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所有论文

121. 题目: Diversity in mechanisms of natural humic acid enhanced current production in soil bioelectrochemical systems
文章编号: N24070407
期刊: Bioresource Technology
作者: Xintong Gao, Kaixuan Liu, Chong Zhang, Xian Cao, Takashi Sakamakic, Xianning Li
更新时间: 2024-07-04
摘要: The quinoid component of humic acids (HAs) had been studied as exogenous electron mediators (EMs), but the redox-mediating abilities of other functional groups remained unclear. This study evaluated the effects of various HAs functional groups on cellular respiration and extracellular electron transfer. The three EMs increased the current density compared to the control. Current density increased significantly after adding ultraviolet-irradiated HAs (UV-HAs), suggesting that nitrogenous group-mediated redox reactions contributed to high-density current generation. Structural equation model (SEM) results indicated that the contribution of nitrogen-containing groups to electron transfer could exceed 20%. This study proposed a synergistic mechanism: in the soil microbial fuel cells (soil-MFCs), HAs accelerated their component evolution through irreversible redox reactions and promoted extracellular electron transfer. Additionally, HAs-induced high expression of -Cyts could further enhance high-density current generation. This study demonstrates that humic acids enhance electron transfer and current in bioelectrochemical systems, aiding sustainable energy optimization.

122. 题目: Principal role of fungi in soil carbon stabilization during early pedogenesis in the high Arctic
文章编号: N24070406
期刊: Proceedings of the National Academy of Sciences of the United States of America
作者: Juan Carlos Trejos-Espeleta, Juan P Marin-Jaramillo, Steven K Schmidt, Pacifica Sommers, James A Bradley, William D Orsi
更新时间: 2024-07-04
摘要: Climate warming is causing widespread deglaciation and pioneer soil formation over glacial deposits. Melting glaciers expose rocky terrain and glacial till sediment that is relatively low in biomass, oligotrophic, and depleted in nutrients. Following initial colonization by microorganisms, glacial till sediments accumulate organic carbon and nutrients over time. However, the mechanisms driving soil nutrient stabilization during early pedogenesis after glacial retreat remain unclear. Here, we traced amino acid uptake by microorganisms in recently deglaciated high-Arctic soils and show that fungi play a critical role in the initial stabilization of the assimilated carbon. Pioneer basidiomycete yeasts were among the predominant taxa responsible for carbon assimilation, which were associated with overall high amino acid use efficiency and reduced respiration. In intermediate- and late-stage soils, lichenized ascomycete fungi were prevalent, but bacteria increasingly dominated amino acid assimilation, with substantially decreased fungal:bacterial amino acid assimilation ratios and increased respiration. Together, these findings demonstrate that fungi are important drivers of pedogenesis in high-Arctic ecosystems that are currently subject to widespread deglaciation from global warming.

123. 题目: Effects of wet-dry alternation on organic phosphorus dynamics and sediment characteristics in the intertidal zone of Nansi Lake
文章编号: N24070405
期刊: Ecotoxicology and Environmental Safety
作者: Xu Zhang, Fuai Chen, Dajiang Yan, Yong Guan Zhu, Yanhao Zhang, Zhibin Zhang
更新时间: 2024-07-04
摘要: The study of the fractions and distribution characteristics of organic phosphorus in the sediment of the water level fluctuating zone of Nansi Lake is conducive to revealing the transformation of phosphorus in the lake, and has important scientific significance for controlling the eutrophication of Nansi Lake. Based on the sediment of the water level fluctuation zone of Nansi Lake. The improved Hedley continuous grading extraction, ultraviolet-visible spectroscopy and three-dimensional fluorescence spectroscope were used to characterize the structural characteristics and stability of organic molecules in the sediment, and to reflect the differences in the structure and stability of organophosphate in the water level fluctuating zone. Principal component analysis (PCA), Redundancy analysis (RDA) and correlation heat map analysis were used to analyze the correlation between phosphorus and physicochemical index. The results showed that the alternation between wet-dry conditions was more favorable for the release of phosphorus from sediment, compared to continuous inundation conditions. Moreover, the higher the frequency of wet-dry alternations, the greater the release of phosphorus in different forms from the sediment. Wet-dry alternation resulted in a reduction of substituent on the aromatic rings of sediment DOM (dissolved organic matter), and the continuous drying would increase the molecular weight and humidification degree of DOM in the sediment. Correlation analysis showed that NaOH-P content in sediment was significantly negatively correlated with TP, IP, OP and various organophosphorus forms, indicating a close transformation relationship between phosphorus forms in sediment. The results can provide a scientific basis for controlling the release of endogenous phosphorus and the risk of eutrophication in Nansi Lake.

