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41. 题目: Low molecular weight organic acids mobilize soil organic phosphorus for enzymatic hydrolysis in a temperate montane peatland
文章编号: N25020510
期刊: Biogeochemistry
作者: Yuchen Suo, Tong Li, Christian von Sperber, Leming Ge, Chenhao Cao, Zhifeng Zhai, Zhaojun Bu, Meng Wang
更新时间: 2025-02-05
摘要:

The stability of carbon (C) stocks in peatlands is intricately linked to phosphorus (P) bioavailability. Given that organic P compounds (Po) can make up to 89% of total soil P in these ecosystems, it is vital to understand their role in regulating plant productivity and organic matter decomposition. Despite this significance, the mechanisms controlling P bioavailability remain poorly understood. Plants and soil microorganisms primarily regulate the release of soil P via low-molecular-weight organic acids (LMWOAs) and modulate the hydrolysis of Po through phosphatase enzymes, particularly phosphomonoesterase, phytase, and phosphodiesterase. This study investigated the role of LMWOAs, derived from root exudates of dominant vascular plants and Sphagnum leachates in a temperate montane peatland, in facilitating the release of P. We also quantified the ability of these plants to hydrolyze Po from various LMWOA-extracted fractions by adding phosphomonoesterase, phytase, and phosphodiesterase. The results show that peatland plants predominantly exuded muconic, azelaic, 3-hydroxybutyric, and malonic acids. The concentration of enzymatically hydrolyzed Po in the water-extracted fraction was 8.1 ± 3.4 mg kg−1. Notably, azelaic and malonic acids were effective in releasing over 58% of soil P (330–798 mg kg−1), with more than 88% of this P being in organic form. In the azelaic and malonic acid-extracted fractions, the concentration of enzymatically hydrolyzed Po concentration was 123.7 ± 32.1 mg kg−1, accounting for 23% of the LMWOA-extracted Po. Phytase, the most important phosphatase enzyme, accounts for 66% (47–88%) of the enzymatically hydrolyzed Po (81.9 ± 20.9 mg kg−1). Our study demonstrates that LMWOA-mediated release of Po is an essential prerequisite for enzymatic hydrolysis of Po in organic peat soils. However, only a small portion of LMWOA-extracted Po can be hydrolyzed by phosphatase enzymes. The different composition and efficacy of LMWOAs from species of different plant functional types highlight the necessity to consider changes in vegetation composition, as this could significantly impact P dynamics in peatlands and, consequently, the stability of their C stocks.

42. 题目: Mitigation of soil salinity by biochar and halophytes
文章编号: N25020509
期刊: Geoderma
作者: Qiang Xu, Yibin Xu, Hanji Xia, Han Han, Mingsi Li, Ping Gong, Chunxia Wang, Yufang Li, Pengfei Li, Hongguang Liu
更新时间: 2025-02-05
摘要: Biochar is widely recognized as a significant agricultural management practice globally. Nevertheless, its application typically emphasizes incorporation into topsoil, while the potential benefits of biochar interlayers in ameliorating saline wastelands in arid regions remain insufficiently understood. A study was conducted to investigate the impact of biochar interlayers on the dynamics and distribution of water and salt in saline wasteland soils cultivated with Suaeda salsa (S. salsa) during growth and non-growth periods. Over three consecutive years, a field experiment was implemented with four biochar application rates: 0 Mg/ha (CK), 15 Mg/ha (M1), 45 Mg/ha (M2), and 75 Mg/ha (M3). The biochar was uniformly distributed at a depth of 40 cm, and the original soil from the 0–40 cm layer was refilled. The results demonstrate that biochar interlayers reduced groundwater evaporation and minimized surface salt accumulation during the non-growth period, leading to a reduction in soil salinity by 13.14 %–49.62 % in the 0–40 cm layer, with a bimodal salinity distribution pattern observed at 0 cm and 45 cm depths. During the growth period, biochar significantly enhanced water retention and reduced salinity. Water content increased by 0.14 %–18.92 %, and salt content decreased by 24.51 %–36.64 % within the 0–40 cm soil layer, with salt aggregating at 40–60 cm depths. The root system of S. salsa utilized water and salt from the biochar interlayer, resulting in a marked increase in salt content within plant organs. Concentrations of Na+, Cl, and SO42− decreased, while K+, Ca2+, and Mg2+ levels increased in these organs. The yield of S. salsa improved by 22.12 %–65.92 %, and salt absorption efficiency rose by 30.62 %–85.03 %. However, excessive biochar applications may hinder surface soil desalination and pose risks of secondary salinization. Thus, a moderate biochar application rate of 45 Mg/ha is recommended for effective water retention and salt suppression in saline wastelands.

