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61. 题目: Metal-modified biochars prepared from blue algae and their ability of adsorbing phosphates from water and utilization as soil amendment 文章编号: N24103011 期刊: Journal of Environmental Chemical Engineering 作者: Huangbo Chen, Xinqing Zhang, Yuxin Xiao, Shaogui Yang, Shiyin Li, Jijie Kong, Cheng Sun, Huan He 更新时间: 2024-10-30 摘要: The problem of blue algae accumulation can be alleviated by utilizing blue algae as biomass for resource utilization, which can remove excess phosphates from water to alleviate eutrophication. Herein, Magnesium (Mg) and/or lanthanum (La) were used to modify biochar via high-temperature slow pyrolysis with blue algae as the raw biomass. These modified biochars exhibited abundant carbon (18.0%-50.3%), oxygen content (17.4%-49.1%), along with a high specific surface area (82.26-233.80 m2/g). The surface of metal-modified biochar was enriched with hydroxyl and carboxyl groups and metal elements were efficiently incorporated into biochars. Adsorption kinetic and isotherm experiments were conducted under the optimal pyrolysis temperature of 600 °C, pH of 6.0, and adsorbent dosage of 2.0 g/L. The adsorption kinetics studies by metal-modified biochars for phosphate fitted well pseudo-second-order model Redlich-Peterson isotherm model. Biochar modified by Mg and La exhibited the highest removal efficiency (97.8%) for phosphate at adsorption equilibrium. The adsorption mechanism involved the electrostatic interaction between hydroxylated metal oxides and negatively charged phosphate ions and the precipitation of phosphate ions through chemical reactions with metal oxides in the solution. After phosphate adsorption, the pristine and metal-modified biochars derived from blue algae were applied as the soil amendment. Biochar adsorbed phosphate apparently improved the germination rate of seeds facilitated the height, width, weight, and chlorophyll content of vegetable seedlings, and induced oxidative stress, which proved that the biochar recovered after adsorption was a high-quality soil amendment. This study provides a new approach for the treatment of phosphate wastewater and the algae application. |
62. 题目: Investigation of the formation and variability of dissolved inorganic carbon and dissolved organic carbon in the water of a small river (on the example of the Styr River, Ukraine) 文章编号: N24103010 期刊: Environmental Monitoring and Assessment 作者: Olha Biedunkova, Pavlo Kuznietsov 更新时间: 2024-10-30 摘要: This paper presents the results of a study on the dynamics in the concentrations of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) in water samples collected from the Styr River between 2019 and 2022. The concentrations of DIC and DOC were measured using an Elementar liqui TOC II analyzer. The study methodology involved analyzing the changes in DIC and DOC concentrations and their relationship with flow rates, temperature, seasonality, and other indicators such as hydrogen pH levels, total alkalinity (TA), and total dissolved solids (TDS). The purpose of this article is to identify patterns in the formation and changes of DIC and DOC concentrations in the Styr River. The concentrations of DIC and DOC in the samples ranged from 1.55 to 4.93 mM and 0.49 to 1.43 mM, respectively, with DOC accounting for an average of 22% of the total dissolved carbon content. The highest DOC concentrations were observed in summer, while the highest DIC concentrations were observed in winter. Based on the results, it can be concluded that water flow and temperature have an impact on DOC concentration, while flow, temperature, and pH affect DIC concentration. There was no correlation between DIC and DOC concentrations, but a strong positive relationship (r = 0.9056, p < 0.001) was found between DIC and TA concentrations. Therefore, the main factors influencing DIC in the Styr River are those that affect the carbonate equilibrium, such as leaching of carbonate and silicate rocks, CO2 absorption from the atmosphere, and changes in pH. Additionally, the concentration of DOC is influenced by biological activity and is higher during the warm season. These findings can be used to develop a strategy for managing water resources in the Styr River basin and to assess and predict the ecological state of the river. Graphical |
