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21. 题目: Waste-derived permeable reactive barrier to treat heavy metals and organic matter in groundwater affected by landfill leachate
文章编号: N24041920
期刊: Environmental Earth Sciences
作者: W T H Jayawardane, W K C N Dayanthi
更新时间: 2024-04-19
摘要:

Landfill leachate contributes to groundwater pollution. The Permeable Reactive Barrier (PRB) is a sustainable in-situ method to remediate groundwater. Finding cost-effective and efficient reactive materials is a key problem with PRBs. Hence, the present study aimed to assess the applicability of two composite reactive media beds derived from several waste materials (building waste, sludge, sea sand, iron particles, bagasse, saw dust, bio char, fly ash and coconut coir pith) for PRBs to treat groundwater contaminated by landfill leachate. The study comprised two identical laboratory-scale PRB reactors: an experimental reactor and a control reactor. Each reactor included two reactive media beds in series. In the experimental reactor, one of the two beds was filled with a composite reactive media derived from waste materials with high particle densities, while the other was filled with waste materials of low particle densities. In contrast, both the beds of the control reactor were filled with Granular Activated Carbon (GAC). The experimental PRB demonstrated removal rates of 97.08 ± 0.11% (Pb), 65.01 ± 2.14% (Mn), 55.03 ± 1.06% (Fe) and 78.34 ± 1.58% (COD). The control reactor achieved removal rates of 99.26 ± 0.08% (Pb), 94.46 ± 1.13% (Mn), 80.23 ± 0.93%(Mn) and 98.83 ± 0.14% (COD). The shear strength reductions were 19%, 27%, and 11% for the high-density, low-density, and GAC beds, respectively. The associated reductions in hydraulic conductivity were 24%, 12%, and 35%. The waste-derived reactive media possess multiple properties sourced from different materials and can address the removal of multiple contaminants simultaneously, comparable to GAC.

22. 题目: Co-application of biochar and selenium nanoparticles improves yield and modifies fatty acid profile and essential oil composition of fennel (Foeniculum vulgare Mill.) under cadmium toxicity
文章编号: N24041919
期刊: Environmental Science and Pollution Research
作者: Masoumeh Jahantigh, Marzieh Ghanbari Jahromi, Fatemeh Sefidkon, Marjan Diyanat, Weria Weisany
更新时间: 2024-04-19
摘要:

Fatty acids and essential oils (EOs) are the primary variables that influence the quality of fennel (Foeniculum vulgare Mill.). Soil toxicity to cadmium (Cd) is the main environmental issue facing fennel, and priming methods like soil amendments and nanoparticles (NPs) are commonly utilized to deal with it. The goal of the current study was to examine the effects of biochar (BC) and selenium nanoparticles (Se NPs) on fennel plants in Cd-contaminated soils. The pot experiment was conducted with Cd stress at 0, 10, and 20 mg kg−1 soil, BC at 5% (v/v), and foliar-spraying Se NPs at 40 mg L−1 as a factorial completely randomized design (CRD) at a greenhouse condition in 2022. The findings demonstrated that Cd toxicity significantly decreased plant performance, while BC and Se NPs enhanced it. Without BC and Se NPs, Cd toxicity at 20 mg kg−1 soil decreased biological yield (39%), seed yield (37%), EO yield (32%), and monounsaturated fatty acids (14%), while increased saturated fatty acid (26%) and polyunsaturated fatty acids (40%) of fennel. The main EO profile was anethole (65.32–73.25%), followed by limonene (16.12–22.07%), fenchone (5.57–6.83%), and estragole (2.25–3.65%), which mainly were oxygenated monoterpenes. The combined application of BC and Se NPs improved the yield, EO production, and fatty acid profile of fennel plants under Cd stress, increasing the plants’ resistance to Cd toxicity.

23. 题目: The formation of humic acid and micro-aggregates facilitated long-time soil organic carbon sequestration after Medicago sativa L. introduction on abandoned farmlands
文章编号: N24041918
期刊: Geoderma
作者: Xin Song, Zi-Qiang Yuan, Chao Fang, Zhen-Hong Hu, Feng-Min Li, Jordi Sardans, Josep Penuelas
更新时间: 2024-04-19
摘要: The substantial carbon sequestration observed in abandoned farmland assumes a pivotal role in mitigating the impacts of global warming. However, it remains unclear how to effectively manage abandoned farmlands to achieve this goal, especially over the long term, and understand the underlying mechanisms. The introduction of legumes can augment vegetation coverage, mitigate soil erosion, and ameliorate soil quality. A long-term study has been conducted in the semiarid region of the Loess Plateau since 2003, with a focus on revegetation strategies involving the introduction of alfalfa ( L.) and sweet clover ( L.), while natural abandonment (fallow) served as a control. In this study, we utilized a physical–chemical combination approach to investigate the carbon sequestration process within the 0–20 cm soil layer. Our results demonstrated that, in comparison to the fallow, alfalfa introduction significantly increased soil organic carbon (SOC), light fraction organic carbon (LFOC), and heavy fraction organic carbon (HFOC) concentrations, whereas no significant differences were observed when comparing with sweet clover. The amount and proportion of humic acid (HA) within HFOC were notably higher in alfalfa fields compared to fallow fields. While soil wet-sieved macro-aggregates (>2 mm and 0.25–2 mm) showed no significant difference between alfalfa and fallow fields, soil wet-sieved micro-aggregates were significantly more abundant in alfalfa fields. These wet-sieved micro-aggregates displayed high levels of humification across all fields. As soil wet-sieved aggregate size increased, the proportions of humin (HM) and HA decreased, while the proportion of fulvic acid (FA) increased. We concluded that the formation of HM, HA, and soil wet-sieved micro-aggregates played key roles in promoting long-term soil carbon storage following alfalfa introduction. These findings enhance our understanding of soil ecosystem responses to future climate change and underscore the significance of species selection in restoration processes to effectively mitigate global warming.