124. 题目: Mechanistic insights into the synergetic remediation and amendment effects of zeolite/biochar composite on heavy metal-polluted red soil
文章编号: N24070404
期刊: Frontiers of Environmental Science & Engineering
作者: Jing Li, Dazhong Yang, Wensong Zou, Xuezhen Feng, Ranhao Wang, Renji Zheng, Siyuan Luo, Zheting Chu, Hong Chen
更新时间: 2024-07-04
摘要:

Red soil, the most critical soil resource in tropical/subtropical regions worldwide, faces tremendous threats, including nutrient deficiency, acidification, and heavy metal contamination. There is a great demand for multifunctional eco-materials capable of modifying this situation. Herein, we used widely distributed soil and biomass to develop a zeolite/biochar composite for synergistic red soil remediation and amendment. With the composite material, the Pb2+ and Cd2+ remediation efficiencies reached 92.8% and 92.9%, respectively, in stems under optimal conditions. Moreover, the acidity and nutrient deficiency conditions of red soil significantly improved. The atomic-scale interaction mechanism during the remediation and amendment process was elucidated with complementary characterization methods, which revealed that in the zeolite/biochar composite material, zeolite contributes to long-term heavy metal remediation effects. Simultaneously, biochar is responsible for soil quality amendment and short-term heavy metal remediation. Furthermore, for the first time, single-atom heavy metal ions were observed on biochar during the remediation process, indicating the broad distribution of single atoms in the natural environment.

125. 题目: Sustainable soil management under drought stress through biochar application: Immobilizing arsenic, ameliorating soil quality, and augmenting plant growth
文章编号: N24070403
期刊: Environmental Research
作者: Abhishek Kumar, Tanushree Bhattacharya, Wasim Akram Shaikh, Arpita Roy
更新时间: 2024-07-04
摘要: Rise in climate change-induced drought occurrences have amplified pollution of metal(loid)s, deteriorated soil quality, and deterred growth of crops. Rice straw-derived biochars (RSB) and cow manure-enriched biochars (CEB) were used in the investigation (at doses of 0%, 2.5%, 5%, and 7.5%) to ameliorate the negative impacts of drought, improve soil fertility, minimize arsenic pollution, replace agro-chemical application, and maximize crop yields. Even in soils exposed to severe droughts, 3 months of RSB and CEB amendment (at 7.5% dose) revealed decreased bulk density (13.7% and 8.9%), and increased cation exchange capacity (6.0% and 6.3%), anion exchange capacity (56.3% and 28.0%), porosity (12.3% and 7.9%), water holding capacity (37.5% and 12.5%), soil respiration (17.8% and 21.8%), and nutrient contents (especially N and P). Additionally, RSB and CEB decreased mobile (30.3% and 35.7%), bio-available (54.7% and 45.3%), and leachable (55.0% and 56.5%) fractions of arsenic. Further, pot experiments with Bengal gram and coriander plants showed enhanced growth (62–188% biomass and 90–277% length) and reduced arsenic accumulation (49–54%) in above ground parts of the plants. Therefore, biochar application was found to improve physico-chemical properties of soil, minimize arsenic contamination, and augment crop growth even in drought-stressed soils. The investigation suggests utilisation of cow manure for eco-friendly fabrication of nutrient-rich CEB, which could eventually promote sustainable agriculture and circular economy. With the increasing need for sustainable agricultural practices, the use of biochar could provide a long-term solution to enhance soil quality, mitigate the effects of climate change, and ensure food security for future generations. Future research should focus on optimizing biochar application across various soil types and climatic conditions, as well as assessing its long-term effectiveness.

