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Nordahl SL, Scown CD. Recommendations for life-cycle assessment of recyclable plastics in a circular economy. Chem Sci 2024; 15:9397-9407. [PMID: 38939149 PMCID: PMC11206198 DOI: 10.1039/d4sc01340a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 05/21/2024] [Indexed: 06/29/2024] Open
Abstract
Technologies that enable plastic circularity offer a path to reducing waste generation, improving environmental quality, and reducing reliance on fossil feedstocks. However, life-cycle assessment (LCA) methods commonly applied to these systems fall far short of capturing the full suite of advantages and tradeoffs. This perspective highlights inconsistencies in both the research questions and methodological choices across the growing body of LCA literature for plastics recycling. We assert that conducting LCAs on the basis of tonnes of waste managed vs. tonnes of recycled plastics yields results with fundamentally different conclusions; in most cases, analyses of recyclable plastics should focus on the unit of recycled product yielded. We also offer straightforward paths to better approach LCAs for recycling processes and plastics in a circular economy by rethinking study design (metrics, functional unit, system boundaries, counterfactual scenarios), upstream assumptions (waste feedstock variability, pre-processing requirements), and downstream assumptions (closed-loop vs. open-loop systems, material substitution). Specifically, we recommend expanding to metrics beyond greenhouse gases by including fossil carbon balances, net diversion of waste from landfill, and quantity of avoided plastic waste leakage to the environment. Furthermore, we highlight the role that plastic waste plays as a problematic contaminant in preventing greater diversion of all wastes to recycling, energy recovery, and composting, suggesting that plastics may hold a shared responsibility for the system-wide greenhouse gas emissions that occur when mixed wastes are landfilled.
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Affiliation(s)
- Sarah L Nordahl
- Energy Technologies Area, Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley CA 94720 USA
| | - Corinne D Scown
- Energy Technologies Area, Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley CA 94720 USA
- Joint BioEnergy Institute 5885 Hollis Street Emeryville CA 94608 USA
- Biosciences Area, Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley CA 94720 USA
- Energy & Biosciences Institute, University of California Berkeley CA 94720 USA
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Zebec Ž, Poberžnik M, Lobnik A. Enzymatic Hydrolysis of Textile and Cardboard Waste as a Glucose Source for the Production of Limonene in Escherichia coli. Life (Basel) 2022; 12:life12091423. [PMID: 36143460 PMCID: PMC9500893 DOI: 10.3390/life12091423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 09/05/2022] [Accepted: 09/07/2022] [Indexed: 12/07/2022] Open
Abstract
Cellulose containing textiles (cotton) and cardboard/carton waste represent a large reservoir of untapped organic carbon. These wastes have enormous potential for use as carbon feedstock in industrial biotechnological processes. Essentially, cotton/cardboard (CC) waste is pure cellulose (with some additives) in the form of polymerised glucose consisting of β-(1→4)-linked D-glucose subunits. One of the largest and most diverse classes of natural chemicals that can be produced from glucose are terpenes with a wide range of applications as flavours, fragrances, pharmaceuticals, biopesticides, and biofuels. Here we have investigated the bioconversion of CC waste into the exemplary terpene limonene as a proof of concept. Six different CC waste streams were enzymatically hydrolysed and used to produce limonene using the Escherichia coli (E. coli) microbial cell factory. The D-glucose content in the CC hydrolysate (glucose juice) was determined and then metabolised by E. coli via a manipulated heterogeneous biolipid synthesis pathway (the mevalonate pathway) to produce limonene. This study represents an important proof of concept for the production of terpenes from hydrolysed CC waste streams.
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Affiliation(s)
- Žiga Zebec
- Faculty of Mechanical Engineering, University of Maribor, Smetanova Ul. 17, 2000 Maribor, Slovenia
- Correspondence:
| | | | - Aleksandra Lobnik
- Faculty of Mechanical Engineering, University of Maribor, Smetanova Ul. 17, 2000 Maribor, Slovenia
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Barkhordari A, I Guzman M, Ebrahimzadeh G, Sorooshian A, Delikhoon M, Jamshidi Rastani M, Golbaz S, Fazlzadeh M, Nabizadeh R, Norouzian Baghani A. Characteristics and health effects of particulate matter emitted from a waste sorting plant. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 150:244-256. [PMID: 35868092 DOI: 10.1016/j.wasman.2022.07.012] [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: 01/29/2022] [Revised: 06/01/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
Solid waste components can be recycled in waste paper and cardboard sorting plants (WPCSP) through a multistep process. This work collected 15 samples every six days from each of the 9 points selected to study the processes taking place in a WPCSP (135 particulate matter samples total). Examining the concentration and size fraction of particulate matter (i.e., PM1, PM2.5 and PM10) in WPCSP is an essential issue to notify policy makers about the health impacts on exposed workers. The major activities for increasing of the concentration of PM in various processing units in the WPCSP, especially in hand-picking routes I and II were related to manual dismantling, mechanical grinding, mechanical agitation, and separation and movement of waste. The results of this work showed that a negative correlation between temperature and particulate matter size followed the order PM10 > PM2.5 > PM1. Exposure to PM2.5 and PM10 in the WPCSP lead to possible risk (HI = 5.561 and LTCRs = 3.41 × 10-6 to 9.43 × 10-5 for PM2.5 and HI = 7.454 for PM10). The exposure duration and the previous concentrations had the most effect on the ILCRs and HQs for PM2.5 and PM10 in all sampling sites. Hence, because WPCSP are infected indoor environments (I/O ratio > 1), the use of control methods such as isolation of units, misting systems, blower systems equipped with bag houses, protective equipment, a mechanical ventilation system, and additional natural ventilation can reduce the amount of suspended PM, enhance worker safety, and increase the recycling rate.