24. 题目: Nontargeted Analysis of Coumarins in Source Water and Their Formation of Chlorinated Coumarins as DBPs in Drinking Water
文章编号: N24041917
期刊: Environmental Science & Technology
作者: Haozhe Liu, Meng Zou, Hongyan Pei, Chunjing Chen, Yan Huang, Lilin Xiong, Qian Wu, Rongrong Qiao, Xiaojie Sun, Lei Li, Jun Yang, Jing Zhang, Guang Huang
更新时间: 2024-04-19
摘要: Coumarin was detected as one of the most abundant compounds by nontargeted analysis of natural product components in actual water samples prior to disinfection. More importantly, prechlorination of humic acid generated 3-hydroxycoumarin and monohydroxy-monomethyl-substituted coumarin with a total yield of ≤10.1%, which suggested the humic substance in raw water is an important source of coumarins. 7-Hydroxycoumarin, 6-hydroxy-4-methylcoumarin, 6,7-dihydroxycoumarin, and 7-methoxy-4-methylcoumarin were identified in raw water by high-performance liquid chromatography–tandem high-resolution mass spectrometry because only some coumarin standards were commercially available. Their chlorination generated monochlorinated and polychlorinated coumarins, and their structures were confirmed by the synthesized standards. These products could form at various dosages of chlorine and pH levels, and some with a concentration of 600 ng/L can be stable in tap water for days. 3,6,8-Trichloro-7-hydroxycoumarin, 3-chloro-7-methoxy-4-methylcoumarin, and 3,6-dichloro-7-methoxy-4-methylcoumarin were first identified in finished water with concentrations of 0.0670, 78.1, and 14.7 ng/L, respectively, but not in source water, suggesting that they are new DBPs formed during disinfection. The cytotoxicity of 3-chloro-7-methoxy-4-methylcoumarin in CHO-K1 cells was comparable to those of 2,6-dibromo-1,4-benzoquinone and 2,6-dichloro-1,4-benzoquinone in TIC-Tox analyses, suggesting that further investigation of their occurrence and control in drinking water systems is warranted.

25. 题目: Role of biochar in superoxide-dominated dye degradation in catalyst-activated peroxymonosulphate process
文章编号: N24041916
期刊: Chemosphere
作者: E Nandana, Anand Harsh Dwivedi, P V Nidheesh
更新时间: 2024-04-19
摘要: In recent times, the application of biochar (BC) as an upcoming catalyst for the elimination of recalcitrant pollutants has been widely explored. Here, an iron loaded bamboo biochar activated peroxymonosulphate (PMS) process was tested for removing Congo red (CR) dye from water medium. The catalyst was synthesized using a green synthesis method using neem extracts and characterized using SEM, FTIR, and XRD. The effects of various operating parameters, including solution pH, catalyst dosage, and pollutant dosage, on dye degradation efficiency were examined. The results showed that at the optimized conditions of 300 mg L PMS concentration, 200 mg L catalyst dosage, and pH 6, about 89.7% of CR dye (initial concentration 10 ppm) was removed at 60 min of operation. Scavenging experiments revealed the significant contribution of O, OH, and O for dye degradation, with a major contribution of O. The activation of PMS was mainly done by biochar rather than iron (loaded on biochar). The catalyst was highly active even after four cycles.