126. 题目: Role of Source, Mineralogy, and Organic Complexation on Lability and Fe Isotopic Composition of Terrestrial Fe sources to the Gulf of Alaska
文章编号: N24070402
期刊: ACS Earth and Space Chemistry
作者: Linqing Huang, Sarah M Aarons, Bess G Koffman, Wenhan Cheng, Lena Hanschka, Lee Ann Munk, Jordan Jenckes, Emmet Norris, Carli A Arendt
更新时间: 2024-07-04
摘要: Iron (Fe) is a key trace nutrient supporting marine primary production, and its deposition in the surface ocean can impact multiple biogeochemical cycles. Understanding Fe cycling in the subarctic is key for tracking the fate of particulate-bound sources of oceans in a changing climate. Recently, Fe isotope ratios have been proposed as a potential tool to trace sources of Fe to the marine environment. Here, we investigate the Fe isotopic composition of terrestrial sources of Fe including glacial sediment, loess, volcanic ash, and wildfire aerosols, all from Alaska. Results show that the δ56Fe values of glaciofluvial silt, glacial dissolved load, volcanic ash, and wildfire aerosols fall in a restricted range of δ56Fe values from −0.02 to +0.12‰, in contrast to the broader range of Fe isotopic compositions observed in loess, −0.50 to +0.13‰. The Fe isotopic composition of the dissolved load of glacial meltwater was consistently lighter compared to its particulate counterpart. The ‘aging’ (exposure to environmental conditions) of volcanic ash did not significantly fractionate the Fe isotopic composition. The Fe isotopic composition of wildfire aerosols collected during an active fire season in Alaska in the summer of 2019 was not significantly fractionated from those of the average upper continental crust composition. We find that the δ56Fe values of loess (<5 μm fraction) were more negative (−0.32 to +0.05‰) with respect to all samples measured here, had the highest proportion of easily reducible Fe (5.9–59.6%), and were correlated with the degree of chemical weathering and organic matter content. Transmission electron spectroscopy measurements indicate an accumulation of amorphous Fe phases in the loess. Our results indicate that Fe isotopes can be related to Fe lability when in the presence of organic matter and that higher organic matter content is associated with a distinctly more negative Fe isotope signature likely due to Fe-organic complexation.

127. 题目: Performance and mechanistic study of biochar and magnesium-enhanced phytoremediation in cadmium-contaminated soil by alfalfa
文章编号: N24070401
期刊: Chemosphere
作者: Xing Shen, Taotao Sun, Min Dai, Mian M Ahson Aslam, Changsheng Peng
更新时间: 2024-07-04
摘要: Recently, phytoremediation has been regarded as a green and environment friendly technique to treat metals contaminated soils. Thus, in this study, pot experiments were designed to investigate the combine effects of biochar and magnesium (MPs) to purify cadmium (Cd)-contaminated soils by L. (alfalfa). The results showed that the combined use of biochar and Mg significantly increased the accumulation of Cd and promoted the transport of Cd from root to shoot in alfalfa, simultaneously. Importantly, the combined use of biochar and Mg could increase the accumulation of Cd in shoot and whole plant (shoot + root) of alfalfa up-to 59.1% and 23.1%, respectively. Moreover, the enhancement mechanism can be analyzed from several aspects. Firstly, the photosynthesis was enhanced, which was beneficial to plant growth. The product of photosynthesis provided energy for uptake and transport of Cd. Meanwhile, its transport in phloem could promote the transport of Cd. Secondly, the enhancement of antioxidant capacity of alfalfa effectively protected the membrane structure of alfalfa, which indicated that Cd could enter alfalfa from the channel on the cell membrane. Lastly, the chemical form of Cd and microbial community structure in soil were changed. Overall, these changes reduced the Cd toxicity in soil, enhanced the resistance capability of alfalfa, increased the Cd uptake by alfalfa and promoted the growth of alfalfa. Thus, the obtained results suggested that the combined use of biochar and Mg is an effective approach to enhance phytoremediation performance for purifying Cd-contaminated soils.