43. 题目: Confirming the key factors influencing the biosynthesis and regulation of organic nitrogen in composting
文章编号: N25020508
期刊: Journal of Environmental Management
作者: Zishuai Zhang, Guofeng Zu, Quanli Liu, Yang Liu, Beidou Xi, Qiuling Dang, Jing Su
更新时间: 2025-02-05
摘要: Organic nitrogen (ON) possesses the ability to sustain a stable nitrogen supply fertility during composting. However, research on the biosynthesis and regulation of ON remains limited. The results indicated that despite variations in microbial communities between the chicken manure composting (T group) and kitchen waste digestate composting (F group), their functional genes were remarkably similar, and the microorganisms exhibited similar functions. The microbial community structure of T group was more complex than that of F group. Network analysis identified Saccharomonospora, Corynebacterium, and Thermobifida as the core microorganisms in T group, whereas Oceanobacillus, Staphylococcus, and Fictibacillus were predominant in F group. These microorganisms play a role in the biosynthesis and regulation of various forms of ON (including amino acid nitrogen (AAN), amino sugar nitrogen (ASN), amide nitrogen (AN) and hydrolyzable unknown nitrogen (HUN)) and may contribute to differences in ON production due to the distinct nature of the materials. The core functional genes of the two groups of materials were determined by random forest model. Although differences in functional genes were present between F group and T group, the most crucial genes for ON biosynthesis in both groups were those with ammonia assimilation (such as glnE, gltB, gltD, etc.). The nitrogen transformation processes associated with these core genes can be modulated by managing the activity of multifunctional microorganisms, particularly through the control of ammonia assimilation, nitrate reduction, and ammonification, which are related to NH4+ levels. Notably, electric conductivity (EC), temperature (Tem.), pH, and NH4+ were the pivotal environmental factors influencing the biosynthesis of ON. This investigation enhances our understanding of the previously underexplored mechanisms of ON biosynthesis and regulation.

44. 题目: Soil minerals regulate soil organic carbon accumulation through glomalin-related soil protein along an elevation gradient in a mountain arid ecosystem
文章编号: N25020507
期刊: Environmental Research
作者: Guangxing Zhao, Zhihao Zhang, Weiqi Wang, Mengfei Cong, Xinping Dong, Yanju Gao, Zhaobin Mu, Yan Lu, Lei Li, Akash Tariq, Jordi Sardans, Josep Penuelas, Fanjiang Zeng
更新时间: 2025-02-05
摘要: Soil minerals and glomalin-related soil protein (GRSP), as key soil binding agents, play a crucial role in enhancing soil organic carbon (SOC) sequestration. However, the key driving mechanisms of SOC accumulation process mediated by soil minerals and GRSP remain poorly understood in the arid elevation gradients. This study aimed to evaluate how soil minerals and GRSP affect SOC accumulation across an elevation gradient ranging from 1707 to 3548 m a.s.l on the northern slope of the Central Kunlun Mountains. We collected soil samples from two depths (0–10 cm and 10–30 cm) across the elevation gradient. Bulk soil organic carbon (OC), aggregate-associated OC content, Al/Fe oxides, Ca2+, and GRSP all increased along the elevational gradient at both soil depths of 0–10 cm and 10–30 cm. Specifically, microaggregate OC constituted the larger proportion and played a crucial role in promoting SOC accumulation. Random forest analysis revealed that soil minerals (41.63–60.75%) were the dominant factors driving SOC accumulation. Partial least squares path modelling revealed that SOC accumulation was directly influenced by GRSP, climate, and elevation; indirectly influenced by soil minerals and physiochemical factors. Soil minerals regulated SOC accumulation primarily through GRSP. Overall, the contribution of soil minerals to SOC accumulation processes in mountain ecosystems was considerably greater than that of climate and vegetation. These findings highlight the critical of soil minerals and GRSP factors in regulating SOC accumulation in arid mountain ecosystem, providing valuable insights for climate change mitigation strategies.

45. 题目: Differential contributions of microbial necromass to humic acid during composting of organic wastes
文章编号: N25020506
期刊: Environmental Research
作者: Wenjie Chen, Yan Yang, Xia Liang, Su Chang, Yuan Chang, Nannan Miao, Ting Xu, Deli Chen, Yuquan Wei
更新时间: 2025-02-05
摘要: Microbial necromass is a crucial source of stable organic matter in composting, yet its role in the humification process remains poorly understood. This study aims to explore the contribution of microbial necromass carbon (MNC) to humic acid (HA) formation during the composting of sewage sludge (SS), kitchen waste (KW), and pig manure (PM), and to examine the involvement of fungal communities in microbial necromass humification. The results show that fungal necromass carbon (FNC) consistently contributes more to MNC than bacterial necromass carbon (BNC), with FNC accounting for over 60% of MNC across all treatments. KW exhibited the highest accumulation of FNC (4.09 to 98.92 g/kg), and its MNC contribution to total organic carbon was 23.63%, significantly higher than sewage sludge (5.57%) and pig manure (7.47%). The carbon-to-nitrogen (C/N) ratio was found to be a critical factor influencing microbial growth, necromass accumulation, and HA formation, with a lower C/N ratio promoting faster microbial turnover and enhancing MNC contribution to HA. The analysis also revealed that Ascomycota dominated the maturation phase, with a significant role in driving humification, especially in KW. Structural equation modeling confirmed that FNC and BNC are directly influenced by the C/N ratio, which in turn affects HA formation This study enhances our understanding of microbial necromass dynamics and its contribution to humic substance formation, providing valuable insights for improving compost quality and optimizing composting strategies for enhanced carbon sequestration.

