amounts of produced municipal solid waste. Unmanaged municipal solid waste pollutes the environment, so its use as a potential renewable energy source would aid in meeting both increased energy needs and waste management. This review investigates emerging strategies and monitoring tools for municipal solid waste management. Waste monitoring using high-end technologies and energy recovery from MSW has been discussed. It comprehensively covers environmental and economic relevance of waste management technologies based on innovations achieved through the integration of approaches.
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Affiliation(s)
- Nidhi Kundariya
- Gujarat Pollution Control Board, Gandhinagar-382 010, Gujarat, India; Kadi Sarva Vishwavidyalaya, Gandhinagar, Gujarat 382015, India
| | - Swayansu Sabyasachi Mohanty
- Gujarat Pollution Control Board, Gandhinagar-382 010, Gujarat, India; Central University of Gujarat, Gandhinagar- 382030, Gujarat, India
| | - Sunita Varjani
- Gujarat Pollution Control Board, Gandhinagar-382 010, Gujarat, India.
| | - Huu Hao Ngo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Jonathan W C Wong
- Institute of Bioresource and Agriculture, Hong Kong Baptist University, Hong Kong, PR China
| | | | - Jo-Shu Chang
- Department of Chemical Engineering and Materials Science, College of Engineering, Tunghai University, Taichung, Taiwan; Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung, Taiwan; Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - How Yong Ng
- National University of Singapore, Environmental Research Institute, 5A Engineering Drive 1, Singapore 117411, Singapore
| | - Sang-Hyoun Kim
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of South Korea
| | - Xuan-Thanh Bui
- Faculty of Environment and Natural Resources, Ho Chi Minh City University of Technology (HCMUT), Ho Chi Minh City 700000, Vietnam; Key Laboratory of Advanced Waste Treatment Technology, Vietnam National University Ho Chi Minh (VNU-HCM), Linh Trung ward, Thu Duc district, Ho Chi Minh City 700000, Vietnam
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12
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Molaey R, Yesil H, Calli B, Tugtas AE. Enhanced heavy metal leaching from sewage sludge through anaerobic fermentation and air-assisted ultrasonication. CHEMOSPHERE 2021; 279:130548. [PMID: 33878691 DOI: 10.1016/j.chemosphere.2021.130548] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 03/18/2021] [Accepted: 04/07/2021] [Indexed: 06/12/2023]
Abstract
Interest in using stabilized sewage sludge in agriculture is mainly to benefit from its nutrient content, soil conditioning properties, and water holding capacity. Therefore, sludge management practice needs to be directed from treatment liability towards the recovery of chemical assets embedded in sludge. In this study, anaerobic fermentation process integrated with a new treatment method; i.e., air-assisted ultrasonication, was used to assess the leaching of heavy metals (HM) from waste activated sludge (WAS). Fermentation processes resulted in 9390 mg COD/L of volatile fatty acids (VFAs) production, 26% Ni solubilization and up to 3.4% solubilization of other target metals (Cu and Zn). Application of the air-assisted ultrasonication as a post-treatment to fermentation process stimulated the migration and transformation of HMs to the liquid fraction of the digestate. Applying specific energy input greater than 9 kJ/g total solids (TS) through ultrasonication and supplying air with constant flow rate of 0.875 L of air/(L of digestate.min) resulted in leaching of more than 83% of Ni, 82% of Cu and 80% of Zn.
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Affiliation(s)
- Rahim Molaey
- Department of Environmental Engineering, Marmara University, 34722, Goztepe, Istanbul, Turkey; Kabul Polytechnic University, Kabul, Afghanistan.
| | - Hatice Yesil
- Department of Environmental Engineering, Marmara University, 34722, Goztepe, Istanbul, Turkey.
| | - Baris Calli
- Department of Environmental Engineering, Marmara University, 34722, Goztepe, Istanbul, Turkey.
| | - Adile Evren Tugtas
- Department of Environmental Engineering, Marmara University, 34722, Goztepe, Istanbul, Turkey.
