23年11月20日文献情报（8篇）

23年11月20日文献情报

1. 题目: Unveiling changes in the complexation of dissolved organic matter with Pb(II) by photochemical and microbial degradation using fluorescence EEMs-PARAFAC

文章编号: N23112008
期刊: Environmental Pollution
作者: Liyang Yang, Linwei Chen, Wan-E Zhuang, Zhuoyi Zhu
更新时间: 2023-11-20
摘要:

Dissolved organic matter (DOM) is very important in determining the speciation, behaviors, and risk of metal pollutants in aquatic ecosystems. Photochemical and microbial degradation are key processes in the cycling of DOM, yet their effects on the DOM-Pb(II) interaction remain largely unknown. This was studied by examining the complexation of river DOM with Pb(II) after degradation, using fluorescence quenching titration and excitation-emission matrices-parallel factor analysis (EEMs-PARAFAC). Three humic-like and two protein-like components were identified, with strong removals of humic-like components and decreasing average molecular weight and humification degree of DOM by photo- and photo-microbial degradation. The changes in humic-like abundance and structure resulted in notable weakening of their interaction with Pb(II). The tryptophan-like C2 was also mainly removed by photo-degradation, while the tyrosine-like C3 could be either removed or accumulated. The Pb(II)-binding of protein-like components was generally weaker but was enhanced in some degradation groups, which might be related to the lowering competition from humic-like components. The binding parameters correlated significantly with the DOM indices, which were dominated by photo-degradation for humic-like components but by seasonal variations for the tyrosine-like component. These results have implications for understanding the key mechanisms underlying the variability of the DOM-metal interaction in aquatic environments.

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2. 题目: Effects of land conversion to cropland on soil organic carbon in montane soils of Northeast China from 1985 to 2020

文章编号: N23112007
期刊: Catena
作者: Xiang Wang, Kaishan Song, Zongming Wang, Sijia Li, Yingxin Shang, Ge Liu
更新时间: 2023-11-20
摘要:

Soil organic carbon (SOC) plays important roles in soil ecological function, soil conservation, and the global carbon cycle. With the increase of population and food demand, more and more croplands were reclaimed in mountainous areas. However, land conversion to cropland can lead to evident changes of SOC. The innovation of this study was to quantify the changes of SOC for different land covers in montane soils. Eight hundred twenty-nine topsoil samples were collected from dryland in Northeast China, and each soil sample was collected at least 200 m off the road at every 5–10 km interval, and five sites were mixed as one soil sample. Landsat 8 images were acquired from the bare soil period, and land cover data for 1985–2020 were obtained from Yang and Huang (2021). The surface reflectance of the 829 topsoil samples (0–20 cm) was extracted from Landsat 8 images. Then, a SOC prediction hybrid model was built after k-means clustering based on measured SOC using the potassium dichromate heating method, and a probability hybrid model was developed for SOC mapping. Land conversion to cropland was assigned to eight periods (i.e., five-year intervals from 1985 to 2020) based on land cover data, and the conversion percentages of different land cover types to cropland were calculated. Seven mountainous sub-regions were selected in Northeast China based on distribution of cropland and mountains to analyze the effects of land conversion to cropland on SOC. Our study showed that (1) the hybrid model had a higher accuracy than the global model, and the hybrid model led to the R² of 0.77 and RMSE of 4.66 g kg⁻¹ for validation samples. (2) Land conversion to cropland was mainly from forest in the 1980 s (proportion of 67.13%) and from grassland after 2015 (proportion of 52.24%). (3) SOC decreases with an average rate of 0.30 g kg ^-1 per five years from 1985 to 2020, and the slope of land conversion to cropland increases with an average rate of 0.35° per five years from 1985 to 2020; (4) SOC of land conversion to cropland from forests decreased by 2.04 g kg⁻¹, and wetland has an evident decrease trend (decrease by 1.84 g kg⁻¹) and an increasing trend from barren (increase by 4.07 g kg⁻¹). Our results suggested that land conversion to cropland has a negative effect on SOC in montane soils and should control land conversion to cropland to protect natural resources.

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3. 题目: Characterization of the dynamic aging and leached dissolved organic carbon from biodegradable and conventional plastics under photooxidation

文章编号: N23112006
期刊: Journal of Environmental Management
作者: Yue Yu, Yu Yao, Tanveer M Adyel, Sayyed Shahid Iqbal, Jun Wu, Lingzhan Miao, Jun Hou
更新时间: 2023-11-20
摘要:

Biodegradable plastics have been regarded as promising candidates in the struggle against plastic pollution. However, the aging and dynamic leaching process of biodegradable and conventional plastics under photooxidation is still unclear. Herein, three types of non-biodegradable plastics (polypropylene, polyethylene, and polyethylene terephthalate), and two types of biodegradable plastics (polylactic acid and cornstarch-based plastics) were treated with 21 days of photooxidation followed by 13 days of dark conditions. Scanning electron microscopy was applied to display the morphological changes. Also, the carbonyl index, oxygen-to-carbon ratio, and contact angle were utilized to characterize the aging degree of the plastic surface. Unexpectedly, biodegradable plastics did not always display a greater aging degree than non-biodegradable plastics. Moreover, the dissolved organic carbon during the leaching process was identified using excitation-emission matrix fluorescence spectroscopy. The findings suggested that biodegradable plastics showed the potential to release more dissolved organic carbon. Particularly, the polylactic acid plastic displayed higher concentrations and more types of dissolved organic carbon release than that of conventional plastics in our experiment. This research highlights the necessity for monitoring the aging process of both biodegradable and non-biodegradable plastics and the non-negligible ecological risk of leached organic pollutants due to plastic degradation.

