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61. 题目: Soil organic matter diagenetic state informs boreal forest ecosystem feedbacks to climate change | |||||
62. 题目: Preliminary Assessment of Pyrolysis Biochar Derived from Milk/Dairy Processing Sludge as a Potential Component of Fertilizers | |||||
63. 题目: Selective removal behavior of lead and cadmium from calcium-rich solution by MgO loaded soybean straw biochars and mechanism analysis Modified biochars has great potential for removing heavy metals from aquatic environments, but the removal of heavy metals by biochars is usually significantly affected by the co-presence of the macro amount of metal ions, such as Ca. Enhancing the ion exchange capacity of biochar by increasing its alkali metal content is a very prospective method to improve its selectivity. In this paper, MgO loaded biochar (MBC) was synthesized by co-pyrolysis of soybean straw and MgCl2·6H2O for selective remove Pb and Cd from calcium-rich wastewater. MBC exhibited excellent selective adsorption performance for Pb and Cd in calcium-rich wastewater due to the successful loading of MgO. The adsorption capacities of MBC for Pb and Cd were 582.57 and 167.40 mg/g, and the removal efficiency of Ca below 2.5% with an initial concentration of 800 mg/L. The ion exchange capacities of Pb and Cd enhanced almost 27 and 23 times than BC. By analyzing the results of BET, XRD, SEM-EDS, XPS and FTIR, the adsorption mechanisms of MBC were mainly including ion exchange, precipitation with minerals, and interaction with oxygen-containing functional groups. The easy preparation method and high selective adsorption capacity makes MBC an ideal alternative for efficiently selective removal Pb and Cd from calcium-rich wastewater. | |||||
64. 题目: Comparative study on effects of pH, electrolytes, and humic acid on the stability of acetic and polyacrylic acid coated magnetite nanoparticles The poor colloidal stability of magnetite nanoparticles (MNPs) limits their mobility and application, so various organic coatings (OCs) were applied to MNPs. Here, a comparative study on the colloidal stability of MNPs coated with acetic (HAc) and polyacrylic acids (PAA) was conducted under varied pH (5.0–9.0) in the presence of different concentrations of cations and anions, as well as humic acid (HA). Comparing the effects of various cations and anions, the stability of both HAc/PAA-MNPs followed the order: Na+ > Ca2+and PO43− > SO42− > Cl−, which could be explained by their adsorption behaviors onto HAc/PAA-MNPs and the resulting surface charge changes. Under all conditions even with more anion adsorption onto HAc-MNPs (0.14–22.56 mg/g) than onto PAA-MNPs (0.04–18.34 mg/g), PAA-MNPs were more negatively charged than HAc-MNPs, as PAA has a lower pHIEP (2.6 ± 0.1) than that of HAc (3.7 ± 0.1). Neither the HAc nor PAA coatings were displaced by phosphate even at considerably high phosphate concentration. Compared with HAc-MNPs, the stability of PAA-MNPs was greatly improved under all studied conditions, which could be due to both stronger electrostatic and additional steric repulsion forces among PAA-MNPs. Besides, under all conditions, Derjaguin-Landau-Verwey-Overbeek (DLVO) explained well the aggregation kinetic of HAc-MNPs; while extended DLVO (EDLVO) successfully predict that of PAA-MNPs, indicating steric forces among PAA-MNPs. The aggregation of HAc/PAA-MNPs was all inhibited in varied electrolyte solutions by HA (2 mg C/L) addition. This study suggested that carboxyl coatings with higher molecular weights and pKa values could stabilize MNPs better due to stronger electrostatic and additional steric repulsion. However, in the presence of HA, these two forces were mainly controlled by adsorbed HA instead of the organic pre-coatings on MNPs. | |||||
65. 题目: Long-term cover cropping improved soil bacterial community and soil multifunctionality in a Carya cathayensis plantation Chinese hickory (Carya cathayensis Sarg.), a nut tree unique to China, is an important source of high-class nuts and oil. However, the intensive management practices, especially removing all the understory, lead to the soil degradation in Chinese hickory plantation. Thus, cover cropping is applied to improve and maintain soil quality and productivity. Soil multifunctionality (SMF) is a practical index to comprehensively assess different soil environmental factors with complicated interactions. However, the long-term effects of cover cropping on soil bacterial community and SMF