Pub Date : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012074
F J Zhang, L Zhang, C Li, S J Gao
The discharge of seepage water from undersea tunnel structures, often treated as wastewater, inherently carries a substantial reservoir of untapped low-grade thermal energy. Unfortunately, comprehensive investigations into harnessing this latent potential remain notably limited. This study introduced an innovative strategy through the design of an undersea tunnel seepage seawater source heat pump system. Distinguished by the integration of a capillary front-end heat exchanger, this system aimed to effectively exploit the frequently disregarded low-grade thermal energy present in the seepage water of undersea tunnel structures. The seawater seepage from the tunnel is transported to the car park at the tunnel entrance, and a seawater energy pool is constructed by storing seawater in its underground space. The use of capillary network placed in the energy pool in the front heat exchanger, water source heat pump units, circulating water pumps and fan coil end device composed of underground undersea tunnel seepage seawater source heat pump system for the building heating and cooling. Furthermore, a comparative assessment was conducted, contrasting this novel system with the traditional air-conditioning setup that utilizes chillers and gas boilers as cooling and heating sources. The aim was to evaluate its capacity for energy conservation and emission reduction. The findings from the study strongly affirmed the viability of the proposed seepage seawater source heat pump system within undersea tunnels. It boasted the potential to achieve annual savings of 53.55 tce, highlighting a noteworthy energy-saving rate of 21.2%. Concurrently, reductions in CO2, SO2, and particulate emissions amounted to 132.28 t/a, 1.07 t/a, and 0.54 t/a, respectively. This study not only stands as a reference for the strategic utilization of seepage seawater from undersea tunnel structures, prioritizing energy conservation and emission reduction, but also pioneers innovative approaches toward resource optimization and environmental sustainability, meeting the inherent needs of carbon peaking and carbon neutrality goals.
{"title":"Seawater source heat pump system based on capillary heat exchanger for seepage in submarine tunnel: a case study","authors":"F J Zhang, L Zhang, C Li, S J Gao","doi":"10.1088/1755-1315/1372/1/012074","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012074","url":null,"abstract":"\u0000 The discharge of seepage water from undersea tunnel structures, often treated as wastewater, inherently carries a substantial reservoir of untapped low-grade thermal energy. Unfortunately, comprehensive investigations into harnessing this latent potential remain notably limited. This study introduced an innovative strategy through the design of an undersea tunnel seepage seawater source heat pump system. Distinguished by the integration of a capillary front-end heat exchanger, this system aimed to effectively exploit the frequently disregarded low-grade thermal energy present in the seepage water of undersea tunnel structures. The seawater seepage from the tunnel is transported to the car park at the tunnel entrance, and a seawater energy pool is constructed by storing seawater in its underground space. The use of capillary network placed in the energy pool in the front heat exchanger, water source heat pump units, circulating water pumps and fan coil end device composed of underground undersea tunnel seepage seawater source heat pump system for the building heating and cooling. Furthermore, a comparative assessment was conducted, contrasting this novel system with the traditional air-conditioning setup that utilizes chillers and gas boilers as cooling and heating sources. The aim was to evaluate its capacity for energy conservation and emission reduction. The findings from the study strongly affirmed the viability of the proposed seepage seawater source heat pump system within undersea tunnels. It boasted the potential to achieve annual savings of 53.55 tce, highlighting a noteworthy energy-saving rate of 21.2%. Concurrently, reductions in CO2, SO2, and particulate emissions amounted to 132.28 t/a, 1.07 t/a, and 0.54 t/a, respectively. This study not only stands as a reference for the strategic utilization of seepage seawater from undersea tunnel structures, prioritizing energy conservation and emission reduction, but also pioneers innovative approaches toward resource optimization and environmental sustainability, meeting the inherent needs of carbon peaking and carbon neutrality goals.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"61 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141713506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012030
C.Z. Soh, Z. Chang, J.Y. Sum, S. P. Yeap, P.V Chai, Z. A. Jawad
This study explores the functionalization of polyethersulfone (PES) ultrafiltration (UF) membranes using zwitterion-functionalized graphene oxide (GO) and assesses their interactions with solutes of different charges, both neutral and anionic. Initially, PES nanocomposite membranes were synthesized, incorporating varying dosages (ranging from 0-1 % (w/w)) of glycine-functionalized graphene oxide (Gly/GO) and diglycine-functionalized graphene oxide (diGly/GO) through a direct blending method. The physicochemical properties, including hydrophilicity, surface morphology, and porosity of these membranes were characterized using sessile-drop contact angle, tabletop scanning electron microscopy (SEM), and gravimetric methods, respectively. Subsequently, the antifouling performance of these synthesized membranes was assessed by exposing them to a solution containing sucrose as a neutral model foulant and humic acid as an anionic foulant. The incorporation of zwitterion-functionalized graphene oxide nanoparticles improved the surface wettability of the nanocomposite membrane, enhancing its resistance to sucrose fouling. This was supported by a reduction in flux declination ratio (e.g., 40.6 % for pristine PES, 29.7 % for 1.0 % (w/w) Gly/GO PES, and 33.1 % for 1.0 % (w/w) diGly/GO PES) and an increase in flux recovery ratio (67.2 % for pristine PES, 79.7 % for 1.0 % (w/w) Gly/GO PES, and 80.0% for 1.0 % (w/w) diGly/GO PES). The improvement in antifouling characteristics is attributed to the formation of a hydration layer on the membrane surface, which inhibits sucrose deposition. However, zwitterion-functionalized PES nanocomposite membranes displayed a higher affinity for anionic humic acid, resulting in a substantial flux decline and a lower flux recovery ratio. Overall, this research provides insights into the roles of surface wettability and the charge interactions between solutes and the membrane surface, both of which are crucial factors in determining fouling severity and the restorability of spent membranes.
