CHEMOSPHERE
·
2022
·
IF 8.943
Boqiang Li,Fei Yang,Baiyang Chen,Juan Li,Lijuan Zhu,Wen-Tao Li
Dissolved organic nitrogen (DON) plays a key role in many biogeochemistry and engineering processes such as forming nitrogenous disinfection byproducts . However, detecting aqueous DON at trace levels is challenging currently because conventional DON conversion methods have very high method detection limits (MDL). In addition, DON is measured indirectly by subtracting dissolved inorganic nitrogen (DIN) from total dissolved nitrogen (TDN), which can propagate analytical errors of each analyte. In order to solve these issues, we isolated DON from DIN with electrodialysis before and herein tested vacuum ultraviolet (VUV) in tandem with several oxidants to convert DON completely into nitrate for subsequent N analysis. Results showed that H 2 O 2 was more suitable than chlorine and persulfate because VUV/chlorine or VUV/persulfate is either inefficient to convert DON or subjected to nonnegligible N loss. To verify the efficiency, we evaluated the effects of typical water and operating variables on the conversions of four model DON compounds and their yields of nitrate. Under optimal conditions (pH 10.3 and 500 mg/L H 2 O 2 ), the process converted DON completely into nitrate within just 60 min. Compared to conventional TDN analytical methods, the VUV/H 2 O 2 method features not only better analytical precision but also lower MDL because the formed nitrate can be analyzed at very low MDL by ion chromatography (IC). So, this approach moves one step further to achieve a conceptually new DON analytical method by coupling electrodialysis, VUV/H 2 O 2 , and IC.
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
高影响因子
WATER RESEARCH
·
2025
·
IF 12.4
Xinyu Li,Cui Zeng,Xiurong Han,Liqiang Fan,Jing Zhao,Yingzhe Wang,Xiulin Wang,Keqiang Li
Multitudinous dissolved organic nitrogen (DON) enters seawater from Ulva prolifera green tides impacting phytoplankton community structure in the Yellow Sea. Field investigations and cultural experiments on U. prolifera -derived DON aging revealed its regulatory effects. The green-tide outbreak area of the Southern Yellow Sea exhibits a seasonal cycle where dominance shifts from diatoms to dinoflagellates effected by young to aging U. prolifera -derived DON from summer to spring. Diatom abundance rose significantly following the summer green tide outbreak, fueled by young, protein-rich DON released by U. prolifera . After autumn and winter aging, U. prolifera -derived DON was dominant from protein-like to humic-like components, and dinoflagellates bloomed in the green tide outbreak area. An aging U. prolifera -derived DON adding culture experiment of Chaetoceros curvisetus and Prorocentrum minimum proved that old and young DON promoted dinoflagellate and diatom growth, respectively. Diatoms preferred 0 and 12 days-aged DON (DON 0 and DON 12 ) with tyrosine B and tryptophan T components, whereas dinoflagellate favored 80 days-aged DON (DON 80 ) with humic acid E and UV fulvic acid A components. DON 0 and DON 12 can be absorbed by diatoms with higher uptake ( k up ) and growth ( k G ) constants than by dinoflagellates under low leucine aminopeptidase (LAP) conditions. Dinoflagellates absorb old DON with higher k up and k G values under higher LAP concentrations than diatoms. This was consistent with the loop of U. prolifera -derived DON turning over the seasonal succession of diatom dinoflagellates in the green-tide outbreak area. This study revealed mechanism of seasonal dinoflagellate- U. prolifera -diatom cycle, and provided new insights for impacts of U. prolifera green tides on phytoplankton regime shift, thus, acting as a basis for marine management strategies.
研究领域:
海洋生物学
·
生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2015
·
IF 5.636
Anbang Zhu,Baiyang Chen,Liang Zhang,Paul Westerhoff
This study evaluated electrodialysis (ED) for direct, accurate, and precise dissolved organic nitrogen (DON) analysis in water. Unlike conventional methods that calculate DON as the difference between total dissolved nitrogen (TDN) and dissolved inorganic nitrogen (DIN), we designed a compact ED reactor as a pretreatment tool that completely separates DIN from DON in water and then measures DON by equating DON to TDN. The experiments confirmed that the ED pretreatment process can achieve 99% removal of all three major DIN species (i.e., ammonia, nitrite, and nitrate) and an average recovery rate of 88% for an array of model DON compounds of varying characteristics (e.g., urea, amino acids, tripeptide, protein, and humic substances). Variations in nitrogen removal and recovery might be explained by a combined effect of molecular weight, acid dissociation ability (pKa), aromaticity, and ED reactor configurations. For model solutions with DIN/DON ratios varying from 1 to 10 mg-N/mg-N, the relative standard deviations in DON concentrations were considerably lower with ED pretreatment (<10%) than without pretreatment (47%). A survey of seven field samples, including lake water, tap water, and treated wastewater, also demonstrated the benefits of using ED pretreatment as compared with a conventional DON analysis method. Overall, this study provides evidence and mechanistic insight for a new DON detection method that uses ED pretreatment. The ED unit is robust for separating DIN and DON, and thus it may facilitate more frequent detection of DON and ultimately enhances understanding of DON issues in the environmental studies.
