Pub Date : 2024-12-17DOI: 10.1016/j.psep.2024.12.071
Nevim Genç, Elif Durna Pişkin
Microbial fuel cell (MFC)’s are sustainable resource recovery technologies that produce green energy. While sewage sludge fed with dairy industry wastewater was oxidized in the anode, the energy production and treatment potentials of MFCs in which nitrate was reduced under abiotic-biotic conditions in the cathode compartment were evaluated. It was determined how the performance changed when the conditions of the cathode compartment were changed as biotic (heterotrophic-autotrophic) and abiotic. The performance of the MFC was evaluated by anodic and cathodic coulombic efficiency (CE), maximum power density, chemical oxygen demand (COD) and NO3- removal. Considering the MFC performance criteria and the cost of the carbon source added to the catholytes, the preference order of the MFCs was determined using a multi-criterion decision methodology called the PROMETHEE approach, which allowed for pairwise comparison of alternatives on a criterion basis using preference functions. Accordingly, abiotic MFC˃autotrophic MFC˃heterotrophic MFC preference order was obtained. It was revealed that all criteria except nitrate removal efficiency had a positive effect on the selection of abiotic MFC. Although the nitrate removal efficiency in abiotic MFC was lower than biotic MFCs, the energy production performance was determined to be quite high.
{"title":"Evaluation of simultaneous energy production and biotic and abiotic nitrate removal in microbial fuel cells (MFCs): Selection of the most suitable MFC by a multi-criteria decision methodology","authors":"Nevim Genç, Elif Durna Pişkin","doi":"10.1016/j.psep.2024.12.071","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.071","url":null,"abstract":"Microbial fuel cell (MFC)’s are sustainable resource recovery technologies that produce green energy. While sewage sludge fed with dairy industry wastewater was oxidized in the anode, the energy production and treatment potentials of MFCs in which nitrate was reduced under abiotic-biotic conditions in the cathode compartment were evaluated. It was determined how the performance changed when the conditions of the cathode compartment were changed as biotic (heterotrophic-autotrophic) and abiotic. The performance of the MFC was evaluated by anodic and cathodic coulombic efficiency (CE), maximum power density, chemical oxygen demand (COD) and NO<ce:inf loc=\"post\">3</ce:inf><ce:sup loc=\"post\">-</ce:sup> removal. Considering the MFC performance criteria and the cost of the carbon source added to the catholytes, the preference order of the MFCs was determined using a multi-criterion decision methodology called the PROMETHEE approach, which allowed for pairwise comparison of alternatives on a criterion basis using preference functions. Accordingly, abiotic MFC˃autotrophic MFC˃heterotrophic MFC preference order was obtained. It was revealed that all criteria except nitrate removal efficiency had a positive effect on the selection of abiotic MFC. Although the nitrate removal efficiency in abiotic MFC was lower than biotic MFCs, the energy production performance was determined to be quite high.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"41 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867688","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 large amounts of CO gas produced during tunnel blasting operations pose a serious threat to safe production, and finding an effective method to eliminate CO from smoke and airflow remains a significant challenge. Based on the characteristics of thermal regeneration and the principle of catalytic oxidation, we designed a CO filtration and elimination device for smoke and airflow that can perform in-situ thermal regeneration. The device eliminates CO by drawing it from the smoke and airflow and bringing it into contact with catalytic particles. The Co3O4 catalyst, synthesized through particle forming processes, exhibits good strength and catalytic activity, meeting the application requirements of the device. Catalyst regeneration is accomplished through in-situ heating and hot air purging. Multiple modular testing experiments validated the feasibility of the particle-based catalyst device. Subsequently, a full set of small-scale prototypes was developed, and CO concentration surge experiments demonstrated that under ambient humidity conditions of 61.2 %-68.5 %, the prototype achieved a CO elimination rate of 72.59 % after 500 seconds. Finally, full-scale tests in the Dalian Bay subsea tunnel further verified its practical performance, with CO elimination rates exceeding 71.4 % in two elimination cycles and a regeneration rate of over 98 %. The test results indicate that the smoke and airflow CO filtration and elimination device can effectively remove CO from smoke and airflow, and holds great potential for widespread application in tunnel blasting operations.