本研究探讨了使用齐聚物功能化氧化石墨烯（GO）对聚醚砜（PES）超滤膜进行功能化的问题，并评估了它们与不同电荷（包括中性电荷和阴离子电荷）的溶质之间的相互作用。首先，通过直接混合法合成了聚醚砜纳米复合膜，其中加入了不同剂量（0-1%（w/w）不等）的甘氨酸功能化氧化石墨烯（Gly/GO）和二甘氨酸功能化氧化石墨烯（diGly/GO）。采用无梗水滴接触角、台式扫描电子显微镜（SEM）和重量法分别对这些膜的亲水性、表面形貌和孔隙率等理化性质进行了表征。随后，将这些合成膜暴露在含有蔗糖（中性污垢模型）和腐植酸（阴离子污垢）的溶液中，对其防污性能进行了评估。加入齐聚物功能化的氧化石墨烯纳米颗粒改善了纳米复合膜的表面润湿性，提高了其抗蔗糖污垢的能力。通量衰减率的降低（例如，原生石墨烯膜的通量衰减率为 40.6%）证明了这一点、原始 PES 为 40.6%，1.0%（重量比）Gly/GO PES 为 29.7%，1.0%（重量比）diGly/GO PES 为 33.1%），通量恢复比增加（原始 PES 为 67.2%，1.0%（重量比）Gly/GO PES 为 79.7%，1.0%（重量比）diGly/GO PES 为 80.0%）。防污特性的改善归功于膜表面水合层的形成，它抑制了蔗糖的沉积。然而，齐聚物功能化的 PES 纳米复合膜对阴离子腐植酸的亲和力更高，导致通量大幅下降，通量回收率降低。总之，这项研究深入揭示了表面润湿性和溶质与膜表面之间电荷相互作用的作用，这两者都是决定污垢严重程度和废膜可恢复性的关键因素。
{"title":"Development of zwitterion-functionalized graphene oxide/polyethersulfone nanocomposite membrane and fouling evaluation using solutes of varying charges","authors":"C.Z. Soh, Z. Chang, J.Y. Sum, S. P. Yeap, P.V Chai, Z. A. Jawad","doi":"10.1088/1755-1315/1372/1/012030","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012030","url":null,"abstract":"\u0000 This study explores the functionalization of polyethersulfone (PES) ultrafiltration (UF) membranes using zwitterion-functionalized graphene oxide (GO) and assesses their interactions with solutes of different charges, both neutral and anionic. Initially, PES nanocomposite membranes were synthesized, incorporating varying dosages (ranging from 0-1 % (w/w)) of glycine-functionalized graphene oxide (Gly/GO) and diglycine-functionalized graphene oxide (diGly/GO) through a direct blending method. The physicochemical properties, including hydrophilicity, surface morphology, and porosity of these membranes were characterized using sessile-drop contact angle, tabletop scanning electron microscopy (SEM), and gravimetric methods, respectively. Subsequently, the antifouling performance of these synthesized membranes was assessed by exposing them to a solution containing sucrose as a neutral model foulant and humic acid as an anionic foulant. The incorporation of zwitterion-functionalized graphene oxide nanoparticles improved the surface wettability of the nanocomposite membrane, enhancing its resistance to sucrose fouling. This was supported by a reduction in flux declination ratio (e.g., 40.6 % for pristine PES, 29.7 % for 1.0 % (w/w) Gly/GO PES, and 33.1 % for 1.0 % (w/w) diGly/GO PES) and an increase in flux recovery ratio (67.2 % for pristine PES, 79.7 % for 1.0 % (w/w) Gly/GO PES, and 80.0% for 1.0 % (w/w) diGly/GO PES). The improvement in antifouling characteristics is attributed to the formation of a hydration layer on the membrane surface, which inhibits sucrose deposition. However, zwitterion-functionalized PES nanocomposite membranes displayed a higher affinity for anionic humic acid, resulting in a substantial flux decline and a lower flux recovery ratio. Overall, this research provides insights into the roles of surface wettability and the charge interactions between solutes and the membrane surface, both of which are crucial factors in determining fouling severity and the restorability of spent membranes.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"46 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141690017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012003
G. Augusto, C. L. Gatus, A. Ubando, L. G. Gan Lim, J. Gonzaga
The wind resource assessment has been used effectively to identify the classification of wind turbines at a particular wind farm site. The current study used WAsP software and various statistical methods such as graphical, energy pattern factor, standard deviation, and Rayleigh distribution methods to find the Weibull parameters by evaluating the raw data collected from August 2005 until July 2006 at four (4) different heights of the meteorological mast station in Bayanzhaganxiang, China. The Weibull parameters were utilized to find the annual mean wind speed, probability density, and cumulative distribution functions of wind conditions at the reference heights of 70 m, 50 m, 30 m, and 10 m. The wind shear coefficient was 0.130 with an overall roughness factor of 0.0385 m, suggesting the site vicinity is an open country with no significant structures and vegetation. The results also showed that the post-processed output from WAsP and standard deviation method at the sensor’s height of 70 m have a correlation coefficient and confidence level of 0.99977 and above 95%, respectively. Based on the turbine classification from GL Wind 2003 and IEC 61400-1 Ed.2, it was found that the turbine class ideal for the site is class III wind turbines with an annual mean wind speed of 7.439 m/s at a hub height of 99 m. The measured wind power density at hub height was calculated according to IEC 61400-12-1, which yields 464.36 W/m2. The characteristic wind turbulence at 70 m high is IEC subclass B. Among the selected wind turbines, the net annual energy production with efficiency is 8,059.57 MWh/year using Avantis AV1010, with the highest capacity factor of 40.05%. It has been found that the lowest energy generation cost is US$ 0.0292/kWh for a period of 20 years.