in Chinese hickory plantations remain unknown. In this study, a field experiment was conducted in a Chinese hickory plantation in Zhejiang province, China, from 2011 to 2021. The effects of cover crops including oilseed rape (Brassica chinensis, OR), Chinese milk vetch (Astragalus sinicus, CMV), and the mixtures of oilseed rape and Chinese milk vetch (OC) on the soil bacterial community and SMF were compared with no cover crop (NC). We employed high throughput sequencing of 16 S rRNA to study soil bacterial community, and adopted the averaging approach to determine the SMF value based on soil carbon (C) and nitrogen (N) storage, potential enzymatic activity, and active nutrient pool. The results revealed that long-term cover cropping significantly improved soil C and N content, which stimulated the soil potential enzymatic activity. And consequently, soil labile nutrient concentrations were increased, suggesting better soil active nutrient pool. The proliferation of bacteria utilizing easily-decomposed organic matter was therefore promoted. Hence, SMF was significantly improved by cover cropping. And OC effectively combined species-specific functions including nutrient retention and utilization. Consequently, OC showed the best improvement of soil environmental factors including C and N storage, active nutrient pool, and potential enzymatic activity among cover cropping treatments. It is therefore that OC manifested better SMF than sole cover crops strategies. Random forest modeling and partial least squares path modeling (PLS-PM) revealed that soil C storage, pH, and potential enzymatic activity, were dominant predictors of SMF. Additionally, C and N storage, and pH directly influenced bacterial richness and composition positively or negatively. This study provides insight into the effects of different cover crops on the soil bacterial community and SMF in Chinese hickory plantations, and highlighted the great potential of the legume-cruciferae cover cropping strategy on SMF improvement. These findings have implications for the optimization of sustainable forest management practices in degraded forest plantations. | |||||
66. 题目: Temporal variation of mineralization rates and its influence on carbon storage over the last 50 years in Bohai Bay, China Recorded information on marine sediments is affected by mineralization. In this study, we collected sediment samples from Bohai Bay, where human interference is typically high. Overall, the CO2 fluxes in the columnar sediments decreased with increasing depth. The change in constants revealed a “C-curve” in which the mineralization rate first decreased significantly (i.e., from the 2020s to the 1980s) and subsequently increased slowly (i.e., from the 1980s to 1965). This may be explained by the fact that sediments from the 1980s–2020s were markedly influenced by the sedimentation rate, whereas sediments from the 1960s–1980s were predominantly influenced by microbial action. The loss of organic carbon due to mineralization accounted for approximately 15–20 % of the initial total organic carbon; therefore, when performing an inversion of the historical environment change using information derived from organic carbon in marine sediments, the influence of mineralization on this information should be fully considered. | |||||
67. 题目: Exotic Spartina alterniflora invasion enhances sediment N-loss while reducing N retention in mangrove wetland Wide and rapid Spartina alterniflora invasion has threatened the sustainability of coastal wetlands of China, and has a significant impact on sediment biogeochemical cycle. However, the effects of exotic Spartina alterniflora invasion on sediment dissimilatory nitrates (NOx−) reduction processes and mechanisms underlying these pathways in mangrove wetlands have not been well studied. Here, denitrification (DEN), anaerobic ammonium oxidation (ANA) and dissimilatory nitrate reduction to ammonium (DNRA) rates, contributions (DEN%, ANA%, and DNRA%), associated functional genes (nirS, anammox 16S rRNA and nrfA) and controlling factors were investigated in surface sediments (0–5 cm) in mangrove and Spartina alterniflora communities and ecotone of the Zhangjiang Estuary, China. Significant spatial differences in DEN, DNRA, DEN%, and DNRA% were found among different plant communities (p < 0.05 for all). DEN is the dominant pathway of NOx− reduction processes in Spartina alterniflora community (87–89 %) and ecotone (75–78 %), while DEN (41–51 %) and DNRA (36–51 %) compete with each other in mangrove community. Organic matter was the most dominating factor controlling DEN and DNRA rates. Without accounting for confounding factors, Spartina alterniflora invasion significantly reduced the nitrogen retention index (NIRI), causing a large amount of nitrogen (N) loss in wetlands. We estimated that Spartina alterniflora invasion has increased sediment N-loss (831.09 ± 55.16 t N yr−1) but reduced N retention (783.48 ± 37.73 t N yr−1) in mangrove habitats of China within last 40 years (1980–2020). Thus, Spartina alterniflora invasion enhances sediment N-loss while reducing N retention in mangrove wetlands, which may threaten the mangrove buffer function and wetland N pools protection in estuarine and coastal ecosystems. | |||||
68. 题目: Does Surface Roughness Necessarily Increase the Fouling Propensity of Polyamide Reverse Osmosis Membranes by Humic Acid? | |||||
69. 题目: Application, mechanism and prospects of Fe-based/ Fe-biochar catalysts in heterogenous ozonation process: A review A growing number of novel organic contaminants have escalated the demands and challenges for water treatment technology. Advanced oxidation processes based on ozone have the advantage of strong oxidative capacity and higher efficiency, which have promising application prospects in the treatment of refractory organic contaminants. Biochar has attracted a lot of interest in recent years in wastewater treatment owing to its porous structure, portable preparation and outstanding stability. Moreover, iron species are widely used in catalytic ozonation owing to their magnetic polarization, vast abundance and low price. Despite a plethora of research on Fe-based catalysts in ozonation process, the heterogeneous catalytic ozonation with Fe-loaded biochar lacks a comprehensive compendium. This review intends to introduce the research progress on Fe-based catalysts and Fe-loaded biochar in heterogeneous catalytic ozonation progress, summarize and further explore the mechanisms and detection techniques of various active components in catalytic ozonation, as well as providing fresh insights for future research. | |||||
70. 题目: Novel insights into the predominant factors affecting the bioavailability of polycyclic aromatic hydrocarbons in industrial contaminated areas using PLS-developed model Bioavailability is recognized as a useful technical standard for risk assessment and pollution rehabilitation. However, knowledge on the bioavailability of polycyclic aromatic hydrocarbons (PAHs) in contaminated site soils is still limited, especially concerning the influential mechanism. With an abundance of soil collections from nine industrial areas in China, the bioavailabilities, as conceptually defined as bioconcentration factors (BCFs) of PAHs were analyzed using biomimetic extraction of hydroxypropyl-β-cyclodextrin (HPCD). Apart from the total content of PAHs varying with the different pyrogenic sources, the BCFs were greatly dependent on the soil physicochemical properties from the spatial scale and inversely proportional to the number of rings. Pearson correlation analysis indicated a weak relationship between bioavailability and the soil dissolved organic matter (DOM), pH and particle size. To incorporate the soil physicochemical properties and structural characteristics of PAHs determined by density functional theory (DFT), the optimum model for bioavailability was developed for BCFs by partial least square (PLS) analysis. The PLS-derived model was shown to be predictive within the applicability domain (AD). The structural characteristics, e.g., molecular polarizability and frontier orbital energy level that favor the soil adsorption of PAH isomers via dispersion interactions, and electron exchanges were indicated to be more impactful on bioavailability than soil environmental factors. However, soil factors should not be neglected, because the pH, DOM, etc. Were significantly influential. It makes sense that the higher DOM causes greater bioavailability via increasing the free-dissolved fractions of PAHs. Interestingly, the effect of pH on bioavailability was spectrally validated by excitation-emission matrix (EEM) fluorescence, showing that the interaction between DOM and pyrene strengthened the fluorescence quenching of chromophores with the decline in pH. | |||||