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
Environmental Technology & Innovation
·
2025
·
IF 7.1
Hua Huang,Xiaoyan Liu,Xianying Shan,Jingrong Yang,Lijuan Ding,Rongyu Zhang,Jiale Dai,Yanzhong Zhen,Jian Wang,Di Guo,Yu Liu,Wenfeng Jiang,Zhirui Niu
Since hydrothermal aqueous phase (HAP) contains abundant nutrients and humic-like substances, it is developed as nitrogen (N) fertilizer to improve plant growth and soil quality. However, significant NH 3 volatilization is a major drawback in dryland soil. To solve this problem, a compound fertilizer of HAP and urea was modified with various dosage (0.25 % - 5.0 %) of urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT). The NH 3 , N loss, and lettuce growth were evaluated in parallel soil column and pot experiments. Results showed that increasing NBPT dosage increased soil dissolved organic N (DON) and ON while decreased NH 4 -N, NH 3 , N loss, urease activity, and ureC . NBPT successfully inhibited ammonification. Increasing NBPT dosage increased NO 3 -N but decreased PAO and AOA . The utilization rate of metabolic substrate (NH 4 -N) was more important for forming NO 3 -N, as evidenced by the negative correlation of NO 3 -N and NH 3 . The DON from HAP included N-heterocyclic compounds, which are toxic for nitrifiers. The toxic DON also significantly decreased root dry weight by 22.31 % when 5.0 % NBPT was added. The optimal additive dosages were 0.5 % and 2.0 % in the column and pot experiments, respectively, which decreased NH 3 and N loss by 45.38 % and 32.08 %. Further increasing NBPT dosage no longer decreased N loss but did harm to plant root. Therefore, this study demonstrated that an appropriate addition of NBPT to HAP fertilizer can effectively reduce ammonia volatilization and N loss. The innovative technique would promote the utilization of HAP resource within the context of sustainable dryland agriculture.
研究领域:
农业科学
·
植物生理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
·
2024
·Vol. 129
·期 10
·e2024JC021373
·
IF 3.3
Kan Chen,Rui Yang,Min Li,Yanan Chen,Xiurong Han,Jing Zhao,Keqiang Li,Xiulin Wang
Human-induced dissolved organic nitrogen (DON) input is impacting coastal ecosystems globally, and the shift from diatoms to dinoflagellates may be associated with increasing DON concentrations and changing DON compositions. Based on field microcosm experiments, changes in three-dimensional fluorescence component and extracellular leucine aminopeptidase activity were used to reveal the effects of DON on diatom and dinoflagellate growth. Additionally, a Nutrients–bi-Phytoplankton–Detritus biogeochemical model was employed to elucidate the kinetic mechanism of DON on the shift from diatoms to dinoflagellates in the Bohai Sea (BS). Our results revealed that shifting diatom–dinoflagellate dominance was associated with the hydrophobic component of terrestrial DON. Dinoflagellates (i.e., Karenia mikimotoi ) efficiently assimilated humic-like substances in hydrophobic DON; whereas, diatoms (i.e., Chaetoceros spp.) efficiently utilized the protein-like components in hydrophilic DON. The reason for this was the higher extracellular leucine aminopeptidase activity of dinoflagellates compared to that of diatoms, which enabled them to degrade humic-like substances and protein-like components more effectively. The modeling study clarified that the DON composition, particularly the proportion of hydrophobic DON, regulated the shift from diatoms to dinoflagellates. Our study provides insight into the mechanisms underlying phytoplankton regime shifts in the BS and valuable guidance for decreasing eutrophication by controlling terrestrial DON inputs and compositions. Key Points Karenia mikimotoi can efficiently assimilate humic-like substances Chaetoceros spp. can efficiently utilize protein-like components Karenia mikimotoi has higher extracellular leucine aminopeptidase activity than Chaetoceros spp. Plain Language Summary Human-induced nitrogen input is causing major changes in coastal ecosystems worldwide and posing a threat to human well-being. In the Bohai Sea (BS), the increase in DON concentrations and changes in its composition have been linked to harmful algal blooms and a shift from diatom to dinoflagellate dominance. This study investigated the mechanism behind the shift from diatoms to dinoflagellates using field experiments, a biogeochemical model, and techniques for analyzing organic chemicals. Our findings indicated that dinoflagellates (represented by Karenia mikimotoi ) can efficiently assimilate humic-like substances in hydrophobic DON, and that diatoms (represented by Chaetoceros spp.) can effectively utilize protein-like components in hydrophilic DON. This difference arose because of higher extracellular leucine aminopeptidase activity in dinoflagellates compared to diatoms, enabling them to degrade humic-like substances and protein-like components more effectively. Our modeling study further revealed that the DON composition, particularly the proportion of hydrophobic DON, regulated the shift from diatoms to dinoflagellates. These insights into the mechanisms driving phytoplankton regime shifts in the BS provide valuable guidance for mitigating eutrophication by controlling terrestrial DON inputs and compositions.