{"title":"Wind resource assessment for turbine class identification in Bayanzhaganxiang, China","authors":"G. Augusto, C. L. Gatus, A. Ubando, L. G. Gan Lim, J. Gonzaga","doi":"10.1088/1755-1315/1372/1/012003","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012003","url":null,"abstract":"\u0000 The wind resource assessment has been used effectively to identify the classification of wind turbines at a particular wind farm site. The current study used WAsP software and various statistical methods such as graphical, energy pattern factor, standard deviation, and Rayleigh distribution methods to find the Weibull parameters by evaluating the raw data collected from August 2005 until July 2006 at four (4) different heights of the meteorological mast station in Bayanzhaganxiang, China. The Weibull parameters were utilized to find the annual mean wind speed, probability density, and cumulative distribution functions of wind conditions at the reference heights of 70 m, 50 m, 30 m, and 10 m. The wind shear coefficient was 0.130 with an overall roughness factor of 0.0385 m, suggesting the site vicinity is an open country with no significant structures and vegetation. The results also showed that the post-processed output from WAsP and standard deviation method at the sensor’s height of 70 m have a correlation coefficient and confidence level of 0.99977 and above 95%, respectively. Based on the turbine classification from GL Wind 2003 and IEC 61400-1 Ed.2, it was found that the turbine class ideal for the site is class III wind turbines with an annual mean wind speed of 7.439 m/s at a hub height of 99 m. The measured wind power density at hub height was calculated according to IEC 61400-12-1, which yields 464.36 W/m2. The characteristic wind turbulence at 70 m high is IEC subclass B. Among the selected wind turbines, the net annual energy production with efficiency is 8,059.57 MWh/year using Avantis AV1010, with the highest capacity factor of 40.05%. It has been found that the lowest energy generation cost is US$ 0.0292/kWh for a period of 20 years.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"39 23","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141690112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012052
N. Guevarra, D. Cuevas, C. Pescos, A. Sibal, L. Carrillo
Wastewater pollution remediation connects to goal 6 of the United Nations 17 Sustainable Development Goals (SDG) ensuring availability and sustainable management of water and sanitation for all. Conventional and advanced wastewater treatment are quite expensive to operate to fully comply with regulatory standards in the country. Phyto-vortex integrated system is an alternative tertiary wastewater treatment system that interfaces with an oil and grease skimmer and vortex technology, relying on green plants and a variety of soil substrates to remediate wastewater. The research evaluated the potential of the Phyto-vortex system and its performance in the reduction of domestic wastewater pollutants. Plants and soil substrates were selected via Analytic Hierarchy Process (AHP) using one-way sensitivity analysis. Common reed, Vetiver grass, and Canna Lily were planted in constructed reed beds with various soil matrices using substrates laid at different levels. The beds operate continuously as a horizontal subsurface flow treating 5 m3 of a sewage treatment effluent per day with 1-3 days hydraulic retention time (HRT). The vortex unit aerates the water for further removal of gaseous pollutants. Samples were taken at designated points for 18 weeks. Analysis of the results shows a maximum reduction of 92% for biochemical oxygen demand (BOD), 60 % for chemical oxygen demand(COD), and 70 % for total suspended solids (TSS). Concentration of identified heavy metals in the influent are within the regulatory standards except for a rise in zinc concentration which was 97% reduced in the system. The percentage reduction of pollutants varies each week with nitrates decreasing in the range of 50% to 99%, phosphates from 8% to 39.5%, and ammonia from 45.65% to 99%. Varying environmental conditions such as monsoon rains and extreme heat caused algal blooms and plant disease affecting the results. Lower temperatures and lower humidity favor a decrease in the levels of the pollutants while higher temperature, higher humidity favor an increase in the levels of Nitrates, Phosphates, and Ammonia. The overall results show an effective integrated system of phytoremediation coupled with a vortex unit in the reduction of wastewater pollutants.