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13
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Digestate Post-Treatment Strategies for Additional Biogas Recovery: A Review. SUSTAINABILITY 2021. [DOI: 10.3390/su13169295] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Anaerobic digestion (AD) is a process in which microorganisms, under oxygen-free conditions, convert organic matter into biogas and digestate. Normally, only 40–70% of biomass is converted into biogas; therefore, digestate still contains significant amounts of degradable organic matter and biogas potential. The recovery of this residual biogas potential could optimize substrate utilization and lower methane emissions during digestate storage and handling. Post-treatment methods have been studied with the aim of enhancing the recovery of biogas from digestate. This review summarizes the studies in which these methods have been applied to agricultural and wastewater digestate and gives a detailed overview of the existing scientific knowledge in the field. The current studies have shown large variation in outcomes, which reflects differences in treatment conditions and digestate compositions. While studies involving biological post-treatment of digestate are still limited, mechanical methods have been relatively more explored. In some cases, they could increase methane yields of digestate; however, the extra gain in methane has often not covered treatment energy inputs. Thermal and chemical methods have been studied the most and have yielded some promising results. Despite all the research conducted in the area, several knowledge gaps still should be addressed. For a more thorough insight of the pros and cons within post-treatment, more research where the effects of the treatments are tested in continuous AD systems, along with detailed economic analysis, should be performed.
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Cesaro A. The valorization of the anaerobic digestate from the organic fractions of municipal solid waste: Challenges and perspectives. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 280:111742. [PMID: 33308930 DOI: 10.1016/j.jenvman.2020.111742] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 11/12/2020] [Accepted: 11/24/2020] [Indexed: 05/12/2023]
Abstract
The anaerobic digestion is a well-established process for the treatment of organic solid waste, pursuing its conversion into a methane rich gas destined to energy generation. Research has largely dealt with the enhancement of the overall bioconversion yields, providing several strategies to maximize the production of bio-methane from the anaerobic processing of a wide variety of substrates. Nevertheless, the valorization of the process effluents should be pursued as well, especially if the anaerobic digestion is regarded in the light of the circular economy principles. Aim of this work is in identifying the state of the art of the strategies to manage the digestate from the anaerobic processing of the organic fractions of municipal solid waste. Conventional approaches are described and novel solutions are figured out in order to highlight their potential scale up as well as to address future research perspectives.
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Affiliation(s)
- Alessandra Cesaro
- Department of Civil, Architectural and Environmental Engineering, University of Napoli Federico II, via Claudio 21, 80125, Napoli, Italy.
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15
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Li Y, Zhao J, Krooneman J, Euverink GJW. Strategies to boost anaerobic digestion performance of cow manure: Laboratory achievements and their full-scale application potential. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 755:142940. [PMID: 33348487 DOI: 10.1016/j.scitotenv.2020.142940] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/03/2020] [Accepted: 10/04/2020] [Indexed: 06/12/2023]
Abstract
Cow manure represents a surplus manure waste in agricultural food sectors, which requires proper disposal. Anaerobic digestion, in this regard, has raised global interest owing to its apparent environmental benefits, including simultaneous waste diminishment and renewable energy generation. However, dedicated intensifications are necessary to promote the degradation of recalcitrant lignocellulosic components of cow manure. Hence, this manuscript presents a review of how to exploit cow manure in anaerobic digestion through different incentives extensively at lab-scale and full-scale. These strategies comprise 1) co-digestion; 2) pretreatment; 3) introduction of additives (trace metals, carbon-based materials, low-cost composites, nanomaterials, and microbial cultures); 4) innovative systems (bio-electrochemical fields and laser irradiation). Results imply that co-digestion and pretreatment approaches gain the predominance on promoting the digestion performance of cow manure. Particularly, for the co-digestion scenario, the selection of lignin-poor co-substrate is highlighted to produce maximum synergy and pronounced removal of lignocellulosic compounds of cow manure. Mechanical, thermal, and biological (composting) pretreatments generate mild improvement at laboratory-scale and are proved applicable in full-scale facilities. It is noteworthy that the introduction of additives (Fe-based nanomaterials, carbon-based materials, and composites) is acquiring more attention and shows promising full-scale application potential. Finally, bio-electrochemical fields stand out in laboratory trials and may serve as future reactor modules in agricultural anaerobic digestion installations treating cow manure.
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Affiliation(s)
- Yu Li
- Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Jing Zhao
- Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Janneke Krooneman
- Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Gert Jan Willem Euverink
- Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands.