128. 题目: Evaluation of effects of heat released from SOC decomposition on soil carbon stock and temperature
文章编号: N24070312
期刊: Global Change Biology
作者: Ye Huang, Lin Huang, Chunjing Qiu, Philippe Ciais
更新时间: 2024-07-03
摘要: Heat released from soil organic carbon (SOC) decomposition (referred to as microbial heat hereafter) could alter the soil's thermal and hydrological conditions, subsequently modulate SOC decomposition and its feedback with climate. While understanding this feedback is crucial for shaping policy to achieve specific climate goal, it has not been comprehensively assessed. This study employs the ORCHIDEE-MICT model to investigate the effects of microbial heat, referred to as heating effect, focusing on their impacts on SOC accumulation, soil temperature and net primary productivity (NPP), as well as implication on land-climate feedback under two CO2 emissions scenarios (RCP2.6 and RCP8.5). The findings reveal that the microbial heat decreases soil carbon stock, predominantly in upper layers, and elevates soil temperatures, especially in deeper layers. This results in a marginal reduction in global SOC stocks due to accelerated SOC decomposition. Altered seasonal cycles of SOC decomposition and soil temperature are simulated, with the most significant temperature increase per unit of microbial heat (0.31 K J−1) occurring at around 273.15 K (median value of all grid cells where air temperature is around 273.15 K). The heating effect leads to the earlier loss of permafrost area under RCP8.5 and hinders its restoration under RCP2.6 after peak warming. Although elevated soil temperature under climate warming aligns with expectation, the anticipated accelerated SOC decomposition and large amplifying feedback on climate warming were not observed, mainly because of reduced modeled initial SOC stock and limited NPP with heating effect. These underscores the multifaceted impacts of microbial heat. Comprehensive understanding of these effects would be vital for devising effective climate change mitigation strategies in a warming world.

129. 题目: Superoxide Photoproduction from Wetland Plant-Derived Dissolved Organic Matter: Implications for Biogeochemical Impacts of Plant Invasion
文章编号: N24070311
期刊: Environmental Science & Technology
作者: Yu Fu, Chunxiao Xu, Xiaojing Liu, Yanna Xue, Lingli Wang, Qingchao Li, Yuqi Xia, Zhen Zhang, Jialin Chen, Jinhui Cao, Sifan Qiu, Zhaohui Wang
更新时间: 2024-07-03
摘要: Although the impacts of exotic wetland plant invasions on native biodiversity, landscape features, and carbon–nitrogen cycles are well appreciated, biogeochemical consequences posed by ecological competition, such as the heterogeneity of dissolved organic matter (DOM) from plant detritus and its impact on the formation of reactive oxygen species, are poorly understood. Thus, this study delves into O2•– photogeneration potential of DOM derived from three different parts (stem, leaf, and panicle) of invasive Spartina alterniflora (SA) and native Phragmites australis (PA). It is found that DOM from the leaves of SA and the panicles of PA has a superior ability to produce O2•–. With more stable aromatic structures and a higher proportion of sulfur-containing organic compounds, SA-derived DOM generally yields more O2•– than that derived from PA. UVA exposure enhances the leaching of diverse DOM molecules from plant detritus. Based on the reported monitoring data and our findings, the invasion of SA is estimated to approximately double the concentration of O2•– in the surrounding water bodies. This study can help to predict the underlying biogeochemical impacts from the perspective of aquatic photochemistry in future scenarios of plant invasion, seawater intrusion, wetland degradation, and elevated solar UV radiation.

130. 题目: Innovative insights into organic nitrogen degradation through protein family domains analysis in chicken and pig manure composting using metagenomic sequencing
文章编号: N24070310
期刊: Bioresource Technology
作者: Lin Zhu, Caihong Huang, Lipin Li, Simiao Wang, Xinxin Wu, Guangchun Shan, Yu Tian
更新时间: 2024-07-03
摘要: The nitrogen loss in composting is primarily driven by the transformation of organic nitrogen, yet the mechanisms underlying the degradation process remain incompletely understood. This study employed protein family domains (Pfams) analysis based on metagenomic sequencing to investigate the functional characteristics, key microorganisms, and environmental parameters influencing organic nitrogen degradation in chicken manure and pig manure composting. 154 Pfams associated with ammonification function were identified. Predominant Pfams: proteolytic peptidase, followed by chitin/cell wall degraders, least involved in nucleic acid degradation. Ammonifying microbial diversity was basically consistent among compost types, particularly in the thermophilic stage with the peak of abundance of dominant ammonifying microorganisms. Viruses played an important role in ammonification process, especially Uroviricota. 26 key ammonifying genera were identified by the microbial network. pH dominated the metabolic activity of ammonifying microorganisms in various manure compost types, primarily consisting of protein-degrading bacteria with stable community structures.