{"title":"Performance evaluation of pilot phyto-vortex integrated system in the reduction of wastewater pollutants","authors":"N. Guevarra, D. Cuevas, C. Pescos, A. Sibal, L. Carrillo","doi":"10.1088/1755-1315/1372/1/012052","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012052","url":null,"abstract":"\u0000 Wastewater pollution remediation connects to goal 6 of the United Nations 17 Sustainable Development Goals (SDG) ensuring availability and sustainable management of water and sanitation for all. Conventional and advanced wastewater treatment are quite expensive to operate to fully comply with regulatory standards in the country. Phyto-vortex integrated system is an alternative tertiary wastewater treatment system that interfaces with an oil and grease skimmer and vortex technology, relying on green plants and a variety of soil substrates to remediate wastewater. The research evaluated the potential of the Phyto-vortex system and its performance in the reduction of domestic wastewater pollutants. Plants and soil substrates were selected via Analytic Hierarchy Process (AHP) using one-way sensitivity analysis. Common reed, Vetiver grass, and Canna Lily were planted in constructed reed beds with various soil matrices using substrates laid at different levels. The beds operate continuously as a horizontal subsurface flow treating 5 m3 of a sewage treatment effluent per day with 1-3 days hydraulic retention time (HRT). The vortex unit aerates the water for further removal of gaseous pollutants. Samples were taken at designated points for 18 weeks. Analysis of the results shows a maximum reduction of 92% for biochemical oxygen demand (BOD), 60 % for chemical oxygen demand(COD), and 70 % for total suspended solids (TSS). Concentration of identified heavy metals in the influent are within the regulatory standards except for a rise in zinc concentration which was 97% reduced in the system. The percentage reduction of pollutants varies each week with nitrates decreasing in the range of 50% to 99%, phosphates from 8% to 39.5%, and ammonia from 45.65% to 99%. Varying environmental conditions such as monsoon rains and extreme heat caused algal blooms and plant disease affecting the results. Lower temperatures and lower humidity favor a decrease in the levels of the pollutants while higher temperature, higher humidity favor an increase in the levels of Nitrates, Phosphates, and Ammonia. The overall results show an effective integrated system of phytoremediation coupled with a vortex unit in the reduction of wastewater pollutants.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"50 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141691283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012019
T. C. Wan, S Pan, X R Wang, Y Cui, Y. D. Yuan, H Y Wang, Q. Ge, J L Liu
To lower environmental-based operation costs, many literatures studied the relationship between the energy generation side (EGS) and building load (BL) demand side based on solar-based integrated energy systems (SIESs), without directly considering the effect of energy from energy transportation and storage side (ETSS) on BL demand, which may result in waste of solar energy extracted. To enhance energy utilization, this study proposed an analysis method that renewable energy source shares among different buildings was investigated based on the supply relationship between energy from the ETSS side and BL demand side. ETSS included an electric boiler/chiller (EB/C), double-effect absorption heat pump (AHP) and tank. According to the energy sources from ETSS and building loads for a hotel, a residence and a hospital on a heating/cooling day. The proposed analysis method was used to develop the potential of available renewable energy through energy sharing from the perspective of the energy consumption differences of the three buildings. The results presented that the potential of renewable energy utilization was further developed by reasonably operating the use and storage of energy sources from ETSS based on the optimization between energy sources from EGS and building loads. Energy source shares among different buildings with different energy consumption characteristics enhanced energy efficiency according to reasonably change the useable time of energy sources from tanks. When a building required a large number of energy sources, the buildings with low energy consumption directly shared renewable energy without considering the use of energy storage. This study can provide a reference for optimizing the design of integrated energy system (IES)-based architecture with different building loads.
