Pub Date : 2024-12-27DOI: 10.1016/j.psep.2024.12.103
Mingyang Dai, Qiuyan Xue, Tuo Guo, Qingjie Guo
The present study involved an in-depth simulation and evaluation of a 10 MWth food waste chemical looping gasification to hydrogen system, conducted using Aspen Plus process simulation software. The study extensively investigated process optimization, economic evaluation, and the environmental impacts associated with the application of this technology. The simulation results showed that maintaining a fuel reactor temperature at 850°C, an H2O/C ratio of 0.6, and an O/C of 0.45 yielded an H2/CO of 1.718, Y of 1.209 m3/kg, and CEG of 51.78 %. Life cycle assessment indicated favorable outcomes concerning environmental impacts. Particularly, the system operational in the Qingdao region showed a global warming potential of 1763.5 kgCO2-eq and an acidification potential of 16.77 kgSO2-eq. Economic analysis revealed that the system offers substantial economic benefits with a return on investment of 11.23 %, a payback period of 6.283 years, and a net present value of 1.201 × 106 $. The cost of this process significantly undercuts that of renewable hydrogen production, providing considerable environmental advantages by effectively utilizing waste resources and reducing waste disposal issues. Given its cost-effectiveness and environmental benefits, chemical looping gasification technology for hydrogen production from food waste holds wide-ranging future application potential.
{"title":"Process Optimization And Life Cycle Assessment In a 10MWth food waste chemical looping gasification system for hydrogen production","authors":"Mingyang Dai, Qiuyan Xue, Tuo Guo, Qingjie Guo","doi":"10.1016/j.psep.2024.12.103","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.103","url":null,"abstract":"The present study involved an in-depth simulation and evaluation of a 10 MW<ce:inf loc=\"post\">th</ce:inf> food waste chemical looping gasification to hydrogen system, conducted using Aspen Plus process simulation software. The study extensively investigated process optimization, economic evaluation, and the environmental impacts associated with the application of this technology. The simulation results showed that maintaining a fuel reactor temperature at 850°C, an H<ce:inf loc=\"post\">2</ce:inf>O/C ratio of 0.6, and an O/C of 0.45 yielded an H<ce:inf loc=\"post\">2</ce:inf>/CO of 1.718, Y of 1.209 m<ce:sup loc=\"post\">3</ce:sup>/kg, and CEG of 51.78 %. Life cycle assessment indicated favorable outcomes concerning environmental impacts. Particularly, the system operational in the Qingdao region showed a global warming potential of 1763.5 kgCO<ce:inf loc=\"post\">2-eq</ce:inf> and an acidification potential of 16.77 kgSO<ce:inf loc=\"post\">2-eq</ce:inf>. Economic analysis revealed that the system offers substantial economic benefits with a return on investment of 11.23 %, a payback period of 6.283 years, and a net present value of 1.201 × 10<ce:sup loc=\"post\">6</ce:sup> $. The cost of this process significantly undercuts that of renewable hydrogen production, providing considerable environmental advantages by effectively utilizing waste resources and reducing waste disposal issues. Given its cost-effectiveness and environmental benefits, chemical looping gasification technology for hydrogen production from food waste holds wide-ranging future application potential.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"127 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-27DOI: 10.1016/j.psep.2024.12.099
Shunfeng Jiang, Rui Zhang, Zhiquan Wang, Min Zhao, Xiangyong Zheng
Zero-valent iron (ZVI) has been extensively utilized for the reductive removal of contaminants from water. However, the passivation and aggregation of ZVI in aqueous matrices significantly impact its removal efficiency. In this study, a ZVI-loaded biochar (ZVI/BC) was synthesized through the in situ pyrolysis of ash-rich biomass and iron salt and employed for the removal of Se(IV). The resulting ZVI/BC achieved a remarkable 98.2 % removal of Se(IV) within 300 minutes, nearly 6.5 times more effective than commercial ZVI. Kinetic analyses indicated that ZVI/BC can rapidly remove Se(IV) with a rate constant of 1.04 × 10⁻³ g/(mg·min) and an equilibrium adsorption capacity of 101.0 mg/g. Notably, it was discovered that the ash content in biochar significantly influences the Se(IV) removal efficiency of ZVI/BC. Experimental and theoretical calculations demonstrated that the ash in ZVI/BC enhances Se(IV) removal by promoting the accumulation of Se(IV) and facilitating the electron transfer process. This study provides a novel strategy for improving the utilization efficiency of ZVI and offers a deeper understanding of the removal mechanisms for Se(IV).