131. 题目: Evolution of black carbon and brown carbon during summertime in Southwestern China: An assessment of control measures during the 2023 Chengdu Summer World University Games
文章编号: N24070309
期刊: Environmental Pollution
作者: Zhier Bao, Xiaoling Zeng, Jiawei Zhou, Fumo Yang, Keding Lu, Chongzhi Zhai, Xin Li, Miao Feng, Qinwen Tan, Yang Chen
更新时间: 2024-07-03
摘要: The 31st FISU Summer World University Games (SWUG) was held in Chengdu, southwestern China, from July 22 to August 8, 2023. A series of control measures were carried out to ensure good air quality during the SWUG, providing an opportunity to investigate the atmospheric behaviors of light-absorbing aerosols under such a substantial disturbance caused by the control measures. To assess the impacts of emission controls on primary pollutants, a field campaign was conducted at a rural site in Chengdu to investigate the characterization of equivalent black carbon (eBC). The changes of eBC concentrations before, during, and after the SWUG were characterized. The sources of eBC were resolved, and the impacts of atmospheric processes on the absorption capacity were also investigated. During the SWUG, the eBC concentration decreased by 12.1 % and 25.3 % compared with those before and after the SWUG. A fossil fuel combustion (eBC) and a biomass burning (eBC) originated eBC were resolved using the aethalometer model. Both eBC and eBC decreased during the SWUG, indicating the effectiveness of control measures. After the SWUG, the influence of biomass burning emissions became more and more significant, and the contribution of brown carbon (BrC) to light absorption at 370–660 nm increased by 52, 19, 7, 6, and 17 % compared to those during the SWUG. As the biomass burning emitted aerosols aged, the absorption Ångström exponent and (BrC) decreased gradually, which was mainly due to the photobleaching of the chromophores during the daytime. eBC was mainly affected by strong wind, while high eBC concentration was mainly attributed to the gradual accumulation of biomass-burning emissions near the observation site. The results show the significant reduction of eBC with the implementation of the air pollution mitigation campaign, and provide insights on the impacts of atmospheric processes on BC optical properties during summertime.

132. 题目: Enhanced immobilization of cadmium and lead in contaminated soil using calcium alginate-modified HAP biochar: Improvements in soil health and microbial diversity
文章编号: N24070308
期刊: Environmental Pollution
作者: Yining Ji, Na Zheng, Qirui An, Sujing Wang, Siyu Sun, Xiaoqian Li, Changcheng Chen, Shuhai Sun, Yifu Jiang
更新时间: 2024-07-03
摘要: A novel adsorbent, calcium alginate-modified HAP (Hydroxyapatite)-wood ear mushroom sticks biochar (CA-HAP), was synthesized to enhance the immobilization of Cd and Pb in soil. Over 150 days, applying CA-HAP at concentrations of 0%–3% in contaminated soils from Chenzhou City in Hunan Province (CZ) and Shenyang City in Liaoning Province (SY) resulted in decreased effective concentrations of Cd and Pb. Specifically, in CZ soil, Cd and Pb decreased by 30.9%–69.3% and 31.9%–78.6%, respectively, while in SY soil, they decreased by 27.5%–53.7% and 26.4%–62.3%, respectively. Characterization results, obtained after separating CA-HAP from the soil, indicate that complexation, co-precipitation, and ion exchange play crucial roles in the efficient immobilization of Cd and Pb by CA-HAP. Additionally, adjusting the amount of CA-HAP added allows modulation of soil pH, leading to increased soil organic matter and nutrient content. Following treatment with CA-HAP for immobilizing Cd and Pb, soil bacteria abundance and diversity increased, further promoting heavy-metal immobilization.