46. 题目: Mechanistic insights into enhanced haloacetaldehyde formation from algal organic matters after pre-ozonation: A combined computational and experimental study
文章编号: N25020505
期刊: Journal of Hazardous Materials
作者: Haipei Huang, Da Sheng, Lingjun Bu, Shumin Zhu, Shiqing Zhou
更新时间: 2025-02-05
摘要: Pre-ozonation is widely used in the treatment of algae-containing water. Recent studies suggest that pre-ozonation could enhance the formation of haloacetaldehydes (HALs) but the mechanisms have not been clearly clarified. The study assessed the formation of dichloroacetaldehyde (DCAL) and trichloroacetaldehyde (TCAL) from model algal organic matters (Gly-Ala and Leu-Ala), and clarified the transformation mechanisms from the insight of quantum chemical computations. Results demonstrated a significant increase in HALs formation potential after pre-ozonation. When the dosage of O3 was 0.5 mg L−1, the formation of DCAL and TCAL increased 100 % and 113 % after chlorination, respectively. The initial pH of pre-ozonation was observed to be an important factor that influenced the HALs formation potential. The alkaline conditions promoted the formation of HALs, while acidic conditions have an inhibitory effect. Furthermore, the ultra-performance liquid chromatography high-resolution mass spectrometry (UPLC-HRMS) was applied to identify the transformation products of the pre-ozonation-chlorination process. Combined with quantum chemical computations, the transformation pathways of HALs were proposed. It was found that pre-ozonation promotes the formation of acetaldehyde, an intermediate during the formation of HALs. The initial pH plays an important role in the production of HALs, which influenced the reaction pathways and affected OH• formation. This study provides an in-depth analysis of the reaction mechanism and offers new theoretical insights for mitigating, controlling, and managing the risks associated with HALs.

47. 题目: Insights into the enhanced uranium reduction efficiency through extracellular polymeric substances from Desulfovibrio vulgaris UR1 induced by mediating materials
文章编号: N25020504
期刊: Bioresource Technology
作者: Guangming Xu, Xinyao Liu, Juncheng Han, Kexin Shao, Haotian Yang, Jing Yuan, Junfeng Dou
更新时间: 2025-02-05
摘要: Understanding the role of extracellular polymeric substances (EPS) in the microbial reduction of uranium accelerated by mediating materials is crucial for enhancing the bioremediation of uranium-contaminated wastewater. In this study, biochar- and magnetite-loaded Desulfovibrio vulgaris UR1 exhibited significantly higher uranium reduction efficiency, with increases of 1.52 and 1.44 times respectively within one day. After loading with mediating materials, the charge transfer resistance of EPS was reduced, facilitating the extracellular electron transfer process. The increase of redox components, such as aromatic compounds and flavins, in EPS explained the enhanced extracellular electron transfer capacity. Moreover, the higher α-helix content in extracellular proteins could promote electron hopping. Proteomics analysis showed that extracellular proteins involved in iron-sulfur cluster binding, oxidoreductase activity, and electron transfer were significantly up-regulated, which facilitated the rapid microbial reduction of uranium. These findings provide valuable insights into the in-depth development of bioremediation technology for uranium-contaminated wastewater.