63. 题目: Rapid Generation of Microplastics and Plastic-Derived Dissolved Organic Matter from Food Packaging Films under Simulated Aging Conditions 文章编号: N24103009 期刊: Environmental Science & Technology 作者: Liuwei Wang, Jing Gao, Wei-Min Wu, Jian Luo, Michael S Bank, Albert A Koelmans, John J Boland, Deyi Hou 更新时间: 2024-10-30 摘要: In this study, we show that low-density polyethylene films, a prevalent choice for food packaging in everyday life, generated high numbers of microplastics (MPs) and hundreds to thousands of plastic-derived dissolved organic matter (DOM) substances under simulated food preparation and storage conditions. Specifically, the plastic film generated 66–2034 MPs/cm2 (size range 10–5000 μm) under simulated aging conditions involving microwave irradiation, heating, steaming, UV irradiation, refrigeration, freezing, and freeze–thaw cycling alongside contact with water, which were 15–453 times that of the control (plastic film immersed in water without aging). We also noticed a substantial release of plastic-derived DOM. Using ultrahigh-resolution mass spectrometry, we identified 321–1414 analytes with molecular weights ranging from 200 to 800 Da, representing plastic-derived DOM containing C, H, and O. The DOM substances included both degradation products of polyethylene (including oxidized forms of oligomers) and toxic plastic additives. Interestingly, although no apparent oxidation was observed for the plastic film under aging conditions, plastic-derived DOM was more oxidized (average O/C increased by 27–46%) following aging with a higher state of carbon saturation and higher polarity. These findings highlight the future need to assess risks associated with MP and DOM release from plastic wraps. |
64. 题目: Combining biochar with schwertmannite-based solid to enhance co-removal of ciprofloxacin and roxarsone as well as to improve regenerative capacity 文章编号: N24103008 期刊: Chemical Engineering Journal 作者: Ting Li, Xin Du, Xiqing Wang, Yujun Zhou, Jiansheng Li, Murong Wang, Lixiang Zhou 更新时间: 2024-10-30 摘要: The widespread use of antibiotics and roxarsone (ROX) in the livestock industry poses significant challenges for their safe and efficient disposal. Schwertmannite (Sch) has been recognized as a promising environmental material for the removal of ROX due to its dual functionality in both heterogeneous Fenton reaction and arsenic adsorption. However, Sch as a typical Fe-based material generally exhibits a low adsorption capacity for antibiotics. Herein, a biochar (BC) loaded Sch-based material was developed to enhance the co-adsorption capacity for ciprofloxacin (CIP) and ROX, while enabling adsorbent regeneration via heterogeneous Fenton reaction. Under the conditions of 0.6 g/L adsorbent, 80–200 mg/L pollutants (CIP and ROX), and pH 6, the maximum adsorption capacities of Sch/Fe3O4/BC for CIP (66.9 mg/g) and ROX (220.9 mg/g) were obviously higher than that of other Fe-based adsorbents. Sch/Fe3O4/BC demonstrated regeneration efficiencies of ∼80 % for CIP and ∼60 % for ROX after seven cycles of experimentation. The adsorption mechanisms were elucidated as synergistic interactions involving pore-filling interaction, π-π electron donor–acceptor interaction, H-bonding, As-Fe coordination, and electrostatic attraction. Additionally, oxidation also contributed to the co-removal of CIP (∼27 %) and ROX (∼24 %) during the adsorption process. This study not only addresses the safe disposal of CIP and ROX but also introduces an innovative approach for the treatment of multi-pollutant contamination in water systems. |
65. 题目: Understanding the ionic hydrogel-forming property of extracellular polymeric substances: differences in lipopolysaccharides between flocculent and granular sludge 文章编号: N24103007 期刊: Water Research 作者: Ji Li, Xiaodi Hao, Mark C M van Loosdrecht, Yuemei Lin 更新时间: 2024-10-30 摘要: An interesting and potential property of extracellular polymeric substances (EPS) is the hydrogel formation with calcium ions. Aiming at understanding the significant difference in the hydrogel formed between EPS from flocculent and granular sludge, a targeted investigation of the lipopolysaccharides (LPS), one of the important EPS components, was performed. LPS was isolated from the EPS of flocculent and granular sludge, and both the glycan and the lipid A parts of LPS were characterized and compared. The morphology of LPS-calcium (LPS-Ca) aggregates were visualized by the polymyxin B-based fluorescent probe. The LPS constituted about 25% and 15% of the EPS from flocculent and granular sludge, respectively. The flocculent sludge LPS showed a lower amount of glycans, shorter glycan chain length, lower molecular weight, and higher possibility of containing unsaturated lipids than the granular sludge EPS. The flocculent sludge LPS-Ca aggregates demonstrated invert structures with the water phase in between, contributing to the fluid-like property of the respect EPS-Ca. In contrast, with the remarkably different chemical structure, LPS-Ca aggregates from granular sludge displayed bilaminar multilayered morphology, contributing to the solid, self-standing hydrogel of EPS-Ca. |