{"title":"Enhanced selenite removal performance of zero valent iron-biochar composite by in situ formed Fe2SiO4 during ash-rich biomass pyrolysis","authors":"Shunfeng Jiang, Rui Zhang, Zhiquan Wang, Min Zhao, Xiangyong Zheng","doi":"10.1016/j.psep.2024.12.099","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.099","url":null,"abstract":"Zero-valent iron (ZVI) has been extensively utilized for the reductive removal of contaminants from water. However, the passivation and aggregation of ZVI in aqueous matrices significantly impact its removal efficiency. In this study, a ZVI-loaded biochar (ZVI/BC) was synthesized through the in situ pyrolysis of ash-rich biomass and iron salt and employed for the removal of Se(IV). The resulting ZVI/BC achieved a remarkable 98.2 % removal of Se(IV) within 300 minutes, nearly 6.5 times more effective than commercial ZVI. Kinetic analyses indicated that ZVI/BC can rapidly remove Se(IV) with a rate constant of 1.04 × 10⁻³ g/(mg·min) and an equilibrium adsorption capacity of 101.0 mg/g. Notably, it was discovered that the ash content in biochar significantly influences the Se(IV) removal efficiency of ZVI/BC. Experimental and theoretical calculations demonstrated that the ash in ZVI/BC enhances Se(IV) removal by promoting the accumulation of Se(IV) and facilitating the electron transfer process. This study provides a novel strategy for improving the utilization efficiency of ZVI and offers a deeper understanding of the removal mechanisms for Se(IV).","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"49 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The safe handling of municipal solid waste incineration fly ash (MSWI-FA) is imperative due to its leaching of heavy metals (HMs), particularly after extensive carbonation. Taking advantage of a "waste-treating-waste" strategy, this study systematically screened the coupled process of silica fume addition, water washing, and low-temperature sintering, and pioneered the conversion of MSWI-FA to a safe and friendly level. The function of silica fume during co-sintering was contingent upon pre-desalination, which determined whether to stabilize or solubilize the HMs. Without pre-desalination, the sintering of MSWI-FA with silica fume exacerbated the leachability and environmental risk of HMs compared to the untreated MSWI-FA. Interestingly, desalination and then silica-assisted sintering (W/Si-Sint) at 700°C reduced the leachability of HMs by 99.9 %, with Cd leaching less than one-fifth of the GB16889 limit and Pb and Zn being undetectable. Heavy metal stability was maintained over a broad pH range (2.64–13.5) and 50 days of natural exposure. Risk assessments confirmed the HMs in treated MSWI-FA at safe levels and posed low ecological risks in leachates. Additionally, the W/Si-Sint process achieved a 2.77-fold mass reduction in MSWI-FA and enabled a favorable recovery of Pb and Zn. Advanced analyses like spherical-aberration-corrected scanning transmission electron microscopy (Cs-STEM) provided new insights into the stabilization mechanisms.
{"title":"Desalination and then silica fume-assisted sintering render MSWI fly ash reliably safe: Heavy metal stabilization and mechanistic insights","authors":"Bojun Li, Xingzhao Chen, Xuejun Guo, Xiaoqiong Wu, Siwen Leng","doi":"10.1016/j.psep.2024.12.109","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.109","url":null,"abstract":"The safe handling of municipal solid waste incineration fly ash (MSWI-FA) is imperative due to its leaching of heavy metals (HMs), particularly after extensive carbonation. Taking advantage of a \"waste-treating-waste\" strategy, this study systematically screened the coupled process of silica fume addition, water washing, and low-temperature sintering, and pioneered the conversion of MSWI-FA to a safe and friendly level. The function of silica fume during co-sintering was contingent upon pre-desalination, which determined whether to stabilize or solubilize the HMs. Without pre-desalination, the sintering of MSWI-FA with silica fume exacerbated the leachability and environmental risk of HMs compared to the untreated MSWI-FA. Interestingly, desalination and then silica-assisted sintering (W/Si-Sint) at 700°C reduced the leachability of HMs by 99.9 %, with Cd leaching less than one-fifth of the GB16889 limit and Pb and Zn being undetectable. Heavy metal stability was maintained over a broad pH range (2.64–13.5) and 50 days of natural exposure. Risk assessments confirmed the HMs in treated MSWI-FA at safe levels and posed low ecological risks in leachates. Additionally, the W/Si-Sint process achieved a 2.77-fold mass reduction in MSWI-FA and enabled a favorable recovery of Pb and Zn. Advanced analyses like spherical-aberration-corrected scanning transmission electron microscopy (Cs-STEM) provided new insights into the stabilization mechanisms.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"34 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-26DOI: 10.1016/j.psep.2024.12.091
Yanyan Chi, Siyang Liu, Di Ming, Xiaoyu Huang, Rong Zhang, Keke Yin
