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Zhou Y, Lin F, Ling Z, Zhan M, Zhang G, Yuan D. Comparative study by microwave pyrolysis and conventional pyrolysis of pharmaceutical sludge: Resourceful disposal and antibiotic adsorption. JOURNAL OF HAZARDOUS MATERIALS 2024; 468:133867. [PMID: 38402683 DOI: 10.1016/j.jhazmat.2024.133867] [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: 12/28/2023] [Revised: 02/17/2024] [Accepted: 02/21/2024] [Indexed: 02/27/2024]
Abstract
Compared with conventional pyrolysis, microwave pyrolysis has superior heat transfer performance and promotes the decomposition of organic matter. The paper focuses on the harmless treatment and resource utilization of pharmaceutical sludge (PS) by microwave heating and conventional heating methods. The experimental results showed that the conventional pyrolysis gas is dominated by CO2, CO and H2. For microwave pyrolysis gas, the "microwave effect" promoted secondary cracking of volatile fractions and increases the content of CH4, CxHy, H2 and CO through condensation, aromatization, and dehydrogenation. Conventional pyrolysis oils contained the highest percentage of oxygenated compounds. However, high-temperature microwave radiation accelerated the cleavage of polar oxygenated molecular bonds and long-chain hydrocarbons, thereby increasing the aromatics content of pyrolysis oils. The solid residues obtained from microwave pyrolysis is highly graphitized and porous, with a surface area of 146.2 m2/g. Furthermore, the solid residue was rich in pyridine-N and pyrrole-N that could be utilized for adsorption and catalysis. The MA-600 removes up to 99% of tetracycline (TC) in 6 h. It was also found that the adsorption process of TC by the two pyrolysis residues was consistent with the proposed secondary and Freundlich models.
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Affiliation(s)
- Yifan Zhou
- College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou 310018, China
| | - Fawei Lin
- College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou 310018, China; School of Environmental Science and Engineering, Tianjin University/Tianjin Key Lab of Biomass/Wastes Utilization, Tianjin 300072, China.
| | - Zhongqian Ling
- College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou 310018, China
| | - Mingxiu Zhan
- College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou 310018, China
| | - Guangxue Zhang
- College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou 310018, China
| | - Dingkun Yuan
- College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou 310018, China; School of Environmental Science and Engineering, Tianjin University/Tianjin Key Lab of Biomass/Wastes Utilization, Tianjin 300072, China.
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Lakavathu S, Reddy VK, Singh N, Kamble P, Jadhav J, Choudhury AR, Palani SG. Feasibility study of faecal sludge treatment by Geotube and jute tube-based technologies. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:124382-124400. [PMID: 37950778 DOI: 10.1007/s11356-023-30746-8] [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: 02/23/2023] [Accepted: 10/25/2023] [Indexed: 11/13/2023]
Abstract
The decentralized standalone treatment of faecal sludge is a generally cumbersome, energy-intensive, and expensive process. Particle size enlargement, dewatering, and disinfection are the crucial unit operations that contribute to the major portion of the operational expenditure. Therefore, the present study took up the task to investigate and yield a natural alternative to each of the above-delineated unit operations. Crushed seed powders of Moringa, Guilandina bonduc, Nirmali, tamarind, soap nut, nutmeg, jackfruit, and custard apple were experimented as natural coagulants, while a double-stitched cow dung-lined jute tube was utilized as the media for solid-liquid separation. Finally, the powder of Neem and custard apple seed and leaf were considered herbal disinfectants for the separated liquid and solid fractions, respectively. The findings of the physicochemical and biological analyses of the above unit operations were compared with a conventional polymer-based Geotube-driven treatment scheme. The natural alternatives registered some promising outcomes. However, the combined treatment efficiency of 79.32% (mean value of TS, TSS, TDS, COD, and BOD percentage removal) for pollutant removal and disinfection could not exceed the value of 97.98% offered by the conventional method. Further, the financial comparison for processing a 10 KL batch of FS indicates that the conventional scheme is considerably cheaper (USD 7.95) than the herbal alternate (USD 22.1). Therefore, though the present findings depict promising alternatives for sustainable and eco-friendly faecal sludge treatment, the authors advocate conducting further research to address the existing challenges to facilitate their seamless implementation on a field-scale level.