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Boni MR, Polettini A, Pomi R, Rossi A. Effect of ultrasonic post-treatment on anaerobic digestion of lignocellulosic waste. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2021; 39:221-232. [PMID: 32597378 DOI: 10.1177/0734242x20931940] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
This paper evaluates the effects of ultrasonication (US) applied, individually or in combination with a mechanical treatment, to the effluent of anaerobic digestion (AD) of lignocellulosic waste, on methane (CH4) production. US of the substrate downstream of AD is a relatively novel concept aimed at improving the degradation of recalcitrant components in order to enhance the overall energy efficiency of the process. US tests were carried out on real digestate samples at different energies (500-50,000 kJ/kg total solids (TS), corresponding to sonication densities of 0.08-0.45 W/ml). AD tests were performed on mixtures of sonicated (Sus) and untreated (S) substrate at two different Sus: S ratios (25:75 and 75:25 w/w), simulating post-sonicated material recycling to the biological process. The US effect was estimated through the solubilization degree of organic matter, as well as the CH4 production yield and kinetics, which were all found to be enhanced by the treatment. At Sus: S = 75:25 and Es ≥ 20,000 kJ/kg TS (0.25 W/ml), CH4 production improved by 20% and the values of the kinetic parameters increased by 64-82%.
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Affiliation(s)
- Maria Rosaria Boni
- Department of Civil and Environmental Engineering, Sapienza University of Rome, Rome, Italy
| | - Alessandra Polettini
- Department of Civil and Environmental Engineering, Sapienza University of Rome, Rome, Italy
| | - Raffaella Pomi
- Department of Civil and Environmental Engineering, Sapienza University of Rome, Rome, Italy
| | - Andreina Rossi
- Department of Civil and Environmental Engineering, Sapienza University of Rome, Rome, Italy
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Díaz AI, Oulego P, González JM, Laca A, Díaz M. Physico-chemical pre-treatments of anaerobic digestion liquor for aerobic treatment. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 274:111189. [PMID: 32801104 DOI: 10.1016/j.jenvman.2020.111189] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 07/14/2020] [Accepted: 08/01/2020] [Indexed: 06/11/2023]
Abstract
Centrifugation of anaerobically digested sewage sludge gives rise to a solid phase, which could be employed as a fertilizer, and a liquid fraction (ADL), which should be treated before being spilled out. This is not an easy task because this liquor is characterized for presenting high COD (~16000 mg O2/L), high ammonium content (~4000 mg/L) and low biodegradability (BOD5/COD ~0.2). With the objective to pre-treat this aqueous waste before its treatment by means of more traditional aerobic processes, different physico-chemical methods (ultrasound, ozonation, hydrolysis and wet air oxidation) were assessed in this work. Ultrasound and thermal hydrolysis gave solubilizations around 47% and 68% respectively. The best results in terms of total COD removal were obtained when wet air oxidation (8 h, 160 C-200 °C and 6.0 MPa) and ozonation (8 h, 25 °C, 12 g/h O3) techniques were employed achieving COD degradations of 71% and 38%, respectively. The pre-treatment of ADL with the four assayed techniques improved considerably the biodegradability (BOD5/COD) of the effluent, with values around 0.3-0.4, depending on the treatment. The experimental data were successfully fitted by kinetic models and the kinetic constants for the solubilization and degradation steps were obtained. Application of the proposed models can be of interest for the optimization and selection of the most suitable techniques and operational conditions, in each particular case.
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Affiliation(s)
- Ana Isabel Díaz
- Department of Chemical and Environmental Engineering. University of Oviedo. C/Julián Clavería, s/n, E-33006, Oviedo, Asturias, Spain
| | - Paula Oulego
- Department of Chemical and Environmental Engineering. University of Oviedo. C/Julián Clavería, s/n, E-33006, Oviedo, Asturias, Spain
| | - J Manuel González
- R&D, COGERSA SAU. C/ La Zoreda, s/n, E-33697, Gijón, Asturias, Spain
| | - Adriana Laca
- Department of Chemical and Environmental Engineering. University of Oviedo. C/Julián Clavería, s/n, E-33006, Oviedo, Asturias, Spain.