66. 题目: Exploring the traits and possible ecological risks of heavy metals in biochars derived from rice husk and sugar beet pulp 文章编号: N24103006 期刊: Environmental Monitoring and Assessment 作者: Farzad Moradi-Choghamarani, Farshid Ghorbani 更新时间: 2024-10-30 摘要: This research investigated the properties and potential environmental hazards associated with biochars derived from rice husk (RH) and sugar beet pulp (SBP), both of which are rich in heavy metals (HMs). The results indicated that the concentration of various HM fractions is significantly affected by the type of feedstock and the pyrolysis temperature. Specifically, the total concentrations of HMs in biochars produced at 600 °C were found to be 10–140% higher than those in the original biomasses, a phenomenon attributed to the precipitation of HMs. Cd was a notable exception, exhibiting a reduction of 3–7% in the resultant biochars when compared to biomass, likely attributable to its volatilization. The results also revealed that the F1 + F2 fraction of HMs were largely transformed into F3 + F4 fraction during combustion, indicating that pyrolysis may reduce the ecotoxicity of HMs present in contaminated biomass. However, the process did not effectively diminish the F1 and F2 fractions of Cr and Cd. Elevated pyrolysis temperature significantly enhanced the reduction of HMs phytoavailability. Specifically, the phytoavailability of HMs in biochars produced at 600 °C exhibited a decrease ranging from 10 to 92% when compared to the original biomass. Conversely, an unexpected rise in the phytoavailable fractions of Cr and Cd was noted in both RH and SBP biochars as the pyrolytic temperature increased, which correspondingly raised the potential ecological risk index (PERI). All materials analyzed exhibited a very high risk level, with PERI values exceeding 800, primarily due to the significant toxicity of Cd. Excluding Cd from consideration, the biomasses and their resultant biochars displayed PERI values ranging from 7 to 13. It is important to acknowledge that pyrolysis may not effectively diminish the environmental toxicity associated with HMs present in contaminated biomass, thereby limiting its safe application. |
67. 题目: The autotoxicity of dissolved organic matter from Microcystis may be a contributor to the decline of its bloom 文章编号: N24103005 期刊: Water Research 作者: Jun Sha, Lirong Song, Chao Liu, Fang Bai, Haiyang Zhang, Zichao Gong, Tianli Li, Jin Liu, Guangbin Gao, Yunlu Jia 更新时间: 2024-10-30 摘要: Microcystis blooms frequently occur in freshwaters worldwide, causing detrimental impacts on the ecosystems and human health. Studying the mechanisms behind the decline of Microcystis blooms can aid in mitigating their harmful effects. However, there is currently a dearth of research in this area. In this study, we examined the dissolved organic matter (DOM) collected during the growth of axenic Microcystis. Axenic Microcystis produces toxic DOM during its growth, which accumulate in the medium. Further, the DOM obtained from decline phase of Microcystis blooms exhibited a strong inhibitory effect on the growth of fresh Microcystis cultures. It is postulated that DOM may contribute to decline of Microcystis blooms. Meanwhile, potential autotoxic components in Microcystis DOM were analyzed by integrating column chromatography fractionation, identification and Microcystis growth inhibition assay. The results showed that the autotoxic components consisted mainly of small molecule hydrophobic base. Moreover, we evaluated the influence of key environmental factors such as nutrient and temperature on the autotoxic DOM in Microcystis cultures. Nutrient deficiency and low temperature may promote the accumulation of autotoxic substances. The study provided a new perspective on the decay process of cyanobacterial bloom, and offered new ideas for the development of natural algicidal agents. |
68. 题目: Seawater boosts oxytetracycline (OTC) residues in struvite via hydroxyapatite (HAP) and dissolved organic matter (DOM) co-precipitation 文章编号: N24103004 期刊: Journal of Hazardous Materials 作者: Degui Gao, Yuefei Huang, Shungui Zhou, Bing Li, Guangqian Wang 更新时间: 2024-10-30 摘要: Seawater, as an alternative magnesium (Mg) source, has the potential to improve the overall economic and environmental footprint of struvite production compared to the use of pure Mg salts. However, the presence of other ions in seawater may affect the migration of tetracyclines (TCs), commonly found in wastewater, potentially reducing the quality of the recovered product, and posing environmental risks. But these effect has not been illustrated before. This study investigated the impact of seawater on oxytetracycline (OTC) migration during struvite recovery from swine wastewater. Under varying pH levels and Mg/P molar ratios, the OTC content in recovered struvite was ranged from 19 to 103 μg/g, which was 6 to 43 μg/g when using MgCl2 as Mg source. The key factor influencing OTC content was identified as Ca2+ in seawater. The co-precipitation of hydroxyapatite (HAP) and the incorporation of dissolved organic matter (DOM) were the primary reasons for increased OTC content. Interactions between Ca2+ on HAP surfaces and the carbonyl oxygen of OTC, along with ternary complex formations involving Ca2+, DOM, and OTC, facilitated OTC migration through adsorption onto struvite. Notably, increasing the Mg/P molar ratio reduced OTC enrichment due to the competition between Ca2+ and Mg2+. Density functional theory (DFT) calculations supported these interfacial interactions. These findings enhanced the understanding of antibiotic migration during phosphorus (P) recovery using seawater as alternative Mg source and suggested solutions for reducing P recovery contamination in the future. |