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Affiliation(s)
- Sakkubai Lakavathu
- Centre for Environment, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Hyderabad, Telangana, 500085, India
| | - Vamshi Krishna Reddy
- Centre for Environment, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Hyderabad, Telangana, 500085, India
| | - Neha Singh
- Chadwick's FSM Laboratory, Banka BioLoo Limited, Shed no-37, Industrial Development Area, Mallapur, Secunderabad, 500076, India
| | - Pramod Kamble
- Department of Environmental Science, School of Earth Sciences, Central University of Rajasthan, Ajmer, Rajasthan, 305817, India
| | - Jayesh Jadhav
- Department of Environmental Sciences, Savitribai Phule Pune University, Pune, Maharashtra, 411007, India
| | - Atun Roy Choudhury
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Hyderabad Campus, Secunderabad, Telangana, 500078, India
| | - Sankar Ganesh Palani
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Hyderabad Campus, Secunderabad, Telangana, 500078, India.
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Strande L, Evans B, von Sperling M, Bartram J, Harada H, Nakagiri A, Nguyen VA. Urban Sanitation: New Terminology for Globally Relevant Solutions? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:15771-15779. [PMID: 37819045 PMCID: PMC10603773 DOI: 10.1021/acs.est.3c04431] [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: 06/09/2023] [Indexed: 10/13/2023]
Abstract
Progress toward Sustainable Development Goals for global access to safe sanitation is lagging significantly. In this Feature, we propose that misleading terminology leads to errors of categorization and hinders progress toward sanitation service provision in urban areas. Binary classifications such as "offsite/onsite" and "sewered/nonsewered" do not capture the need for "transport to treatment" or the complexity of urban sanitation and should be discarded. "Fecal sludge management" is used only in the development context of low- or middle-income countries, implying separate solutions for "poor" or "southern" contexts, which is unhelpful. Terminology alone does not solve problems, but rather than using outdated or "special" terminology, we argue that a robust terminology that is globally relevant across low-, middle-, and upper-income contexts is required to overcome increasingly unhelpful assumptions and stereotypes. The use of accurate, technically robust vocabulary and definitions can improve decisions about management and selection of treatment, promote a circular economy, provide a basis for evidence-based science and technology research, and lead to critical shifts and transformations to set policy goals around truly safely managed sanitation. In this Feature, the three current modes of sanitation are defined, examples of misconceptions based on existing terminology are presented, and a new terminology for collection and conveyance is proposed: (I) fully road transported, (II) source-separated mixed transport, (III) mixed transport, and (IV) fully pipe transported.
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Affiliation(s)
- Linda Strande
- Eawag:
Swiss Federal Institute of Aquatic Science and Technology, Department of Sanitation, Water and Solid Waste for
Development (Sandec), Überlandstrasse 133, Dübendorf 8600, Switzerland
| | - Barbara Evans
- School
of Civil Engineering, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
| | - Marcos von Sperling
- Department
of Sanitary and Environmental Engineering, Federal University of Minas Gerais, Av. Antônio Carlos 6627 - Campus Pampulha, Belo Horizonte 31270-901, Brazil
| | - Jamie Bartram
- School
of Civil Engineering, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
| | - Hidenori Harada
- Graduate
School of Asian and African Area Studies, Kyoto University, Yoshida-shimoadachi-cho 46, Sakyo, Kyoto 606-8501, Japan
| | - Anne Nakagiri
- Department
of Civil and Environmental Engineering, Kyambogo University, Kyambogo Road, Kampala, P.O. Box 1, Kyambogo, Uganda
| | - Viet-Anh Nguyen
- Institute
of Environmental Science and Engineering (IESE), Hanoi University of Civil Engineering (HUCE), 55 Giai Phong Road, Hanoi 113068, Vietnam
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Koulouri ME, Templeton MR, Fowler GD. Source separation of human excreta: Effect on resource recovery via pyrolysis. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 338:117782. [PMID: 37015142 DOI: 10.1016/j.jenvman.2023.117782] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 03/13/2023] [Accepted: 03/19/2023] [Indexed: 06/19/2023]
Abstract