{"title":"Experimental study on a smoke airflow CO filtration and elimination device based on particulate Co3O4 catalyst","authors":"Sheng He, Shuo Gao, Jia Li, Yitao Yu, Jianguo Wu, Jiaxin Shi, Xiao Wang, Xiaoyu Chen, Fubao Zhou","doi":"10.1016/j.psep.2024.12.062","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.062","url":null,"abstract":"The large amounts of CO gas produced during tunnel blasting operations pose a serious threat to safe production, and finding an effective method to eliminate CO from smoke and airflow remains a significant challenge. Based on the characteristics of thermal regeneration and the principle of catalytic oxidation, we designed a CO filtration and elimination device for smoke and airflow that can perform in-situ thermal regeneration. The device eliminates CO by drawing it from the smoke and airflow and bringing it into contact with catalytic particles. The Co<ce:inf loc=\"post\">3</ce:inf>O<ce:inf loc=\"post\">4</ce:inf> catalyst, synthesized through particle forming processes, exhibits good strength and catalytic activity, meeting the application requirements of the device. Catalyst regeneration is accomplished through in-situ heating and hot air purging. Multiple modular testing experiments validated the feasibility of the particle-based catalyst device. Subsequently, a full set of small-scale prototypes was developed, and CO concentration surge experiments demonstrated that under ambient humidity conditions of 61.2 %-68.5 %, the prototype achieved a CO elimination rate of 72.59 % after 500 seconds. Finally, full-scale tests in the Dalian Bay subsea tunnel further verified its practical performance, with CO elimination rates exceeding 71.4 % in two elimination cycles and a regeneration rate of over 98 %. The test results indicate that the smoke and airflow CO filtration and elimination device can effectively remove CO from smoke and airflow, and holds great potential for widespread application in tunnel blasting operations.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"24 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867692","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 rapid growth of lithium-ion batteries (LIBs) in recent years has produced a large number of spent LIBs that need to be recycled urgently. The effective separation of cathode active materials from spent LIBs by froth flotation is an important step in the recovery process. Herein, the low-temperature roasting pretreatment is used to change the surface wettability of electrode material particles to achieve the efficient flotation separation of cathode material and graphite. The phase composition, surface morphology and surface wettability of the roasted electrode materials were systematically investigated, and the variation of polyvinylidene fluoride (PVDF) binder with temperature was observed by atomic force microscopy and investigated by molecular dynamics simulation. After roasting at 350 ℃, a large number of hydrophilic sites are exposed on the surface of the cathode material due to the condensation of PVDF, and after intensive flotation by carboxymethyl cellulose, the grade of cathode active material reached 94.02 %. It is worth noting that PVDF does not decompose at the used temperature for LIBs recycling, which can save energy and prevent the release of fluoride and other gases into the environment. It is believed that the provided idea has reference meaning for the efficient and sustainable recycling of LIBs.
{"title":"A green and facile pretreatment for flotation separation of electrode materials from spent lithium-ion batteries: Low-temperature roasting-induced deformation of PVDF","authors":"Yuanyuan Li, Lijun Deng, Xiaona Zou, Yingwei Wang, Liang Si, Junchao Wang, Yijun Cao, Jianyong He, Guosheng Li","doi":"10.1016/j.psep.2024.12.048","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.048","url":null,"abstract":"The rapid growth of lithium-ion batteries (LIBs) in recent years has produced a large number of spent LIBs that need to be recycled urgently. The effective separation of cathode active materials from spent LIBs by froth flotation is an important step in the recovery process. Herein, the low-temperature roasting pretreatment is used to change the surface wettability of electrode material particles to achieve the efficient flotation separation of cathode material and graphite. The phase composition, surface morphology and surface wettability of the roasted electrode materials were systematically investigated, and the variation of polyvinylidene fluoride (PVDF) binder with temperature was observed by atomic force microscopy and investigated by molecular dynamics simulation. After roasting at 350 ℃, a large number of hydrophilic sites are exposed on the surface of the cathode material due to the condensation of PVDF, and after intensive flotation by carboxymethyl cellulose, the grade of cathode active material reached 94.02 %. It is worth noting that PVDF does not decompose at the used temperature for LIBs recycling, which can save energy and prevent the release of fluoride and other gases into the environment. It is believed that the provided idea has reference meaning for the efficient and sustainable recycling of LIBs.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"13 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867694","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 : 2024-12-16DOI: 10.1016/j.psep.2024.12.060