26. 题目: Long-term conservation tillage increase cotton rhizosphere sequestration of soil organic carbon by changing specific microbial CO2 fixation pathways in coastal saline soil
文章编号: N24041915
期刊: Journal of Environmental Management
作者: Xunya Su, Le Zhang, Hao Meng, Han Wang, Jiaxue Zhao, Xuezhen Sun, Xianliang Song, Xiaopei Zhang, Lili Mao
更新时间: 2024-04-19
摘要: Coastal saline soil is an important reserve resource for arable land globally. Data from 10 years of continuous stubble return and subsoiling experiments have revealed that these two conservation tillage measures significantly improve cotton rhizosphere soil organic carbon sequestration in coastal saline soil. However, the contribution of microbial fixation of atmospheric carbon dioxide (CO) has remained unclear. Here, metagenomics and metabolomics analyses were used to deeply explore the microbial CO fixation process in rhizosphere soil of coastal saline cotton fields under long-term stubble return and subsoiling. Metagenomics analysis showed that stubble return and subsoiling mainly optimized CO fixing microorganism (CFM) communities by increasing the abundance of , , and , and improving composition diversity. Conjoint metagenomics and metabolomics analyses investigated the effects of stubble return and subsoiling on the reverse tricarboxylic acid (rTCA) cycle. The conversion of citrate to oxaloacetate was inhibited in the citrate cleavage reaction of the rTCA cycle. More citrate was converted to acetyl-CoA, which enhanced the subsequent CO fixation process of acetyl-CoA conversion to pyruvate. In the rTCA cycle reductive carboxylation reaction from 2-oxoglutarate to isocitrate, synthesis of the oxalosuccinate intermediate product was inhibited, with strengthened CO fixation involving the direct conversion of 2-oxoglutarate to isocitrate. The collective results demonstrate that stubble return and subsoiling optimizes rhizosphere CFM communities by increasing microbial diversity, in turn increasing CO fixation by enhancing the utilization of rTCA and 3-hydroxypropionate/4-hydroxybutyrate cycles by CFMs. These events increase the microbial CO fixation in the cotton rhizosphere, thereby promoting the accumulation of microbial biomass, and ultimately improving rhizosphere soil organic carbon. This study clarifies the impact of conservation tillage measures on microbial CO fixation in cotton rhizosphere of coastal saline soil, and provides fundamental data for the improvement of carbon sequestration in saline soil in agricultural ecosystems.

27. 题目: Variation of soil organic matter with particle size in the wind erosion region of northern China
文章编号: N24041914
期刊: Catena
作者: Xintong Wu, Saiya Wang, Hong Cheng, Yang Yang
更新时间: 2024-04-19
摘要: Soil wind erosion is one of the most important surface processes in the arid and semi-arid regions of northern China, which serves as an important driver for the migration and turnover of soil organic matter (SOM) and should be given full attention in regional as well as in global carbon cycles. Wind tends to transport fine soil particles typically enriched with SOM, which, however, has been frequently ignored and the mean SOM of the bulk soil is instead used in the carbon budgets at various scales. The objective was then to characterize the variations of SOM with soil particle size and to establish the predictive models for SOM in the wind erosion region of northern China. A total of 84 soil samples were collected in the wind erosion region of northern China, covering 3 climatic regions, 17 erodible soil types, and 5 land uses. Each sample was sieved into 8 size classes of 0–63, 63–100, 100–150, 150–200, 200–250, 250–300, 300–400 and 400–880 μm using the classical dry sieving method, and the potassium dichromate volumetric method was applied to determine SOM for each class. No matter for which size class, SOM basically decreased from east to west, which was consistent with the spatial distribution trends of precipitation and the normalized difference vegetation index (NDVI). The magnitudes and variations of SOM with particle size, moreover, differed among soil types and land uses. For most of the soil samples, i.e., 63 out of the total 84 (75 %), SOM generally decreased with particle size. Whereas for the remaining samples, SOM tended to increase or remained rather consistent as the particle size increased. The relationships between SOM and particle size highly depended on the climatic factors of precipitation and temperature, as well as the vegetation type and health as indicated in the magnitudes of NDVI. The corresponding models developed exhibited high accuracies for SOM prediction, which were capable of explaining 70–90 % of the total SOM variations. These findings hold important implications for understanding the mechanisms of carbon loss in the wind erosion region of northern China.

28. 题目: Influence of dissolved organic matter with different molecular weight from chicken manure on ferrihydrite adsorption and re-release of antimony(V)
文章编号: N24041913
期刊: Journal of Environmental Management
作者: Xiaoshan Qiu, Meiqing Chen, Pingxiao Wu, Yihao Li, Leiye Sun, Zhongbo Shang, Tianming Wang, Zhi Dang, Nengwu Zhu
更新时间: 2024-04-19
摘要: Applying organic fertilizer is the main way to enhance soil fertility through the interfacial reaction between mineral and dissolved organic matter (DOM). However, the interfacial reaction between minerals and DOM may influence antimony(V) (Sb(V)) mobility in agricultural soils around antimony mines. In our study the ferrihydrite (Fh) was chosen as a representative mineral, to reveal the effect of its interaction with chicken manure organic fertilizer (CM-DOM) with Fh on Sb(V) migration. In this study, we investigated different organic matter molecular weights and C/Fe molar ratios. Our findings indicated that the addition of CM-DOM decreased the adsorption of Sb(V) by Fh and promoted the re-release of Sb(V) adsorbed on Fh. This effect was enhanced by increasing the C/Fe molar ratio. Fh mainly affects its interaction with Sb(V) through electrostatic gravitational interaction and ligand exchange, but the presence of CM-DOM weakens the electrostatic interaction between Fh and Sb(V) as well as competes with Sb(V) for the hydroxyl reactive site on Fh surface. In addition, the smaller molecular weight fraction (<10 kDa) of CM-DOM has higher aromaticity and hydrophobicity, which potentially leads to more intense competition with Sb(V) for the reaction sites on Fh. Therefore, the application of organic fertilizer may promote Sb(V) migration, posing significant risks to soil ecosystems and human health, which should be a concern in field soil cultivation.