Dewatered alum sludge, utilized as a rooftop greening substrate, is closely associated with the resource utilization of water treatment plant sludge and the advancement of sponge city infrastructure. However, the feasibility and specific performance of using dewatered alum sludge in rooftop greening applications remain uncertain. In this study, alum sludge from the Qujiang Water Plant in Xi’an was used to formulate a rooftop greening substrate. The experimental substrate comprised 33 % air-dried alum sludge, 33 % coconut coir, and 33 % landscaping waste, while the control substrate consisted of 33 % sandy loam, 33 % peat, and 33 % humus, with both treatments supplemented by an appropriate amount of slow-release fertilizer. Sedum hispanicum was cultivated under natural rooftop conditions, and its growth was monitored over 13 months. Additionally, a bare roof served as the control to evaluate the effects of the rooftop greening system on rainwater retention, cooling, and dust suppression. Results showed that Sedum hispanicum performed well in the experimental substrate, achieving a 100 % rooting rate, an initial coverage rate increase of 35.49 %, and a sustained coverage of over 70 % in the later stages, with a mortality rate of less than 20 % under extreme conditions, comparable to the performance in natural soil. The rooftop greening system with the alum sludge substrate demonstrated rainwater retention capacities of 78.26 % and 40.67 %, and runoff delay times of 46.96 minutes and 24.40 minutes during artificial simulations of heavy (43.70 mm) and torrential rainfall (79.22 mm), respectively. Cooling efficiency exceeded 20 %, while dust suppression reached 73.83 %. These findings highlight the significant environmental and economic advantages of using alum sludge as a rooftop greening substrate, providing a viable strategy for the resource-efficient disposal of water treatment sludge.
{"title":"Utilization of dewatered alum sludge from water treatment plants as a sustainable green roof substrate","authors":"Yanyan Chi, Siyang Liu, Di Ming, Xiaoyu Huang, Rong Zhang, Keke Yin","doi":"10.1016/j.psep.2024.12.091","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.091","url":null,"abstract":"Dewatered alum sludge, utilized as a rooftop greening substrate, is closely associated with the resource utilization of water treatment plant sludge and the advancement of sponge city infrastructure. However, the feasibility and specific performance of using dewatered alum sludge in rooftop greening applications remain uncertain. In this study, alum sludge from the Qujiang Water Plant in Xi’an was used to formulate a rooftop greening substrate. The experimental substrate comprised 33 % air-dried alum sludge, 33 % coconut coir, and 33 % landscaping waste, while the control substrate consisted of 33 % sandy loam, 33 % peat, and 33 % humus, with both treatments supplemented by an appropriate amount of slow-release fertilizer. Sedum hispanicum was cultivated under natural rooftop conditions, and its growth was monitored over 13 months. Additionally, a bare roof served as the control to evaluate the effects of the rooftop greening system on rainwater retention, cooling, and dust suppression. Results showed that Sedum hispanicum performed well in the experimental substrate, achieving a 100 % rooting rate, an initial coverage rate increase of 35.49 %, and a sustained coverage of over 70 % in the later stages, with a mortality rate of less than 20 % under extreme conditions, comparable to the performance in natural soil. The rooftop greening system with the alum sludge substrate demonstrated rainwater retention capacities of 78.26 % and 40.67 %, and runoff delay times of 46.96 minutes and 24.40 minutes during artificial simulations of heavy (43.70 mm) and torrential rainfall (79.22 mm), respectively. Cooling efficiency exceeded 20 %, while dust suppression reached 73.83 %. These findings highlight the significant environmental and economic advantages of using alum sludge as a rooftop greening substrate, providing a viable strategy for the resource-efficient disposal of water treatment sludge.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"34 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-26DOI: 10.1016/j.psep.2024.12.086
Mohamed Hamdy, Muhammad Zubair Shahid, Ahmad Salam Farooqi, Mohammed El-Adawy, Mohamed Mahmoud, Sulaiman A. Alarifi, Medhat A. Nemitallah
A thorough analysis of clean hydrogen production methods within oil and gas wells is provided. Focus is given on the recent advances in In-situ combustion (ISC), and In-situ gasification (ISG). Several factors influence in-well hydrogen production, including geological considerations such as reservoir characteristics and operating conditions, in addition to geochemical conditions involving reactants and reaction control. These factors collectively determine the feasibility and efficiency of in-well hydrogen production techniques. Case studies and field demonstrations which provide valuable insights into the practical application of these techniques are provided. Studies have shown that ISC can produce up to 16 % hydrogen, but ISG is an efficient method that can produce syngas with concentrations of up to 50 % hydrogen. Techno-economic evaluations estimated hydrogen production costs