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4. 题目: Effects of afforestation and upslope distance on soil moisture and organic carbon, and trade-off between them, on the Loess Plateau hillslopes

文章编号: N23112005
期刊: Catena
作者: Xuemei Mei, Chuangui Wang, Guojun Zhang, Xiaoming Zhang, Peng Li, Zhengyan Ren, Wei Leng
更新时间: 2023-11-20
摘要:

Large-scale afforestation is considered controversial as an ecosystem renewal strategy for the Loess Plateau of China, since it may increase soil organic carbon (SOC) but may also exacerbate water shortages. In our study, we aimed to clarify how afforestation and slope affect soil moisture content (SMC) and SOC and their interaction particularly for deep hillslope profiles on long hillslopes, in terms of the trade-off between soil moisture and organic carbon. This study investigated SMC and SOC density (SOCD) from 0 to 400 cm hillslope depth profiles at 20 m intervals uphill to 100 m in the May and October (the beginning and end of the growing period, respectively) from 2015 to 2017. The three sampling sites were located in Robinia pseudoacacia plantation, natural forest, and natural grassland as the control. Soil moisture deficit and SOC sequestration of plantation were compared to those of grassland, and the trade-off between SMC and SOCD was evaluated. The results showed that SMC and SOCD were the lowest in the Robinia pseudoacacia plantation, indicating that the plantation exhibited a greater soil moisture deficit and SOC loss than the grassland. In the plantation and natural forestland, the subsoil (100–400 cm) exhibited greater soil moisture deficit and SOC loss than the soil (0–100 cm). SOCD increased while SMC decreased with upslope distance for all hillslope layers in both plantation and natural forestland. The downslope sites exhibited more severe soil moisture deficit, and greater SOC loss than the upslope sites. Natural grassland exhibited low water depletion and high SOC sequestration. Further, the downslope plantation sites exhibited the lowest root mean square deviation for the relationship between SMC and SOCD. Based on these findings, a vegetation restoration strategy involving afforestation of downslope patches within a contiguous grassland matrix may achieve high-level maintenance of ecosystem services. These findings provide a theoretical basis for vegetation restoration on the Loess Plateau.

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5. 题目: Highly efficient activation of periodate by a manganese-modified biochar to rapidly degrade methylene blue

文章编号: N23112004
期刊: Environmental Research
作者: Jiamin Gong, Honghui Jiang, Xiang Li, Hao Cheng, Ziqi Wang, Jingju Cai, Meifang Li, Ping Wang, Hui Wang, Xi Hu, Xinjiang Hu
更新时间: 2023-11-20
摘要:

In this study, the manganese oxide/biochar composites (Mn@BC) were synthesized from Phytolacca acinosa Roxb. The Mn@BC was analyzed via techniques of Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction analysis (XRD). The results show that MnO_x is successfully loaded on the surface of BC, and the load of MnO_x can increase the number of surface functional groups of BC. X-ray photoelectron spectroscopy (XPS) shows that MnO_x loaded on BC mainly exists in three valence forms: Mn(Ⅱ), Mn(Ⅲ), and Mn(Ⅳ). The ability of Mn@BC to activate periodate (PI) was studied by simulating the degradation of methylene blue (MB) dye. The degradation experiment results showed that the MB removal rate by the Mn@BC/PI system reached 97.4% within 30 min. The quenching experiment and electron paramagnetic resonance (EPR) analysis confirmed that Mn@BC can activate PI to produce iodate (IO₃•), singlet oxygen (¹O₂), and hydroxyl radical (•OH), which can degrade MB during the reaction. Response surface methodology (RSM) based on Box-Behnken Design (BBD) was used to determine the interaction between pH, Mn@BC and PI concentration in the Mn@BC/PI system, and the optimum technological parameters were determined. When pH = 5.4, Mn@BC concentration 0.56 mg/L, PI concentration 1.1 mmol/L, MB removal rate can reach 98.05%. The cyclic experiments show that Mn@BC can be reused. After four consecutive runs, the removal rate of MB by the Mn@BC/PI system is still 82%, and the Mn@BC/PI system also shows high performance in treating MB in actual water bodies and degrading other pollutants. This study provides a practical method for degrading dyes in natural sewage.