29. 题目: Short-term effects of biochar and compost on soil microbial community, C and N cycling, and lettuce (Lactuca sativa L.) yield in a Mediterranean environment
文章编号: N24041912
期刊: Applied Soil Ecology
作者: L Massaccesi, I Nogués, V Mazzurco Miritana, L Passatore, M Zacchini, F Pietrini, S Carloni, R Marabottini, M C Moscatelli, S Marinari
更新时间: 2024-04-19
摘要: Despite the use of biochar as a soil amendment has been widely studied as a promising strategy for climate change mitigation, to date, due to the extremely heterogeneous nature of this material, there is not a general agreement of the scientific community about its soil amendment potential. In the present paper, a comprehensive approach has been adopted to test the short-term effects of biochar alone or in combination with compost on soil biochemical properties related to C and N cycling functions, microbial community, and lettuce ( L.) yield in a Mediterranean environment. With this purpose, a randomized block field trial was set up within an experimental area of about 500 m. The four treatments tested were: 1) Control (C), no treatment; 2) Compost (CMP); 3) Biochar (BIO); 4) Compost-Biochar mixture (CMP + BIO in the ratio 9:1 /w). After 45 days of cultivation, the biomass of well-developed lettuce plants was increased from 2- to 2.5-fold in all amended soils with respect to the control one. The CMP amended soils showed a higher effect with respect to the BIO amended soils on enzymatic activities (increase in β-glucosidase, SEI, synthetic enzymatic index, and butyrate esterase) and microbial community structure evaluated by the Ester-linked Fatty Acid Methyl Ester (El-FAME) profiling (increase in G- bacteria, total fungi, and AMF). The increase in the activity and abundance of the microbial community in CMP amended soils could indicate that the organic matter provided by the compost is more readily mineralized than that added with the biochar. Moreover, the BIO amended soils showed the lowest qCO and ecoenzymatic C:N ratio and the highest MIC (1.4 %), indicating a C immobilization process into the microbial biomass and a greater limitation for N with respect to C, offset by an increase in N-cycling enzyme activity. In the short term, even if the number of well-developed plants increased in all treated soils, a boost of soil C and N cycling was evident with CMP and BIO amendments respectively. Conversely, the combination of CMP with BIO (CMP + BIO) did not provide any synergic effect, probably because requiring longer periods. For these reasons repeated combined treatments can be suggested to reach a cumulative effect on soil quality over time using a balanced C:N ratio in the mixture amendment.

30. 题目: Positive profile of natural small molecule organic matters on emerging antivirus pharmaceutical elimination in advance reduction process: A deep dive into the photosensitive mechanism of triplet excited state compounds
文章编号: N24041911
期刊: Water Research
作者: Jing Yang, Yongjie Fan, Zhilei Lu, Yuxin Guo, Jintao Huang, Kaicong Cai, Qiyuan Sun, Feifeng Wang
更新时间: 2024-04-19
摘要: Natural small molecular organic matter (NSOM), ubiquitous in natural waters and distinct from humic acid or fulvic acid, is a special type of dissolved organic matter (DOM) which is characterized as strong photosensitivity and simple molecular structure. However, little study had been directed on the role of NSOM in eliminating emerging contaminants in advanced reduction process (ARP). This study took three small molecular isomeric organic acids (p−hydroxybenzoic acid, pHBA; salicylic acid, SA; m−hydroxybenzoic acid, mHBA) as the representative substances of NSOM to explore these mechanisms on promoting Ribavirin (RBV, an anti COVID−19 medicine) degradation in ultraviolet activated sulfite (UV/Sulfite) process. The results demonstrated that the observed degradation rate constant of RBV (k) was 7.56 × 10 s in UV/Sulfite process, indicating that hydrated electron (e) from UV/Sulfite process could not effectively degrade RBV, while it increased by 178 and 38 times when pHBA and SA were introduced into UV/Sulfite process respectively, suggesting that pHBA and SA strongly promoted RBV degradation while mHBA had no promotion on RBV abatement in UV/Sulfite process. Transient absorption spectra and reactive intermediates scavenging experiment indicated that the triplet excited state pHBA and SA (pHBA* and SA*) contributed to the degradation of RBV through non−radical process. Notably, e played the role of key initiator in transforming pHBA and SA into their triplet states. The difference of k in UV/Sulfite/pHBA and UV/Sulfite/SA process was attributed to different generation pathways of pHBA* and SA* (high molar absorptivity at the wavelength of 254 nm and photosensitive cycle, respectively) and their second order rate constants towards RBV (k = 8.60 × 10 M s and k = 6.81 × 10 M s). mHBA could not degrade RBV for its lack of intramolecular hydrogen bond and low molar absorptivity at 254 nm to abundantly transform into its triplet state. k increased as pH increased from 5.0 to 11.0 in UV/Sulfite/SA process, due to the high yield of e in alkaline condition which promoted the generation of SA* and the stable of the absorbance of SA at 254 nm. By contrast, k underwent a process of first increasing and then decreasing in UV/Sulfite/pHBA process as the increase of pH, and its highest value achieved in a neutral condition. This lied in the exposure of e increased as the increase of pH which promoted the generation of pHBA*, while the molar absorptivity of pHBA at 254 nm decreased as the increase of pH in an alkaline condition which inhibited the yield of pHBA*. The RBV degradation pathways and products toxicity assessment indicated that UV/Sulfite/pHBA had better detoxification performance on RBV than UV/Sulfite/SA process. This study disclosed a novel mechanism of emerging contaminants abatement through non-radical process in NSOM mediated ARP, and provide a wide insight into positive profile of DOM in water treatment process, instead of only taking DOM as a quencher of reactive intermediates.