Mohaned Hammad, Steven Angel, Ahmed K. Al-kamal, Anam Asghar, Mena-Alexander Kräenbring, Adil Amin, Haakon T.A. Wiedemann, Amin S. Amin, Vineetha Vinayakumar, Torsten C. Schmidt, Christopher W.M. Kay, Doris Segets, Hartmut Wiggers
Improving the efficiency and stability of heterogeneous catalysts is essential for effectively utilizing peroxymonosulfate activation in industrial wastewater treatment. Perovskite ABO3 catalysts with high structural flexibility have gained considerable attention in the peroxymonosulfate activation for the removal of hazardous organic compounds from wastewater. However, there is still considerable potential for catalytic enhancement due to the ease of tailoring its composition and structure. Herein, we introduce a scalable method to synthesize LaCo0.2Mn0.8O3 with the aim of improving the catalytic performance. Interestingly, LaCo0.2Mn0.8O3 with abundant oxygen vacancies and improved dispersion stability exhibited enhanced catalytic degradation of carbamazepine compared to the LaMnO3 and LaCoO3 catalysts in the peroxymonosulfate activation system. The partial substitution of manganese by cobalt in LaMnO3 leading to the LaCo0.2Mn0.8O3+peroxymonosulfate system maintains a relatively high performance over repeated usage. Furthermore, the LaCo0.2Mn0.8O3 catalyst exhibited excellent catalytic performance and stability across a broad pH range (3–9). Electron paramagnetic resonance and radical quenching experiment tests demonstrated singlet oxygen (1O2) as the primary active species for carbamazepine degradation in the LaCo0.2Mn0.8O3+ peroxymonosulfate system, while free radicals, such as sulfate radicals (SO4•–), hydroxyl radicals (•OH), and superoxide radicals (O2•–), played a minor role in the carbamazepine removal. Taken together, this research provides significant insight into the effect of B-site substitution on the catalytic performance of perovskite catalysts.
{"title":"Spray-flame synthesis of LaCo0.2Mn0.8O3 for selective peroxymonosulfate activation into singlet oxygen towards efficient degradation of carbamazepine","authors":"Mohaned Hammad, Steven Angel, Ahmed K. Al-kamal, Anam Asghar, Mena-Alexander Kräenbring, Adil Amin, Haakon T.A. Wiedemann, Amin S. Amin, Vineetha Vinayakumar, Torsten C. Schmidt, Christopher W.M. Kay, Doris Segets, Hartmut Wiggers","doi":"10.1016/j.psep.2024.12.060","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.060","url":null,"abstract":"Improving the efficiency and stability of heterogeneous catalysts is essential for effectively utilizing peroxymonosulfate activation in industrial wastewater treatment. Perovskite ABO<ce:inf loc=\"post\">3</ce:inf> catalysts with high structural flexibility have gained considerable attention in the peroxymonosulfate activation for the removal of hazardous organic compounds from wastewater. However, there is still considerable potential for catalytic enhancement due to the ease of tailoring its composition and structure. Herein, we introduce a scalable method to synthesize LaCo<ce:inf loc=\"post\">0.2</ce:inf>Mn<ce:inf loc=\"post\">0.8</ce:inf>O<ce:inf loc=\"post\">3</ce:inf> with the aim of improving the catalytic performance. Interestingly, LaCo<ce:inf loc=\"post\">0.2</ce:inf>Mn<ce:inf loc=\"post\">0.8</ce:inf>O<ce:inf loc=\"post\">3</ce:inf> with abundant oxygen vacancies and improved dispersion stability exhibited enhanced catalytic degradation of carbamazepine compared to the LaMnO<ce:inf loc=\"post\">3</ce:inf> and LaCoO<ce:inf loc=\"post\">3</ce:inf> catalysts in the peroxymonosulfate activation system. The partial substitution of manganese by cobalt in LaMnO<ce:inf loc=\"post\">3</ce:inf> leading to the LaCo<ce:inf loc=\"post\">0.2</ce:inf>Mn<ce:inf loc=\"post\">0.8</ce:inf>O<ce:inf loc=\"post\">3</ce:inf>+peroxymonosulfate system maintains a relatively high performance over repeated usage. Furthermore, the LaCo<ce:inf loc=\"post\">0.2</ce:inf>Mn<ce:inf loc=\"post\">0.8</ce:inf>O<ce:inf loc=\"post\">3</ce:inf> catalyst exhibited excellent catalytic performance and stability across a broad pH range (3–9). Electron paramagnetic resonance and radical quenching experiment tests demonstrated singlet oxygen (<ce:sup loc=\"post\">1</ce:sup>O<ce:inf loc=\"post\">2</ce:inf>) as the primary active species for carbamazepine degradation in the LaCo<ce:inf loc=\"post\">0.2</ce:inf>Mn<ce:inf loc=\"post\">0.8</ce:inf>O<ce:inf loc=\"post\">3</ce:inf>+ peroxymonosulfate system, while free radicals, such as sulfate radicals (SO<ce:inf loc=\"post\">4</ce:inf><ce:sup loc=\"post\">•–</ce:sup>), hydroxyl radicals (<ce:sup loc=\"post\">•</ce:sup>OH), and superoxide radicals (O<ce:inf loc=\"post\">2</ce:inf><ce:sup loc=\"post\">•–</ce:sup>), played a minor role in the carbamazepine removal. Taken together, this research provides significant insight into the effect of B-site substitution on the catalytic performance of perovskite catalysts.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"202 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889373","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}