69. 题目: Reviews and syntheses: Opportunities for robust use of peak intensities from high-resolution mass spectrometry in organic matter studies 文章编号: N24103003 期刊: Biogeosciences 作者: William Kew, Allison Myers-Pigg, Christine H Chang, Sean M Colby, Josie Eder, Malak M Tfaily, Jeffrey Hawkes, Rosalie K Chu, James C Stegen 更新时间: 2024-10-30 摘要: . Earth's biogeochemical cycles are intimately tied to the biotic and abiotic processing of organic matter (OM). Spatial and temporal variations in OM chemistry are often studied using direct infusion, high-resolution Fourier transform mass spectrometry (FTMS). An increasingly common approach is to use ecological metrics (e.g., within-sample diversity) to summarize high-dimensional FTMS data, notably Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). However, problems can arise when FTMS peak-intensity data are used in a way that is analogous to abundances in ecological analyses (e.g., species abundance distributions). Using peak-intensity data in this way requires the assumption that intensities act as direct proxies for concentrations. Here, we show that comparisons of the same peak across samples (within-peak) may carry information regarding variations in relative concentration, but comparing different peaks (between-peak) within or between samples does not. We further developed a simulation model to study the quantitative implications of using peak intensities to compute ecological metrics (e.g., intensity-weighted mean properties and diversity) that rely on information about both within-peak and between-peak shifts in relative abundance. We found that, despite analytical limitations in linking concentration to intensity, ecological metrics often perform well in terms of providing robust qualitative inferences and sometimes quantitatively accurate estimates of diversity and mean molecular characteristics. We conclude with recommendations for the robust use of peak intensities for natural organic matter studies. A primary recommendation is the use and extension of the simulation model to provide objective guidance on the degree to which conceptual and quantitative inferences can be made for a given analysis of a given dataset. Broad use of this approach can help ensure rigorous scientific outcomes from the use of FTMS peak intensities in environmental applications. |
70. 题目: Calcium regulates nitrogen removal in constructed wetlands: The interactions between dissolved organic matter and microbial response 文章编号: N24103002 期刊: Chemical Engineering Journal 作者: Dongdong Yao, Huijun Xie, Yunkai Li, Shiwen Zhang, Na Dai, Zhen Hu, Haiming Wu, Shuang Liang, Jian Zhang 更新时间: 2024-10-30 摘要: Limited carbon bioavailability in low C/N tailwater aggravated the difficulty of nitrogen (N) removal. Calcium (Ca) can regulate carbon transformation, but the effects of Ca on N removal in constructed wetlands (CWs) remain elusive. To fill the gap, this study constructed two types of Ca-based CWs, and the results revealed that the removal efficiencies of nitrate (NO3−-N) and total nitrogen (TN) in Ca-based CWs increased by 9.83–22.25 % and 8.59–18.72 %, respectively, compared to control group. The proportion of protein-like DOM and P/H index (represent bioavailability of DOC) increased in Ca-based CWs, supporting the growth of heterotrophic denitrifiers and facilitated NO3−-N and TN removal. In addition to directly enhancing complete denitrification, Ca-based CWs also optimize the N removal pathway. Moreover, Ca enhanced complexity and robust of the microbial network, increased microbial communication, thereby jointly facilitating N removal. This study highlighted Ca improved N removal by collaborating the interactions of DOM transformation and microbial activity, which provided an abundant and cheap substrate for the treatment of low C/N wastewater by CWs |