31. 题目: Molecular transformation of dissolved organic matter in manganese ore-mediated constructed wetlands for fresh leachate treatment
文章编号: N24041910
期刊: Journal of Environmental Management
作者: Md. Hasibur Rahaman, Tong Yang, Zhongyi Zhang, Wenbo Liu, Zhongbing Chen, Jacek Mąkinia, Jun Zhai
更新时间: 2024-04-19
摘要: The organic matter (OM) and nitrogen in Fresh leachate (FL) from waste compression sites pose environmental and health risks. Even though the constructed wetland (CW) can efficiently remove these pollutants, the molecular-level transformations of dissolved OM (DOM) in FL remain uncertain. This study reports the molecular dynamics of DOM and nitrogen removal during FL treatment in CWs. Two lab-scale vertical-flow CW systems were employed: one using only sand as substrates (act as a control, CW-C) and the other employing an equal mixture of manganese ore powder and sand (experimental, CW-M). Over 488 days of operation, CW-M exhibited significantly higher removal rates for chemical oxygen demand (COD), ammonia nitrogen (NH-N), and dissolved organic matter (represented by dissolved organic carbon, DOC) at 98.2 ± 2.5%, 99.2 ± 1.4%, and 97.9 ± 1.9%, respectively, in contrast to CW-C (92.8 ± 6.8%, 77.1 ± 28.1%, and 74.7 ± 9.5%). The three-dimensional fluorescence excitation-emission matrix (3D-EEM) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analyses unveiled that the influent DOM was predominantly composed of readily biodegradable protein-like substances with high carbon content and low unsaturation. Throughout treatment, it led to the degradation of low O/C and high H/C compounds, resulting in the formation of DOM with higher unsaturation and aromaticity, resembling humic-like substances. CW-M showcased a distinct DOM composition, characterized by lower carbon content yet higher unsaturation and aromaticity than CW-C. The study also identified the presence of , reported as Mn-oxidizing bacteria with significantly higher abundance in the upper and middle layers of CW-M, facilitating manganese cycling and improving DOM removal. Key pathways contributing to DOM removal encompassed adsorption, catalytic oxidation by manganese oxides, and microbial degradation. This study offers novel insights into DOM transformation and removal from FL during CW treatment, which will facilitate better design and enhanced performance.

32. 题目: Upstream land use with microbial downstream consequences: Iron and humic substances link to Legionella spp.
文章编号: N24041909
期刊: Water Research
作者: Jon Ahlinder, Karolina Ida Anna Eriksson, Maria Hellmér, Emelie Salomonsson, Malin Granberg, Ingrid Dacklin, Josefine Elving, Björn Brindefalk
更新时间: 2024-04-19
摘要: Intensified land use can disturb water quality, potentially increasing the abundance of bacterial pathogens, threatening public access to clean water. This threat involves both direct contamination of faecal bacteria as well as indirect factors, such as disturbed water chemistry and microbiota, which can lead to contamination. While direct contamination has been well described, the impact of indirect factors is less explored, despite the potential of severe downstream consequences on water supply. To assess direct and indirect downstream effects of buildings, farms, pastures and fields on potential water sources, we studied five Swedish lakes and their inflows. We analysed a total of 160 samples in a gradient of anthropogenic activity spanning four time points, including faecal and water-quality indicators. Through species distribution modelling, Random Forest and network analysis using 16S rRNA amplicon sequencing data, our findings highlight that land use indirectly impacts lakes via inflows. Land use impacted approximately one third of inflow microbiota taxa, in turn impacting ∼20–50 % of lake taxa. Indirect effects via inflows were also suggested by causal links between e.g. water colour and lake bacterial taxa, where this influenced the abundance of several freshwater bacteria, such as and . However, it was not possible to identify direct effects on the lakes based on analysis of physiochemical- or microbial parameters. To avoid potential downstream consequences on water supply, it is thus important to consider possible indirect effects from upstream land use and inflows, even when no direct effects can be observed on lakes. (a genus containing bacterial pathogens) illustrated potential consequences, since the genus was particularly abundant in inflows and was shown to increase by the presence of pastures, fields, and farms. The approach presented here could be used to assess the suitability of lakes as alternative raw water sources or help to mitigate contaminations in important water catchments. Continued broad investigations of stressors on the microbial network can identify indirect effects, avoid enrichment of pathogens, and help secure water accessibility.