Macroalgae, commonly known as seaweeds, are a major cultivated species in the aquaculture industry, and a key component in the food and pharmaceutical industries due to their hydrocolloid fraction. Recently, macroalgae have been revisited as marine-derived carbon donors or “blue carbon” donors due to their superior carbon sequestration potential and accessibility to human intervention in terms of climate change mitigation action. There is an ongoing debate on including macroalgae as “blue carbon” in addition to the conventional blue carbon sources, namely salt marshes, mangroves, and seagrass. Existing experimental evidence indicates that macroalgal carbon fixation is high next only to phytoplankton, and the fixed carbon is channeled via vertical and horizontal transport along with a considerable level of sink in sediments. Macroalgae are phylogenetically diverse, and based on their taxonomical position and morphological features, they are an attractive feedstock for biofuel production. This review assesses the potential of macroalgae as a feedstock for the production of biogas/biomethane. The role of the inherent biomass composition of biomethane in anaerobic digestion and other parameters influencing biogas yield are discussed. Commercial realization of macroalgal biomethane via life cycle assessment, techno-economic assessment, and exergy analysis, with future research outlook, is presented. Macroalgae present a potential marine-derived alternative compared to terrestrial carbon feedstock, and macroalgal biomethane is an untapped resource waiting to be explored.
{"title":"Recent trends in anaerobic digestion of macroalgae for blue carbon derived biofuels – A review","authors":"Dillirani Nagarajan, Guruvignesh Senthilkumar, Chiu-Wen Chen, Jo-Shu Chang, Cheng-Di Dong","doi":"10.1016/j.psep.2024.12.035","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.035","url":null,"abstract":"Macroalgae, commonly known as seaweeds, are a major cultivated species in the aquaculture industry, and a key component in the food and pharmaceutical industries due to their hydrocolloid fraction. Recently, macroalgae have been revisited as marine-derived carbon donors or “blue carbon” donors due to their superior carbon sequestration potential and accessibility to human intervention in terms of climate change mitigation action. There is an ongoing debate on including macroalgae as “blue carbon” in addition to the conventional blue carbon sources, namely salt marshes, mangroves, and seagrass. Existing experimental evidence indicates that macroalgal carbon fixation is high next only to phytoplankton, and the fixed carbon is channeled via vertical and horizontal transport along with a considerable level of sink in sediments. Macroalgae are phylogenetically diverse, and based on their taxonomical position and morphological features, they are an attractive feedstock for biofuel production. This review assesses the potential of macroalgae as a feedstock for the production of biogas/biomethane. The role of the inherent biomass composition of biomethane in anaerobic digestion and other parameters influencing biogas yield are discussed. Commercial realization of macroalgal biomethane via life cycle assessment, techno-economic assessment, and exergy analysis, with future research outlook, is presented. Macroalgae present a potential marine-derived alternative compared to terrestrial carbon feedstock, and macroalgal biomethane is an untapped resource waiting to be explored.