48. 题目: Seasonal characterization of primary and secondary sources of fine PM-bound water-soluble organic carbon in central Los Angeles
文章编号: N25020503
期刊: Atmospheric Environment
作者: Yashar Aghaei, Mohammad Mahdi Badami, Mohammad Aldekheel, Ramin Tohidi, Constantinos Sioutas
更新时间: 2025-02-05
摘要: Understanding the sources and formation processes of fine particulate matter (PM2.5) is crucial for improving urban air quality and public health. This study provides a real-time analysis of PM2.5-bound water-soluble organic carbon (WSOC) and related carbonaceous species during winter, spring, and summer periods in 2023–2024, aiming to identify their major sources in central Los Angeles. Using advanced online monitoring equipment, including a Sunset Laboratory EC/OC analyzer and a custom-developed setup including a total organic carbon (TOC) analyzer coupled with a particle collection system, we obtained hourly measurements of organic carbon (OC), its fractions (OC1-OC4, based on volatility), elemental carbon (EC), and WSOC. Positive matrix factorization (PMF) identified three principal PM2.5 sources: vehicular emissions, secondary organic carbon (SOC) formation influenced by nighttime aqueous-phase chemical processes, and SOC formation driven by daytime photochemical reactions. Vehicular emissions dominated EC levels, accounting for 86–95% across seasons. This factor also had high contributions from nitrogen oxides (NOₓ) (75–82%), vehicle counts (approximately 85%), and OC1 (51–83%), reflecting the persistent influence of traffic emissions. Nighttime SOC formation was significant in winter, with WSOC and OC4 contributing 58% and 40% to this factor. In contrast, daytime photochemical SOC formation was prominent in summer, with WSOC and OC4 contributing 63% and 47%, and ozone loading up to 89%, reflecting increased photochemical activity. Spring exhibited a mix of aqueous and photochemical SOC formation, with similar contributions from WSOC (38-35%) and OC4 (35-33%), reflecting the transitional season's mixed SOC formation mechanisms. Diurnal profiles revealed that primary emissions peaked during morning rush hours, while secondary formation processes elevated OC levels at night in winter and during afternoons in summer. The EC tracer method corroborated these findings by estimating primary and secondary organic carbon levels, highlighting significant seasonal and diurnal variations in carbonaceous aerosols. These results emphasize the need for targeted strategies addressing both primary emissions and the precursors of secondary aerosol formation, to improve air quality in Los Angeles.

49. 题目: Can the aging process necessarily weaken the effect of biochar on cadmium-contaminated soil remediation: considering biochar at different pyrolysis temperatures and aging treatment
文章编号: N25020502
期刊: Environmental Geochemistry and Health
作者: Jianxin Fan, Ting Duan, Xingyu Wu, Maoyu Liao, Jiaoxia Sun
更新时间: 2025-02-05
摘要:

Biochar has widely used to immobilize soil heavy metals in recent years, while the properties of biochar varied with environmental conditions. The influence of biochar aging on fixation and speciation transformation of Cd in soil remains unclear. This study explores how biochar aging affects the fixation and speciation transformation of Cd in soil. Rice straw biochar (RBC) prepared at different pyrolysis temperatures (300 °C, 500 °C, and 700 °C) was aged under three treatments (drying and watering cycle (DW), H2O2 oxidation (HO), and citric acid acidification (CA)) to investigate the effects of the aging process on the adsorption and passivation capacity for Cd. Results showed that the aging treatment increased Cd adsorption on RBC300 by 73.69% to 216.15%, while adsorption on RBC500 and RBC700 decreased by 11.52% to 74.56% and 7.40% to 75.89%, respectively. The addition of both fresh and aged RBC raised pH, DOC, and TOC in Cd-contaminated soil, aiding in Cd fixation. Either fresh or aged RBC addition enhance the stability of Cd in soil. Compared to CK treatment, residual Cd content rose by 28.63% to 43.71%, while both acid-extractable and reducible Cd contents decreased by 9.144% to 10.95%. Furthermore, the available Cd content in the soil saw a reduction of 10.45% to 30.77%, and high-temperature pyrolytic RBC exhibited a stronger capacity for Cd passivation in the soil. Both fresh and aged RBC indirectly reduced Cd bioavailability by affecting soil pH, DOC, and TOC, and the nature aging process (DW) did not weaken the effect of biochar on Cd-contaminated soil remediation. Thus, biochar has a long-term potential for mitigating Cd pollution in farmland.

50. 题目: Characterization of modified rape straw biochar in immobilizing Aspergillus sydowii W1 pellets and evaluation on its role as a novel composite for di(2-ethylhexyl) phthalate degradation
文章编号: N25020501
期刊: Journal of Hazardous Materials
作者: Chunyu Li, Qian Liu, Luyao Mao, Wenfan Zhang, Jianing Zhang, Dongze Niu, Dongmin Yin, Huhe Taoli, Jianjun Ren
更新时间: 2025-02-05
摘要: Di(2-ethylhexyl) phthalate (DEHP) is one of the most widely used plasticizers, which has harmful biological effects and poses a serious threat to ecological environments and human health. In this study, a novel strain Aspergillus sydowii W1 was reported with DEHP degradation ability. Under the optimal conditions of 35°C and pH 6.0, strain W1 degraded 68.48% of 50 mg/L DEHP within 120 h, while the biochar immobilized W1 can enhance the removal efficiency by 15.33%. The immobilized W1 also showed excellent performance in DEHP polluted wastewater with concentration of 50 mg/L, and its removal rate reached 85.72% within 144 h. Interestingly, the fermented broth of strain W1 has the activity of hydrolyzing DEHP, and the highest value of crude enzyme activity was at 35°C and pH 8.5. In addition, nine metabolic products of DEHP degraded by strain W1 were identified by HPLC-MS/MS and GC-MS. In combination with these intermediates and related enzymatic analysis, two possible catabolism pathways of DEHP degradation by strain W1 were concluded. This study confirmed that immobilized W1 is an effective composite for removing DEHP in water environment and also strengthened our understanding on the DEHP degradation process of A. sydowii.