33. 题目: Feasibility study of Aesculus turbinata fruit shell-derived biochar for ammonia removal in wastewater and its subsequent use as nitrogen fertilizer
文章编号: N24041908
期刊: Chemosphere
作者: Jae-In Lee, Chuluuntsetseg Jadamba, Chang-Gu Lee, Sung-Chang Hong, Jin-Ho Kim, Soo-Cheul Yoo, Seong-Jik Park
更新时间: 2024-04-19
摘要: In the face of increasing nitrogen demand for crop cultivation driven by population growth, this study presents a sustainable solution to address both the heightened demand and the energy-intensive process of nitrogen removal from wastewater. Our approach involves the removal of nitrogen from wastewater and its subsequent return to the soil as a fertilizer. Using biochar derived from fruit shells (ATFS), a by-product of post-medical use, we investigated the effect of pyrolysis temperature on the NH–N adsorption capacity of ATFS biochar (ATFS-BC). Notably, the ATFS-BC pyrolyzed at 300 °C (ATFS-BC300) exhibited the highest NH–N adsorption capacity of 15.61 mg/g. The superior performance of ATFS-BC300 was attributed to its higher number of oxygen functional groups and more negatively charged surface, which contributed to the enhanced NH–N adsorption. The removal of NH–N by ATFS-BC300 involved both physical diffusion and chemisorption, with NH–N forming a robust multilayer adsorption on the biochar. Alkaline conditions favored NH–N adsorption by ATFS-BC300; however, the presence of trivalent and divalent ions hindered this process. Rice plants were cultivated to assess the potential of NH–N adsorbed ATFS-BC300 (NH-ATFS-BC300) as a nitrogen fertilizer. Remarkably, medium doses of NH-ATFS-BC300 (594.5 kg/ha) exhibited key agronomic traits similar to those of the commercial nitrogen fertilizer in rice seedlings. Furthermore, high doses of NH-ATFS-BC300 demonstrated superior agronomic traits compared to the commercial fertilizer. This study establishes the viability of utilizing ATFS-BC300 as a dual-purpose solution for wastewater treatment and nitrogen fertilizer supply, presenting a promising avenue for addressing environmental challenges.

34. 题目: Tracking the changes of dissolved organic matter throughout the city water supply system with optical indices
文章编号: N24041907
期刊: Journal of Environmental Management
作者: Jinjin Lin, Liyang Yang, Wan-E Zhuang, Yue Wang, Xiaochen Chen, Jia Niu
更新时间: 2024-04-19
摘要: Dissolved organic matter (DOM) is important in determining the drinking water treatment and the supplied water quality. However, a comprehensive DOM study for the whole water supply system is lacking and the potential effects of secondary water supply are largely unknown. This was studied using dissolved organic carbon (DOC), absorption spectroscopy, and fluorescence excitation-emission matrices-parallel factor analysis (EEM-PARAFAC). Four fluorescent components were identified, including humic-like C1–C2, tryptophan-like C3, and tyrosine-like C4. In the drinking water treatment plants, the advanced treatment using ozone and biological activated carbon (O-BAC) was more effective in removing DOC than the conventional process, with the removals of C1 and C3 improved by 17.7%–25.1% and 19.2%–27.0%. The absorption coefficient and C1–C4 correlated significantly with DOC in water treatments, suggesting that absorption and fluorescence could effectively track the changes in bulk DOM. DOM generally remained stable in each drinking water distribution system, suggesting the importance of the treated water quality in determining that of the corresponding network. The optical indices changed notably between distribution networks of different treatment plants, which enabled the identification of changing water sources. A comparison of DOM in the direct and secondary water supplies suggested limited impacts of secondary water supply, although the changes in organic carbon and absorption indices were detected in some locations. These results have implications for better understanding the changes of DOM in the whole water supply system to help ensure the supplied water quality.

