Pub Date : 2024-09-02DOI: 10.3389/fenvs.2024.1393011
Yong Huang, Di You, Haozhen Yu, Chengye Yang, Jiawen Mao
Clarifying the spatial correlation characteristics and influencing factors of coupling coordination between Foreign Direct Investment (FDI) flow networks and carbon transfer networks in countries along the Belt and Road Initiative is of utmost importance for the formulation of regional carbon governance strategies and the establishment of a high-quality Green Silk Road. This study used a comprehensive approach combining social network analysis and coupling coordination model to measure the coupling coordination degree of FDI flow networks and carbon transfer networks of 67 Belt and Road countries from 2010 to 2016. In addition, a modified gravity model is used to characterize the spatial correlation network structure of coupling coordination between the two networks, and the QAP regression analysis method is applied to investigate the factors influencing the spatial association network. The results are as follows: 1) The spatial correlation network of coupling coordination between the two networks has good accessibility and relatively high overall network stability. 2) Countries such as Qatar and the United Arab Emirates occupy central positions in the network, while Bahrain and Jordan are positioned on the periphery of the network. 3) The spatial correlation network can be divided into three sectors: net outflow, net inflow, and bidirectional overflow sectors. 4) Spatial adjacency, bilateral investment treaties, economic development, and institutional quality have significant positive effects on the spatial association network, while the industrial structure and the level of infrastructure development have a significant negative impact. This study proposes an indicator system for the coupling coordination between FDI flow networks and carbon transfer networks. The aim is to investigate the coupling coordination relationship between FDI flow networks and carbon emission transfer networks in countries along the Belt and Road Initiative, providing important guidance for the formulation of regional cooperative carbon emission reduction strategies in other regions.
{"title":"A study on the spatial correlation network structure and its influencing factors of coupling coordination between FDI flow network and carbon transfer network in the belt and road initiative countries","authors":"Yong Huang, Di You, Haozhen Yu, Chengye Yang, Jiawen Mao","doi":"10.3389/fenvs.2024.1393011","DOIUrl":"https://doi.org/10.3389/fenvs.2024.1393011","url":null,"abstract":"Clarifying the spatial correlation characteristics and influencing factors of coupling coordination between Foreign Direct Investment (FDI) flow networks and carbon transfer networks in countries along the Belt and Road Initiative is of utmost importance for the formulation of regional carbon governance strategies and the establishment of a high-quality Green Silk Road. This study used a comprehensive approach combining social network analysis and coupling coordination model to measure the coupling coordination degree of FDI flow networks and carbon transfer networks of 67 Belt and Road countries from 2010 to 2016. In addition, a modified gravity model is used to characterize the spatial correlation network structure of coupling coordination between the two networks, and the QAP regression analysis method is applied to investigate the factors influencing the spatial association network. The results are as follows: 1) The spatial correlation network of coupling coordination between the two networks has good accessibility and relatively high overall network stability. 2) Countries such as Qatar and the United Arab Emirates occupy central positions in the network, while Bahrain and Jordan are positioned on the periphery of the network. 3) The spatial correlation network can be divided into three sectors: net outflow, net inflow, and bidirectional overflow sectors. 4) Spatial adjacency, bilateral investment treaties, economic development, and institutional quality have significant positive effects on the spatial association network, while the industrial structure and the level of infrastructure development have a significant negative impact. This study proposes an indicator system for the coupling coordination between FDI flow networks and carbon transfer networks. The aim is to investigate the coupling coordination relationship between FDI flow networks and carbon emission transfer networks in countries along the Belt and Road Initiative, providing important guidance for the formulation of regional cooperative carbon emission reduction strategies in other regions.","PeriodicalId":12460,"journal":{"name":"Frontiers in Environmental Science","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-08-30DOI: 10.3389/fenvs.2024.1418982
MengChao Zhao, Xiang Xiao, Yang Le
As an urbanization effort propelled by administrative measures, city-county merger has been particularly prevalent in the administrative district adjustments of prefecture-level cities in China. However, there has been scant research focusing on the policy’s impact on the efficiency of green utilization of urban land. We selected panel data from Chinese prefecture-level cities from 2003 to 2020, employing the slack-based measure (SBM) model that accounts for undesirable outputs, in conjunction with the Malmquist-Luenberger (ML) productivity index, to measure the efficiency of green land use in cities. Building on this, we utilized the staggered difference-in-differences (DID) model to investigate the impact of policies expanding cities through land leasing on the green utilization efficiency of urban land. Our findings indicate that the city-county merger has generally led to a decline in the efficiency of green utilization of urban land. Further mechanism analysis suggests that local governments’ excessive focus on land leasing for economic development, leading to a low-quality development model, is a significant factor contributing to the decline in green utilization efficiency of urban land. Specifically, the city-county merger policy indirectly reduces land green utilization efficiency by increasing industrial land leasing revenue, the number of industrial polluting enterprises, lowering the rationalization level of urban industrial structure, and raising the overachievement of urban economic growth targets. Further research reveals that the policy has heterogeneous impacts on land green utilization efficiency across different regions, city sizes, administrative levels, economic development levels, and urban planning types. The policy has a more significant inhibitory effect on land green utilization efficiency in non-eastern regions, smaller cities, peripheral cities, underdeveloped cities, and resource-based cities. Our study confirms that as a significant urbanization reform initiative, the effectiveness of the city-county merger still relies on the traditional extensive growth model based on land expansion, which is not conducive to enhancing the efficiency of green land use in cities.