研究领域:
海洋生态学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
PEST MANAGEMENT SCIENCE
·
2021
·Vol. 78
·期 2
·506-520
·
IF 4.845
Ming Zhao,Hongjun Zhou,Li Hao,Huayao Chen,Xinhua Zhou
BACKGROUND As the global population grows, large quantities of agrochemicals are used to secure food demand and there is an urgent need to develop efficient and environmentally friendly pesticides and fertilizers. Compared with traditional pesticides, nanopesticide formulations can achieve better foliar wettability, chemical stability, and water dispersibility without or with the minimal use of organic solvents, in line with the development of sustainable agriculture. RESULTS In this research, glycidyl methacrylate (GMA) was used as an intermediate and glycine methyl ester (GLY) was used as an organic nitrogen source to modify carboxymethyl cellulose (CMC) to synthesize a pesticide nanocarrier CMC-PGMA-GLY. A nanopesticide EB@CMC-PGMA-GLY (EB@CPG) was formed by the hydrophobic and electrostatic interactions of emamectin benzoate (EB), which had good water dispersion. The good affinity of the composite towards leaves led to the effective moistening of the leaf surface by the pesticide and through the pH control pesticide release. Biological experiments show that nanopesticides can maintain high insecticidal activity and have no toxicity to seed germination. The results of pot experiment showed that the nanocarriers could be used as an organic nitrogen fertilizer to increase the fresh weight of plants by 39.77%. CONCLUSIONS This environmentally friendly pesticide carrier can be used as a fertilizer to provide sufficient nutrients for crops, opening a new method for the development of sustainable agriculture. © 2021 Society of Chemical Industry.
研究领域:
农业科学
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Haoyuan Zhang,Peng Gao,Yongze Liu,Ziwen Du,Li Feng,Liqiu Zhang
Nitrogenous disinfection by-products (N-DBPs) raise increasing concerns because of their high genotoxicity, cytotoxicity, and carcinogenicity compared to carbonaceous disinfection by-products (C-DBPs). Nitrogen-containing disinfectants, dissolved organic nitrogen (DON), and inorganic nitrogen may all promote the formation of N-DBPs. Therefore, it is urgent to explore the dominant nitrogen source of N-DBPs under the coexistence of multiple nitrogen sources. In this study, the effects of amino acids, nitrate, ammonia, and chloramine as different types of nitrogen sources on the formation of five N-DBPs were investigated systematically, including chloroacetonitrile (CAN), dichloroacetonitrile (DCAN), bromochloroacetonitrile (BCAN), dibromoacetonitrile (DBAN) and dichloroacetamide (DCAcAm). L-Aspartic acid (L-Asp) as the organic nitrogen source showed a high potential on the formation of N-DBPs by forming acetonitrile intermediates. Ammonia as the inorganic nitrogen source consumed oxidants and changed the existing form of chloramine, thus inhibiting the formation of N-DBPs. Instead of providing nitrogen to N-DBPs, nitrate as a salt promoted the volatilization of N-DBPs, thereby reducing the detected N-DBPs. Furthermore, an isotope labeling method was applied to clearly trace the nitrogen sources of N-DBPs via GC–MS with electron ionization. 15 N-chloramine, 15 N-amino acid, 15 N-nitrate and 15 N-ammonia were selected as the corresponding isotopic nitrogen sources. The results indicated that chloramine was the major nitrogen contributor to five N-DBPs during the chloramination of L-Asp under the coexistence of multiple nitrogen sources, ranging from 61 % to 79 %. The influence of environmental factors (reaction time, pH, and bromide) on the formation of N-DBPs during chloramination was also investigated. There was competition between brominated N-DBPs and chlorinated N-DBPs in chloramination. With the increase of reaction time or bromine, the formation potentials of chlorinated N-DBPs gradually decreased, while brominated N-DBPs gradually increased. Moreover, higher pH inhibited the generation of N-DBPs.