| | - Mario Díaz
- Department of Chemical and Environmental Engineering. University of Oviedo. C/Julián Clavería, s/n, E-33006, Oviedo, Asturias, Spain
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Somers MH, Azman S, Bollansée G, Goedemé T, Leermakers M, Alonso-Fariñas B, Appels L. Behavior of trace elements and micronutrients in manure digestate during ozone treatment. CHEMOSPHERE 2020; 252:126477. [PMID: 32222523 DOI: 10.1016/j.chemosphere.2020.126477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 03/09/2020] [Accepted: 03/11/2020] [Indexed: 06/10/2023]
Abstract
Digestate treatment techniques have recently been proposed as a strategy to increase the ultimate biogas yield from dairy manure and to improve the digestate quality as an organic fertilizer. These studies however rarely take the trace elements (TE) and nutrient partitioning into account. This study focusses on ozone treatment (5-40 g O3 kg-1 Total Solids (TS)) as a digestate treatment technique to control the concentration of TE and nutrients in the liquid phase of the digestate. Controlling the TE and nutrient concentrations in the liquid and solid digestate can improve the agronomic value of dairy manure digestate. The ozone concentration of the gas stream entering reactor was 48.53 g O3/Nm³ or 3.4% w/w O3 in O2-gas. The experiments were repeated using pure oxygen gas to investigate its influence. The results from ozonation and oxygenation of the dairy manure digestates revealed that O3 treatment up to 40 g O3 kg-1 TS did not have a more pronounced effect on the biochemical parameters compared to supplementation of pure O2. Ozonation of the digestate and the supernatant showed that the TE concentration in the liquid phase followed a parabolic profile. The observed initial increase in this parabolic profile was explained by the release of TE from the organic matter to the supernatant causing an increase in TE concentration, followed by a decrease due to precipitation of TE as hydroxides and sulfides, due to the increasing pH and sulphur concentrations.
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Affiliation(s)
- Matthijs H Somers
- KU Leuven Department of Chemical Engineering, Process and Environmental Technology Lab, Jan Pieter De Nayerlaan 5, B-2860, Sint-Katelijne-Waver, Belgium
| | - Samet Azman
- KU Leuven Department of Chemical Engineering, Process and Environmental Technology Lab, Jan Pieter De Nayerlaan 5, B-2860, Sint-Katelijne-Waver, Belgium
| | - Giel Bollansée
- KU Leuven Department of Chemical Engineering, Process and Environmental Technology Lab, Jan Pieter De Nayerlaan 5, B-2860, Sint-Katelijne-Waver, Belgium
| | - Toon Goedemé
- EAVISE: Embedded and Artificially Intelligent Vision Engineering, KU Leuven, De Nayer Campus, J. de Nayerlaan 5, B-2860, Sint-Katelijne-Waver, Belgium
| | - Martine Leermakers
- Department of Analytical, Environmental and Geo-Chemistry, Vrije Universiteit Brussel, 1050, Brussels, Belgium
| | - Bernabé Alonso-Fariñas
- Departamento de Ingeniería Química y Ambiental, Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, Camino de Los Descubrimientos s/n, 41092, Seville, Spain
| | - Lise Appels
- KU Leuven Department of Chemical Engineering, Process and Environmental Technology Lab, Jan Pieter De Nayerlaan 5, B-2860, Sint-Katelijne-Waver, Belgium.
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High-Solids Anaerobic Digestion Followed by Ultrasonication of Digestate and Wet-Type Anaerobic Digestion for Enhancing Methane Yield from OFMSW. Processes (Basel) 2020. [DOI: 10.3390/pr8050555] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
High-solids anaerobic digestion of organic fraction of municipal solid waste often shows inefficient biomethane recovery due to mass transfer limitations. Consequently, this study presents a two-stage anaerobic digestion process combining high-solids anaerobic digestion followed by ultrasonication of digestate and wet-type anaerobic digestion for effective biomethane recovery from the organic fraction of municipal solid waste. The high-solids anaerobic digestion yielded methane production of 210 L CH4/kg volatile solids (VS). The digestate from the high-solids anaerobic digestion process was ultrasonicated at three different specific energy inputs (1000, 2500, and 5000 kJ/kg total solids (TS)). The increases in the soluble chemical oxygen demand (SCOD) concentrations (8%–32%) and volatile solids (VS) removal efficiencies (3.5%–10%) at different specific energy inputs were linearly correlated (R2 = 0.9356). Thus, ultrasonication led to the solubilization of particulate organics and released soluble organic matters. All ultrasonicated digestate samples showed significantly higher biomethane yields than that observed for the untreated digestate samples. The highest methane yield of 132 L CH4/kg VS was observed for a specific energy input of 5000 kJ/kg TS, which was 1.94 times higher than the control (68 L CH4/kg VS). Although specific energy inputs of 1000 kJ/kg TS and 2500 kJ/kg TS showed comparable methane yields (113–114 L CH4/kg VS), they were ~1.67 times higher than the control. Overall, our results suggest that an integrated system of high-solids and wet-type anaerobic digestion with pre-ultrasonication of digestate has the potential to provide a technically viable solution to enhance biomethane recovery from the organic fraction of municipal solid waste.