{"title":"The impact of city-county mergers on urban land green utilization efficiency: evidence from China","authors":"MengChao Zhao, Xiang Xiao, Yang Le","doi":"10.3389/fenvs.2024.1418982","DOIUrl":"https://doi.org/10.3389/fenvs.2024.1418982","url":null,"abstract":"As an urbanization effort propelled by administrative measures, city-county merger has been particularly prevalent in the administrative district adjustments of prefecture-level cities in China. However, there has been scant research focusing on the policy’s impact on the efficiency of green utilization of urban land. We selected panel data from Chinese prefecture-level cities from 2003 to 2020, employing the slack-based measure (SBM) model that accounts for undesirable outputs, in conjunction with the Malmquist-Luenberger (ML) productivity index, to measure the efficiency of green land use in cities. Building on this, we utilized the staggered difference-in-differences (DID) model to investigate the impact of policies expanding cities through land leasing on the green utilization efficiency of urban land. Our findings indicate that the city-county merger has generally led to a decline in the efficiency of green utilization of urban land. Further mechanism analysis suggests that local governments’ excessive focus on land leasing for economic development, leading to a low-quality development model, is a significant factor contributing to the decline in green utilization efficiency of urban land. Specifically, the city-county merger policy indirectly reduces land green utilization efficiency by increasing industrial land leasing revenue, the number of industrial polluting enterprises, lowering the rationalization level of urban industrial structure, and raising the overachievement of urban economic growth targets. Further research reveals that the policy has heterogeneous impacts on land green utilization efficiency across different regions, city sizes, administrative levels, economic development levels, and urban planning types. The policy has a more significant inhibitory effect on land green utilization efficiency in non-eastern regions, smaller cities, peripheral cities, underdeveloped cities, and resource-based cities. Our study confirms that as a significant urbanization reform initiative, the effectiveness of the city-county merger still relies on the traditional extensive growth model based on land expansion, which is not conducive to enhancing the efficiency of green land use in cities.","PeriodicalId":12460,"journal":{"name":"Frontiers in Environmental Science","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-08-30DOI: 10.3389/fenvs.2024.1400569
Han Xiao, Yu Yang, Qiyuan Liu, Yongge Zang, Xinying Lian, Fu Xia, Yonghai Jiang
Spring discharge decline induced by increasing groundwater pumping under the background of increasing water demand for agricultural, industrial, and domestic utilizations has been recognized as a significant geo-environmental issue which poses a great threat to springshed eco-environmental safety. In this study, numerical approach was utilized and a series of 3D groundwater flow models based on the MODFLOW module were developed to simulate current-stage and future trends of spring discharges under the impacts of increasing groundwater pumping due to the rapid development of tourism in the BL spring located in Xilin Gol League in east Inner Mongolia (China), for the purpose of understanding the responses of spring discharges to various groundwater pumping scenarios in future. Simulation results indicated that: (1) spring discharge has reduced from 201.4 m3/d to 193.7 m3/d (reduction ratio of 3.80%) under current-stage pumping scheme; (2) the spring-discharge-affected zone is 2.025 km2 under current-stage pumping scheme and groundwater pumping within this zone contributes to spring discharge decline; (3) impact of the pumping well located nearest to the BL spring is the most significant while impact of the pumping well located farthest to the BL spring is negligible; and (4) spring discharge would reduce 25%, 50%, 75%, and 100% if total pumping rate of the seven abstraction wells would increase from 45.8 m3/d (current-stage pumping scheme) to 297.7, 586.2, 888.5, and 1,176 m3/d, respectively. The outcome of this study can provide useful references for advising sustainable groundwater exploitation strategies to meet the requirement of groundwater supply under the premise of spring discharge management and eco-environmental protection.