51. 题目: Characterization of glycoprotein and its interaction with sludge dewatering: The neglected role of glycoprotein
文章编号: N25020406
期刊: Chemical Engineering Journal
作者: Mohammad Nabi, Yizhang Jiang, Wei Ding, Ruiyao Wang, Yue Jiang, Yuyan Lin, Zijun Xu, Keke Xiao
更新时间: 2025-02-04
摘要: The composition of extracellular polymeric substances (EPS) significantly influences sludge dewatering performance. Currently, the role of glycoprotein in sludge dewatering had been long ignored due to the complexity of glycans present in EPS. Via extraction and characterization, this study identified the presence of glycoprotein and quantified its amount in five different sludge samples. Pseudomonas aeruginosa (responsible for lectin production and glycoprotein biosynthesis) and carbohydrate-active enzymes (mainly glycoside hydrolases and glycosyl transferases) were noted in all samples via the metagenome assembly and taxonomic classification analysis. Fluorescence lectin staining further confirmed glycoprotein presence. The dewatering performance of two types of anaerobic digested sludge (ADS) was worse compared to three types of waste activated sludge (WAS), along with higher glycoprotein content in both soluble EPS (S-EPS) and bound EPS (B-EPS) of ADS compared to WAS. Further Pearson’s correlation results indicated that the content of glycoprotein in B-EPS was correlated with the bound water content (correlation coefficient = 0.96, probability < 0.01). The effects of glycoprotein on sludge dewatering performance were closely related with the destruction of tryptophan-like and tyrosine-like proteins, fulvic acid-like components, humic acid-like components, and CHOS compounds in B-EPS as well as the presence of 3-turn helix in B-EPS. Extra addition of glycoprotein into sludge samples showed unobservable effects on the van der Waals attraction, but significantly improved the acid-base interaction energy, the electric double layer energy, and the total energy by increasing repulsive interaction and creating higher energy barrier for aggregation. This study unveils the importance of glycoprotein in sludge dewatering. As such, regulating the removal of glycoprotein in B-EPS by destructing the affinity towards bound water may enhance sludge dewatering performance for protein-rich sludge.

52. 题目: Comparison of different methods for estimating microbial biomass in biochar-amended soils
文章编号: N25020405
期刊: Soil Biology and Biochemistry
作者: Sara Paliaga, Vito Armando Laudicina, Sofia Maria Muscarella, Daniel Said-Pullicino, Luigi Badalucco
更新时间: 2025-02-04
摘要: Biochar use as a soil amendment can improve soil functions, enhances microbial activity, and increases crop production. However, due to its high sorptive capacity, it may interfere with traditional methods for determining soil microbial biomass, specifically chloroform fumigation-incubation (FI) and fumigation-extraction (FE). This study aimed to assess the impact of biochar on microbial biomass determination using traditional methods and a new CO2 high pressurization (CO2HP) technique. Five treatments were set up: unamended soil (control), and soil amended with two types of biochar, produced at 440 °C (B440) or 880 °C (B880), at two application rates (20 or 40 t ha−1). Following cell lysis by fumigation or CO2HP, released microbial C (ΔCmic) was estimated by determining microbial respiration over a 10-d incubation (FI and CO2HP-I methods, respectively) or by extracting soluble organic C (FE, and CO2HP-E, respectively), while released microbial N (ΔNmic) was estimated by determining extractable total N exclusively by FE and CO2HP-E methods.Without biochar, ΔCmic estimates were similar across FE, FI, and CO2HP-E methods. Contrarily, CO2HP-I method greatly overestimated ΔCmic compared to the other three methods, particularly at the higher biochar rate, suggesting that the adsorption of CO2 within biochar pores during CO2HP treatment and subsequent slow release during incubation could have produced artifacts. The presence of B880 resulted in a decrease in ΔCmic values, which might have been caused by an acclimation of microbial biomass to new habitat. Contrarily, the addition of B440, increased ΔCmic when determined by the FE method, compared to FI and CO2HP-E methods. This suggested an overestimation of extractable C after fumigation, possibly due to adsorption of CHCl3 by the B440 biochar, rich in functional groups, that might have bound CHCl3. We concluded that biochar interfered with the determination of ΔCmicand ΔNmic as a function of both type and amount added.