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6. 题目: Dissolved organic carbon leaching from microplastics and bioavailability in coastal ecosystems

文章编号: N23112003
期刊: Science of the Total Environment
作者: L G Egea, F G Brun, R Jiménez-Ramos
更新时间: 2023-11-20
摘要:

The dissolved organic carbon (DOC) leached from two types of microplastics (polyethylene and polypropylene) frequently found in coastal areas were evaluated in situ. Subsequently, the bioavailability of leached DOC was assessed for microbial inocula from different coastal communities (i.e., estuarine and open-coastal waters, river-mouth waters and seagrass beds). Leached DOC was largely biodegradable (as much as 85 %). However, seagrass beds and river-mouth waters exhibited lower DOC utilization efficiency than estuarine and open-coastal waters, probably because of differences in their microbial communities. The labile/recalcitrant ratio of DOC leached from plastic was similar under illuminated and dark conditions, whereas DOC leached from polyethylene, rather than DOC leached from polypropylene, was preferentially used by microbial communities. We estimated that as many as 21,000 metric tons of DOC leached from plastics may be released into ocean annually. Our results support the need to consider the potential impacts of coastal plastic pollution on microbial communities, including consideration of the trophic webs and coastal carbon cycle.

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7. 题目: A comprehensive evaluation of biochar for enhancing nitrogen removal from secondary effluent in constructed wetlands

文章编号: N23112002
期刊: Chemical Engineering Journal
作者: Fucheng Guo, Yang Luo, Min Nie, Feifei Zheng, Gongliang Zhang, Yi Chen
更新时间: 2023-11-20
摘要:

Biochar has been used to improve nitrogen removal in constructed wetland (CW) treating secondary effluent from wastewater treatment plants (WWTPs). Nevertheless, the mechanism on enhancing nitrogen removal is unclear. Herein, biochar derived from three typical wetland plants, Typha latifolia (TLB), Phragmites australis (PAB), and Cyperus alternifolius (CAB) at 300 °C, were used as substrates in CWs to uncover the gap. Results indicated that the total nitrogen removal efficiencies of TLB-CWs (59.84 %), PAB-CWs (65.08 %), and CAB-CWs (78.61 %) were significantly higher than the gravel control (39.20 %). Biochar enhanced plant growth for nitrogen uptake and boosted the secretion of root exudates for fueling microbial denitrification. Meanwhile, biochar notably increased the activities of dehydrogenase, electron transport system, and denitrifying enzymes and enriched the corresponding genes. Mass balance calculation showed that microbial denitrification was dominated in nitrogen removal in CWs. Pearson correlation analysis revealed that the proportion of C = O and pyrrolic N in biochar’s surface, biochar’s electron accepting capacity and electron donating capacity, and the lignin proportion of biochar feedstock, were significantly correlated with the removal efficiency of nitrogen. PLS-SEM demonstrated that biochar boosted nitrogen removal in CWs by enhancing plant growth, which promoted microbial activities. Overall, our results showed the enhancing interactive mechanisms among biochar properties, plant growth and microbial enzyme activity.

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8. 题目: Adsorption of trace heavy metals through organic compounds enriched biochar using isotherm adsorption and kinetic models

文章编号: N23112001
期刊: Environmental Research
作者: Fiza Pir Dad, Waqas-ud-Din Khan, Faiza Sharif, Abdul Sattar Nizami
更新时间: 2023-11-20
摘要:

Trace heavy metals such as copper and nickel, when exceeds a certain level, cause detrimental effects on the ecosystem. The current study examined the potential of organic compounds enriched rice husk biochar (OCEB's) to remove the trace heavy metals from an aqueous solution in four steps. In 1st step, biochar’ physical and chemical properties were analyzed through scanning electron microscope (SEM) and Fourier transforms infrared spectroscopy (FTIR). In the 2nd step, two biochar vis-a-vis glycine, alanine enriched biochar (GBC, ABC) was selected based on their adsorption capacity of four different metals Cr, Cu, Ni and Pb (chromium, copper, nickel, and lead). These two adsorbents (GBC, ABC) were further used to evaluate the best interaction of biochar for metal immobilization based on varying concentrations and times. Langmuir isotherm model suggested that the adsorption of Ni and Cu on the adsorbent surface supported the monolayer sorption. The qmax value of GBC for Cu removal increased by 90% compared to SBC (Simple rice husk biochar). The interaction of Cu and Ni with GBC and ABC was chemical, and 10 different time intervals were studied using pseud first and second-order kinetics models. The current study has supported the pseudo second-order kinetic model, which exhibited that the sorption of Ni and Cu occurred due to the chemical processes. The % removal efficiency with GBC was enhanced by 21% and 30% for Cu and Ni, respectively compared to the SBC. It was also noticed that GBC was 21% more efficient for % removal efficiency than the CBC. The study's findings supported that organic compound enriched rice husk biochar (GBC and ABC) is better than SBC for immobilizing the trace heavy metals from an aqueous solution.

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