133. 题目: Integrating Mobile and Fixed-Site Black Carbon Measurements to Bridge Spatiotemporal Gaps in Urban Air Quality
文章编号: N24070307
期刊: Environmental Science & Technology
作者: Chirag Manchanda, Robert A Harley, Julian D Marshall, Alexander J Turner, Joshua S Apte
更新时间: 2024-07-03
摘要: Urban air pollution can vary sharply in space and time. However, few monitoring strategies can concurrently resolve spatial and temporal variation at fine scales. Here, we present a new measurement-driven spatiotemporal modeling approach that transcends the individual limitations of two complementary sampling paradigms: mobile monitoring and fixed-site sensor networks. We develop, validate, and apply this model to predict black carbon (BC) using data from an intensive, 100-day field study in West Oakland, CA. Our spatiotemporal model exploits coherent spatial patterns derived from a multipollutant mobile monitoring campaign to fill spatial gaps in time-complete BC data from a low-cost sensor network. Our model performs well in reconstructing patterns at fine spatial and temporal resolution (30 m, 15 min), demonstrating strong out-of-sample correlations for both mobile (Pearson’s R ∼ 0.77) and fixed-site measurements (R ∼ 0.95) while revealing features that are not effectively captured by a single monitoring approach in isolation. The model reveals sharp concentration gradients near major emission sources while capturing their temporal variability, offering valuable insights into pollution sources and dynamics.

134. 题目: Low-Cost Hourly Ambient Black Carbon Measurements at Multiple Cities in Africa
文章编号: N24070306
期刊: Environmental Science & Technology
作者: Abhishek Anand, N’Datchoh Evelyne Touré, Julien Bahino, Sylvain Gnamien, Allison Felix Hughes, Raphael E Arku, Victoria Owusu Tawiah, Araya Asfaw, Tesfaye Mamo, Sina Hasheminassab, Solomon Bililign, Vaios Moschos, Daniel M Westervelt, Albert A Presto
更新时间: 2024-07-03
摘要: There is a notable lack of continuous monitoring of air pollutants in the Global South, especially for measuring chemical composition, due to the high cost of regulatory monitors. Using our previously developed low-cost method to quantify black carbon (BC) in fine particulate matter (PM2.5) by analyzing reflected red light from ambient particle deposits on glass fiber filters, we estimated hourly ambient BC concentrations with filter tapes from beta attenuation monitors (BAMs). BC measurements obtained through this method were validated against a reference aethalometer between August 2 and 23, 2023 in Addis Ababa, Ethiopia, demonstrating a very strong agreement (R2 = 0.95 and slope = 0.97). We present hourly BC for three cities in sub-Saharan Africa (SSA) and one in North America: Abidjan (Côte d’Ivoire), Accra (Ghana), Addis Ababa (Ethiopia), and Pittsburgh (USA). The average BC concentrations for the measurement period at the Abidjan, Accra, Addis Ababa Central summer, Addis Ababa Central winter, Addis Ababa Jacros winter, and Pittsburgh sites were 3.85 μg/m3, 5.33 μg/m3, 5.63 μg/m3, 3.89 μg/m3, 9.14 μg/m3, and 0.52 μg/m3, respectively. BC made up 14–20% of PM2.5 mass in the SSA cities compared to only 5.6% in Pittsburgh. The hourly BC data at all sites (SSA and North America) show a pronounced diurnal pattern with prominent peaks during the morning and evening rush hours on workdays. A comparison between our measurements and the Goddard Earth Observing System Composition Forecast (GEOS-CF) estimates shows that the model performs well in predicting PM2.5 for most sites but struggles to predict BC at an hourly resolution. Adding more ground measurements could help evaluate and improve the performance of chemical transport models. Our method can potentially use existing BAM networks, such as BAMs at U.S. Embassies around the globe, to measure hourly BC concentrations. The PM2.5 composition data, thus acquired, can be crucial in identifying emission sources and help in effective policymaking in SSA.

135. 题目: Carbon sequestration in coastal sediments via in situ capping with steel slag
文章编号: N24070305
期刊: Journal of Cleaner Production
作者: Kyeongmin Kim, Nakashita Shinya, Umi Sholikah, Yuki Doida, Tadashi Hibino
更新时间: 2024-07-03
摘要: A 4000 m steel slag (SS) bed was constructed in the brackish water area for water quality remediation in 2017. This study demonstrates the ability of SS to stimulate carbon sequestration based on one-year pilot and SS beds. The pilot SS bed increased the soil organic matter (SOM) content by 5.1 wt %, sequestering sewage-derived organic carbon (C) as SOM. Notably, recalcitrant SOM increased by over 40 %, indicating long-term retention of C in the sediment. SS increased the C density in the sediment by approximately two times, exceeding that of the dense carbon ecosystems found in global seagrass meadows and peatlands. The complexation of the low-molecular-weight C with iron in SS was the main pathway for C fixation. Benthic animal investigations showed that SS capping fostered an anaerobic fauna ecosystem, aiding biotic C sequestration. Algae proliferation on the SS bed suggested complex benthic ecosystems with photosynthetic carbon fixation. Overall, SS beds offer a new abiotic carbon sequestration pathway with environmental restoration benefits; capping with metal-containing material is potentially more economical and sustainable compared to traditional landfilling.