ranging from $0.23 to $0.68 per kilogram, depending on system design and operational conditions, with air separation units contributing up to 72 % of capital costs. Optimization studies revealed that an oxygen-to-carbon (O/C) ratio of 0.5 and a steam-to-carbon (S/C) ratio of 2 yielded peak hydrogen production at a reservoir temperature of 675 K. Technical challenges which include efficiency and productivity, effective monitoring, control, and overcoming technical limitations are discussed. The environmental challenges involving managing potential reservoir impacts, greenhouse gas emissions, water usage, chemical interactions, and subsurface integrity are clarified. The economic challenges addressed encompass cost analysis, market potential, and the integration of renewable energy sources. A novel framework for optimizing in-well hydrogen production processes by addressing critical techno-economic and environmental challenges is hence provided.
{"title":"Recent advances of in-well hydrogen production with integrated in-situ carbon dioxide sequestration: A comprehensive review","authors":"Mohamed Hamdy, Muhammad Zubair Shahid, Ahmad Salam Farooqi, Mohammed El-Adawy, Mohamed Mahmoud, Sulaiman A. Alarifi, Medhat A. Nemitallah","doi":"10.1016/j.psep.2024.12.086","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.086","url":null,"abstract":"A thorough analysis of clean hydrogen production methods within oil and gas wells is provided. Focus is given on the recent advances in In-situ combustion (ISC), and In-situ gasification (ISG). Several factors influence in-well hydrogen production, including geological considerations such as reservoir characteristics and operating conditions, in addition to geochemical conditions involving reactants and reaction control. These factors collectively determine the feasibility and efficiency of in-well hydrogen production techniques. Case studies and field demonstrations which provide valuable insights into the practical application of these techniques are provided. Studies have shown that ISC can produce up to 16 % hydrogen, but ISG is an efficient method that can produce syngas with concentrations of up to 50 % hydrogen. Techno-economic evaluations estimated hydrogen production costs ranging from $0.23 to $0.68 per kilogram, depending on system design and operational conditions, with air separation units contributing up to 72 % of capital costs. Optimization studies revealed that an oxygen-to-carbon (O/C) ratio of 0.5 and a steam-to-carbon (S/C) ratio of 2 yielded peak hydrogen production at a reservoir temperature of 675 K. Technical challenges which include efficiency and productivity, effective monitoring, control, and overcoming technical limitations are discussed. The environmental challenges involving managing potential reservoir impacts, greenhouse gas emissions, water usage, chemical interactions, and subsurface integrity are clarified. The economic challenges addressed encompass cost analysis, market potential, and the integration of renewable energy sources. A novel framework for optimizing in-well hydrogen production processes by addressing critical techno-economic and environmental challenges is hence provided.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"14 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-26DOI: 10.1016/j.psep.2024.12.101
Mohamed A. Ismail, Ghanim Kadhim Abdul Sada, Abdelfattah Amari, Noureddine Elboughdiri, Abdul Amir H. Kadhum, Ibrahim Elbadawy, Abdusalom Umarov, Sanjarbek Madaminov
This study proposes a novel concentrating solar power (CSP)-based energy system designed to enhance energy efficiency and sustainability for a commercial building in Riyadh, Saudi Arabia. The system integrates a heliostat field with advanced technologies, including the Kalina cycle (KC), thermoelectric generator (TEG), Rankine cycle (RC), and proton exchange membrane (PEM) electrolyzer, to simultaneously generate electricity and hydrogen. Waste heat recovery is utilized to improve energy efficiency and support heating, ventilation, and air conditioning (HVAC) systems, while the produced hydrogen is stored for use during peak demand or nighttime. A comprehensive techno-economic simulation evaluates the system's performance from energy, exergy, and economic perspectives, with sensitivity analysis identifying critical parameters. Key findings reveal that higher direct normal irradiation (DNI) significantly enhances system performance, increasing electricity generation from 2885 kW to 6310 kW and hydrogen production from 16.92 to 36.94 kg/h. Optimization of pressure ratios in the Brayton cycle and lower pinch point temperature differences further improve efficiency and cost-effectiveness. The hybrid optimization approach, combining artificial neural networks (ANNs) and a genetic algorithm (GA), reduces optimization time from 183 hours to 4 minutes, achieving an exergy efficiency of 24.42 % and a cost rate of 310.51 $/h. The system achieves annual hydrogen production of 197,706.4 kg, with peak electricity output of 4025 kW in July. This scalable and efficient energy solution reduces reliance on external energy sources, contributing to sustainable urban energy systems.