71. 题目: Enhanced removal of biolabile oxygen-depleted dissolved organic matter by coagulation-adsorption process Improves biological stability of reclaimed water 文章编号: N24103001 期刊: Chemical Engineering Journal 作者: Hang He, Niannian Sun, Lanfeng Li, Hao Zhou, Xiaoyin Yang, Jing Ai, Xiaofang Yang, Chengzhi Hu, Dongsheng Wang, Weijun Zhang 更新时间: 2024-10-30 摘要: Ensuring biological stability, signifying the maintenance of an unchanged bacterial concentration and composition during water distribution, is essential for mitigating the microbial hazards of reclaimed water. However, the interplay between chlorine-resistant bacteria (CRB) regrowth and molecular transformation of biodegradable organic matter in chlorinated reclaimed water distribution system remain unclear. This work investigated the transformation of dissolved organic matter (DOM) in reclaimed water treated by coagulation and by coagulation-adsorption over a 20-day incubation following chlorination, as well as its interactions with CRB through high-resolution mass spectrometer and high-throughput sequencing. The DOM biotransformation profile and DOM-bacteria interaction network collectively revealed the overall substrate preference and metabolic pattern of CRB (e.g., Methylobacterium-Methylorubrum, Acidovorax, and Sphingomonas), which evinced a propensity for utilizing oxygen-depleted DOM (O/C < 0.5) and producing oxygen-enriched DOM (O/C > 0.4). The incorporation of powdered activated carbon during coagulation markedly decreased the level of biodegradable DOM (4.33 mg C/L) and subsequently retarded the regrowth of CRB by one day compared to coagulation alone, attributable to the selective adsorption of DOM molecules with low O/C onto the activated carbon. This work underscores the critical role of the enhanced removal of oxygen-depleted DOM in ameliorating the biological stability of waters. |
72. 题目: New insights into the prediction for the potential of soil organic carbon accumulation: From the perspective of non-equilibrium statistical mechanics. 文章编号: N24102903 期刊: Journal of Environmental Management 作者: Chenglong Liang, Yanan Ding, Zuozheng Xu, Yuxuan Jiang, Peilin Huang, Yanfeng Shi, Lizhe Liu 更新时间: 2024-10-29 摘要: The accumulation of soil organic carbon (SOC) is significant for soil health and ecosystem services. Numerous studies have assessed the dynamic changes of SOC by considering the microbial system as an equilibrium system. However, they failed to reveal the complexity of the SOC accumulation/loss process, as the microbial system is a non-equilibrium system affected by stochastic fluctuations from the external environment. This study is the first to explore the complex non-equilibrium relationship between microbial carbon use efficiency (CUE) and SOC by using potential landscape and flux in non-equilibrium statistical mechanics. Nitrogen (N) was identified as the most critical environmental factor influencing CUE on a global scale, with the transition between the carbon loss state and the carbon sequestration state observed along N gradients. Random perturbations of other environmental factors could also trigger transition. Non-equilibrium thermodynamic quantities indicated that carbon sequestration had the potential to be achieved when N = 0.5 g/kg, where active soil management measures should be taken. Furthermore, the non-equilibrium relationship between CUE and SOC was clarified through potential energy analysis, where the average deviation between predictions and actual observations of SOC is about 1.9792 g/kg. This study provides an effective framework for predicting SOC accumulation. |
73. 题目: Straw and Biochar Amendments Over a Decade Differently Modulates Denitrification Gas Products 文章编号: N24102902 期刊: Water, Air, & Soil Pollution 作者: Quan Tang, Wenxia Dai, Jiacheng Niu, Jing Wang, Weiqin Yin, Xiaoyuan Yan, Yuji Jiang, Yi Cheng, Shengsen Wang, Xiaozhi Wang 更新时间: 2024-10-29 摘要: Straw return is a sustainable agricultural strategy aimed at raising soil organic carbon (SOC), but tends to stimulate nitrous oxide (N2O) emissions, potentially counteracting gains in SOC sequestration. Nevertheless, knowledge gaps remain on how long-term different forms of straw incorporation (direct straw return or pyrolyzed to biochar) affect N2O production and reduction, and interactions with associated key nitrogen (N)-cycling microbial communities. Here, the emission rates and proportions of N2O and N2 emissions were quantified using a 13-year field trial with sequential incorporation of straw or straw-derived biochar, and interactions with key functional genes were assessed by metagenomic sequencing. Results revealed that incorporation of straw and biochar increased N2O emission rates by 2.55 and 0.54 folds, while that of N2 by 6.41 and 9.77 folds, respectively, compared with conventional fertilization. Correspondingly, the N2O/(N2O + N2) ratios were reduced by 10.75% and 39.74% with straw and biochar treatments. Higher N2O emissions with straw incorporation were primarily driven by concurrent increase in labile C and N sources with nitrate and nitrite reducers (narG, narH, nirK, nirS, norB) outweighing the N2O reducer (nosZ). In contrast, biochar incorporation decreased nitrate levels, increased electron conductivity and the N2O reducer (nosZ), which accelerated N2 emissions and reduced the N2O/(N2O + N2) ratio. Moreover, reduced N2O/(N2O + N2) ratios were closely associated with altered denitrifier communities, with genera belonging to Acidobacteriota being the key contributors to biochar incorporation, and Pseudomonadota being the dominant contributors to straw. Overall, biochar incorporation was more efficient in reducing global warming potential and increasing SOC sequestration, as evidenced by lower N2O/(N2O + N2) ratios and higher SOC levels. This work provides valuable insights designing net-zero C strategies towards sustainable agricultural C sequestration and greenhouse gas mitigation to address the challenges posed by global climate change. |