136. 题目: Cd(II) and Zn(II) adsorption on lignite‐derived humic substances and cattle manure biochar
文章编号: N24070304
期刊: Clean - Soil Air Water
作者: Yihan Zhao, M Anne Naeth
更新时间: 2024-07-03
摘要: Excessive industrial release of trace elements may pose a great risk to the environment. Conventional remediation treatments have considerable limitations, making less expensive new technologies an important research area. Batch experiments were conducted at room temperature to investigate the use of two lignite‐derived humic products (nano‐humus and humic powder) and a cattle manure biochar as adsorbents in the removal of cadmium and zinc from laboratory synthesized water. Nano‐humus was most effective in adsorbing Cd(II), wherein 89% adsorption was rapidly achieved in 15 min. The adsorbed amount of Cd(II) and Zn(II) both increased with initial metal ion concentrations from 25 to 125 mg L−1. Despite being produced from the same sources, nano‐humus and humic powder showed different properties and adsorption behaviors. The adsorption mechanism of nano‐humus followed the Freundlich isotherm model and pseudo‐second‐order kinetic model, indicating multilayer chemisorption. Humic powder followed the pseudo‐second‐order kinetic model, although it had a low isotherm model fit, implying chemisorption‐dominated adsorption. Cattle manure biochar followed the Freundlich isotherm and pseudo‐first‐order kinetics model, suggesting diffusion‐dominated multilayer adsorption. Of the three adsorbents tested, nano‐humus had greatest potential as an effective and inexpensive material for metal remediation.

137. 题目: Topsoil dilution by subsoil admixture had less impact on soil organic carbon stock development than fertilizer form and erosion state
文章编号: N24070303
期刊: Science of the Total Environment
作者: Shrijana Vaidya, Mathias Hoffmann, Maren Dubbert, Katja Kramp, Marten Schmidt, Gernot Verch, Michael Sommer, Jürgen Augustin
更新时间: 2024-07-03
摘要: Enhancing the agroecosystems carbon (C) sink function for climate mitigation faced challenges, particularly with traditional measures with limited suitability for increasing soil organic carbon (SOC) stocks. Inducing a SOC undersaturation in the topsoil by abrupt subsoil admixture is a way to create an additional C sink. However, the deep tillage traditionally used for this topsoil dilution was not always successful. It was due to a lack of knowledge and suitable approaches to record the effect of all relevant factors in SOC recovery, including soil conditions and fertilizer forms.

138. 题目: The influence of burn severity on dissolved organic carbon concentrations across a stream network differs based on seasonal wetness conditions
文章编号: N24070302
期刊: Biogeosciences
作者: Katie A Wampler, Kevin D Bladon, Allison N Myers-Pigg
更新时间: 2024-07-03
摘要: . Large, high-severity wildfires in many regions across the globe have increased concerns about their impacts on carbon cycling in watersheds. Altered sources of carbon and changes in catchment hydrology after wildfire can lead to shifts in dissolved organic carbon (DOC) concentrations in streams, which can have negative impacts on aquatic ecosystem health and downstream drinking-water treatment. Despite its importance, post-fire DOC responses remain relatively unconstrained in the literature, and we lack critical knowledge of how burn severity, landscape elements, and climate interact to affect DOC concentrations. To improve our understanding of the impact of burn severity on DOC concentrations, we measured DOC at 129 sites across a stream network extending upstream, within, and downstream of a large, high-severity wildfire in Oregon, USA. We collected samples across the study sub-basin during four distinct seasonal wetness conditions. We used our high-spatial-resolution data to develop spatial stream network (SSN) models to predict DOC across the stream network and to improve our understanding of the controls on DOC concentrations. Spatially, we found no obvious wildfire signal – instead, we observed a pattern of increasing DOC concentrations from the high-elevation headwaters to the sub-basin outlet, while the mainstem maintained consistently low DOC concentrations. This suggests that effects from large wildfires may be “averaged” out at higher stream orders and larger spatial scales. When we grouped DOC concentrations by burn severity group, we observed a significant decrease in the variability of DOC concentrations in the moderate and high burn severity sub-catchments. However, our SSN models were able to predict decreases in DOC concentrations with increases in burn severity across the stream network. Decreases in DOC concentrations were also highly variable across seasonal wetness conditions, with the greatest (−1.40 to −1.64 mg L−1) decrease occurring in the high-severity group during the wetting season. Additionally, our models indicated that in all seasons, baseflow index was more influential in predicting DOC concentrations than burn severity was, indicating that groundwater discharge can obscure the impacts of wildfire in a stream network. Overall, our results suggested that landscape characteristics can regulate the DOC response to wildfire. Moreover, our results also indicated that the seasonal timing of sampling can influence the observed response of DOC concentrations to wildfire.