{"title":"Numerical modeling the impacts of increasing groundwater pumping upon discharge decline of the BL Spring located in Xilin Gol League in east inner Mongolia, China","authors":"Han Xiao, Yu Yang, Qiyuan Liu, Yongge Zang, Xinying Lian, Fu Xia, Yonghai Jiang","doi":"10.3389/fenvs.2024.1400569","DOIUrl":"https://doi.org/10.3389/fenvs.2024.1400569","url":null,"abstract":"Spring discharge decline induced by increasing groundwater pumping under the background of increasing water demand for agricultural, industrial, and domestic utilizations has been recognized as a significant geo-environmental issue which poses a great threat to springshed eco-environmental safety. In this study, numerical approach was utilized and a series of 3D groundwater flow models based on the MODFLOW module were developed to simulate current-stage and future trends of spring discharges under the impacts of increasing groundwater pumping due to the rapid development of tourism in the BL spring located in Xilin Gol League in east Inner Mongolia (China), for the purpose of understanding the responses of spring discharges to various groundwater pumping scenarios in future. Simulation results indicated that: (1) spring discharge has reduced from 201.4 m<jats:sup>3</jats:sup>/d to 193.7 m<jats:sup>3</jats:sup>/d (reduction ratio of 3.80%) under current-stage pumping scheme; (2) the spring-discharge-affected zone is 2.025 km<jats:sup>2</jats:sup> under current-stage pumping scheme and groundwater pumping within this zone contributes to spring discharge decline; (3) impact of the pumping well located nearest to the BL spring is the most significant while impact of the pumping well located farthest to the BL spring is negligible; and (4) spring discharge would reduce 25%, 50%, 75%, and 100% if total pumping rate of the seven abstraction wells would increase from 45.8 m<jats:sup>3</jats:sup>/d (current-stage pumping scheme) to 297.7, 586.2, 888.5, and 1,176 m<jats:sup>3</jats:sup>/d, respectively. The outcome of this study can provide useful references for advising sustainable groundwater exploitation strategies to meet the requirement of groundwater supply under the premise of spring discharge management and eco-environmental protection.","PeriodicalId":12460,"journal":{"name":"Frontiers in Environmental Science","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-08-30DOI: 10.3389/fenvs.2024.1420708
Yiru Chen, Guangcheng Ma
The purpose of this paper is to examine whether the development of carbon finance can promote sustainable economic growth in China through spatial spillover effects. On the basis of a theoretical analysis of this mechanism, this paper takes 30 provincial-level administrative regions in China as the research object and uses a variety of spatial econometric analysis techniques to empirically test them. It assesses sustainable economic development measured by green total factor productivity (GTFP). This study documents a significant and positive impact of province-level carbon finance improvement on sustainable economic growth through improving technological progress and increasing technological market turnover. The economic influence of carbon finance on sustainable economic growth is still positive after considering possible endogeneity concerns. Results reveal heterogeneity and spatial spillover effects of carbon finance on GTFP, notably stronger in eastern regions compared to central and western ones. We find that the technological progress and technological market turnover have significant and positive promotional effects on GTFP with increasing levels of carbon finance. This paper provides policy implications for improving sustainable economic development.
{"title":"The characteristics and mechanisms of carbon finance development on green economic efficiency: an empirical analysis based on endogenous economic growth model","authors":"Yiru Chen, Guangcheng Ma","doi":"10.3389/fenvs.2024.1420708","DOIUrl":"https://doi.org/10.3389/fenvs.2024.1420708","url":null,"abstract":"The purpose of this paper is to examine whether the development of carbon finance can promote sustainable economic growth in China through spatial spillover effects. On the basis of a theoretical analysis of this mechanism, this paper takes 30 provincial-level administrative regions in China as the research object and uses a variety of spatial econometric analysis techniques to empirically test them. It assesses sustainable economic development measured by green total factor productivity (GTFP). This study documents a significant and positive impact of province-level carbon finance improvement on sustainable economic growth through improving technological progress and increasing technological market turnover. The economic influence of carbon finance on sustainable economic growth is still positive after considering possible endogeneity concerns. Results reveal heterogeneity and spatial spillover effects of carbon finance on GTFP, notably stronger in eastern regions compared to central and western ones. We find that the technological progress and technological market turnover have significant and positive promotional effects on GTFP with increasing levels of carbon finance. This paper provides policy implications for improving sustainable economic development.","PeriodicalId":12460,"journal":{"name":"Frontiers in Environmental Science","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-08-30DOI: 10.3389/fenvs.2024.1444015
Denielle Perry, Riley K. Swanson, Abraham E. Springer
The Colorado River is a vital water source for the western United States, yet the river is governed by disjointed and outdated policies that have left water management fragmented and water quantities overallocated. Groundwater is an overlooked component of Colorado River Basin (CRB) water supplies, making it vulnerable to overuse from disparities in uncoordinated protective management strategies. In this study, we analyzed state level groundwater policies to reveal the diversity and efficacy of groundwater governance mechanisms. The existing groundwater management plans for each state throughout the basin are fragmented and limited in scope. We found that with policies only covering 22% of the basin, they do not provide adequate protection at the basin scale for the sustainable use of groundwater resources in the face of increasing demands, creating a positive feedback loop that reinforces the scarcity issue. We conclude that a comprehensive management plan that can fully address resource use throughout the CRB is necessary for the sustainable use of groundwater and its contribution to base flow in the Colorado River. We suggest that such a plan could be derived through an interstate compact like the Colorado River Compact that is used for surface water management.