74. 题目: Long-term carbon storage in shelf sea sediments reduced by intensive bottom trawling 文章编号: N24102901 期刊: Nature Geoscience 作者: Wenyan Zhang, Lucas Porz, Rümeysa Yilmaz, Klaus Wallmann, Timo Spiegel, Andreas Neumann, Moritz Holtappels, Sabine Kasten, Jannis Kuhlmann, Nadja Ziebarth, Bettina Taylor, Ha Thi Minh Ho-Hagemann, Frank-Detlef Bockelmann, Ute Daewel, Lea Bernhardt, Corinna Schrum 更新时间: 2024-10-29 摘要: Bottom trawling represents the most widespread anthropogenic physical disturbance to seafloor sediments on continental shelves. While trawling-induced changes to benthic ecology have been widely recognized, the impacts on long-term organic carbon storage in marine sediments remains uncertain. Here we combined datasets of sediment and bottom trawling for a heavily trawled region, the North Sea, to explore their potential mutual dependency. A pattern emerges when comparing the surface sediment organic carbon-to-mud ratio with the trawling intensity represented by the multi-year averaged swept area ratio. The organic carbon-to-mud ratio exhibits a systematic response to trawling where the swept area ratio is larger than 1 yr−1. Three-dimensional physical–biogeochemical simulation results suggest that the observed pattern is attributed to the correlated dynamics of mud and organic carbon during transport and redeposition in response to trawling. Both gain and loss of sedimentary organic carbon may occur in weakly trawled areas, whereas a net reduction of sedimentary organic carbon is found in intensely trawled grounds. Cessation of trawling allows restoration of sedimentary carbon stock and benthic biomass, but their recovery occurs at different timescales. Our results point out a need for management of intensely trawled grounds to enhance the CO2 sequestration capacity in shelf seas. |
75. 题目: Different elemental stoichiometries of Fe‐limited Trichodesmium when grown under inorganic and organic phosphorus sources 文章编号: N24102708 期刊: Limnology and Oceanography 作者: Xuechao Wang, Thomas J Browning, Eric P Achterberg, Martha Gledhill 更新时间: 2024-10-27 摘要: Trichodesmium spp. is a colonial diazotrophic cyanobacterium found in the oligotrophic (sub)tropical oceans, where its distribution is strongly regulated by the availability of phosphorus and iron. The bulk carbon : nitrogen : phosphorus elemental composition of phytoplankton has previously been shown to depart from classical “Redfield” values under nutrient‐limitation conditions. We hypothesized that the abundance of intracellular metabolites and the extended Redfield ratios of Trichodesmium, including a range of trace elements, are variable in response to conditions of phosphorus and iron limitation that are found in the ocean. To test this, we grew Trichodesmium under trace metal–controlled conditions, where phosphorus was supplied as either dissolved inorganic phosphorus (DIP) or dissolved organic phosphorus (DOP) from iron depleted to elevated levels. We found that the steady‐state extended Redfield ratios of Trichodesmium under the iron‐depleted condition was (C106N15.82P0.62)1000Fe2.26Zn2.37Mn1.68Cu0.68Ni0.31Mo0.42Co0.03 for the DIP treatment where Trichodesmium was under iron limitation, and (C106N13.89P0.49)1000Fe3.38Zn2.51Mn0.97Cu0.52Ni0.42Mo0.33Co0.03 for the DOP treatment where Trichodesmium was under iron–phosphorus co‐limitation. Mean steady‐state cellular iron : carbon in the DIP treatment (iron limited) was only 50% of that in the control treatment, while zinc : carbon was elevated twofold. The average extended Redfield ratios following recovery from iron limitation was (C106N16.8P0.7)1000Fe4.41Zn1.44Mn1Cu0.52Ni0.19Mo0.3Co0.03 for the DIP and (C106N15.9P0.73)1000Fe7.36Zn2.24Mn1.08Cu0.71Ni0.63Mo0.38Co0.02 for the DOP treatment. No significant changes were observed in the carbon‐normalized abundance of targeted metabolites produced by Trichodesmium, under the different treatments. These results suggest Trichodesmium employs different strategies to cope with iron/phosphorus limitation, which is reflected in its extended Redfield ratios. |