{"title":"Design and optimization of a modified solar-driven energy system utilizing advanced heat recovery methods for electricity and hydrogen production in sustainable urban applications","authors":"Mohamed A. Ismail, Ghanim Kadhim Abdul Sada, Abdelfattah Amari, Noureddine Elboughdiri, Abdul Amir H. Kadhum, Ibrahim Elbadawy, Abdusalom Umarov, Sanjarbek Madaminov","doi":"10.1016/j.psep.2024.12.101","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.101","url":null,"abstract":"This study proposes a novel concentrating solar power (CSP)-based energy system designed to enhance energy efficiency and sustainability for a commercial building in Riyadh, Saudi Arabia. The system integrates a heliostat field with advanced technologies, including the Kalina cycle (KC), thermoelectric generator (TEG), Rankine cycle (RC), and proton exchange membrane (PEM) electrolyzer, to simultaneously generate electricity and hydrogen. Waste heat recovery is utilized to improve energy efficiency and support heating, ventilation, and air conditioning (HVAC) systems, while the produced hydrogen is stored for use during peak demand or nighttime. A comprehensive techno-economic simulation evaluates the system's performance from energy, exergy, and economic perspectives, with sensitivity analysis identifying critical parameters. Key findings reveal that higher direct normal irradiation (DNI) significantly enhances system performance, increasing electricity generation from 2885 kW to 6310 kW and hydrogen production from 16.92 to 36.94 kg/h. Optimization of pressure ratios in the Brayton cycle and lower pinch point temperature differences further improve efficiency and cost-effectiveness. The hybrid optimization approach, combining artificial neural networks (ANNs) and a genetic algorithm (GA), reduces optimization time from 183 hours to 4 minutes, achieving an exergy efficiency of 24.42 % and a cost rate of 310.51 $/h. The system achieves annual hydrogen production of 197,706.4 kg, with peak electricity output of 4025 kW in July. This scalable and efficient energy solution reduces reliance on external energy sources, contributing to sustainable urban energy systems.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"82 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142967763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-25DOI: 10.1016/j.psep.2024.12.088
Annika Anders, Harun Cakir, Frank Ohnemüller, Harald Platen, Ulrich Kornhaas, Harald Weigand
The recovery of phosphorus (P) from wastewater is crucial for circularity of plant nutrients. While wastewater treatment plants (WWTPs) employing enhanced biological P removal offer potential for P recovery by biological P re-dissolution, its scalability and performance under real-world conditions remain underexplored. Here we report on a pilot-scale test (15 m3 return sludge per day) for rapid P recovery from return sludge at a full-scale municipal WWTP induced by acetate supplementation and subsequent P precipitation as a soil amendment and fertilizer. In a total of 54 re-dissolution batches (treatment time approx. 80 min), supernatant P concentrations varied greatly. Batches were combined and used as the feed at 19.2–22.7 mg P/L for fluidized bed precipitation with dolomite seed grains. This step was highly efficient since upon milk of lime addition (pH >9.6), 99 % of the P-input load precipitated onto the dolomite, forming a calcium phosphate layer with 0.9–1.9 wt% P. Trace element levels in the product complied with the German Fertilizer Ordinance. Residual ortho-P effluent levels were ≤ 0.3 mg P/L. The precipitate is valuable in terms of soil pH regulation, while providing Ca, Mg, and P as plant nutrients. However, the poor overall recovery of 1.9 % of total sludge P clearly highlights the challenges of re-dissolution and phase separation at the pilot-scale. These arise from the combined biological and chemical P elimination strategy used at the particular WWTP, variations in acetate-induced re-dissolution kinetics, and inefficient sedimentation for solid/liquid separation. Perspectives for process optimization and improved overall recovery are discussed.