{"title":"Renewable energy sharing based on the effect of energy supply from energy transportation and storage side on building load demand","authors":"T. C. Wan, S Pan, X R Wang, Y Cui, Y. D. Yuan, H Y Wang, Q. Ge, J L Liu","doi":"10.1088/1755-1315/1372/1/012019","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012019","url":null,"abstract":"\u0000 To lower environmental-based operation costs, many literatures studied the relationship between the energy generation side (EGS) and building load (BL) demand side based on solar-based integrated energy systems (SIESs), without directly considering the effect of energy from energy transportation and storage side (ETSS) on BL demand, which may result in waste of solar energy extracted. To enhance energy utilization, this study proposed an analysis method that renewable energy source shares among different buildings was investigated based on the supply relationship between energy from the ETSS side and BL demand side. ETSS included an electric boiler/chiller (EB/C), double-effect absorption heat pump (AHP) and tank. According to the energy sources from ETSS and building loads for a hotel, a residence and a hospital on a heating/cooling day. The proposed analysis method was used to develop the potential of available renewable energy through energy sharing from the perspective of the energy consumption differences of the three buildings. The results presented that the potential of renewable energy utilization was further developed by reasonably operating the use and storage of energy sources from ETSS based on the optimization between energy sources from EGS and building loads. Energy source shares among different buildings with different energy consumption characteristics enhanced energy efficiency according to reasonably change the useable time of energy sources from tanks. When a building required a large number of energy sources, the buildings with low energy consumption directly shared renewable energy without considering the use of energy storage. This study can provide a reference for optimizing the design of integrated energy system (IES)-based architecture with different building loads.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"227 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141692753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012045
C. J. Junio, P. A. Ontar, V. J. Rutaquio, J. M. Manlapaz, E. B. Braga, C. Tugade, C. Pescos
The discharge of untreated wastewater into rivers and water bodies poses significant environmental and public health risks. High concentrations of contaminants like heavy metals and pharmaceuticals disrupt rivers, exacerbating waterborne diseases, and leading to unsafe water in the Philippines. This study proposed the use of horizontal-flow constructed wetlands as a tertiary treatment method utilizing the plants: vetiver grass, common reed, and canna lily, to reduce pollutant concentrations in wastewater. This is to ensure compliance with water quality guidelines and general effluent standards under the Class SB Category, water suitable for fishery, tourist zones, and recreational activities. The research investigated the efficiency of phytoremediation beds in removing pollutants from wastewater under fixed hydraulic retention times. The efficiency of reducing pollutants and adsorption isotherms (Freundlich and Langmuir) were calculated to analyze the results of the sampling. Phytoremediation bed 1 demonstra ted efficient ammonia removal by 64.64%. Phytoremediation bed 2 was proficient in reducing nitrates at 83.85%, while phytoremediation bed 3 effectively reduced phosphate to an average of 26.26%, achieved after a 6-hour retention time. In addition, Freundlich adsorption isotherm was observable in most parameters in phytoremediation bed 1 such as ammonia as nitrogen, TDS, COD, and DO. Phytoremediation bed 3 exhibited the same adsorption isotherm on ammonia as nitrogen. Conclusively, the phytoremediation system met the Department of Environment and Natural Resources - Updated Water Quality Guidelines and General Effluent Standard (GES) for all parameters tested.
{"title":"Horizontal-flow constructed wetlands by phytoremediation using vetiver grass, common reed, and canna lily as tertiary wastewater treatment for the reduction of pollutant concentrations of ammonia, phosphates, and nitrates","authors":"C. J. Junio, P. A. Ontar, V. J. Rutaquio, J. M. Manlapaz, E. B. Braga, C. Tugade, C. Pescos","doi":"10.1088/1755-1315/1372/1/012045","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012045","url":null,"abstract":"\u0000 The discharge of untreated wastewater into rivers and water bodies poses significant environmental and public health risks. High concentrations of contaminants like heavy metals and pharmaceuticals disrupt rivers, exacerbating waterborne diseases, and leading to unsafe water in the Philippines. This study proposed the use of horizontal-flow constructed wetlands as a tertiary treatment method utilizing the plants: vetiver grass, common reed, and canna lily, to reduce pollutant concentrations in wastewater. This is to ensure compliance with water quality guidelines and general effluent standards under the Class SB Category, water suitable for fishery, tourist zones, and recreational activities. The research investigated the efficiency of phytoremediation beds in removing pollutants from wastewater under fixed hydraulic retention times. The efficiency of reducing pollutants and adsorption isotherms (Freundlich and Langmuir) were calculated to analyze the results of the sampling. Phytoremediation bed 1 demonstra ted efficient ammonia removal by 64.64%. Phytoremediation bed 2 was proficient in reducing nitrates at 83.85%, while phytoremediation bed 3 effectively reduced phosphate to an average of 26.26%, achieved after a 6-hour retention time. In addition, Freundlich adsorption isotherm was observable in most parameters in phytoremediation bed 1 such as ammonia as nitrogen, TDS, COD, and DO. Phytoremediation bed 3 exhibited the same adsorption isotherm on ammonia as nitrogen. Conclusively, the phytoremediation system met the Department of Environment and Natural Resources - Updated Water Quality Guidelines and General Effluent Standard (GES) for all parameters tested.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"63 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141693472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012006
J. M. E. Abarro, J. A. Paraggua
Pseudo-2-dimensional (P2D) models are computationally efficient tools for accurately predicting the battery’s performance. These models have been widely used to simulate lithium-ion batteries, but their application can be extended to other battery chemistries. Nickel-iron batteries are one type of storage that is regaining attention due to their durability and large theoretical specific capacity. However, their tendency to form an irreversible passivation layer and hydrogen gas leads to lower overall specific capacity and charging efficiency. Physics-based models of impedance spectra can help understand and interpret mass transport, thermodynamic, and reaction processes in a system. Batteries, being nonlinear systems in nature, can be better evaluated through nonlinear electrochemical impedance spectroscopy (NLEIS), an extension of the traditional electrochemical impedance spectroscopy (EIS), to break the degeneracy of a linear model. Base case parameters were used to generate the impedance spectra by applying moderate-amplitude current modulations. This work compared the first harmonic linear response and the second harmonic nonlinear response simulated through a P2D model. Unlike EIS, the nonlinear response shows sensitivity to charge transfer symmetry. At the negative electrode, the nonlinear response demonstrates strong dependence on the kinetic properties, suggesting that the overall battery performance is mainly influenced by the processes at the negative electrode-electrolyte interface.