76. 题目: Long-term application of manure increased soil amino acid pool under maize-maize-soybean rotation system 文章编号: N24102707 期刊: Journal of Soils and Sediments 作者: Tong Lu, Zonglin Lu, Junmei Shi, Yuying Liu, Yan Wang, Jinfeng Yang, Xue Li, Xiaori Han, Yonghuan Wang 更新时间: 2024-10-27 摘要: PurposeManure application affects soil chemical and biochemical properties and organic nitrogen (ON). In this study, we aimed to study the long-term application of manure on soil amino acid pools and the underlying mechanisms that remain unquantified. MethodsWe studied the effects of 41-year manure application on soil ON fractions and amino acid pools during various crop seasons under maize-maize-soybean rotation. This study includes four treatments: no fertilization, inorganic nitrogen + phosphorus + potassium fertiliser (NPK), NPK + 13.5 t ha−1 manure, and NPK + 27 t ha−1 manure (M2NPK). ResultsThe highest values for soil organic carbon (SOC), total nitrogen, pH, urease, and protease activity were observed in both the maize and soybean seasons under M2NPK. The contents of acidolysable ammonium nitrogen, acidolysable amino acid nitrogen (AAN), and ON in soil peaked under M2NPK in both seasons. Long-term high manure additions increased total soil amino acid content by 183% and 174% in 2019 and 2020, respectively. Acidic, alkaline, and neutral amino acid contents peaked during both seasons under M2NPK. Glycine, alanine, proline, lysine, serine, and valine were the predominant amino acid species in the soil, regardless of fertilization. M2NPK treatment led to increases of 88–151%, 79–129%, 70–114%, 87–97%, and 68–72% in the contents of Tyr, Leu, Ile, Glu, and Asp, respectively, compared to NPK. The structural equation modelling (SEM) indicated that SOC, pH, urease, and protease activity were the pathways that manure application alter the AAN pool by collectively accounting for 97% of the AAN variability. Further, our findings from SEM had a direct positive effect of AN on AAN under exogenous N input with a path coefficient of 0.35. ConclusionThe addition of manure can improve soil properties, increase the amino acid pool, and enhance the amino acid pool availability under long-term crop rotation systems. In conclusion, the application of manure represents a practical approach to enhance soil nitrogen fertility and promote sustainable agricultural development. |
77. 题目: Sargassum beaching on mangrove sediments shifts microbial and crab metabolisms and enhances blue carbon storage 文章编号: N24102706 期刊: Limnology and Oceanography 作者: Mathias Chynel, Gwenaël Abril, Mélissa Narayaninsamy, Loris Deirmendjian, Frédéric Guérin, Charlotte Dromard, Tarik Meziane 更新时间: 2024-10-27 摘要: Benthic metabolism and net carbon accumulation in mangroves sediments strongly depend on the quantity and quality of organic matter (OM) supplied, including material brought by coastal waters such as the macroalgae Sargassum spp. Mesocosms were used to assess the effect of eutrophication by Sargassum on mangrove sediments. The concentration of fatty acids (FAs), organic carbon and its carbon isotopic signature, and the sediments–air CO2 fluxes were used to follow the evolution of sedimentary OM in surface and subsurface sediments for 60 d. Sargassum beaching shifted microbial and crab metabolism, leading to a preferential degradation of the labile fraction of OM from both Sargassum (δ13C = −17.7‰ and high concentration of essential FAs) and mangrove leaves (δ13C: −28.9‰ and high concentrations of 18:2ω6 and 18:3ω3). Fatty acids composition of crabs hepatopancreas revealed they preferentially fed on Sargassum and these invertebrates also increased the particulate OM tidal export. In addition, microbial activity at the sediment surface was enhanced, as revealed by strong production of branched FAs and higher CO2 fluxes in mesocosms containing Sargassum. However, Sargassum beaching also increased the transfer and preservation of more refractory OM from mangrove leaves found in higher quantity in subsurface sediments (6–8 cm) after 60 d. Inputs of macroalgae induced a negative priming effect and enhanced the preservation of blue carbon in the sediments. This negative priming effect was enhanced by crab activities. These biotic interactions that include microbial communities apparently make mangrove efficient in storing carbon in a context of growing eutrophication of the tropical ocean. |
78. 题目: Unveiling the impact of low-molecular-weight organic acids on enrofloxacin sorption in North China agricultural soil: Insights and implications. 文章编号: N24102705 期刊: Journal of Environmental Management 作者: Yufeng Jiang, Jiali Wu, Zhewei Liu, Rui He, Xiaozhen Zhang, Kui Huang, Yingqin Wu 更新时间: 2024-10-27 摘要: Low-molecular-weight organic acids (LMWOAs) play a crucial role as components of dissolved organic matter in soil, influencing the sorption/desorption, degradation, and plant uptake of diverse pollutants within the agricultural soil ecosystem. This study delves into the sorption behavior and mechanism of the fluoroquinolone antibiotic enrofloxacin (ENR) on agricultural soil in North China, focusing on the impact of LMWOAs. Through batch equilibrium experiments, we explored the sorption/desorption kinetics of ENR under varying conditions such as temperature, pH, ion strength, and ion type, with the addition of acetic