53. 题目: One-step synthesis of iron-rich biochar for efficient hexavalent chromium removal: Adsorption-reduction performance, mechanism and column experiments
文章编号: N25020404
期刊: Journal of Environmental Chemical Engineering
作者: Yulin Zeng, Lu Zhou, Xiangyu Wang, Guanhao Zhang, Xunli Bao, Zhijun Yan, Wang Ma
更新时间: 2025-02-04
摘要: The residual sludge generated from steel wastewater treatment is abundant in iron resource and its recycling has attracted widespread attention. In this study, a novel iron-rich biochar (FSB) with acceptable environmental risk was developed by one-step pyrolysis using steel sludge as raw material, and its adsorption-reduction efficiency and column experiments for hexavalent chromium [Cr(VI)] were determined. The results showed that pyrolysis can effectively reduce the potential environmental risk of iron-rich sludge and effectively enrich iron resources in the biochar matrix. The heavy metal accumulation pattern, potential environmental risk and Cr(VI) adsorption-reduction performance of FSB were affected by pyrolysis temperature, and the optimal performance was achieved at a pyrolysis temperature of 500℃, and the maximum adsorption capacity of FSB pyrolyzed at 500℃ (FSB500) could be as high as 200 mg g-1. The apparent model fitting showed that Cr(VI) removal by FSB500 was an adsorption-reduction-adsorption process as follows: (i) Cr(VI) was attracted onto FSB500 by electrostatic force; (ii) the oxygen-containing functional groups, persistent free radicals, and endogenous iron on the FSB500 surface acted as the electron donors to convert Cr(VI) to Cr(III); (iii) the released Cr(III) complexed on the FSB500 surface again. In the column experiment, FSB500 showed a high removal capacity of 55.94 mg g-1 under specific conditions. Thus, this study suggests that iron-rich sludge can be prepared into biochar for resource utilization and can be used as an effective alternative for Cr(VI) wastewater treatment.

54. 题目: Iron-loaded Chinese herbal medicine residue biochar for heterogeneous catalytic ozonation of malathion wastewater
文章编号: N25020403
期刊: Separation and Purification Technology
作者: Yihan Chen, Di Chai, Xiangyu Zhang, Zelun Jiang, Hongjia Yao, Xinrui Yuan, Xing Chen, Kangping Cui, Yi Wang
更新时间: 2025-02-04
摘要: China is a major producer of medicinal materials, with northern Anhui as a key production area. The accumulation of herbal residues from medicinal plant cultivation, along with organophosphate pesticide pollution, poses serious environmental challenges, which have garnered significant attention. To enable resource utilization of herbal residues and meet the deep treatment needs for organophosphate pesticides, especially malathion (MAL), this study prepared iron-based biochar (Fe-C) using pyrolysis and hydrothermal methods, developing an iron-based biochar-ozone (Fe-C/O3) advanced oxidation system. Results show that iron oxides are uniformly distributed on the biochar surface, providing abundant active sites for MAL degradation. With an initial MAL concentration of 50 mg/L, the study investigated the effects of iron content, pH, processing methods, and ozone dosage, confirming the Fe-C/O3 system’s ability to efficiently degrade MAL within 30 min. Density functional theory (DFT) analysis revealed MAL’s strong nucleophilic reactivity, and UPLC-MS/MS identified six degradation intermediates, suggesting a degradation pathway with malaoxon (P1) as a key intermediate. Toxicity assessments of degradation products indicated an overall decrease in toxicity, with •O2 and 1O2 as primary reactive oxygen species. In summary, this research provides a viable approach for high-value utilization of herbal residues and demonstrates the Fe-C/O3 system’s potential for efficient degradation of organophosphate pesticides, offering valuable insights for environmental remediation and sustainable agricultural waste management.

55. 题目: Can We Constrain Geographical Variability in the Biological Carbon Pump's Transfer Efficiency From Observations?
文章编号: N25020402
期刊: Geophysical Research Letters
作者: A Rufas, S Khatiwala, K M Bisson, A P Martin, H A Bouman
更新时间: 2025-02-04
摘要: The biological carbon pump (BCP) transfers large amounts of carbon from the atmosphere into the ocean's interior, contributing to carbon sequestration. Studies on latitudinal variability in organic carbon transfer to depth have yielded inconsistent results, likely due to methodological differences. To address this, we compiled particulate organic carbon (POC) flux data and BCP metrics from time-series locations across biogeographically distinct ocean regions. We integrated multiple BCP observational techniques, including diverse collection and processing protocols, capturing diverse facets of POC flux at varying spatio-temporal resolutions. To ensure comparability, we harmonized errors and used Monte Carlo error propagation to calculate uncertainties consistently. Our analysis reveals large local uncertainties that obscure expected latitudinal variations in BCP metrics. While such variations may exist, they remain difficult to identify with current observational data. Our findings underscore the need for sustained POC flux observations, standardization of protocols, and intercalibration of technologies to identify geographic BCP patterns.