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Affiliation(s)
- Abdullah Barkhordari
- Environmental and Occupational Health Research Center, Shahroud University of Medical Sciences, Shahroud, Iran
| | - Marcelo I Guzman
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA
| | - Gholamreza Ebrahimzadeh
- Department of Environmental Health Engineering, Faculty of Health, Zabol University of Medical Sciences, Zabol, Iran
| | - Armin Sorooshian
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA; Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
| | - Mahdieh Delikhoon
- Department of Occupational Health Engineering, School of Public Health, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mehdi Jamshidi Rastani
- Environmental and Occupational Health Research Center, Shahroud University of Medical Sciences, Shahroud, Iran
| | - Somayeh Golbaz
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Fazlzadeh
- Department of Environmental Health, School of Health, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Ramin Nabizadeh
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
| | - Abbas Norouzian Baghani
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
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Baghani AN, Golbaz S, Ebrahimzadeh G, Guzman MI, Delikhoon M, Rastani MJ, Barkhordari A, Nabizadeh R. Characteristics and assessing biological risks of airborne bacteria in waste sorting plant. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 232:113272. [PMID: 35121253 DOI: 10.1016/j.ecoenv.2022.113272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/14/2022] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
Examining the concentration and types of airborne bacteria in waste paper and cardboard sorting plants (WPCSP) is an urgent matter to inform policy makers about the health impacts on exposed workers. Herein, we collected 20 samples at 9 points of a WPCSP every 6 winter days, and found that the most abundant airborne bacteria were positively and negatively correlated to relative humidity and temperature, respectively. The most abundant airborne bacteria (in units of CFU m-3) were: Staphylococcus sp. (72.4) > Micrococcus sp. (52.2) > Bacillus sp. (30.3) > Enterococcus sp. (24.0) > Serratia marcescens (20.1) > E. coli (19.1) > Pseudomonas sp. (16.0) > Nocardia sp. (1.9). The lifetime average daily dose (LADD) for the inhalation and dermal routes for the intake of airborne bacteria ranged from 3.7 × 10-3 ≤ LADDInhalation ≤ 2.07 × 101 CFU (kg d)-1 and 4.75 × 10-6 ≤ LADDDermal ≤ 1.64 × 10-5 CFU (kg d)-1, respectively. Based on a sensitivity analysis (SA), the concentration of airborne bacteria (C) and the exposure duration (ED) had the most effect on the LADDInhalation and LADDDermal for all sampling locations. Although the Hazard Quotient of airborne bacteria was HQ < 1, an acceptable level, the indoor/outdoor ratio (1.5 ≤ I/O ≤ 6.6) of airborne bacteria typically exceeded the threshold value (I/O > 2), indicating worker's exposure to an infected environment. Therefore, in the absence of sufficient natural ventilation the indoor ambient conditions of the WPCSP studied should be controlled by supplying mechanical ventilation.
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Affiliation(s)
- Abbas Norouzian Baghani
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
| | - Somayeh Golbaz
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Gholamreza Ebrahimzadeh
- Department of Environmental Health Engineering, Faculty of Health, Zabol University of Medical Sciences, Zabol, Iran
| | - Marcelo I Guzman
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA.
| | - Mahdieh Delikhoon
- Department of Occupational Health Engineering, School of Public Health, Isfahan University of Medical Sciences, Isfahan, Iran.
| | - Mehdi Jamshidi Rastani
- Department of Occupational Health Engineering, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran
| | - Abdullah Barkhordari
- Department of Occupational Health Engineering, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran; Environmental and Occupational Health Research Center, Shahroud University of Medical Sciences, Shahroud, Iran
| | - Ramin Nabizadeh
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
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Ivan MNAS, Saleque AM, Ahmed S, Cheng PK, Qiao J, Alam TI, Tsang YH. Waste Egg Tray and Toner-Derived Highly Efficient 3D Solar Evaporator for Freshwater Generation. ACS APPLIED MATERIALS & INTERFACES 2022; 14:7936-7948. [PMID: 35119819 DOI: 10.1021/acsami.1c22215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
With the advancement of civilization, water purification, as well as management and disposal of ever-increasing municipal solid waste (MSW), and e-waste, have become global concerns. To address these issues in a sustainable way, a 3D solar evaporator has been proposed in this paper by repurposing recycled paper from MSW in the form of egg trays and waste dry toner (e-waste) using a facile fabrication method. The unique 3D porous structure, fibrous surface, superior water absorbing capability as well as low thermal conductivity of wastepaper-derived egg trays make them an excellent candidate for an efficient solar evaporator, while the waste toner powder coating significantly enhances the optical absorbance capacity. Under 1 sun illumination, the proposed solar evaporator demonstrates an excellent evaporation rate and efficiency of 1.3 kg/m2 h and 78.5%, respectively. Moreover, the competitive advantage of the 3D structure in collecting solar irradiance at various light incident angles in comparison to a 2D structure, excellent cycle stability, low processing temperature, and the use of low-cost waste materials enable its use for large-scale water purification systems.