伪二维（P2D）模型是准确预测电池性能的高效计算工具。这些模型已被广泛用于模拟锂离子电池，但其应用范围也可扩展到其他电池化学成分。镍铁电池因其耐用性和较大的理论比容量而重新受到关注。然而，它们容易形成不可逆的钝化层和氢气，导致整体比容量和充电效率降低。基于物理的阻抗谱模型有助于理解和解释系统中的质量传输、热力学和反应过程。电池本质上是非线性系统，通过非线性电化学阻抗谱（NLEIS）（传统电化学阻抗谱（EIS）的扩展）可以更好地评估电池，从而打破线性模型的退化。通过应用中等振幅的电流调制，使用基本情况参数生成阻抗谱。这项研究比较了第一次谐波线性响应和通过 P2D 模型模拟的第二次谐波非线性响应。与 EIS 不同，非线性响应显示出对电荷转移对称性的敏感性。在负极，非线性响应对动力学特性有很强的依赖性，这表明电池的整体性能主要受负极-电解质界面过程的影响。
{"title":"A pseudo-2-dimensional model of the nonlinear impedance response of a nickel-iron battery","authors":"J. M. E. Abarro, J. A. Paraggua","doi":"10.1088/1755-1315/1372/1/012006","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012006","url":null,"abstract":"\u0000 Pseudo-2-dimensional (P2D) models are computationally efficient tools for accurately predicting the battery’s performance. These models have been widely used to simulate lithium-ion batteries, but their application can be extended to other battery chemistries. Nickel-iron batteries are one type of storage that is regaining attention due to their durability and large theoretical specific capacity. However, their tendency to form an irreversible passivation layer and hydrogen gas leads to lower overall specific capacity and charging efficiency. Physics-based models of impedance spectra can help understand and interpret mass transport, thermodynamic, and reaction processes in a system. Batteries, being nonlinear systems in nature, can be better evaluated through nonlinear electrochemical impedance spectroscopy (NLEIS), an extension of the traditional electrochemical impedance spectroscopy (EIS), to break the degeneracy of a linear model. Base case parameters were used to generate the impedance spectra by applying moderate-amplitude current modulations. This work compared the first harmonic linear response and the second harmonic nonlinear response simulated through a P2D model. Unlike EIS, the nonlinear response shows sensitivity to charge transfer symmetry. At the negative electrode, the nonlinear response demonstrates strong dependence on the kinetic properties, suggesting that the overall battery performance is mainly influenced by the processes at the negative electrode-electrolyte interface.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"6 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141694029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012057
Nur Zaqira Izzati Sukhairul Zaman, A. R. Abbas, M. F. Zainal, A. Quek, Wan Nur Syuhada Wan Ata, M. F. K. Mohd Yapandi, Z. F. Ibrahim
Empty fruit bunches (EFB) constitute a significant residual byproduct of the palm oil mill industry in Malaysia, representing approximately 22% of the weight of every fresh fruit bunch. This study aims to evaluate the environmental impacts associated with electricity generation utilizing EFB as a primary fuel through a cradle – to – grave life cycle assessment (LCA) approach. The system boundary encompasses the power plant construction, fuel preparation, electricity generation and all transportation activities throughout its life cycle. The EFBs are sourced from seven palm mills situated within a 50-kilometer radius of the plant. SimaPro 9.4.02 software integrated with Ecoinvent 3.8 database was employed to quantify the magnitudes of significant environmental indicators, such as global warming potential (GWP), ozone depletion potential (ODP), acidification potential (AP), eutrophication potential (EP), and photochemical oxidant creation potential (POCP), based on a functional unit of 1 kWh of electricity produced. The emission rate for the biomass plant stands at – 5.31 kgCO2eq/kWh, signifying a net carbon sink. The electricity generation process accounts for a substantial 96.48% of the total CO2eq/kWh emissions, thus bearing the greatest environmental burden. The construction phase of the biomass plant contributes approximately 3.06% of the total emissions, while the EFB transportation to the power plant represents a minor 0.19% of the overall emissions. A sensitivity analysis was conducted to evaluate the plant’s efficiency across fiscal years 2018 to 2021 and its corresponding global warming impacts. In 2021, the plant’s operations resulted in the most significant carbon avoidance, given the combustion of a high volume of EFB (188 kilotons) to produce 49.3GWh of electricity. The findings from this study serve as a valuable benchmark for evaluating emissions in the context of the empty fruit bunch-based plant in Peninsular Malaysia, hence offering profound insights into the environmental sustainability of the palm oil industry.