{"title":"Phosphorus recovery from municipal sewage sludge using bio-based re-dissolution with acetate and precipitation as calcium phosphate on dolomite seed grains – A pilot-scale study under real-world conditions","authors":"Annika Anders, Harun Cakir, Frank Ohnemüller, Harald Platen, Ulrich Kornhaas, Harald Weigand","doi":"10.1016/j.psep.2024.12.088","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.088","url":null,"abstract":"The recovery of phosphorus (P) from wastewater is crucial for circularity of plant nutrients. While wastewater treatment plants (WWTPs) employing enhanced biological P removal offer potential for P recovery by biological P re-dissolution, its scalability and performance under real-world conditions remain underexplored. Here we report on a pilot-scale test (15 m<ce:sup loc=\"post\">3</ce:sup> return sludge per day) for rapid P recovery from return sludge at a full-scale municipal WWTP induced by acetate supplementation and subsequent P precipitation as a soil amendment and fertilizer. In a total of 54 re-dissolution batches (treatment time approx. 80 min), supernatant P concentrations varied greatly. Batches were combined and used as the feed at 19.2–22.7 mg P/L for fluidized bed precipitation with dolomite seed grains. This step was highly efficient since upon milk of lime addition (pH >9.6), 99 % of the P-input load precipitated onto the dolomite, forming a calcium phosphate layer with 0.9–1.9 wt% P. Trace element levels in the product complied with the German Fertilizer Ordinance. Residual ortho-P effluent levels were ≤ 0.3 mg P/L. The precipitate is valuable in terms of soil pH regulation, while providing Ca, Mg, and P as plant nutrients. However, the poor overall recovery of 1.9 % of total sludge P clearly highlights the challenges of re-dissolution and phase separation at the pilot-scale. These arise from the combined biological and chemical P elimination strategy used at the particular WWTP, variations in acetate-induced re-dissolution kinetics, and inefficient sedimentation for solid/liquid separation. Perspectives for process optimization and improved overall recovery are discussed.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"9 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142967766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The inhibitory effect of triclocarban (TCC) on biological nitrogen removal process had been widely reported, but the adaptive effect of nitrifiers and the changes of TCC fate at long-term exposure are not clear. The present study aimed to investigate the effect of TCC on the partial nitrification (PN) process and its interaction with nitrifiers via the nitrite accumulation, TCC degradation path, and microbial community response at long-term exposure. The results showed that the accumulation of NO2--N was observed after a long period of operation. Interestingly, the concentration of NO3--N was also decreased. Moreover, long-term exposure of TCC increased the activity of ammonia monooxygenase (AMO) and increased the secretion of extracellular polymeric substances (EPS) to resist the toxicity of TCC. Mass balance analysis showed that the biodegradation efficiency of TCC adsorbed in sludge increased from 4.30 % to 70.57 %. Meanwhile, abundance of AOB with long-term exposure of TCC increased, while abundance of NOB decreased. In addition, the abundance of TCC degrading bacteria (i.e., Sphingomonas) also increased. This indicated that TCC inhibited NOB and enriched TCC-degrading bacteria. The outcome of the present study demonstrated the changes of TCC fate and its interaction with nitrifiers at long-term exposure, which provided a basis for the treatment of TCC containing domestic sewage.