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Affiliation(s)
- Md Nahian Al Subri Ivan
- Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University, Hung Hom, Kowloon 99077, Hong Kong
- Shenzhen Research Institute, The Hong Kong Polytechnic University, Shenzhen, Guangdong 518057, People's Republic of China
| | - Ahmed Mortuza Saleque
- Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University, Hung Hom, Kowloon 99077, Hong Kong
- Shenzhen Research Institute, The Hong Kong Polytechnic University, Shenzhen, Guangdong 518057, People's Republic of China
| | - Safayet Ahmed
- Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University, Hung Hom, Kowloon 99077, Hong Kong
- Shenzhen Research Institute, The Hong Kong Polytechnic University, Shenzhen, Guangdong 518057, People's Republic of China
| | - Ping Kwong Cheng
- Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University, Hung Hom, Kowloon 99077, Hong Kong
- Shenzhen Research Institute, The Hong Kong Polytechnic University, Shenzhen, Guangdong 518057, People's Republic of China
| | - Junpeng Qiao
- Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University, Hung Hom, Kowloon 99077, Hong Kong
- Shenzhen Research Institute, The Hong Kong Polytechnic University, Shenzhen, Guangdong 518057, People's Republic of China
| | - Tawsif Ibne Alam
- Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University, Hung Hom, Kowloon 99077, Hong Kong
| | - Yuen Hong Tsang
- Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University, Hung Hom, Kowloon 99077, Hong Kong
- Shenzhen Research Institute, The Hong Kong Polytechnic University, Shenzhen, Guangdong 518057, People's Republic of China
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Anshassi M, Preuss B, Townsend TG. Moving beyond recycling: Examining steps for local government to integrate sustainable materials management. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2021; 71:1039-1052. [PMID: 33949919 DOI: 10.1080/10962247.2021.1924312] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/15/2021] [Accepted: 04/12/2021] [Indexed: 06/12/2023]
Abstract
Recently, local governments experienced unprecedented challenges to their recycling programs and are looking to alternative forms to meet their sustainability goals. Traditionally, waste management policies focus on using a mass-based recycling rate to promote and measure sustainability, however that metric inadvertently promotes recycling over source reduction. Here, we present a metric which measures a community's greenhouse gas (GHG) and energy use footprints for their consumed and end-of-life material streams. Using materials and waste statistics for Florida as an example, we estimated the consumed and discarded masses of 24 materials in 2018. We developed methods and used existing (i.e., WARM, literature) lifecycle assessment data to measure upstream and end-of-life environmental footprints of these materials. The total upstream footprints were approximately 12 and 10 times larger than the end-of-life GHG emissions and energy use footprints, respectively, indicating the need for sustainable materials management application. Mixed paper, cardboard, mixed construction and demolition (C&D) materials had the largest lifecycle footprints. We then use these data to illustrate a method for local governments to apply the alternative metric referred to as the lifecycle footprint reduction target. We demonstrate this target's application in Florida using a hypothetical 20% footprint reduction and provide approaches which focus on increasing the source reduction and recycling potentials of key materials to meet the target. The approaches included a junk mail ban, food donation mandate, cardboard takeback mandate, and building deconstruction mandate and were evaluated for their feasibility in meeting the target; the building deconstruction and the food donation mandate resulted in the greatest and least progress, respectively, toward meeting the target. These approaches provide local government a baseline for continued progress toward SMM application.Implications: Consumer consumption of manufactured products - the packaging for our food and beverages, the products in our homes and offices, the vehicles we drive, and the buildings we live and work in - ultimately must be discarded at the end of their useful life. It is through the management of residential and commercial solid waste that local governments face the consequences of society's materials consumption. Thus, not surprisingly, materials conservation efforts at the government level focus primarily on efforts to recycle waste and divert these materials from landfill disposal. Here we examine a concept whereby local governments - normally charged with collecting and managing residential and commercial waste, and thus setting waste recycling targets - expand their thinking to include all life cycle phases for the materials consumed and discarded in their jurisdiction. In doing so, local governments can now shift from a waste management to a lifecycle-oriented perspective and expand beyond just managing waste to managing materials.
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Affiliation(s)
- Malak Anshassi
- Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL, USA
| | - Beatriz Preuss
- Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL, USA
| | - Timothy G Townsend
- Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL, USA
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