{"title":"Assessing the Environmental Impact of Empty Fruit Bunches for Electricity Generation in Malaysia: A Life Cycle Perspective","authors":"Nur Zaqira Izzati Sukhairul Zaman, A. R. Abbas, M. F. Zainal, A. Quek, Wan Nur Syuhada Wan Ata, M. F. K. Mohd Yapandi, Z. F. Ibrahim","doi":"10.1088/1755-1315/1372/1/012057","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012057","url":null,"abstract":"\u0000 Empty fruit bunches (EFB) constitute a significant residual byproduct of the palm oil mill industry in Malaysia, representing approximately 22% of the weight of every fresh fruit bunch. This study aims to evaluate the environmental impacts associated with electricity generation utilizing EFB as a primary fuel through a cradle – to – grave life cycle assessment (LCA) approach. The system boundary encompasses the power plant construction, fuel preparation, electricity generation and all transportation activities throughout its life cycle. The EFBs are sourced from seven palm mills situated within a 50-kilometer radius of the plant. SimaPro 9.4.02 software integrated with Ecoinvent 3.8 database was employed to quantify the magnitudes of significant environmental indicators, such as global warming potential (GWP), ozone depletion potential (ODP), acidification potential (AP), eutrophication potential (EP), and photochemical oxidant creation potential (POCP), based on a functional unit of 1 kWh of electricity produced. The emission rate for the biomass plant stands at – 5.31 kgCO2eq/kWh, signifying a net carbon sink. The electricity generation process accounts for a substantial 96.48% of the total CO2eq/kWh emissions, thus bearing the greatest environmental burden. The construction phase of the biomass plant contributes approximately 3.06% of the total emissions, while the EFB transportation to the power plant represents a minor 0.19% of the overall emissions. A sensitivity analysis was conducted to evaluate the plant’s efficiency across fiscal years 2018 to 2021 and its corresponding global warming impacts. In 2021, the plant’s operations resulted in the most significant carbon avoidance, given the combustion of a high volume of EFB (188 kilotons) to produce 49.3GWh of electricity. The findings from this study serve as a valuable benchmark for evaluating emissions in the context of the empty fruit bunch-based plant in Peninsular Malaysia, hence offering profound insights into the environmental sustainability of the palm oil industry.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"10 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141694145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012011
L.H. Phuc, P.M. Duc, L.A. Nhuan, T.T. Ly, N.D. Hung
Dual Active Bridge (DAB) converters have gained popularity in electric vehicle charging stations due to their high efficiency and electrical isolation. As the demand for high-powered devices and large-capacity energy storage systems grows, charging systems that integrate multiple interconnected DAB modules are emerging as a promising solution. However, prolonged operation of these modules at high power levels can cause parameter deviations from the initial DAB circuit, resulting in power variations between modules. To overcome parameter deviations, this study presents an enhanced power control approach based on output resistance adjustment, intending to achieve consistent output capacity for multiple DAB modules. In the proposed enhanced power control method, the output resistance of the DAB module is considered to be controllable, and the current-sharing mismatches among DAB modules are fed back to tune the converter output resistance for mitigating current mismatches between modules. Thanks to the proposed control method, each DAB module can operate autonomously and balance the charging current between modules. When one DAB module is suddenly cut out of the system, the other DAB modules still maintain their stability with fully guaranteed load capacity. To demonstrate the feasibility of the enhanced control approach, the small signal model of the DAB system with three modules is derived together with its frequency-amplitude diagram. Then, the effect of virtual resistance on current balancing is comprehensively tested, and the proper control signal with virtual resistance is added to the DAB voltage control loop. The simulation results have demonstrated the reliability of the proposed control method with the ability to balance the charging current between modules and stabilize the system when a single DAB module fails.
双有源桥（DAB）转换器因其高效率和电气隔离而在电动汽车充电站中大受欢迎。随着对高功率设备和大容量储能系统的需求不断增长，集成多个相互连接的 DAB 模块的充电系统正成为一种前景广阔的解决方案。然而，这些模块在高功率水平下长时间运行会导致参数偏离初始 DAB 电路，从而造成模块之间的功率变化。为了克服参数偏差，本研究提出了一种基于输出电阻调整的增强型功率控制方法，旨在实现多个 DAB 模块的一致输出能力。在所提出的增强型功率控制方法中，DAB 模块的输出电阻被认为是可控的，DAB 模块之间的分流失配反馈到调整转换器的输出电阻，以减轻模块之间的电流失配。由于采用了所提出的控制方法，每个 DAB 模块都能自主运行，并平衡模块间的充电电流。当一个 DAB 模块突然退出系统时，其他 DAB 模块仍能保持稳定，并充分保证负载能力。为了证明增强型控制方法的可行性，我们导出了带有三个模块的 DAB 系统的小信号模型及其频幅图。然后，全面测试了虚拟电阻对电流平衡的影响，并在 DAB 电压控制回路中加入了适当的虚拟电阻控制信号。仿真结果表明，所提出的控制方法是可靠的，能够在单个 DAB 模块发生故障时平衡模块间的充电电流并稳定系统。