More people globally are now using on-site sanitation technologies than sewered connections. The management of faecal sludge generated by on-site facilities is still challenging and requires an understanding of all sanitation service chain components and their interactions; from source conditions to treatment and resource recovery. This study aimed to improve the current lack of knowledge regarding these interactions, by establishing a quantifiable relationship between human excreta source separation and resource recovery via pyrolysis. The effects of source separation of faeces and urine on biochar quality were investigated for different pyrolysis temperatures (450 °C, 550 °C, 650 °C) and this information was used to assess energy and nutrient recovery. Results quantify the benefits of urine diversion for nitrogen recovery (70% of total N losses during thermal treatment avoided) and show an increase in the liming potential of the produced faecal-based biochars. The quality of produced solid fuels is also improved when source-separated faeces (SSF) are used as a feedstock for pyrolysis, including a 50% increase in char calorific value. On the other hand, biochars from mixed urine and faeces (MUF) are more rich in phosphorus and potassium, and surface morphology investigation indicates higher porosity compared to SSF biochars. The high salinity of MUF biochars should be considered before agricultural applications. For both biochar types (SSF, MUF), the presence of phosphate compounds of high fertiliser value was confirmed by X-ray diffraction analysis, and temperatures around 500 °C are recommended to optimise nutrient and carbon behaviour when pyrolysing human excreta. These findings can be used for the design of circular faecal sludge management systems, linking resource recovery objectives to source conditions, and vice-versa. Ultimately, achieving consistent resource recovery from human excreta can act as an incentive for universal access to safe and sustainable sanitation.
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Affiliation(s)
- Maria E Koulouri
- Department of Civil and Environmental Engineering, Imperial College London, SW7 2AZ, UK.
| | - Michael R Templeton
- Department of Civil and Environmental Engineering, Imperial College London, SW7 2AZ, UK.
| | - Geoffrey D Fowler
- Department of Civil and Environmental Engineering, Imperial College London, SW7 2AZ, UK.
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Gwenzi W, Marumure J, Makuvara Z, Simbanegavi TT, Njomou-Ngounou EL, Nya EL, Kaetzl K, Noubactep C, Rzymski P. The pit latrine paradox in low-income settings: A sanitation technology of choice or a pollution hotspot? THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 879:163179. [PMID: 37003330 DOI: 10.1016/j.scitotenv.2023.163179] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/04/2023] [Accepted: 03/26/2023] [Indexed: 05/17/2023]
Abstract
Pit latrines are widely promoted to improve sanitation in low-income settings, but their pollution and health risks receive cursory attention. The present narrative review presents the pit latrine paradox; (1) the pit latrine is considered a sanitation technology of choice to safeguard human health, and (2) conversely, pit latrines are pollution and health risk hotspots. Evidence shows that the pit latrine is a 'catch-all' receptacle for household disposal of hazardous waste, including; (1) medical wastes (COVID-19 PPE, pharmaceuticals, placenta, used condoms), (2) pesticides and pesticide containers, (3) menstrual hygiene wastes (e.g., sanitary pads), and (4) electronic wastes (batteries). Pit latrines serve as hotspot reservoirs that receive, harbour, and then transmit the following into the environment; (1) conventional contaminants (nitrates, phosphates, pesticides), (2) emerging contaminants (pharmaceuticals and personal care products, antibiotic resistance), and (3) indicator organisms, and human bacterial and viral pathogens, and disease vectors (rodents, houseflies, bats). As greenhouse gas emission hotspots, pit latrines contribute 3.3 to 9.4 Tg/year of methane, but this could be an under-estimation. Contaminants in pit latrines may migrate into surface water, and groundwater systems serving as drinking water sources and pose human health risks. In turn, this culminates into the pit latrine-groundwater-human continuum or connectivity, mediated via water and contaminant migration. Human health risks of pit latrines, a critique of current evidence, and current and emerging mitigation measures are presented, including isolation distance, hydraulic liners/ barriers, ecological sanitation, and the concept of a circular bioeconomy. Finally, future research directions on the epidemiology and fate of contaminants in pit latrines are presented. The pit latrine paradox is not meant to downplay pit latrines' role or promote open defaecation. Rather, it seeks to stimulate discussion and research to refine the technology to enhance its functionality while mitigating pollution and health risks.
