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Andronikou M, Lytras N, Chrysanthou G, Koutsokeras L, Constantinides G, Stylianou M, Agapiou A, Vyrides I. Biogas upgrading to methane and removal of volatile organic compounds in a system of zero-valent iron and anaerobic granular sludge. Environ Sci Pollut Res Int 2022; 29:87245-87256. [PMID: 35802326 DOI: 10.1007/s11356-022-21750-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 06/26/2022] [Indexed: 06/15/2023]
Abstract
The current study presented a novel process of biogas upgrading to biomethane (higher than 97%) based on anaerobic sludge and zero-valent iron (ZVI) system. When ZVI was added into an aquatic system with anaerobic granular sludge (AnGrSl) under anaerobic abiotic conditions, H2 was generated. Then, the H2 and CO2 were converted by the hydrogenotrophic methanogens to CH4. Biogas upgrading to biomethane was achieved in 4 days in the AnGrSl system (50 g L-1 ZVI, initial pH 5 and 20 g L-1 NaHCO3). In this system, when zero-valent scrap iron (ZVSI) was added instead of ZVI, a more extended period (21 days) was required to achieve biogas upgrading. X-ray diffraction (XRD) analysis revealed that the materials in a reactor with CO2 or biogas headspace, exhibited a mixture of ferrite and the iron carbonate phase of siderite (FeCO3), with the latter being the dominant phase. VOCs analysis in raw biogas (in the system of anaerobic sludge and ZVI) highlighted the reduction of low mass straight- and branched-chain alkanes (C6-C10). Also, H2S and NH3 were found to be substantially reduced when the anaerobic sludge was exposed to ZVI compared to the cases where ZVI was not added. This study found that simultaneously with biogas upgrading, VOCs, H2S and NH3 can be removed in a system of ZVI or ZVSI and AnGrSl under aquatic anaerobic conditions.
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Affiliation(s)
- Maria Andronikou
- Department of Chemical Engineering, Cyprus University of Technology, 57 Anexartisias Str, P.O. BOX 50329, 3603, Limassol, Cyprus
| | - Nikolaos Lytras
- Department of Chemical Engineering, Cyprus University of Technology, 57 Anexartisias Str, P.O. BOX 50329, 3603, Limassol, Cyprus
| | - Georgia Chrysanthou
- Department of Chemical Engineering, Cyprus University of Technology, 57 Anexartisias Str, P.O. BOX 50329, 3603, Limassol, Cyprus
| | - Loukas Koutsokeras
- Department of Mechanical Engineering and Materials Science and Engineering, Cyprus University of Technology, Kitiou Kyprianou 45, 3041, Limassol, Cyprus
- Research Unit for Nanostructured Materials Systems, Cyprus University of Technology, Kitiou Kyprianou 45, 3041, Limassol, Cyprus
| | - Georgios Constantinides
- Department of Mechanical Engineering and Materials Science and Engineering, Cyprus University of Technology, Kitiou Kyprianou 45, 3041, Limassol, Cyprus
- Research Unit for Nanostructured Materials Systems, Cyprus University of Technology, Kitiou Kyprianou 45, 3041, Limassol, Cyprus
| | - Marinos Stylianou
- Department of Chemistry, University of Cyprus, P.O. BOX 20537, 1678, Nicosia, Cyprus
| | - Agapios Agapiou
- Department of Chemistry, University of Cyprus, P.O. BOX 20537, 1678, Nicosia, Cyprus
| | - Ioannis Vyrides
- Department of Chemical Engineering, Cyprus University of Technology, 57 Anexartisias Str, P.O. BOX 50329, 3603, Limassol, Cyprus.