56. 题目: Changes in SOC, pH, and Ca associated with microorganism mediated SOC mineralization and temperature sensitivity following vegetation restoration in karst regions
文章编号: N25020401
期刊: Plant and Soil
作者: Tongxin He, Jun Li, Xinru Du, Guangting Pei, Aihua Wang, Baoqing Hu, Wei Zhang, Weidong Zhang, Jianfei Sun
更新时间: 2025-02-04
摘要:

Background and aims

Soil organic carbon (SOC) mineralization as a major C loss process, determines soil C accumulation following vegetation restoration in degraded land. However, SOC mineralization and underlying microbial mechanisms are still unclear during vegetation restoration in karst desertification areas, where the soil is characterized by high pH and calcium (Ca) content. This lack of clarity hinders the selection of optimal restoration strategies for adapting to karst conditions.

Methods

Four vegetation restoration strategies, which have undergone 12 years of recovery, were selected: natural shrubland (NS), Cornus Wilsoniana Wanaer (CWW), Eriobotrya japonica (EJ), and Cyclobalanopsis glauca (CG). SOC mineralization and its temperature sensitivity (Q10), soil properties, and microbial communities were measured.

Results

SOC mineralization was highest in NS, which decreased by 24.75%, 18.76%, and 33.66%, respectively, in CWW, EJ, and CG. SOC content and pH associated with fungal community structure positively influenced SOC mineralization, with SOC content having the most direct effect. Q10 was highest in CG compared to the other three strategies. Ca and pH associated with Actinobacteria negatively impacted Q10, while the fungal community structure (particularly Basidiomycota) and bacterial Chao1 had positive effects. Furthermore Ca was the most direct influencing factor.

Conclusions

Vegetation restoration types exhibited different effects on SOC mineralization and Q10 in karst areas. Changes in soil SOC content, pH, and Ca associated with microorganisms mediated SOC mineralization and Q10, with fungi and dominant microbial phyla playing significant roles. This highlights the importance of maintaining soil Ca and pH during vegetation restoration in karst regions.

57. 题目: Temperature effects on soil mineral-protected organic carbon are regulated by lithology in humid subtropical forests
文章编号: N25020314
期刊: Catena
作者: Li Tang, Wei Zhang, Peilei Hu, Yingying Ye, Jun Xiao, Jie Zhao, Hongsong Chen, Kelin Wang
更新时间: 2025-02-03
摘要: Metal-bound organic carbon (OC-metal), primarily associated with calcium (Ca) and iron (Fe), represents the bulk of mineral-protected OC and is considered a stable soil organic carbon (SOC) pool. The response of OC-metal to warming, the factors limiting its accumulation, and the role of lithology are largely unknown, hindering our predictions of OC-metal feedback to climate warming. Along a regional temperature gradient in southwestern China, we characterized different types of OC-metal in humid subtropical forest soils developed on two different lithologies and linked them to climate, vegetation, soil microorganisms, and geochemistry. We found that karst forests developed on carbonate bedrock had higher concentrations of Fe (hydr)oxide-bound OC (OC-Fed) than non-karst forests developed on clastic bedrock. Despite high soil pH and Ca, OC-Ca was not dominant in karst forests. A series of geochemical trade-offs spanning lithologies indicated that soil minerals and OC substrate availability limited OC-metal accumulation. Decreases in reactive minerals and increases in Gram-positive bacteria with increasing temperature reduced OC-metal in karst forests. Increases or non-significant changes in reactive minerals and continued plant inputs with increasing temperature attenuated temperature effects on OC-metal in non-karst forests. Lithology regulated the drivers of temperature on minerals and OC substrate availability by affecting vegetation, soil microorganisms, and geochemistry, resulting in different effects of temperature on OC-metal across lithologies. Overall, we highlight the underappreciated role of lithology in regulating SOC in response to climate warming and propose the integration of lithology into Earth system models under global climate change scenarios.