71. 题目: Biochar-derived persistent free radicals and reactive oxygen species reduce the potential of biochar to mitigate soil N2O emissions by inhibiting nosZ Biochar amendment has been proven to generally reduce soil nitrous oxide (N2O) emissions. However, the effects and underlying mechanisms of biochar-derived reactive oxygen species (ROS) on soil N2O emissions are still unclear. Thus, we firstly weakened the intensities of persistent free radicals (PFRs) within biochar using triethanolamine (TEA) as a quencher, and then used soil incubation methods to compare the potentials of TEA-quenched and un-quenched biochar in mitigating soil N2O emissions. The TEA-quenched biochar generated less hydrogen peroxide (H2O2) and hydroxyl radical (•OH), while having a higher soil N2O emission mitigation potential, than the un-quenched biochar. The N2O emissions and the N2O/(N2O + N2) ratio were significantly, positively, correlated with the generated H2O2 and •OH contents. These results demonstrated that biochar-derived ROS weakened biochar's mitigation of soil N2O emissions. The specific mechanisms of biochar-derived ROS on soil N2O emissions were further explored by a ROS scavenging experiment. It was found that scavenging H2O2 by catalase efficiently hindered the generation of •OH, resulting in decreases in N2O emissions and the N2O/(N2O + N2) ratio. Meanwhile, biochar-derived ROS exhibited a more severe inhibition on N2O reductase gene (nosZ) expression than that on the expression of genes responsible for N2O production (nirK and nirS), indicating that biochar-derived ROS weakened biochar's mitigation of soil N2O emissions by inhibiting microbial N2O reduction. Our results imply that controlling the content of biochar-derived ROS is a promising strategy to maximize biochar's potential for mitigating soil N2O emission. | |||||
72. 题目: Photoinduced production of substances with humic-like fluorescence, upon irradiation of water samples from alpine lakes Evidence is here provided that irradiation of some lake water samples can trigger the formation of fluorophores with humic-like properties, at the same time increasing water absorbance. This phenomenon is the opposite of photobleaching, which is often observed when natural waters are irradiated. Photoproduced humic-like fluorophores would be of autochthonous rather than allochthonous origin, which marks a difference with the fraction of humic substances that derives from terrestrial sources. Photogeneration of humic-like compounds can be highlighted in water samples where the fluorescence signal of initially occurring humic substances is low, so that their photobleaching is minimised. Samples that are most likely to show photoinduced formation of humic-like fluorophores are in fact characterised by high values of protein-like vs. humic-like contribution ratios to fluorescence, as evidenced by parallel factor (PARAFAC) analysis. Mountain lakes in late summer appear to be suitable candidates to highlight the described phenomenon. In some cases, lake-water irradiation caused a decrease in the spectral slope of the absorbance that, together with increasing absorbance values, is consistent with an increase in molecular mass and aromaticity of organic matter. The absorbance increase triggered by irradiation might play a role in screening biologically harmful UV radiation, in mountain environments that would otherwise be characterised by very clear water that allows for easy transmission of UV light along the water column. | |||||
73. 题目: Spatio-temporal dynamics of soil organic carbon and total nitrogen: evidenced from 2000 to 2020 in a mixed ecosystem The southwestern part of Bangladesh has a mixed ecosystem, which is directly affected by climate change and undergoing remarkable changes in agricultural activities that are exacerbating the dynamics of soil organic carbon (SOC) and soil total nitrogen (STN). To study the spatial distribution of SOC and STN dynamics in such ecosystem, Dacope Upazila was chosen, and different interpolation methods were applied and compared to find out the best approach to demonstrate the spatial pattern of soil carbon and nitrogen status in 2000 and 2020 and correlated them with the terrain and environmental variables. Soil resource development institute (SRDI) database was used to obtain the SOC and STN of the area in 2000 and 2020. To identify the elevation, aspect, slope, land surface temperature (LST), normalized difference vegetation index (NDVI), and normalized difference water index (NDWI), the digital elevation model (DEM) and satellite images of 2000 and 2020 were downloaded. The results showed that the applied interpolation methods and models did not perform well as the model efficiency (R2) was very low. Furthermore, in 2000, SOC and STN were only positively correlated with EC (p < 0.01) whereas after two decades, SOC and STN showed a positive correlation with elevation (p < 0.01), NDVI (p < 0.01), and negative correlation with NDWI (p < 0.01). In both years, SOC and STN showed a strong positive correlation at p < 0.001 with each other. Due to the poor model performance, it is recommended using extended spatial techniques coupling with environmental variables to increase the accuracy of spatial distribution for a complex ecosystem. | |||||