{"title":"Policy deficiencies and contingency plans: groundwater management implications for baseflow contributions to the Colorado River","authors":"Denielle Perry, Riley K. Swanson, Abraham E. Springer","doi":"10.3389/fenvs.2024.1444015","DOIUrl":"https://doi.org/10.3389/fenvs.2024.1444015","url":null,"abstract":"The Colorado River is a vital water source for the western United States, yet the river is governed by disjointed and outdated policies that have left water management fragmented and water quantities overallocated. Groundwater is an overlooked component of Colorado River Basin (CRB) water supplies, making it vulnerable to overuse from disparities in uncoordinated protective management strategies. In this study, we analyzed state level groundwater policies to reveal the diversity and efficacy of groundwater governance mechanisms. The existing groundwater management plans for each state throughout the basin are fragmented and limited in scope. We found that with policies only covering 22% of the basin, they do not provide adequate protection at the basin scale for the sustainable use of groundwater resources in the face of increasing demands, creating a positive feedback loop that reinforces the scarcity issue. We conclude that a comprehensive management plan that can fully address resource use throughout the CRB is necessary for the sustainable use of groundwater and its contribution to base flow in the Colorado River. We suggest that such a plan could be derived through an interstate compact like the Colorado River Compact that is used for surface water management.","PeriodicalId":12460,"journal":{"name":"Frontiers in Environmental Science","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-08-30DOI: 10.3389/fenvs.2024.1432534
Yang Liu, Yu Wang, Bing Yan, Hengshuo Zhang
Digital technology plays a vital role in driving toward a zero-carbon future. This paper explores whether new infrastructure, serving as carriers for digital technology, contributes to carbon reduction and efficiency gains in cities. Drawing on panel data from 280 Chinese cities spanning 2011 to 2019, we establish a theoretical analytical framework to investigate how new infrastructure influences urban carbon performance through the perspectives of influence, threshold, and spatial spillover effects. The study reveals that new infrastructures development has a contributing effect on the total factor carbon productivity of cities, with consistent results across various testing methods. Additionally, the threshold effect test suggests that the dual threshold of regional energy consumption influences the enhancing effect of new infrastructure on total factor carbon productivity, exhibiting nonlinear characteristics. Furthermore, the spatial spillover effect test suggests that new infrastructure construction accelerates the local carbon emission performance, while having a positive spillover effect on neighboring cities. This study provides innovative ideas and experiences from China for the global realization of simultaneous promotion of digital economy development and energy conservation and emission reduction.
{"title":"The impact of new infrastructure development on urban total factor carbon productivity-empirical evidence based on Chinese cities","authors":"Yang Liu, Yu Wang, Bing Yan, Hengshuo Zhang","doi":"10.3389/fenvs.2024.1432534","DOIUrl":"https://doi.org/10.3389/fenvs.2024.1432534","url":null,"abstract":"Digital technology plays a vital role in driving toward a zero-carbon future. This paper explores whether new infrastructure, serving as carriers for digital technology, contributes to carbon reduction and efficiency gains in cities. Drawing on panel data from 280 Chinese cities spanning 2011 to 2019, we establish a theoretical analytical framework to investigate how new infrastructure influences urban carbon performance through the perspectives of influence, threshold, and spatial spillover effects. The study reveals that new infrastructures development has a contributing effect on the total factor carbon productivity of cities, with consistent results across various testing methods. Additionally, the threshold effect test suggests that the dual threshold of regional energy consumption influences the enhancing effect of new infrastructure on total factor carbon productivity, exhibiting nonlinear characteristics. Furthermore, the spatial spillover effect test suggests that new infrastructure construction accelerates the local carbon emission performance, while having a positive spillover effect on neighboring cities. This study provides innovative ideas and experiences from China for the global realization of simultaneous promotion of digital economy development and energy conservation and emission reduction.","PeriodicalId":12460,"journal":{"name":"Frontiers in Environmental Science","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-08-30DOI: 10.3389/fenvs.2024.1461477