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"3 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889374","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 present study investigated the hydrological connections and mechanisms of water transition based on isotopic tracing in the Baoxing River Basin, an area heavily influenced by human activity located in the plateau edge. The contrasting seasonal isotopic patterns and δD-δ18O plots between river water and groundwater and precipitation indicated that these two waters were recharged by seasonal precipitation and meltwater during the wet season, while the base flow primarily consists of stored water rather than recent input during the dry season. Both river water and groundwater exhibited a significant elevation effect in their δ18O values, however, the elevation gradient was as low as −0.05 to −0.07 ‰/100 m. The low gradient can be attributed to the combined recharge from precipitation and meltwater, which led to an increased contribution of depleted heavy isotopes to surface and groundwater flow as elevation decreases. An inverse water transition time index (ITTI) was calculated for 7 sub-basins based on isotopic damping ratios, which were identified to be positively correlated with the percentage of farmland and negatively correlated with slope. Isotope-derived hydrological information indicated that the extensive agricultural areas on gentle slopes in the Baoxing River Basin may contribute to water quality deterioration and pose increased health threat to the aquatic ecosystems, especially during the dry season with reduced discharge and high evaporation. Accordingly, various measures were proposed to strengthen the control of non-point source pollution from low-slope agricultural land.
{"title":"Stable isotopes reveal the water conversion and transition dynamics in a heavily-polluted plateau marginal basin: implications for aquatic ecosystem protection","authors":"Chengcheng Xia, Jie Wei, Guodong Liu, Xuchenyu Liu, Qiaoxue Peng, Yuchuan Meng","doi":"10.1016/j.psep.2024.12.055","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.055","url":null,"abstract":"The present study investigated the hydrological connections and mechanisms of water transition based on isotopic tracing in the Baoxing River Basin, an area heavily influenced by human activity located in the plateau edge. The contrasting seasonal isotopic patterns and δD-δ<ce:sup loc=\"post\">18</ce:sup>O plots between river water and groundwater and precipitation indicated that these two waters were recharged by seasonal precipitation and meltwater during the wet season, while the base flow primarily consists of stored water rather than recent input during the dry season. Both river water and groundwater exhibited a significant elevation effect in their δ<ce:sup loc=\"post\">18</ce:sup>O values, however, the elevation gradient was as low as −0.05 to −0.07 ‰/100 m. The low gradient can be attributed to the combined recharge from precipitation and meltwater, which led to an increased contribution of depleted heavy isotopes to surface and groundwater flow as elevation decreases. An inverse water transition time index (ITTI) was calculated for 7 sub-basins based on isotopic damping ratios, which were identified to be positively correlated with the percentage of farmland and negatively correlated with slope. Isotope-derived hydrological information indicated that the extensive agricultural areas on gentle slopes in the Baoxing River Basin may contribute to water quality deterioration and pose increased health threat to the aquatic ecosystems, especially during the dry season with reduced discharge and high evaporation. Accordingly, various measures were proposed to strengthen the control of non-point source pollution from low-slope agricultural land.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"31 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867693","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 : 2024-12-15DOI: 10.1016/j.psep.2024.12.054
Guangshuo Wei, Jiazheng Zhang, Daokui Yang, Yang Jin, Xujiang Wang, Jingwei Li, Dongjie Pang, Wenlong Wang, Yanpeng Mao
The significant accumulation of gold tailings (GT) presents a substantial environmental challenge, while existing pathways for their high-value utilization remain limited and lack theoretical underpinning. This study provides a comprehensive exploration of the separation and recovery of silicate components from GT via a hydrothermal treatment conducted under alkaline conditions. The effects of key parameters including GT/NaOH ratio, NaOH concentration, hydrothermal temperature, and hydrothermal time on silica extraction efficiency (SEE) and solid phase mineral composition were systematically investigated. The study elucidated the mechanism of silicate dissolution and zeolite formation. Furthermore, the optimal parameters for silicon extraction, determined using response surface methodology, are 4 hours, 202°C, 6.95 mol/L, and 1:3 g/mL, achieving a SEE of 70.619 %. Employing multivariate nonlinear regression, the study established a robust predictive model capable of forecasting SEE under various experimental conditions. The model demonstrated high predictive accuracy with minimal deviation at different parameters. Additionally, the zeolite materials obtained as byproducts of the hydrothermal process exhibited ion adsorption capabilities, with a maximum CEC of 1.475 meq/g. This research provides a critical theoretical foundation for the valorization of GT, highlighting its potential for high-value applications.