74. 题目: Vermitoxicity of aged biochar and exploring potential damage factors Although biochar is a promising soil amendment, its characteristics change owing to its aging in soil. Studies have shown that some aged biochar is hazardous to plants and soil microbiota. Earthworms are well-known soil ecosystem engineers; nevertheless, the toxic effects of aged biochar on them (vermitoxicity) are yet unknown, and it is necessary to explore the potential risk factors. Here, a series of soil culture experiments were conducted to systematically examine the vermitoxicity of aged biochar at various levels utilizing the earthworm Eisenia fetida and corncob biochar.. Acute toxicity bioassays were also used to evaluate several potential harm factors utilizing modified aged biochar/leaching solutions. The findings showed that both fresh and aged biochar might have adverse effects on earthworms, and that aged biochar was more toxic than fresh biochar with LC50s reduced to 6.89%. Specifically, aged biochar caused earthworm death, growth inhibition with a maximum of 36.6%, and avoidance with 100% avoidance at the application rates of 2% at the individual-behavioral level. At the cellular and physiological-biochemical levels, aged biochar damaged coelomocyte lysosomal membrane stability, disrupted antioxidant enzyme activities, and improved the malondialdehyde (MDA) content in earthworms. Heat-treated and pH-modified aged biochar exhibited less acute toxicity on earthworms than aged biochar, whereas aqueous and acetone extracts showed weak vermitoxicity. As a result, earthworms may be harmed by volatile organic compounds (VOCs), an improper pH, and aqueous and acetone extracts. Additionally, the range of neural red retention times (NRRTs) was reviewed as ∼20–70 min mostly. This study, as far as we know, is the first to evaluate the vermitoxicity of aged biochar and its potential damage factors. The results may enhance our understanding of ecological toxicity of biochar, particularly over the long term, and lead to the development of application standards for biochar amendments to the soil. | |||||
75. 题目: Novel Perfluorooctanesulfonate-Imprinted Polymer Immobilized on Spent Coffee Grounds Biochar for Selective Removal of Perfluoroalkyl Acids in Synthetic Wastewater | |||||
76. 题目: Sediment organic carbon dynamics response to land use change in diverse watershed anthropogenic activities Sediment organic carbon (SOC) is a precious archive that synthesizes anthropogenic processes that remove geochemical fluxes from watersheds. However, the scarcity of inspection about the dynamic mechanisms of anthropogenic activities on SOC limits understanding into how key human factors drive carbon dynamics. Here, four typical basins with similar natural but significantly diverse human contexts (high-moderate-low disturbance: XJ-ZS and YJ-LS) were selected to reconstruct sedimentation rates (SR) and SOC dynamics nearly a century based on 200-cm corers. A partial least squares path model (PLS-PM) was used to establish successive (70 years) and multiple anthropogenic data (population, agriculture, land use, etc.) quantification methods for SOC. Intensified anthropogenic disturbances shifted all SR from pre-stable to post-1960s fluctuating increases (total coefficient: high: 0.63 < low: 0.47 < medium: 0.45). Although land use change was co-critical driver of SOC variations, their trend and extent differed under the dams and other disturbances (SOC mutated in high-moderate but stable in low). For high basin, land use changes increased (0.12) but dams reduced (-0.10) the downstream SOC. Furthermore, SOC mutation corresponded to soil erosion due to urbanization in both periods A and B. For moderate, SOC was reversed with the increase in afforestation and cropland (−0.19) due to the forest excitation effect and deep ploughing, which corresponded to the drought in phase B and the anthropogenic ecological project in A. For low, the increase in SOC corresponded to the Great Leap Forward deforestation in period B and the reed sweep in A, which suggested the minor land change substantially affected (0.16) SOC in fragile environments. Overall, SOC dynamics revealed that anthropogenic activities affected terrestrial and aquatic ecosystems for near the centenary, especially land use. This is constructive for agroforestry management and reservoir construction, consistent with expectations like upstream carbon sequestration and downstream carbon stabilization. | |||||