35. 题目: Temporal drivers of tryptophan-like fluorescent dissolved organic matter along a river continuum
文章编号: N24041906
期刊: Science of the Total Environment
作者: N A Harris, J P R Sorensen, B Marchant, G H Old, P S Naden, M J Bowes, P M Scarlett, D J E Nicholls, L K Armstrong, H D Wickham, D S Read, D Lapworth, T Bond, K Pond
更新时间: 2024-04-19
摘要: Tryptophan-like fluorescence (TLF) is used to indicate anthropogenic inputs of dissolved organic matter (DOM), typically from wastewater, in rivers. We hypothesised that other sources of DOM, such as groundwater and planktonic microbial biomass can also be important drivers of riverine TLF dynamics. We sampled 19 contrasting sites of the River Thames, UK, and its tributaries. Multivariate mixed linear models were developed for each site using 15 months of weekly water quality observations and with predictor variables selected according to the statistical significance of their linear relationship with TLF following a stepwise procedure. The variables considered for inclusion in the models were potassium (wastewater indicator), nitrate (groundwater indicator), chlorophyll-a (phytoplankton biomass), and Total bacterial Cells Counts (TCC) by flow cytometry. The wastewater indicator was included in the model of TLF at 89 % of sites. Groundwater was included in 53 % of models, particularly those with higher baseflow indices (0.50–0.86). At these sites, groundwater acted as a negative control on TLF, diluting other potential sources. Additionally, TCC was included positively in the models of six (32 %) sites. The models on the Thames itself using TCC were more rural sites with lower sewage inputs. Phytoplankton biomass (Chlorophyll-a) was only used in two (11 %) site models, despite the seasonal phytoplankton blooms. It is also notable that, the wastewater indicator did not always have the strongest evidence for inclusion in the models. For example, there was stronger evidence for the inclusion of groundwater and TCC than wastewater in 32 % and 5 % of catchments, respectively. Our study underscores the complex interplay of wastewater, groundwater, and planktonic microbes, driving riverine TLF dynamics, with their influence determined by site characteristics.

36. 题目: Measurement and prediction of gas permeability function for biochar-amended rooted soils
文章编号: N24041905
期刊: Geoderma
作者: X Huang, W Cai, S Bordoloi
更新时间: 2024-04-19
摘要: Biochar amendment have been explored recently for improving hydro-mechanical properties of landfill cover system and enhancing the vegetation for the ecological restoration of post closure landfills. Existing studies have predominantly focused on the hydro-mechanical properties of biochar-amended rooted soils and yet few studies have comprehensively investigated their gas permeability functions in response to unsaturated conditions. The objective of this study is to experimentally and theoretically investigate the coupled effects of biochar and root intensity on CO gas permeability in unsaturated soil. Biochar-amended rooted soil was prepared by growing on granite residual soils with biochar at a mas ratio of 5 %. Gas permeability and unsaturated soil properties (i.e., suction and degree of saturation) were monitored simultaneously. Due to the presence of roots, the maximum gas permeability, hydraulic conductivity, and suction increased by 200 %, 600 %, and 50 %, respectively, compared with bare soil. This was attributed to preferential flow, micropore increasement and negative pressure induced by root growth. However, biochar addition decreased the maximum gas permeability and hydraulic conductivity by 21 % and 33 %, respectively. This was attributed to the pore filling function of biochar, increased capillarity due to intrapore of biochar, and presence of surface functional groups in biochar promoting CO adsorption. A newly developed model was proposed to predict gas permeability with respected to unsaturated soil properties. It was revealed that the gas permeability function of rooted soils showed a strong dependence on the measured root length density. This study highlights the significance of adopting biochar in mitigation of gas emissions in vegetated landfill cover system.

37. 题目: Unrecognized volatile and semi-volatile organic compounds from brake wear
文章编号: N24041904
期刊: Environmental Science: Processes & Impacts
作者: V Perraud, D R Blake, L M Wingen, B Barletta, P S Bauer, J Campos, M J Ezell, A Guenther, K N Johnson, M Lee, S Meinardi, J Patterson, E S Saltzman, A E Thomas, J N Smith, B J Finlayson-Pitts
更新时间: 2024-04-19
摘要: Motor vehicles are among the major sources of pollutants and greenhouse gases in urban areas and a transition to “zero emission vehicles” is underway worldwide. However, emissions associated with brake and tire wear will remain. We show here that previously unrecognized volatile and semi-volatile organic compounds, which have a similarity to biomass burning emissions are emitted during braking. These include greenhouse gases or, these classified as Hazardous Air Pollutants, as well as nitrogen-containing organics, nitrogen oxides and ammonia. The distribution and reactivity of these gaseous emissions are such that they can react in air to form ozone and other secondary pollutants with adverse health and climate consequences. Some of the compounds may prove to be unique markers of brake emissions. At higher temperatures, nucleation and growth of nanoparticles is also observed. Regions with high traffic, which are often disadvantaged communities, as well as commuters can be impacted by these emissions even after combustion-powered vehicles are phased out.