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Affiliation(s)
- Willis Gwenzi
- Grassland Science and Renewable Plant Resources, Faculty of Organic Agricultural Sciences, Universität Kassel, Steinstraße 19, D-37213 Witzenhausen, Germany; Leibniz-Institut für Agrartechnik und Bioökonomie e.V. (ATB), Max-Eyth-Allee 100, 14469 Potsdam, Germany.
| | - Jerikias Marumure
- Department of Physics, Geography and Environmental Sciences, School of Natural Sciences, Great Zimbabwe University, Off Old Great Zimbabwe Road, P.O. Box 1235, Masvingo, Zimbabwe; Department of Life and Consumer Sciences, School of Agriculture and Life Sciences, College of Agriculture and Environmental Sciences, University of South Africa, South Africa
| | - Zakio Makuvara
- Department of Physics, Geography and Environmental Sciences, School of Natural Sciences, Great Zimbabwe University, Off Old Great Zimbabwe Road, P.O. Box 1235, Masvingo, Zimbabwe; Department of Life and Consumer Sciences, School of Agriculture and Life Sciences, College of Agriculture and Environmental Sciences, University of South Africa, South Africa
| | - Tinoziva T Simbanegavi
- Department of Soil Science and Environment, Faculty of Agriculture, Environment, and Food Systems, University of Zimbabwe, Mount Pleasant, Harare P.O. Box MP 167, Zimbabwe
| | | | - Esther Laurentine Nya
- Faculty of Arts, Letters and Social Sciences, University of Maroua, P.O. Box 644, Maroua, Cameroon
| | - Korbinian Kaetzl
- Grassland Science and Renewable Plant Resources, Faculty of Organic Agricultural Sciences, Universität Kassel, Steinstraße 19, D-37213 Witzenhausen, Germany.
| | - Chicgoua Noubactep
- Centre for Modern Indian Studies (CeMIS), University of Göttingen, Waldweg 26, 37073 Göttingen, Germany; Department of Applied Geology, University of Göttingen, Goldschmidtstraße 3, D-37077 Göttingen, Germany; School of Earth Science and Engineering, Hohai University, Fo Cheng Xi Road 8, 211100 Nanjing, PR China.
| | - Piotr Rzymski
- Department of Environmental Medicine, Poznan University of Medical Sciences, 60-806 Poznań, Poland.
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Zhang W, He Y, Xing X, Wang Y, Li Q, Wang L, Zhu Y. In-depth insight into the effects of intrinsic calcium compounds on the pyrolysis of hazardous petrochemical sludge. JOURNAL OF HAZARDOUS MATERIALS 2023; 455:131593. [PMID: 37172378 DOI: 10.1016/j.jhazmat.2023.131593] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 05/01/2023] [Accepted: 05/05/2023] [Indexed: 05/14/2023]
Abstract
To understand the potential effects of intrinsic calcium compounds on sludge pyrolysis, the pyrolysis behavior of petrochemical sludge (PS), calcium carbonate blend PS (CaPS), and decalcified PS (DePS) were investigated using thermogravimetric analysis (TGA) and in-situ Fourier-transform infrared spectroscopy coupled with pyrolysis-gas chromatography and mass spectrometry (Py-GC/MS). The TGA results indicated that decalcification increased and decreased the energy barriers of PS decomposition in ranges 200-350 °C and 350-600 °C, respectively. In contrast, copyrolysis with CaCO3 decreased the activation energy (E) of the pseudoreaction phase 2 (PH2) and altered the mechanism model. Meanwhile, during copyrolysis, char deposition and interaction hindered CaCO3 decomposition. The two-dimensional correlation spectroscopy results, on the other hand, showed that the reaction priority of O-containing groups and CH- vibration of methyl groups were affected by both decalcification and CaCO3 copyrolysis. The Py-GC/MS results indicated that the three sludges mainly released hydrocarbons, N-containing organics, alcohols, aldehydes, and acids. During pyrolysis, CaCO3 also played a neutralization role, which reduced the release of pyrolytic acidic products. In addition, the increase of the pyrolysis temperature increased the hydrocarbon content. This research will guide the industrial application of sludge pyrolysis.