{"title":"Mechanistic insights and predictive modeling of silicate dissolution in gold tailings via alkaline hydrothermal treatment","authors":"Guangshuo Wei, Jiazheng Zhang, Daokui Yang, Yang Jin, Xujiang Wang, Jingwei Li, Dongjie Pang, Wenlong Wang, Yanpeng Mao","doi":"10.1016/j.psep.2024.12.054","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.054","url":null,"abstract":"The significant accumulation of gold tailings (GT) presents a substantial environmental challenge, while existing pathways for their high-value utilization remain limited and lack theoretical underpinning. This study provides a comprehensive exploration of the separation and recovery of silicate components from GT via a hydrothermal treatment conducted under alkaline conditions. The effects of key parameters including GT/NaOH ratio, NaOH concentration, hydrothermal temperature, and hydrothermal time on silica extraction efficiency (SEE) and solid phase mineral composition were systematically investigated. The study elucidated the mechanism of silicate dissolution and zeolite formation. Furthermore, the optimal parameters for silicon extraction, determined using response surface methodology, are 4 hours, 202°C, 6.95 mol/L, and 1:3 g/mL, achieving a SEE of 70.619 %. Employing multivariate nonlinear regression, the study established a robust predictive model capable of forecasting SEE under various experimental conditions. The model demonstrated high predictive accuracy with minimal deviation at different parameters. Additionally, the zeolite materials obtained as byproducts of the hydrothermal process exhibited ion adsorption capabilities, with a maximum CEC of 1.475 meq/g. This research provides a critical theoretical foundation for the valorization of GT, highlighting its potential for high-value applications.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"26 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867695","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 : 2024-12-15DOI: 10.1016/j.psep.2024.12.057
Cindy, Hirofumi Ichinose, Diego M. Mendoza, Kojo T. Konadu, Ryusei Takimoto, Gde Pandhe Wisnu Suyantara, Keiko Sasaki
Despite their relatively higher Au content, double refractory gold ores (DRGOs) have not been developed for economic reasons, as Au grains are trapped by sulfides, and carbonaceous matter can adsorb Au(CN)₂⁻ during cyanidation. The enzymatic treatment of carbonaceous matter is gaining interest due to its eco-friendly benefits. The use of laccase, combined with an electron mediator, has been shown to enhance Au extraction from DRGOs. Although the effectiveness of mediators in improving lignin degradation has been reported, their significance in laccase-mediator system (LMS) treatment of DRGOs has yet to be thoroughly investigated. In this study, the mechanisms of various mediators in LMSs were investigated to improve Au extraction from DRGOs. To observe the degradation of the carbonaceous matter, thermogravimetry, Raman spectroscopy, three-dimensional fluorescence spectrometry, and CHN elemental analysis were utilized. The results demonstrated that the highest Au extraction was achieved after treatment with violuric acid monohydrate-mediated laccase, resulting in 92.9 ± 2.7 % Au extracted from DRGOs, which is equivalent to complete extraction when considering the 8.6 % Au locked in sulfides. The Langmuir model provided a better fit for the mediators' sorption than the Freundlich model, indicating that monolayer sorption is the predominant process in the mediators' adsorptions on pre-treated DRGOs. This proposed LMS represents a novel approach to enhancing our understanding of carbon science in biohydrometallurgy.