acid, oxalic acid, and citric acid individually. Our findings reveal that the sorption and desorption kinetics of ENR-whether with or without LMWOAs-conformed well to the pseudo-second-order kinetic model (R2 ≥ 0.997). The presence of LMWOAs notably enhanced ENR sorption while impeding desorption in soil, with oxalic acid demonstrating the highest promotion effect followed by acetic acid and citric acid. Moreover, the sorption capacity and affinity of ENR decreased with rising solution pH, dropping from 96.8%-98.5% to 30.9%-34.4%. Acidic conditions favored ENR retention in soil, with inhibition of sorption escalating alongside increasing ionic strength. LMWOAs, soil solution pH, and coexisting ions emerge as pivotal factors shaping ENR sorption behavior. Furthermore, LMWOA presence intensified desorption hysteresis of ENR on soil, with a desorption hysteresis coefficient (HI) ≤ 0.124. These results suggest that LMWOAs restrict ENR mobility in the local soil environment, heightening the risk of its accumulation in soil and crops. This study offers valuable insights into the intricate interplay among LMWOAs, ENR sorption dynamics, and environmental outcomes, underscoring the importance of understanding such complexities in agricultural soil management. |
79. 题目: Mitigation of Pharmaceutical Wastewater Toxicity in Anaerobic Reactors Using Metal-Modified Biochar 文章编号: N24102704 期刊: ACS ES&T Engineering 作者: Ahmed Tawfik, Nawaf S Alhajeri, Mohamed Elsamadony, Fangang Meng 更新时间: 2024-10-27 摘要: Anaerobic sequencing batch reactors (ASBRs) treating wastewater rich in ciprofloxacin (CIP) were supplemented with an Fe/Zn@biochar catalyst to improve their performance. ASBR4, with 100 mg Fe/Zn@biochar/gVS, showed substantial increased efficiencies in removing COD and CIP, reaching 86.9 ± 5.8 and 80.9 ± 8.6%, respectively, compared to no biochar addition (25.2% and 51.1% higher, respectively). Likewise, biogas yield augmented from 0.17 ± 0.06 to 0.34 ± 0.02 L/g CODremoved owing to the boosted abundance of acetolactic methanogens, i.e., Methanosaeta and Methanosarcina, which increased from 0.4 and 1.6% in the control ASBR1 to 1.6 and 2.2% in ASBR4, respectively. Microbial enzymatic activities, including dehydrogenase and extracellular polymeric substances (EPSs), highly increased by 38% and >100%, respectively, aiding in biochar adsorption and microbial biodegradation synergy. Fe/Zn@biochar contributed to both CIP adsorption and biodegradation with percentages of 59.5 ± 4.9 and 34.7 ± 2.6%, respectively. The synergistic effect between the biotic and abiotic impacts of Fe/Zn@biochar reached 94.2 ± 7.2%, suggesting that the addition of Fe/Zn@biochar is a promising approach to enhance the CIP-remediation process. |
80. 题目: Deciphering the Intricate Control of Minerals on Deep Soil Carbon Stability and Persistence in Alaskan Permafrost 文章编号: N24102703 期刊: Global Change Biology 作者: Yi‐Xuan Guo, Guang‐Hui Yu, Shuijin Hu, Chao Liang, Andreas Kappler, Mark Torre Jorgenson, Laodong Guo, Georg Guggenberger 更新时间: 2024-10-27 摘要: Understanding the fate of organic carbon in thawed permafrost is crucial for predicting climate feedback. While minerals and microbial necromass are known to play crucial roles in the long‐term stability of organic carbon in subsoils, their exact influence on carbon persistence in Arctic permafrost remains uncertain. Our study, combining radiocarbon dating and biomarker analyses, showed that soil organic carbon in Alaskan permafrost had millennial‐scale radiocarbon ages and contained only 10%–15% microbial necromass carbon, significantly lower than the global average of ~30%–60%. This ancient carbon exhibited a weak correlation with reactive minerals but a stronger correlation with mineral weathering (reactive iron to total iron ratio). Peroxidase activity displayed a high correlation coefficient (p < 10−6) with Δ14C and δ13C, indicating its strong predictive power for carbon persistence. Further, a positive correlation between peroxidase activity and polysaccharides indicates that increased peroxidase activity may promote the protection of plant residues, potentially by fostering the formation of mineral‐organic associations. This protective role of mineral surfaces on biopolymers was further supported by examining 1451 synchrotron radiation infrared spectra from soil aggregates, which revealed a strong correlation between mineral OH groups and organic functional groups at the submicron scale. An incubation experiment revealed that increased moisture contents, particularly within the 0%–40% range, significantly elevated peroxidase activity, suggesting that ancient carbon in permafrost soils is vulnerable to moisture‐induced destabilization. Collectively, this study offers mechanistic insights into the persistence of carbon in thawed permafrost soils, essential for refining permafrost carbon‐climate feedbacks. |
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