{"title":"Long-term exposure of triclocarban to the partial nitrification process: Its fate and microbial dynamics","authors":"Jingying Yan, Dinglei Zhong, Junjie Li, Hengfeng Miao, Kunlun Yang, Peng Gu, Xueli Ren, Jianglei Xiong, Zengshuai Zhang","doi":"10.1016/j.psep.2024.12.090","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.090","url":null,"abstract":"The inhibitory effect of triclocarban (TCC) on biological nitrogen removal process had been widely reported, but the adaptive effect of nitrifiers and the changes of TCC fate at long-term exposure are not clear. The present study aimed to investigate the effect of TCC on the partial nitrification (PN) process and its interaction with nitrifiers via the nitrite accumulation, TCC degradation path, and microbial community response at long-term exposure. The results showed that the accumulation of NO<ce:inf loc=\"post\">2</ce:inf><ce:sup loc=\"post\">-</ce:sup>-N was observed after a long period of operation. Interestingly, the concentration of NO<ce:inf loc=\"post\">3</ce:inf><ce:sup loc=\"post\">-</ce:sup>-N was also decreased. Moreover, long-term exposure of TCC increased the activity of ammonia monooxygenase (AMO) and increased the secretion of extracellular polymeric substances (EPS) to resist the toxicity of TCC. Mass balance analysis showed that the biodegradation efficiency of TCC adsorbed in sludge increased from 4.30 % to 70.57 %. Meanwhile, abundance of AOB with long-term exposure of TCC increased, while abundance of NOB decreased. In addition, the abundance of TCC degrading bacteria (i.e., <ce:italic>Sphingomonas</ce:italic>) also increased. This indicated that TCC inhibited NOB and enriched TCC-degrading bacteria. The outcome of the present study demonstrated the changes of TCC fate and its interaction with nitrifiers at long-term exposure, which provided a basis for the treatment of TCC containing domestic sewage.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"116 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-25DOI: 10.1016/j.psep.2024.12.094
Shanbi Peng, Jia Luo, Wei Li, Jun Jiang, Enbin Liu
Hydrogen-blended natural gas (HBNG) can utilize existing natural gas pipelines and infrastructure for hydrogen transportation. However, the introduction of HBNG pipelines into utility tunnel gas chambers leads to an increased risk of pipeline leakage and diffusion. Consequently, a numerical model for the gas chamber in the utility tunnel is constructed in this study, and the risks of HBNG leakage incidents under different scenarios are analyzed by using detector alarm times, hazardous areas, and combustible cloud volumes as indicators. Targeted hazard control measures for HBNG leakage incidents are proposed from two aspects: optimizing the detector alarm system and enhancing the ventilation system. The results show that under different hydrogen blending ratios (HBRs), leak hole diameters, ventilation speeds, and operating pressures, detectors located directly above the leak hole can rapidly detect leaking gas. However, when gas leaks from the bottom of the pipe (at 6 o′clock) or the leak hole is positioned in the middle downwind, the detector directly above the leak hole may not give an immediate alarm. The alarm time of the furthest detector from the leak hole is inversely correlated with the HBR, leak hole diameter, ventilation speed, and pipeline operating pressure, while the leakage direction has no significant impact on the alarm time for this detector. The diameter of the leak hole, its location, and the ventilation speed are the main factors influencing the extent of hazardous areas and the volume of combustible clouds after natural gas and HBNG leaks within the gas chamber. Additionally, the leak pressure is a key factor affecting the volume of the combustible cloud after the leakage of natural gas and HBNG in the chamber. When the wind speed in the chamber is 4 m/s and the pipeline operating pressure is 0.8 MPa, compared to other leakage scenarios, the hazardous area and the volume of the combustible cloud formed by the gas leakage are largest when the leak hole is located near the inlet. For HBRs of 10 % and 20 %, setting the installation spacing of methane detectors in the chamber to be less than or equal to 13.5 m and 9.5 m respectively, along with adjusting the positions of the vents, can effectively mitigate the impact of accidents.