Peter Onyisi Uhuegbue, Mathias Stein, Karsten Kalbitz, Jörg Schaller
Phosphorus limitation occurs in many soils as a significant amount of soil P is retained in forms inaccessible to plants, such as bound to iron (Fe) minerals. Prior studies have shown that silicon (Si) can mobilize P from the binding sites of such minerals. Several P extraction methods have been developed to account for different P pools. Nevertheless, each of those methods uses different extractants and mechanisms to extract different P pools in soils. However, there is no study comparing different P extraction methods in the presence of Si fertilization. We tested the effect of Si on P mobility and determined the efficiency of water, Calcium acetate lactate (CAL), Mehlich-III, and Bray and Kurtz extraction methods for extracting P in the presence of amorphous silica (ASi) fertilization using two soils of contrasting characteristics. Significantly higher amounts of P were found at 3% ASi treatments (10 and 21 mg P kg-1) compared to the control (4 and 10 mg P kg-1) in the water extract in the high and low-yield soil, respectively just after 6 hours of extraction and increased with time. This may be explained by Si directly competing with P for sorption to Fe minerals. Using CAL extraction, Si addition showed no effect on P extractability. In contrast, the Mehlich-III and Bray extraction methods showed decreasing P extractability, especially at 3% ASi treatment (95 and 60 mg P kg-1) compared to the control (115 and 80 mg P kg-1) for the high-yield soil. The decreasing P contents in the presence of Si found in the Mehlich-III and Bray extracts may be attributed to the decrease in extraction effectiveness of the extractants to extract P while extracting Si and Fe. Our results showed that the Mehlich-III and Bray extraction methods may not be suitable for the determination of P availability in the presence of ASi fertilization since both extractants also extract Si and this may limit the completeness of P extraction. Therefore, in the presence of Si fertilizer, the water extraction method may be suitable to determine P availability and mobilization due to ASi.
许多土壤中都存在磷的限制，因为土壤中大量的磷以植物无法获取的形式存在，例如与铁（Fe）矿物结合。先前的研究表明，硅（Si）可以从此类矿物的结合位点调动磷。目前已开发出几种钾萃取方法，以考虑不同的钾库。然而，每种方法都使用不同的萃取剂和机制来萃取土壤中不同的钾库。然而，目前还没有研究比较不同的钾萃取方法在施用硅肥的情况下的效果。我们利用两种特性截然不同的土壤，测试了硅对磷迁移率的影响，并测定了水、乳酸乙酸钙（CAL）、Mehlich-III 以及 Bray 和 Kurtz 萃取法在施用无定形二氧化硅（ASi）肥料的情况下萃取磷的效率。与对照组（4 和 10 毫克 P kg-1）相比，高产和低产土壤中 3% ASi 处理（10 和 21 毫克 P kg-1）的水提取物中 P 的含量在萃取 6 小时后明显升高，并随着时间的推移而增加。这可能是因为硅直接与磷竞争吸附在铁矿物上。采用 CAL 萃取法，硅的添加对 P 的萃取率没有影响。相反，Mehlich-III 和 Bray 萃取法显示钾萃取率下降，尤其是在 3% ASi 处理时（95 和 60 毫克 P kg-1）与高产土壤的对照（115 和 80 毫克 P kg-1）相比。Mehlich-III萃取法和 Bray 萃取法发现在有硅存在的情况下 P 含量下降，这可能是由于在萃取硅和铁的同时，萃取剂对 P 的萃取效果下降所致。我们的研究结果表明，Mehlich-III 和 Bray 萃取法可能不适合在施用 ASi 肥料的情况下测定钾的供应量，因为这两种萃取剂也会萃取硅，这可能会限制钾萃取的完整性。因此，在施用硅肥的情况下，水萃取法可能适用于测定钾的可得性和因 ASi 而引起的钾移动。
{"title":"Silicon effects on soil phosphorus availability: results obtained depend on the method used","authors":"Peter Onyisi Uhuegbue, Mathias Stein, Karsten Kalbitz, Jörg Schaller","doi":"10.3389/fenvs.2024.1461477","DOIUrl":"https://doi.org/10.3389/fenvs.2024.1461477","url":null,"abstract":"Phosphorus limitation occurs in many soils as a significant amount of soil P is retained in forms inaccessible to plants, such as bound to iron (Fe) minerals. Prior studies have shown that silicon (Si) can mobilize P from the binding sites of such minerals. Several P extraction methods have been developed to account for different P pools. Nevertheless, each of those methods uses different extractants and mechanisms to extract different P pools in soils. However, there is no study comparing different P extraction methods in the presence of Si fertilization. We tested