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Yin H, Liu C, Hu Q, Liu T, Wang S, Gao M, Xu S, Zhang C, Su W. Opposite impact of emission reduction during the COVID-19 lockdown period on the surface concentrations of PM 2.5 and O 3 in Wuhan, China. Environ Pollut 2021; 289:117899. [PMID: 34358865 PMCID: PMC8326756 DOI: 10.1016/j.envpol.2021.117899] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/26/2021] [Accepted: 08/01/2021] [Indexed: 05/28/2023]
Abstract
To prevent the spread of the COVID-19 epidemic, the Chinese megacity Wuhan has taken emergent lockdown measures starting on January 23, 2020. This provided a natural experiment to investigate the response of air quality to such emission reductions. Here, we decoupled the influence of meteorological and non-meteorological factors on main air pollutants using generalized additive models (GAMs), driven by data from the China National Environmental Monitoring Center (CNEMC) network. During the lockdown period (Jan. 23 - Apr. 8, 2020), PM2.5, PM10, NO2, SO2, and CO concentrations decreased significantly by 45 %, 49 %, 56 %, 39 %, and 18 % compared with the corresponding period in 2015-2019, with contributions by S(meteos) of 15 %, 17 %, 13 %, 10 %, and 6 %. This indicates an emission reduction of NOx at least 43 %. However, O3 increased by 43 % with a contribution by S(meteos) of 6 %. In spite of the reduced volatile organic compound (VOC) emissions by 30 % during the strict lockdown period (Jan. 23 - Feb. 14, 2020), which likely reduced the production of O3, O3 concentrations increased due to a weakening of the titration effect of NO. Our results suggest that conventional emission reduction (NOx reduction only) measures may not be sufficient to reduce (or even lead to an increase of) surface O3 concentrations, even if reaching the limit, and VOC-specific measures should also be taken.
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Affiliation(s)
- Hao Yin
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China; Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China
| | - Cheng Liu
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China; Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, University of Science and Technology of China, Hefei, 230026, China; Anhui Province Key Laboratory of Polar Environment and Global Change, University of Science and Technology of China, Hefei, 230026, China.
| | - Qihou Hu
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China
| | - Ting Liu
- School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, China
| | - Shuntian Wang
- Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China; Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China
| | - Meng Gao
- Department of Geography, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - Shiqi Xu
- School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, China
| | - Chengxin Zhang
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, 230026, China
| | - Wenjing Su
- School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, China
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Hall WA, Bellamy DE, Walse SS. Activated carbons from end-products of tree nut and tree fruit production as sorbents for removing methyl bromide in ventilation effluent following postharvest chamber fumigation. J Agric Food Chem 2015; 63:3094-3103. [PMID: 25758836 DOI: 10.1021/jf505193e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
End-products of tree nuts and tree fruits grown in California, USA were evaluated for the ability to remove methyl bromide (MB) from ventilation effluent following postharvest chamber fumigation. Activated carbon sorbents from walnut and almond shells as well as peach and prune pits were prepared using different methods of pyrolysis, activation, and quenching. Each source and preparation was evaluated for yield from starting material (%, m/m) and performance on tests where MB-containing airstreams were directed through a columnar bed of the activated carbon in an experimental apparatus, termed a parallel adsorbent column tester, which was constructed as a scaled-down model of a chamber ventilation system. We report the number of doses needed to first observe the breakthrough of MB downstream of the bed and the capacity of the activated carbon for MB (%, m/m) based on a fractional percentage of MB mass sorbed at breakthrough relative to mass of the bed prior to testing. Results were based on a novel application of solid-phase microextraction with time-weighted averaging sampling of MB concentration in airstreams, which was quantitative across the range of fumigation-relevant conditions and statistically unaffected by relative humidity. Activated carbons from prune pits, prepared either by steam activation or carbon dioxide activation coupled to water quenching, received the greatest number of doses prior to breakthrough and had the highest capacity, approximately 12-14%, outperforming a commercially marketed activated carbon derived from coconut shells. Experimental evidence is presented that links discrepancy in performance to the relative potential for activated carbons to preferentially sorb water vapor relative to MB.
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Affiliation(s)
- Wiley A Hall
- Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, United States Department of Agriculture, 9611 South Riverbend Avenue, Parlier, California 93648-9757, United States
| | - David E Bellamy
- Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, United States Department of Agriculture, 9611 South Riverbend Avenue, Parlier, California 93648-9757, United States
| | - Spencer S Walse
- Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, United States Department of Agriculture, 9611 South Riverbend Avenue, Parlier, California 93648-9757, United States
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