38. 题目: Priming effects by cellulose inputs decrease with warming regardless of the decomposition stages of soil carbon pools
文章编号: N24041903
期刊: Plant and Soil
作者: Junjie Lin, Guoxin Lan, Zhenyu Yang, Shuang Zhou, Dafeng Hui, Peng Wang, Shuai Zhang, Lifeng Ping, Shengdao Shan
更新时间: 2024-04-19
摘要:

Aims

Soil comprises diverse carbon (C) pools undergoing various decomposition stages, each characterized by distinct stability and turnover rates. The response of these C pools to warming with the input of plant residues remains unclear.

Methods

We conducted a 90-day incubation study at 15 °C and 25 °C, introducing 13C-labeled cellulose into soils from old-field (OF), bare-fallow (BF), and bare-fallow plus 815-day pre-incubation (BF+) representing different stages of soil organic matter decomposition.

Results

We estimated the priming effects (PE) of cellulose and found that PE were 30.6%, 59.3%, and 63.0% at 15 °C, and 20.8%, 35.3%, and 39.8% at 25 °C for OF, BF, and BF + soils, respectively. Net C balance was higher in BF and BF + soils than in OF soil by 0.6 − 2.8 mg C g−1 SOC at 15 °C and 1.8 − 3.8 mg C g−1 SOC at 25 °C. This indicated both PE and net C balance declined with warming regardless of soil C pool stability, but much greater in soil C pools at a slower decomposition stage.

Conclusions

Overall, this study underscores warming can uniformly decrease soil C sequestration potential although the distinct priming effects of the soil C pools at different decomposition stages.

39. 题目: Sensitivity of active and stable organic nitrogen to nitrogen and carbon additions: insights from enzymatic hydrolyses in a semi-arid steppe
文章编号: N24041902
期刊: Plant and Soil
作者: Muyu Tian, Nan Jiang, Chunjia Yu, Yulan Zhang, Weiwen Qiu, Zhenhua Chen, Jingkuan Wang, Lijun Chen
更新时间: 2024-04-19
摘要:

Aims

The degradation and transformation of soil organic nitrogen (SON) in semi-arid steppe are regulated by a series of enzymes involved in nitrogen(N) hydrolysis, the influence of N and carbon (C) additions on the soil N reserves, activities of N-hydrolyzing enzymes, and their relationships remain unclear.

Methods

In the Inner Mongolia prairie of China, a field experiment was conducted to study the effects of N (0, 25, 50, 100, 200 kg N ha−1 yr−1) and C (0, 250, 500 kg C ha−1 yr−1) additions on SON fractions and their relationships with N-hydrolyzing enzymes.

Results

Our results indicated that N addition significantly increased active-SON and N-acetyl-β-D-glucosaminidase (NAG) activities and decreased urease activities. C addition significantly increased microbial biomass carbon (MBC), NAG, and urease activities, and decreased protease activity and hydrolyzable unknown-N. N and C additions interacted affected the microbial biomass nitrogen (MBN), MBC: MBN, protease, and amidase activities. Structural equation modeling suggested that N addition had a direct positive effect on hydrolyzable NH4+-N and amino acid-N. Furthermore, N addition indirectly affected amino sugar-N through MBN and the activities of NAG and protease. C addition directly affected urease activity.

Conclusion

Our findings suggest that active-SON responded significantly to N addition, whereas stable-SON did not. Moreover, N-hydrolysis enzymes, especially NAG and proteases, play a fundamental role in the N turnover under N and C additions in semi-arid steppe soils. As such, our work provides useful information for the development of sustainable steppe farming practices.

40. 题目: Insights into the Role of Photobleaching on the Photophysical and Photochemical Properties of Dissolved Black Carbon
文章编号: N24041901
期刊: ACS ES&T Water
作者: Hui Wang, Huaxi Zhou
更新时间: 2024-04-19
摘要: The photochemical behavior of dissolved black carbon (DBC) has attracted increasing attention since DBC plays an important role in the migration and transformation of environmental contaminants in natural waters. However, little is known about the influence of photobleaching on the physicochemical properties of DBC and DBC-involved photodegradation of micropollutants. Herein, photobleaching of DBC was characterized systematically by spectroscopy, chromatography, and probe methods. Size exclusion chromatography and reactive intermediate (RI) determination results suggested that low molecular weight (MW) moieties (<1k Da) in DBC and high MW moieties (>10k Da) in NOM played a pivotal role in the formation of RIs. Following 120 h of photobleaching, the formation of RIs in DBC all decreased remarkably, while the RI yields for NOM were increased. In addition, the decay rate constants for triplet-labile and HO-labile pharmaceutical and personal care products in a DBC solution after 48 h of bleaching were about an order of magnitude lower than those values in a DBC solution without bleaching, probably due to the attenuation of the intermolecular absorption. This study will not only provide useful insights into the photochemical properties of DBC but also reveal the pivotal role of photobleaching in the phototransformation of organic contaminants in natural waters.

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