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Khandelwal H, Thalla AK, Kumar S, Kumar R. Life cycle assessment of municipal solid waste management options for India. BIORESOURCE TECHNOLOGY 2019; 288:121515. [PMID: 31125936 DOI: 10.1016/j.biortech.2019.121515] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/15/2019] [Accepted: 05/17/2019] [Indexed: 06/09/2023]
Abstract
Life Cycle Assessment (LCA) tool can be used for environmental assessment of Municipal Solid Waste Management (MSWM) system. The present study aims to evaluate the impact of MSWM system in Nagpur city, India under four different scenarios. i.e., composting combined with landfilling (S1), material recovery facility (MRF) & composting combined with landfilling (S2), MRF & anaerobic digestion (AD) combined with landfilling (S3) and MRF, AD & composting combined with landfilling (S4) using LCA tool. The sensitivity analysis was also performed for evaluating the influence of recycling rate of valuable resources in all the considered scenarios. The scenarios were compared using Gabi 8.5.0.79 model and CML-1A impact characterization method. S2 was found to have the least environmental impacts on global warming, human toxicity, eutrophication, and photochemical ozone creation potential categories. The sensitivity analysis indicated an inversely proportional relation between change in recycling rate and total environmental burdens.
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Affiliation(s)
- Harshit Khandelwal
- National Institute of Technology Karnataka, Surathkal, Mangluru 575 025, Karnataka, India; CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nehru Marg, Nagpur 440 020, Maharashtra, India
| | - Arun Kumar Thalla
- National Institute of Technology Karnataka, Surathkal, Mangluru 575 025, Karnataka, India
| | - Sunil Kumar
- CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nehru Marg, Nagpur 440 020, Maharashtra, India; United Nations University, Institute for Integrated Management of Material Fluxes and of Resources (UNU-FLORES), Ammonstrasse 74, 01067 Dresden, Germany.
| | - Rakesh Kumar
- CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nehru Marg, Nagpur 440 020, Maharashtra, India
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A critical review: emerging bioeconomy and waste-to-energy technologies for sustainable municipal solid waste management. ACTA ACUST UNITED AC 2019. [DOI: 10.1007/s42768-019-00013-z] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Lippert T, Bandelin J, Schlederer F, Drewes JE, Koch K. Impact of ultrasound-induced cavitation on the fluid dynamics of water and sewage sludge in ultrasonic flatbed reactors. ULTRASONICS SONOCHEMISTRY 2019; 55:217-222. [PMID: 30712849 DOI: 10.1016/j.ultsonch.2019.01.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 01/10/2019] [Accepted: 01/21/2019] [Indexed: 06/09/2023]
Abstract
The fluid dynamics of water, thickened waste activated sludge (WAS, total solids concentration 4.4%) and digested sludge (DS, total solids concentration 2.5%) within a lab-scale ultrasonic flatbed reactor were experimentally investigated. For a visual observation of the opaque sludge flow, sewage sludges were approximated by transparent xanthan solutions with identical flow behavior. The visualization of the flow was realized by use of an ultrasonic reactor with a transparent panel and dye streams injected into the flow. Without ultrasonic treatment, xanthan solutions showed distinct laminar flow behavior (generalized Reynolds numbers < 1), at a flow rate of 100 L/h. In water, dye streams remained coherent as well, but with slightly unsteady features (Reynolds number ∼ 350). Activation of the ultrasound reactor caused strong fluid dynamic disturbance in the water flow and dye streams were dissolved instantly, thus indicating turbulent mixing. For the xanthan solutions, however, mixing was considerably less pronounced. The dye streams in the DS substitute (0.5% xanthan solution) remained overall in laminar shape, but exhibited an eruption-like branching and an increase in diameter with advancing treatment duration. For the solution resembling WAS (2.0% xanthan solution), only weak dye stream disruption was observed, thus indicating that WAS flow in flatbed reactors is nearly laminar during ultrasonic treatment.
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Affiliation(s)
- Thomas Lippert
- Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748 Garching, Germany
| | - Jochen Bandelin
- Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748 Garching, Germany
| | - Felizitas Schlederer
- Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748 Garching, Germany
| | - Jörg E Drewes
- Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748 Garching, Germany
| | - Konrad Koch
- Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748 Garching, Germany.
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