{"title":"Enhancing the biotreatment of carbonaceous matter in double refractory gold ores: The impact of various mediators on laccase performance","authors":"Cindy, Hirofumi Ichinose, Diego M. Mendoza, Kojo T. Konadu, Ryusei Takimoto, Gde Pandhe Wisnu Suyantara, Keiko Sasaki","doi":"10.1016/j.psep.2024.12.057","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.057","url":null,"abstract":"Despite their relatively higher Au content, double refractory gold ores (DRGOs) have not been developed for economic reasons, as Au grains are trapped by sulfides, and carbonaceous matter can adsorb Au(CN)₂⁻ during cyanidation. The enzymatic treatment of carbonaceous matter is gaining interest due to its eco-friendly benefits. The use of laccase, combined with an electron mediator, has been shown to enhance Au extraction from DRGOs. Although the effectiveness of mediators in improving lignin degradation has been reported, their significance in laccase-mediator system (LMS) treatment of DRGOs has yet to be thoroughly investigated. In this study, the mechanisms of various mediators in LMSs were investigated to improve Au extraction from DRGOs. To observe the degradation of the carbonaceous matter, thermogravimetry, Raman spectroscopy, three-dimensional fluorescence spectrometry, and CHN elemental analysis were utilized. The results demonstrated that the highest Au extraction was achieved after treatment with violuric acid monohydrate-mediated laccase, resulting in 92.9 ± 2.7 % Au extracted from DRGOs, which is equivalent to complete extraction when considering the 8.6 % Au locked in sulfides. The Langmuir model provided a better fit for the mediators' sorption than the Freundlich model, indicating that monolayer sorption is the predominant process in the mediators' adsorptions on pre-treated DRGOs. This proposed LMS represents a novel approach to enhancing our understanding of carbon science in biohydrometallurgy.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"27 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925071","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 : 2024-12-15DOI: 10.1016/j.psep.2024.12.058
Tuan Anh Nguyen, Hong Dan Nguyen, Britta Schmalz, Le Luu Tran
Surface water is a primary water source for domestic water treatment systems in many countries around the world, especially in developing countries. The coagulation-flocculation process has been widely applied in water treatment systems due to low cost and easy-to-operate process. This study focuses on optimizing the operational conditions (dosage and pH) in the coagulation-flocculation process with different coagulants for the water supply in upland rural areas of Vietnam, from the lab scale to the pilot scale system. Two prehydrolyzed coagulants, polyaluminium chloride (PAC) and polyferric sulfate (PFS), and aluminum sulfate (alum), were used in the coagulation-flocculation testing. Response surface methodology (RSM) was applied to design the experiments, analyze the results, and optimize the response variables. The results showed that the quadratic regression models of PAC, PFS, and alum were statistically significant at the 95 % confidence level (p < 0.05), and the p values of lack of fit for these models were insignificant (p > 0.05). The optimum conditions for 48.3 % DOC and 92 % turbidity removal using PAC were a dosage of 15 mg/L and a pH of 7.98. Similarity, 47.5 % DOC and 90 % turbidity removal were observed at 43.5 mg/L of PFS and pH 7.08. However, the lower removal efficiencies (37.2 % DOC and 86.7 % turbidity) were recorded at 60 mg/L of alum and pH 7.45. PAC and PFS were found to be more effective than alum in both DOC and turbidity removal from surface water. Notably, a combination of the coagulation process with aeration and a pre-filter system including a 1 micron polypropylene filter column, activated carbon, and cation exchange at the optimal operation conditions of coagulation through the RSM approach can be applied to treat Ba river water into domestic water that meets the national standard.