the effect of Si on P mobility and determined the efficiency of water, Calcium acetate lactate (CAL), Mehlich-III, and Bray and Kurtz extraction methods for extracting P in the presence of amorphous silica (ASi) fertilization using two soils of contrasting characteristics. Significantly higher amounts of P were found at 3% ASi treatments (10 and 21 mg P kg<jats:sup>-1</jats:sup>) compared to the control (4 and 10 mg P kg<jats:sup>-1</jats:sup>) in the water extract in the high and low-yield soil, respectively just after 6 hours of extraction and increased with time. This may be explained by Si directly competing with P for sorption to Fe minerals. Using CAL extraction, Si addition showed no effect on P extractability. In contrast, the Mehlich-III and Bray extraction methods showed decreasing P extractability, especially at 3% ASi treatment (95 and 60 mg P kg<jats:sup>-1</jats:sup>) compared to the control (115 and 80 mg P kg<jats:sup>-1</jats:sup>) for the high-yield soil. The decreasing P contents in the presence of Si found in the Mehlich-III and Bray extracts may be attributed to the decrease in extraction effectiveness of the extractants to extract P while extracting Si and Fe. Our results showed that the Mehlich-III and Bray extraction methods may not be suitable for the determination of P availability in the presence of ASi fertilization since both extractants also extract Si and this may limit the completeness of P extraction. Therefore, in the presence of Si fertilizer, the water extraction method may be suitable to determine P availability and mobilization due to ASi.","PeriodicalId":12460,"journal":{"name":"Frontiers in Environmental Science","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-08-29DOI: 10.3389/fenvs.2024.1402618
Farhad Saffarian, Seyed Ahmad Hosseini, Maryam Mohammadi Roozbahani, Alireza Etminan
IntroductionThe drilling industry is one of the main sectors of the oil industry, and oil drilling is one of the most specialized industrial activities. Large-scale production of sugarcane bagasse in Khuzestan Province creates an environmental opportunity to utilize this agricultural byproduct in different sections as a valuable byproduct. This study aimed to investigate the ability of the raw form of bagasse and its transformed structure in heavy metal fixation in drilling mud and to investigate the efficiency of crude bagasse, processed bagasse, and biochar adsorbents in removing heavy metals from the drilling mud residues of Ahvaz oil field.MethodsSampling of drilling mud waste from Mishan Geological Formation (MGF) and Aghajari Geological Formation (AGF) was done on a vibrating sieve. The treatments examined in this research include the contact time in six levels (30, 60, 90, 120, 150, and 180 min), amount of the adsorbent in three levels (0.1, 0.5, and 1 g), adsorbent type in three levels (crude bagasse, processed bagasse, and biochar), and the formation type in two levels (Aghajari and Mishan). After chemical digestion, the samples were placed in contact with crude bagasse, processed bagasse, and biochar according to the designed conditions. Then, the removal percentages of Ba, Ni, V, Cd, Fe, and Pb were calculated. Means were compared using Duncan’s test at the 1% level.Results and DiscussionThe results showed that the biochar adsorbent is the most efficient compared to other adsorbents. The maximum removal percentages of heavy metals Ba, Ni, V, Cd, Fe, and Pb by crude bagasse are 72.53%, 68.89%, 79.49%, 76.88%, 49.42%, and 85%, respectively. In addition, the results showed that the maximum removal percentages of heavy metals Ba, Ni, V, Cd, Fe, and Pb by crude bagasse are 81/72%, 83/89%, 86/67%, 83/44%, 64/41%, and 90.72%, respectively. The maximum efficiency of biochar for adsorbing heavy metals Ba, Ni, V, Cd, Fe, and Pb is 90.70%, 91.84%, 88.89%, 88.75%, 78.59%, and 97.75%, respectively. The maximum amount of heavy metals adsorbed by all adsorbents was 1 gr/L, and the adsorption efficiency increased by increasing the amount of the adsorbent from 0.2 to 1 gr/L. In examining the effect of contact time, the maximum removal percentage of heavy metals barium and cadmium was obtained in 120 min, nickel and lead in 90 min, and vanadium and iron in 60 min. After the above contact times, there was no increase in the maximum percentage of metal removal.