{"title":"Hazard analysis and control measures for hydrogen-blended natural gas leakage in utility tunnels","authors":"Shanbi Peng, Jia Luo, Wei Li, Jun Jiang, Enbin Liu","doi":"10.1016/j.psep.2024.12.094","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.094","url":null,"abstract":"Hydrogen-blended natural gas (HBNG) can utilize existing natural gas pipelines and infrastructure for hydrogen transportation. However, the introduction of HBNG pipelines into utility tunnel gas chambers leads to an increased risk of pipeline leakage and diffusion. Consequently, a numerical model for the gas chamber in the utility tunnel is constructed in this study, and the risks of HBNG leakage incidents under different scenarios are analyzed by using detector alarm times, hazardous areas, and combustible cloud volumes as indicators. Targeted hazard control measures for HBNG leakage incidents are proposed from two aspects: optimizing the detector alarm system and enhancing the ventilation system. The results show that under different hydrogen blending ratios (HBRs), leak hole diameters, ventilation speeds, and operating pressures, detectors located directly above the leak hole can rapidly detect leaking gas. However, when gas leaks from the bottom of the pipe (at 6 o′clock) or the leak hole is positioned in the middle downwind, the detector directly above the leak hole may not give an immediate alarm. The alarm time of the furthest detector from the leak hole is inversely correlated with the HBR, leak hole diameter, ventilation speed, and pipeline operating pressure, while the leakage direction has no significant impact on the alarm time for this detector. The diameter of the leak hole, its location, and the ventilation speed are the main factors influencing the extent of hazardous areas and the volume of combustible clouds after natural gas and HBNG leaks within the gas chamber. Additionally, the leak pressure is a key factor affecting the volume of the combustible cloud after the leakage of natural gas and HBNG in the chamber. When the wind speed in the chamber is 4 m/s and the pipeline operating pressure is 0.8 MPa, compared to other leakage scenarios, the hazardous area and the volume of the combustible cloud formed by the gas leakage are largest when the leak hole is located near the inlet. For HBRs of 10 % and 20 %, setting the installation spacing of methane detectors in the chamber to be less than or equal to 13.5 m and 9.5 m respectively, along with adjusting the positions of the vents, can effectively mitigate the impact of accidents.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"16 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-25DOI: 10.1016/j.psep.2024.12.093
Anirudha Joshi, Fereshteh Sattari, Lianne Lefsrud, M.A. Khan
Hydrogen is a critical energy carrier in the transition to sustainable energy, but its properties such as high diffusivity, wide flammability range, and low ignition energy, present unique safety challenges during transportation. This study aims to improve on-road hydrogen transport safety by developing a dynamic, traffic-dependent risk assessment framework for both Compressed Gaseous Hydrogen (CGH₂) tube trailers and Liquid Hydrogen (LH₂). A key advancement in this study is the use of dynamic occupancy data, capturing variations in traffic density throughout the day, instead of relying on average traffic density to estimate ignition source distribution. Additionally, a qualitative Hazard and Operability (HAZOP) study was conducted for a potential central distribution terminal in Fort Saskatchewan, Alberta, Canada, to systematically identify process hazards during the loading of hydrogen on-road carriers. Results reveal that the ignition probability for minor CGH2 leaks significantly increases with road occupancy, rising from 0.003 at 0.1 % to 0.149 at 5 %, emphasizing the importance of scheduling transport during off-peak hours Vapor Cloud Explosions (VCE) from LH2 extend up to 257 m, compared to 122.42 m for CGH₂, underscoring the need for stricter land-use planning in densely populated areas. The analysis suggests prioritizing lower-traffic rural routes, which exhibit lower release frequencies (e.g., 1.80E-05 per year), over high-traffic urban routes with higher release frequencies (e.g., 6.47E-05 per year).
{"title":"Risk-based approach for safe terminal operation and route planning of on-road hydrogen distribution network","authors":"Anirudha Joshi, Fereshteh Sattari, Lianne Lefsrud, M.A. Khan","doi":"10.1016/j.psep.2024.12.093","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.093","url":null,"abstract":"Hydrogen is a critical energy carrier in the transition to sustainable energy, but its properties such as high diffusivity, wide flammability range, and low ignition energy, present unique safety challenges during transportation. This study aims to improve on-road hydrogen transport safety by developing a dynamic, traffic-dependent risk assessment framework for both Compressed Gaseous Hydrogen (CGH₂) tube trailers and Liquid Hydrogen (LH₂). A key advancement in this study is the use of dynamic occupancy data, capturing variations in traffic density throughout the day, instead of relying on average traffic density to estimate ignition source distribution. Additionally, a qualitative Hazard and Operability (HAZOP) study was conducted for a potential central distribution terminal in Fort Saskatchewan, Alberta, Canada, to systematically identify process hazards during the loading of hydrogen on-road carriers. Results reveal that the ignition probability for minor CGH2 leaks significantly increases with road occupancy, rising from 0.003 at 0.1 % to 0.149 at 5 %, emphasizing the importance of scheduling transport during off-peak hours Vapor Cloud Explosions (VCE) from LH2 extend up to 257 m, compared to 122.42 m for CGH₂, underscoring the need for stricter land-use planning in densely populated areas. The analysis suggests prioritizing lower-traffic rural routes, which exhibit lower release frequencies (e.g., 1.80E-05 per year), over high-traffic urban routes with higher release frequencies (e.g., 6.47E-05 per year).","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"15 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142967764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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