{"title":"Novel resistance control scheme for mitigating current sharing mismatches in parallel dual active bridge converters for DC fast charging stations","authors":"L.H. Phuc, P.M. Duc, L.A. Nhuan, T.T. Ly, N.D. Hung","doi":"10.1088/1755-1315/1372/1/012011","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012011","url":null,"abstract":"\u0000 Dual Active Bridge (DAB) converters have gained popularity in electric vehicle charging stations due to their high efficiency and electrical isolation. As the demand for high-powered devices and large-capacity energy storage systems grows, charging systems that integrate multiple interconnected DAB modules are emerging as a promising solution. However, prolonged operation of these modules at high power levels can cause parameter deviations from the initial DAB circuit, resulting in power variations between modules. To overcome parameter deviations, this study presents an enhanced power control approach based on output resistance adjustment, intending to achieve consistent output capacity for multiple DAB modules. In the proposed enhanced power control method, the output resistance of the DAB module is considered to be controllable, and the current-sharing mismatches among DAB modules are fed back to tune the converter output resistance for mitigating current mismatches between modules. Thanks to the proposed control method, each DAB module can operate autonomously and balance the charging current between modules. When one DAB module is suddenly cut out of the system, the other DAB modules still maintain their stability with fully guaranteed load capacity. To demonstrate the feasibility of the enhanced control approach, the small signal model of the DAB system with three modules is derived together with its frequency-amplitude diagram. Then, the effect of virtual resistance on current balancing is comprehensively tested, and the proper control signal with virtual resistance is added to the DAB voltage control loop. The simulation results have demonstrated the reliability of the proposed control method with the ability to balance the charging current between modules and stabilize the system when a single DAB module fails.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"76 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141699088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1088/1755-1315/1372/1/012075
Y L Wang, L Zhang, Y S Qu, X. Meng, H. Pang, H Y Wang
Some cities’ subways were constructed early and have been in operation for a long time. A large amount of heat accumulates in the rocks around the subway tunnels, causing the phenomenon of heat accumulation. This situation leads to the inadequate cooling capability of train air-conditioning systems, which, may even cease to function under extreme conditions. Currently, few solutions are available to address this issue. Therefore, this study proposes a new cooling system in subway tunnel. Considering the dusty environment inside the tunnel, the terminal equipment mainly consists of natural convection copper tube finless heat exchangers and a self-flushing device without fans, which cool using piston wind. By comparing field measurements of two tunnels with and without the cooling system in similar locations, the results show that the air temperature in the tunnels is reduced after the cooling system is installed. The results indicate that the average temperature in the tunnels decreases from 30.93 °C to 19.80 °C, marking a reduction of 11.13 °C after the cooling system runs for 24 hours. The temperature change in the tunnel is a long-term process, and actual measurements require significant time consumption. In this study, the long-term effect is predicted using CFD simulation in tunnels. The accuracy and credibility of the CFD simulation have been confirmed through its reasonable agreement with experimental data, with the final temperature after 24 hours achieving a relative error of less than 0.26%. Through the simulation, the temperature at a depth of 10 cm inside the tunnel wall after 24 hours is determined to be 27.56 °C, indicating a reduction of 3.44 °C compared to the initial temperature of 31 °C. This study can provide a reference for other subway tunnel cooling systems and serves as a basis for CFD simulations to verify cooling effects.
{"title":"Cooling performance study of a new cooling system in subway tunnel based on field measurement and CFD simulation","authors":"Y L Wang, L Zhang, Y S Qu, X. Meng, H. Pang, H Y Wang","doi":"10.1088/1755-1315/1372/1/012075","DOIUrl":"https://doi.org/10.1088/1755-1315/1372/1/012075","url":null,"abstract":"\u0000 Some cities’ subways were constructed early and have been in operation for a long time. A large amount of heat accumulates in the rocks around the subway tunnels, causing the phenomenon of heat accumulation. This situation leads to the inadequate cooling capability of train air-conditioning systems, which, may even cease to function under extreme conditions. Currently, few solutions are available to address this issue. Therefore, this study proposes a new cooling system in subway tunnel. Considering the dusty environment inside the tunnel, the terminal equipment mainly consists of natural convection copper tube finless heat exchangers and a self-flushing device without fans, which cool using piston wind. By comparing field measurements of two tunnels with and without the cooling system in similar locations, the results show that the air temperature in the tunnels is reduced after the cooling system is installed. The results indicate that the average temperature in the tunnels decreases from 30.93 °C to 19.80 °C, marking a reduction of 11.13 °C after the cooling system runs for 24 hours. The temperature change in the tunnel is a long-term process, and actual measurements require significant time consumption. In this study, the long-term effect is predicted using CFD simulation in tunnels. The accuracy and credibility of the CFD simulation have been confirmed through its reasonable agreement with experimental data, with the final temperature after 24 hours achieving a relative error of less than 0.26%. Through the simulation, the temperature at a depth of 10 cm inside the tunnel wall after 24 hours is determined to be 27.56 °C, indicating a reduction of 3.44 °C compared to the initial temperature of 31 °C. This study can provide a reference for other subway tunnel cooling systems and serves as a basis for CFD simulations to verify cooling effects.","PeriodicalId":506254,"journal":{"name":"IOP Conference Series: Earth and Environmental Science","volume":"14 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141699948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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