139. 题目: Microalgal extracellular polymeric substances (EPS) and their roles in cultivation, biomass harvesting, and bioproducts extraction
文章编号: N24070301
期刊: Bioresource Technology
作者: Yun Zhou, Xiaocai Cui, Beibei Wu, Ziqi Wang, Ying Liu, Tian Ren, Siqing Xia, Bruce E Rittmann
更新时间: 2024-07-03
摘要: Microalgae extracellular polymeric substances (EPS) are complex high-molecular-weight polymers and the physicochemical properties of EPS strongly affect the core features of microalgae cultivation and resource utilization. Revealing the key roles of EPS in microalgae life-cycle processes in an interesting and novelty topic to achieve energy-efficient practical application of microalgae. This review found that EPS showed positive effect in non-gas uptake, extracellular electron transfer, toxicity resistance and heterotrophic symbiosis, but negative impact in gas transfer and light utilization during microalgae cultivation. For biomass harvesting, EPS favored biomass flocculation and large-size cell self-flocculation, but unfavored small size microalgae self-flocculation, membrane filtration, charge neutralization and biomass dewatering. During bioproducts extraction, EPS exhibited positive impact in extractant uptake, but the opposite effect in cellular membrane permeability and cell rupture. Future research on microalgal EPS were also identified, which offer suggestions for comprehensive understanding of microalgal EPS roles in various scenarios.

140. 题目: Regional differences in molecular characteristics of atmospheric water-soluble organic carbon over northern China: Comparison of remote, rural, and urban environments
文章编号: N24070110
期刊: Science of the Total Environment
作者: Hui Wen, Yue Zhou, Yuhui He, Tianshuang Wang, Wei Pu, Baoqing Zhang, Jiecan Cui, Jun Liu, Xin Wang
更新时间: 2024-07-01
摘要: Atmospheric water-soluble organic carbon (WSOC) is a critical component of airborne particulates. It significantly affects the Earth's energy balance, air quality, and human health. Despite its importance, the molecular composition and sources of WSOC remain unclear, particularly in non-urban areas. In this study, we collected total suspended particulate (TSP) samples from three sites in northern China: Erenhot (remote site), Zhangbei (rural site), and Jinan (urban site). The WSOC components were analyzed using high-performance liquid chromatography coupled with high-resolution mass spectrometry. The results showed that the formula numbers of identified compounds exhibited a decreasing trend of Jinan (2647) > Zhangbei (2046) > Erenhot (1399). Among the assigned formulas, CHO compounds were the most abundant category for all three sites, accounting for 33 %–38 % of the identified compounds, followed by the CHON compounds with contributions of 27 %–30 %. In the remote site of Erenhot, CHO compounds were dominated by oxidized unsaturated organic compounds, and CHON compounds were mainly low-oxygenated aliphatic compounds, suggesting a significant influence of primary emissions. In contrast, the urban site of Jinan showed higher contributions of CHO and CHON compounds with elevated oxidation degrees, indicating the influence of more extensive secondary oxidation processes. Atmospheric WSOC in Erenhot and Zhangbei had abundant reduced sulfur-containing species, likely from coal or diesel combustion, while that in Jinan was characterized by aliphatic organosulfates and nitrooxy-organosulfates, which are mainly associated with traffic emissions and biogenetic sources, respectively. These findings reveal significant differences in the molecular composition of WSOC in different atmospheric environments and improve our understanding of the chemical properties, potential sources, and transformations of organic aerosols.

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