77. 题目: Viral infection switches the balance between bacterial and eukaryotic recyclers of organic matter during coccolithophore blooms Algal blooms are hotspots of marine primary production and play central roles in microbial ecology and global elemental cycling. Upon demise of the bloom, organic carbon is partly respired and partly transferred to either higher trophic levels, bacterial biomass production or sinking. Viral infection can lead to bloom termination, but its impact on the fate of carbon remains largely unquantified. Here, we characterize the interplay between viral infection and the composition of a bloom-associated microbiome and consequently the evolving biogeochemical landscape, by conducting a large-scale mesocosm experiment where we monitor seven induced coccolithophore blooms. The blooms show different degrees of viral infection and reveal that only high levels of viral infection are followed by significant shifts in the composition of free-living bacterial and eukaryotic assemblages. Intriguingly, upon viral infection the biomass of eukaryotic heterotrophs (thraustochytrids) rivals that of bacteria as potential recyclers of organic matter. By combining modeling and quantification of active viral infection at a single-cell resolution, we estimate that viral infection causes a 2–4 fold increase in per-cell rates of extracellular carbon release in the form of acidic polysaccharides and particulate inorganic carbon, two major contributors to carbon sinking into the deep ocean. These results reveal the impact of viral infection on the fate of carbon through microbial recyclers of organic matter in large-scale coccolithophore blooms. | |||||
78. 题目: Standard vs. Natural: Assessing the impact of environmental variables on organic matter decomposition in streams using three substrates | |||||
79. 题目: Nano-biochar: Properties and prospects for sustainable agriculture | |||||
80. 题目: Efficient nitrogen removal through coupling biochar with zero-valent iron by different packing modes in bioretention system Three kinds of bioretention were designed to explore the effects of zero-valent iron (ZVI) and biochar on the nitrogen removal performance and to seek a more reasonable packing method in this study. The results showed that the effluent removal rates of nitrate, ammonium and total nitrogen were 53.30 ± 12.68%, 98.41 ± 0.38% and 64.03 ± 8.72% respectively in Bioretention-3 during the rainfall events, while the nitrate concentration decreased gradually with the increase of drying time. According to the batch experiment, it was found that zero-valent iron could release continuously and stably in Bioretention-3 and Bioretention-1 due to the interception effect of biochar on dissolved oxygen. In addition, biochar in soil layer could protect zero-valent iron from excessive oxidation while biochar in the substrate layer could release organic matter to promote heterotrophic denitrification. Microbial community analysis showed that the dominant phyla were Proteobacteria (20.92–40.81%) and Actinobacteriota (9.89–24.54%). The dominant nitrifying genera was Nitrospira while there were also aerobic denitrifying bacteria (Sphingomonas, Bradyrhizobium and Chryseolinea, etc.) in soil layer. In the substrate layer, there was more ferrous iron-mediated autotrophic denitrification process (Thiobacillus, Geobacter and Denitratisoma, etc.) in Bioretention-1 and Bioretention-3 while a larger proportion of Dissimilatory Nitrate Reduction to Ammonium process (DNRA) (Bacillus, Desulfovibrio and Pseudomonas, etc.) in Bioretention-2. In general, this study showed that biochar addition in soil coupled with mixing zero-valent iron and biochar as substrate layer was a more stable and efficient design through various aspects of evidence. It provides a new way for how to use zero-valent iron and biochar to improve nitrogen removal capacity in stormwater management. | |||||