{"title":"Evaluation of heavy metal fixation ability from drilling waste of oil and gas wells using treated sugarcane bagasse","authors":"Farhad Saffarian, Seyed Ahmad Hosseini, Maryam Mohammadi Roozbahani, Alireza Etminan","doi":"10.3389/fenvs.2024.1402618","DOIUrl":"https://doi.org/10.3389/fenvs.2024.1402618","url":null,"abstract":"IntroductionThe drilling industry is one of the main sectors of the oil industry, and oil drilling is one of the most specialized industrial activities. Large-scale production of sugarcane bagasse in Khuzestan Province creates an environmental opportunity to utilize this agricultural byproduct in different sections as a valuable byproduct. This study aimed to investigate the ability of the raw form of bagasse and its transformed structure in heavy metal fixation in drilling mud and to investigate the efficiency of crude bagasse, processed bagasse, and biochar adsorbents in removing heavy metals from the drilling mud residues of Ahvaz oil field.MethodsSampling of drilling mud waste from Mishan Geological Formation (MGF) and Aghajari Geological Formation (AGF) was done on a vibrating sieve. The treatments examined in this research include the contact time in six levels (30, 60, 90, 120, 150, and 180 min), amount of the adsorbent in three levels (0.1, 0.5, and 1 g), adsorbent type in three levels (crude bagasse, processed bagasse, and biochar), and the formation type in two levels (Aghajari and Mishan). After chemical digestion, the samples were placed in contact with crude bagasse, processed bagasse, and biochar according to the designed conditions. Then, the removal percentages of Ba, Ni, V, Cd, Fe, and Pb were calculated. Means were compared using Duncan’s test at the 1% level.Results and DiscussionThe results showed that the biochar adsorbent is the most efficient compared to other adsorbents. The maximum removal percentages of heavy metals Ba, Ni, V, Cd, Fe, and Pb by crude bagasse are 72.53%, 68.89%, 79.49%, 76.88%, 49.42%, and 85%, respectively. In addition, the results showed that the maximum removal percentages of heavy metals Ba, Ni, V, Cd, Fe, and Pb by crude bagasse are 81/72%, 83/89%, 86/67%, 83/44%, 64/41%, and 90.72%, respectively. The maximum efficiency of biochar for adsorbing heavy metals Ba, Ni, V, Cd, Fe, and Pb is 90.70%, 91.84%, 88.89%, 88.75%, 78.59%, and 97.75%, respectively. The maximum amount of heavy metals adsorbed by all adsorbents was 1 gr/L, and the adsorption efficiency increased by increasing the amount of the adsorbent from 0.2 to 1 gr/L. In examining the effect of contact time, the maximum removal percentage of heavy metals barium and cadmium was obtained in 120 min, nickel and lead in 90 min, and vanadium and iron in 60 min. After the above contact times, there was no increase in the maximum percentage of metal removal.","PeriodicalId":12460,"journal":{"name":"Frontiers in Environmental Science","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
IntroductionBottom sediments play a pivotal role in wetland productivity, and here, eight Gangetic floodplain wetlands of India were studied to assess the sediment physicochemical characteristics and textural analysis.MethodsSediment samples that were collected from each wetland in monsoon and non-monsoon seasons were analysed. ANOVA, Principal component analysis and multiple correlation analysis were used for statistical analysis.Results and DiscussionThroughout the study period, pH (6.90–8.04), EC (0.20–1.64 dS/m), CaCO3 (1.75%–14.50%), available nitrogen (10.22–22.23 mg/100 g sediment), total nitrogen (80.4–333.8 mg/100 g sediment), available phosphorus (0.20–5.61 mg/100 g sediment), and total phosphorus (19.63–173.33 mg/100 g sediment) were recorded. The sediment quality parameters differ significantly (p > 0.05) among the wetlands. Seasonal variation was only observed on total nitrogen and total phosphorus contents. Sediments were dominated by sand. Sediment nutrient (C, N, and P) stoichiometry of wetlands depicted a comparatively little higher C/P (5.96–66.32) ratio and lower C/N (3.34–22.76) and N/P (1.12–9.25) ratios, which revealed that the physicochemical characteristics of the sediments are influenced by anthropogenic sources. Principal component analysis showed the influence of both natural and anthropogenic causes on wetland ecosystems. The geographic information system (GIS) interpolation approach was used in combination with laboratory analysis methods to give a complete spatial resolution of the sediment quality of each wetland. The study suggests that these wetlands’ sediment quality is favorable for fish culture but requires proper management practices to achieve sustainable production. As it is the first time where monitoring physicochemical properties of sediments of these wetlands are presented, this study can be used as a baseline data for comparison in future environmental assessments of the wetlands.