{"title":"Coagulation/floculation as a key unit in the decentralized surface water treatment systems in upland rural areas of Vietnam: Results from a lab scale to a pilot scale system","authors":"Tuan Anh Nguyen, Hong Dan Nguyen, Britta Schmalz, Le Luu Tran","doi":"10.1016/j.psep.2024.12.058","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.058","url":null,"abstract":"Surface water is a primary water source for domestic water treatment systems in many countries around the world, especially in developing countries. The coagulation-flocculation process has been widely applied in water treatment systems due to low cost and easy-to-operate process. This study focuses on optimizing the operational conditions (dosage and pH) in the coagulation-flocculation process with different coagulants for the water supply in upland rural areas of Vietnam, from the lab scale to the pilot scale system. Two prehydrolyzed coagulants, polyaluminium chloride (PAC) and polyferric sulfate (PFS), and aluminum sulfate (alum), were used in the coagulation-flocculation testing. Response surface methodology (RSM) was applied to design the experiments, analyze the results, and optimize the response variables. The results showed that the quadratic regression models of PAC, PFS, and alum were statistically significant at the 95 % confidence level (p < 0.05), and the p values of lack of fit for these models were insignificant (p > 0.05). The optimum conditions for 48.3 % DOC and 92 % turbidity removal using PAC were a dosage of 15 mg/L and a pH of 7.98. Similarity, 47.5 % DOC and 90 % turbidity removal were observed at 43.5 mg/L of PFS and pH 7.08. However, the lower removal efficiencies (37.2 % DOC and 86.7 % turbidity) were recorded at 60 mg/L of alum and pH 7.45. PAC and PFS were found to be more effective than alum in both DOC and turbidity removal from surface water. Notably, a combination of the coagulation process with aeration and a pre-filter system including a 1 micron polypropylene filter column, activated carbon, and cation exchange at the optimal operation conditions of coagulation through the RSM approach can be applied to treat Ba river water into domestic water that meets the national standard.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"3 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889376","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 : 2024-12-15DOI: 10.1016/j.psep.2024.12.052
Wei He, Lang Liu, Zhiyu Fang, Baoning Wei, Qifeng Jia, Mengbo Zhu, Ruofan Wang, Huisheng Qu, Yuheng Gao, Lei Xia
Evaluating the long-term safe operation of storage facilities requires a vital index investigating the performance change of storage backfill materials due to prolonged carbonation. For the first time, this study employed multiple indices to characterize the basic properties of storage backfill under carbonation over two years. The results show that long-term hydration positively influences concrete properties and promotes the development of harmless holes smaller than 20 nm in backfill materials. However, this study also revealed that carbonation for up to two years adversely affects backfill material properties. The carbonation progresses slowly, with a maximum carbonation depth reaching 147 mm. Compared to long-term hydration, the backfill subjected to carbonation curing for two years showed significant disadvantages regarding strength characteristics, permeability, pH levels and pore structure. Specifically, the uniaxial compressive strength decreased from 11.015 MPa to 8.583 MPa. The internal axial permeability of the sample was 0.945 md, and the internal permeability was 0.109 md. The pH of the sample dropped significantly from 12.8 to 6.8, and its porosity increased from 15.67 % to 29.30 %. Carbon sequestration and utilization is a hot topic, and the results of this study should arouse attention to the application of CO2 in the concrete and mine backfill field and provide an essential reference for further research on long-term performance changes of carbonation.
{"title":"Effect of long-term carbonation on strength and permeability of magnesia-coal based solid waste backfill materials","authors":"Wei He, Lang Liu, Zhiyu Fang, Baoning Wei, Qifeng Jia, Mengbo Zhu, Ruofan Wang, Huisheng Qu, Yuheng Gao, Lei Xia","doi":"10.1016/j.psep.2024.12.052","DOIUrl":"https://doi.org/10.1016/j.psep.2024.12.052","url":null,"abstract":"Evaluating the long-term safe operation of storage facilities requires a vital index investigating the performance change of storage backfill materials due to prolonged carbonation. For the first time, this study employed multiple indices to characterize the basic properties of storage backfill under carbonation over two years. The results show that long-term hydration positively influences concrete properties and promotes the development of harmless holes smaller than 20 nm in backfill materials. However, this study also revealed that carbonation for up to two years adversely affects backfill material properties. The carbonation progresses slowly, with a maximum carbonation depth reaching 147 mm. Compared to long-term hydration, the backfill subjected to carbonation curing for two years showed significant disadvantages regarding strength characteristics, permeability, pH levels and pore structure. Specifically, the uniaxial compressive strength decreased from 11.015 MPa to 8.583 MPa. The internal axial permeability of the sample was 0.945 md, and the internal permeability was 0.109 md. The pH of the sample dropped significantly from 12.8 to 6.8, and its porosity increased from 15.67 % to 29.30 %. Carbon sequestration and utilization is a hot topic, and the results of this study should arouse attention to the application of CO<ce:inf loc=\"post\">2</ce:inf> in the concrete and mine backfill field and provide an essential reference for further research on long-term performance changes of carbonation.","PeriodicalId":20743,"journal":{"name":"Process Safety and Environmental Protection","volume":"14 1","pages":""},"PeriodicalIF":7.8,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867699","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：