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Affiliation(s)
- Wenqi Zhang
- School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China; Jiangsu Province Engineering Research Center of Organic solid wastes deeply treatment and hydrogen production, Jiangsu, China
| | - Yahui He
- School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China; Jiangsu Province Engineering Research Center of Organic solid wastes deeply treatment and hydrogen production, Jiangsu, China
| | - Xinxin Xing
- School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China; Jiangsu Province Engineering Research Center of Organic solid wastes deeply treatment and hydrogen production, Jiangsu, China
| | - Yinfeng Wang
- School of Energy Science and Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China; Jiangsu Province Engineering Research Center of Organic solid wastes deeply treatment and hydrogen production, Jiangsu, China.
| | - Qiyuan Li
- School of Chemical Engineering, The University of New South Wales (UNSW), Kensington, New South Wales 2052, Australia
| | - Lei Wang
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China
| | - Yuezhao Zhu
- School of Energy Science and Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu, China; Jiangsu Province Engineering Research Center of Organic solid wastes deeply treatment and hydrogen production, Jiangsu, China
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Ward BJ, Nguyen MT, Sam SB, Korir N, Niwagaba CB, Morgenroth E, Strande L. Particle size as a driver of dewatering performance and its relationship to stabilization in fecal sludge. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 326:116801. [PMID: 36435127 DOI: 10.1016/j.jenvman.2022.116801] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/03/2022] [Accepted: 11/13/2022] [Indexed: 06/16/2023]
Abstract
Poor and unpredictable dewatering performance of fecal sludge is a major barrier to sanitation provision in urban areas not served by sewers. Fecal sludge comprises everything that accumulates in onsite containments, and its characteristics are distinct from wastewater sludges and from feces. There is little fundamental understanding of what causes poor dewatering in fecal sludge. For the first time, we demonstrate that particle size distribution is a driver of dewatering performance in fecal sludge, and is associated with level of stabilization. Higher concentrations of small particles (<10 μm) and smaller median aggregate size (D50) corresponded to poor dewatering performance (measured by capillary suction time (CST) and supernatant turbidity) in field samples from Kenya and Uganda and in controlled laboratory anaerobic storage experiments. More stabilized fecal sludge (higher C/N, lower VSS/TSS) had better dewatering performance, corresponding to lower concentrations of small particles. Samples with the largest aggregates (D50 > 90 μm) had higher abundance of Gammaproteobacteria Pseudomonas, and samples with the smallest aggregates (D50 ≤ 50 μm) were characterized by higher abundance of Bacteroidetes Vadin HA17 and Rikenellaceae. Contrary to common perceptions, stabilization, particle size distribution, and dewatering performance were not dependent on time intervals between emptying of onsite containments or on time in controlled anaerobic storage experiments. Our results suggest that the stabilization process in onsite containments, and hence the dewaterability of sludge arriving at treatment facilities, is not dependent on time in containment but is more likely associated with specific microbial populations and the in-situ environmental conditions which promote or discourage their growth.
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Affiliation(s)
- B J Ward
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland; ETH Zürich, Institute of Environmental Engineering, Zürich, Switzerland.