{"title":"Assessment of the physicochemical properties of the sediment from the Gangetic floodplain wetlands of West Bengal, India, with GIS and a statistical approach","authors":"Basanta Kumar Das, Ajoy Saha, Archan Kanti Das, Purna Chandra, Kausik Mondal, Tania Kayal, Sangeeta Chakraborty, Shreya Bhattacharya, Bigan Kumar Sahoo, Chayna Jana","doi":"10.3389/fenvs.2024.1397715","DOIUrl":"https://doi.org/10.3389/fenvs.2024.1397715","url":null,"abstract":"IntroductionBottom sediments play a pivotal role in wetland productivity, and here, eight Gangetic floodplain wetlands of India were studied to assess the sediment physicochemical characteristics and textural analysis.MethodsSediment samples that were collected from each wetland in monsoon and non-monsoon seasons were analysed. ANOVA, Principal component analysis and multiple correlation analysis were used for statistical analysis.Results and DiscussionThroughout the study period, pH (6.90–8.04), EC (0.20–1.64 dS/m), CaCO<jats:sub>3</jats:sub> (1.75%–14.50%), available nitrogen (10.22–22.23 mg/100 g sediment), total nitrogen (80.4–333.8 mg/100 g sediment), available phosphorus (0.20–5.61 mg/100 g sediment), and total phosphorus (19.63–173.33 mg/100 g sediment) were recorded. The sediment quality parameters differ significantly (<jats:italic>p</jats:italic> &gt; 0.05) among the wetlands. Seasonal variation was only observed on total nitrogen and total phosphorus contents. Sediments were dominated by sand. Sediment nutrient (C, N, and P) stoichiometry of wetlands depicted a comparatively little higher C/P (5.96–66.32) ratio and lower C/N (3.34–22.76) and N/P (1.12–9.25) ratios, which revealed that the physicochemical characteristics of the sediments are influenced by anthropogenic sources. Principal component analysis showed the influence of both natural and anthropogenic causes on wetland ecosystems. The geographic information system (GIS) interpolation approach was used in combination with laboratory analysis methods to give a complete spatial resolution of the sediment quality of each wetland. The study suggests that these wetlands’ sediment quality is favorable for fish culture but requires proper management practices to achieve sustainable production. As it is the first time where monitoring physicochemical properties of sediments of these wetlands are presented, this study can be used as a baseline data for comparison in future environmental assessments of the wetlands.","PeriodicalId":12460,"journal":{"name":"Frontiers in Environmental Science","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-08-29DOI: 10.3389/fenvs.2024.1439954
Yeshitla Agonafir Ayenachew, Birhanu Girma Abebe
Over the past two decades, Addis Ababa has witnessed a relentless transformation in its land use and land cover. Primarily driven by the conversion of agricultural land through extensive expropriation in the city’s expansion areas. The study explores the dynamic land use land cover changes and associated land expropriations from peri-urban farmers in the rapidly growing Addis Ababa, Ethiopia. The study utilized a time series of global land cover and land-use change datasets (GLAD) covering the years 2000–2020. Moreover, empirical data is gathered through a household survey conducted among 349 systematically selected expropriated farmers across four sub-cities of Addis Ababa. The findings underscore a profound shift in the city’s land use and land cover over the past two decades. The built-up area emerges as the predominant land cover, witnessing a substantial increase of 25.28% (13,150.30 ha) over the past two decades. Concurrently, agricultural land and vegetation cover decreased by 15.92% and 9.35%, respectively, indicating a significant outward expansion of the city. This expansive growth, driven by the city’s rapid development, has resulted in extensive land expropriations primarily affecting peri-urban farmers. The expropriations were mainly for housing, investment, industrial parks, and infrastructure development. Thus, we urge the city administration to carefully manage the horizontal expansion of built-up areas at the expense of the agricultural land and vegetation cover. Finally, we recommend holistic and sustainable development strategies, developed collaboratively with local communities and planners, to safeguard the long-term wellbeing of city residents.
{"title":"The dynamics of urbanization, land use land cover changes, and land expropriation in Addis Ababa, Ethiopia","authors":"Yeshitla Agonafir Ayenachew, Birhanu Girma Abebe","doi":"10.3389/fenvs.2024.1439954","DOIUrl":"https://doi.org/10.3389/fenvs.2024.1439954","url":null,"abstract":"Over the past two decades, Addis Ababa has witnessed a relentless transformation in its land use and land cover. Primarily driven by the conversion of agricultural land through extensive expropriation in the city’s expansion areas. The study explores the dynamic land use land cover changes and associated land expropriations from peri-urban farmers in the rapidly growing Addis Ababa, Ethiopia. The study utilized a time series of global land cover and land-use change datasets (GLAD) covering the years 2000–2020. Moreover, empirical data is gathered through a household survey conducted among 349 systematically selected expropriated farmers across four sub-cities of Addis Ababa. The findings underscore a profound shift in the city’s land use and land cover over the past two decades. The built-up area emerges as the predominant land cover, witnessing a substantial increase of 25.28% (13,150.30 ha) over the past two decades. Concurrently, agricultural land and vegetation cover decreased by 15.92% and 9.35%, respectively, indicating a significant outward expansion of the city. This expansive growth, driven by the city’s rapid development, has resulted in extensive land expropriations primarily affecting peri-urban farmers. The expropriations were mainly for housing, investment, industrial parks, and infrastructure development. Thus, we urge the city administration to carefully manage the horizontal expansion of built-up areas at the expense of the agricultural land and vegetation cover. Finally, we recommend holistic and sustainable development strategies, developed collaboratively with local communities and planners, to safeguard the long-term wellbeing of city residents.","PeriodicalId":12460,"journal":{"name":"Frontiers in Environmental Science","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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