58. 题目: Characteristics and plausible formation mechanisms of secondary inorganic and organic aerosols in four seasons and during haze episodes in Beijing
文章编号: N25020313
期刊: Atmospheric Research
作者: Yuewei Sun, Qing Yu, Weihua Qin, Yuepeng Zhang, Ke Xin, Jing Ai, Jing Chen
更新时间: 2025-02-03
摘要: Secondary inorganic aerosols (SIA) and secondary organic aerosols (SOA) are major components of atmospheric particulate matter, however, their exact formation pathways are variable during haze evolution and need to be further clarified. To fully elucidate the characteristics of sulfate, nitrate and secondary organic carbon (SOC) and compare their roles in haze formation, PM2.5 samples were collected in downtown Beijing in four seasons, and PM1, PM2.5, and PM10 samples were collected over the severe haze episodes in winter and spring of 2017. The sulfur oxidation ratio (SOR), nitrogen oxidation ratio (NOR), and SOC/OC ratio were used to indicate the formation intensity of the respective secondary species. Based on the correlation analysis between secondary transformation ratios and their influencing factors, we found that relative humidity (RH) played a dominating role in NO3 formation and partitioning in the aerosol phase throughout the year, while SOR and SOC/OC were highly dependent on both O3 and RH. Different from the monotonic increase of SOR and NOR with RH, the SOC/OC ratio first increased and then decreased with increasing RH. The severe haze episode in winter was characterized by simultaneously enhanced secondary production of SO42−, NO3 and SOC. Whereas, the haze event in spring was featured by dramatically enhanced NO3 concentration, signifying the uniquely high contribution of nitrate to haze formation in spring.

59. 题目: Deciphering the mechanistic insight into modified biochar for distinct anaerobic digestion processes: Surface functional groups and electron-transmitting capabilities
文章编号: N25020312
期刊: Journal of Environmental Chemical Engineering
作者: Yi Han, Yaoyihan Luo, Lu Zhang, Xiejuan Lu, Luo Xi, Xiaohui Wu, Feixiang Zan
更新时间: 2025-02-03
摘要: Biochar, acting as a conductive medium, is widely used to stabilize anaerobic digestion (AD) systems for improved efficiency. However, the crucial characteristics of biochar affecting distinct processes of AD remain unclear. In this study, biochar with various typical characteristic functional group (hydroxyl and carboxyl groups) was purposefully synthesized to explore its specific impact on the AD process. Compared with the control, a substantial increase by 14.72% in methane production (454.04 ± 7.50 mL/g) was achieved with NaOH ball-milled biochar (BMB-NaOH), while the H2SO4 ball-milled biochar (BMB-H2SO4) showed a facilitating effect on organic matter decomposition. Subsequently, a low correlation coefficient value (0.211) ruled out specific surface area as a determining factor of methane production efficiency. Nonetheless, the presence of hydroxyl and carboxyl groups showed positive correlations with methane production and organic matter decomposition efficiency, respectively. The microbial community and metabolic pathways identified electron-rich hydroxyl groups in the biochar as electron donors to enrich methanogen (i.e., Methanobacterium and Methanosaeta), 11.25% for BMB-NaOH vs. 8.14% for BMB-H2SO4. Meanwhile, fermentative bacteria (Georgenia 28.28% for BMB-NaOH vs. 38.82% for BMB-H2SO4) could exploit the electron-deficient carboxyl groups, thereby facilitating the breakdown of large molecules. Together, the diverse surface functional groups primarily affected electron transmission capabilities. The findings of this study illuminate the unique roles of functional groups in microbial electron transfer processes, providing insights for targeted modifications of conductive media.

60. 题目: Humic acid-based anti-freezing and self-healing hydrogel flexible sensors with functional cellulose nanocrystals
文章编号: N25020311
期刊: Chemical Engineering Journal
作者: Pengxiao Liu, Xiangyu Chen, Chenming Wang, Xinyue Cui, Hou Chen, Liangjiu Bai, Wenxiang Wang, Kai Wei, Huawei Yang, Lixia Yang
更新时间: 2025-02-03
摘要: Conventional hydrogels are prone to freezing in severe cold climates, limiting the application of hydrogel-based flexible sensors. This study proposes a strategic design that successfully prepares humic acid-based anti-freezing hydrogels via a one-pot method, which is named P-HPCB hydrogels. It combines modified cellulose nanocrystals (CNCs@BSA), natural organic humic acid (HA), the biomass component L-proline (L-P) and polyvinyl alcohol (PVA) through freeze–thaw cycles. By the way, CNCs@BSA was obtained by grafting bovine serum albumin (BSA) onto cellulose nanocrystals (CNCs). The –OH groups in HA and L-P bind with free H2O molecules, reducing the freezing point of the hydrogels to −35.7 °C, effectively solving the problem of low-temperature freezing. Meanwhile, the addition of CNCs@BSA enhances the maximum tensile stress of the P-HPCB hydrogels to 3.6 MPa and achieves a self-healing efficiency of 86.1%. The flexible sensors constructed with P-HPCB hydrogels can accurately detect and respond to human motion signals even at an extreme low temperature of −30.0 °C, demonstrating excellent sensitivity and stability. This provides insights for the application of hydrogel flexible sensors under severe cold conditions.

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