| | - M T Nguyen
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland; ETH Zürich, Institute of Environmental Engineering, Zürich, Switzerland
| | - S B Sam
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland; ETH Zürich, Institute of Environmental Engineering, Zürich, Switzerland
| | | | - C B Niwagaba
- Makerere University, Department of Civil and Environmental Engineering, Kampala, Uganda
| | - E Morgenroth
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland; ETH Zürich, Institute of Environmental Engineering, Zürich, Switzerland
| | - L Strande
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
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Mong GR, Liew CS, Chong WWF, Mohd Nor SA, Ng JH, Idris R, Chiong MC, Lim JW, Zakaria ZA, Woon KS. Environment impact and bioenergy analysis on the microwave pyrolysis of WAS from food industry: Comparison of CO 2 and N 2 atmosphere. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 319:115665. [PMID: 35842993 DOI: 10.1016/j.jenvman.2022.115665] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/12/2022] [Accepted: 06/30/2022] [Indexed: 06/15/2023]
Abstract
The alarming output of waste activated sludge (WAS) from industries requires proper management routes to minimize its impact on the environment during disposal. Pyrolysis is a feasible way of processing and valorizing WAS into higher-value products of alternate use. Despite extensive research into the potential of WAS through pyrolysis, the technology's long-term viability and environmental impact have yet to be fully revealed. In addition, the environmental effects of utilizing different pyrolysis atmosphere (N2 or CO2) has not been studied before, although benefits of CO2 reactivity during pyrolysis have been discovered. This study evaluates the process's environmental impact, carbon footprint, and bioenergy yield when different pyrolysis atmospheres are used. The global warming potential (GWP) for a functional unit of 1 t of dried WAS is 203.81 kg CO2 eq. The heat required during pyrolysis contributes the most (63.7%) towards GWP due to high energy usage, followed by the drying process (23.6%). Transportation contributes the most towards toxicity impact (59.3%) through dust, NOx, NH3 and SO2 emissions. The initial moisture content of raw WAS (65%) greatly impacts overall energy consumption and environmental impact. Pyrolysis in an N2 atmosphere will result in a higher overall bioenergy yield (833 kWh/tonne) and a lower carbon footprint (-1.09 kg CO2/tonne). However, when CO2 was used, the specific energy value within the biochar is higher (22.26 MJ/kg) due to enhanced carbonization. The carbon content of gas derived increased due to higher CO yield. From an energy perspective, the current setup will achieve a net positive bioenergy yield of 561 kW (CO2) and 833 kW (N2), where end products like biochar, bio-oil and gas can be used for power production. Despite the energy-intensive process, microwave pyrolysis has excellent potential to achieve a negative carbon footprint. The biochar used for soil amendment served as a good carbon sink. The utilization of CO2 as carrier gases provides a pathway to utilize anthropogenic CO2, which helps reduce global warming. This work demonstrates microwave pyrolysis as a negative emission, bioenergy-producing approach for WAS disposal and valorization.
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Affiliation(s)
- Guo Ren Mong
- School of Energy and Chemical Engineering, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria, 43900, Sepang, Selangor, Malaysia.
| | - Chin Seng Liew
- Department of Fundamental and Applied Sciences, HICoE-Centre for Biofuel and Biochemical Research, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, 32610, Seri Iskandar, Perak Darul Ridzuan, Malaysia
| | - William Woei Fong Chong
- School of Mechanical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia; Automotive Development Centre, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia
| | - Siti Aminah Mohd Nor
- QL Figo (Johor) Sdn Bhd, Lot 3627, Jalan Harmoni 1, Taman Harmoni, 81000, Kulai, Johor, Malaysia
| | - Jo-Han Ng
- Faculty of Engineering and Physical Sciences, University of Southampton Malaysia (UoSM), 79200, Iskandar Puteri, Johor, Malaysia
| | - Rubia Idris
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia
| | - Meng Choung Chiong
- Department of Mechanical Engineering, Faculty of Engineering, Technology & Built Environment, UCSI University, 56000, Kuala Lumpur, Malaysia
| | - Jun Wei Lim
- Department of Fundamental and Applied Sciences, HICoE-Centre for Biofuel and Biochemical Research, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, 32610, Seri Iskandar, Perak Darul Ridzuan, Malaysia
| | - Zainul Akmar Zakaria
- School of Mechanical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia
| | - Kok Sin Woon
- School of Energy and Chemical Engineering, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria, 43900, Sepang, Selangor, Malaysia
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Lu C, Zhao H, Wang S, Tang Y. Theoretical investigation on the gas phase reaction mechanism of methanol with Sn and Pb in sludge incineration. J PHYS ORG CHEM 2021. [DOI: 10.1002/poc.4291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Chenggang Lu
- School of Environmental and Municipal Engineering Qingdao University of Technology Qingdao China
| | - Hui Zhao
- School of Environmental and Municipal Engineering Qingdao University of Technology Qingdao China
| | - Shuangjun Wang
- School of Environmental and Municipal Engineering Qingdao University of Technology Qingdao China
| | - Yizhen Tang
- School of Environmental and Municipal Engineering Qingdao University of Technology Qingdao China
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