研究领域:
环境科学
·
公共卫生
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-13
·
IF 15.7
Yuan Ziliang,Han Bo,Liu Bing,Sun Jie,Zhou Peng,Mu Rentao,Zhang Zehui
Reductive-coupling of nitro compounds and alcohols is a sustainable route for constructing C = N bonds in organonitrogen chemicals, yet challenging due to the inertness of α-C sp3 -H bond in alcohols and the vulnerability of C = N bonds towards hydrogenation. Here, we report the surprising catalytic activity of ultrafine alkaline-earth metal oxide MgO nanoclusters (0.9 ± 0.3 nm) that efficiently activate α-C sp3 -H bonds, facilitating the transfer hydrogenation and synthesis of value-added chemicals bearing C = N bonds with high to excellent yields (86–99%). Controlled experiments and characterizations showed the crucial role of oxygen vacancies (O v ) and local Mg environment (Mg-O bond) in MgO for substrate adsorption and activation via electronic interactions between substrate’s negatively charged oxygen atoms and O v sites in MgO nanoclusters. Theoretical calculation further confirmed that O v significantly lowered the energy barrier of the hydrogen atom transfer from α-C sp3 -H in ethanol to the nitro group in nitrobenzene (29.3 vs . 52.9 kcal/mol), which is the rate-determining step with the highest energy barrier in reductive-coupling reactions. Our method not only provides an efficient and sustainable pathway for synthesizing organonitrogen chemicals with C = N bonds but also inspires the exploration of main group element catalysts as alternatives to transition metal and noble metal catalysts for organic transformations.
研究领域:
催化化学
·
材料科学
·
有机合成
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-13
·
IF 15.7
He Yingchun,Ma Dong-Dong,Ma Ke,Li Xiaofang,Han Lili,Wu Xin-Tao,Zhu Qi-Long
Electrochemically constructing C–N and N–C–N bonds provides an economical and sustainable alternative to conventional chemosynthesis. Herein, a hierarchically ordered open superstructure of N-doped carbon isolated with accessible three-coordinated Zn single-atom sites is explored for efficient electrocatalytic N–C–N coupling. Benefiting from the distinctive structural merits, this catalyst enables electrocatalytic preparation of N–C–N bonded compounds from methanol and amines. Notably, the Faradaic efficiency and selectivity of N,N,N’,N’ -tetramethyldiaminomethane reach up to 77% and 96% at 0.8 V, respectively. Further integrating the aminoalkylation reaction, an electro-thermo cascade synthesis is explored with the electrochemically obtained N,N,N’,N’ -tetramethyldiaminomethane serving as a unique reagent, leading to a specific set of organonitrogen compounds with (dimethylamino)methyl substituent, including topotecan hydrochloride, an anti-tumor drug, with a high yield of 95%. Furthermore, the in situ spectroscopic characterization and calculations unveil that the under-coordinated Zn-N 3 sites play a pivotal role in stabilizing the key *CH 2 O intermediate, thereby facilitating subsequent nucleophilic addition with amines.
研究领域:
化学
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2018
·Vol. 97
·期 4
·955-966
·
IF 1.265
Chuang Wang,Guocheng Zhu,Bozhi Ren,Peng Zhang,Andrew Hursthouse
Dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) are important components of the aquatic environment and may produce harmful disinfection by-products through chlorination associated with water treatment processes. Therefore, it is necessary to remove them from the water. Coagulation is a cost-effective water treatment technique as the key unit in the pretreatment of drinking water but deals with DON poorly. We present a study to investigate the enhancement of poly aluminum chloride (PAC) using a cationic polymer for the removal of both DON and DOC. The cationic dimethyl diallyl ammonium chloride (PDMDAAC) polymer was hybridized with PAC to remove DON and DOC. The results showed that the PDMDAAC increased the charge neutralization capacity of PAC and floc aggregation, thereby increasing the settling efficiency of the flocs. The PDMDAAC increased the amount of colloidal species in PAC, which was beneficial to the formation of adsorption-bridging. With the increase of pH, a greater proportion of colloidal adsorption sites were used in the removal of DON. The DOC, DON, and turbidity removal were dependent on multiple interactions through charge neutralization, adsorption-bridging, and floc sweeping. However, DOC and DON removal were primarily determined by adsorption-bridging and floc sweeping, while turbidity removal was mainly dependent on charge neutralization.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Jiancheng Zhao,Zhaohui Guo,Christian Marcus Pedersen,Lingyu Jia,Shiyu Jia,Xianglin Hou,Yingxiong Wang,Yan Qiao
Organonitrogen chemicals are widely used and in great demand in the food, pharmaceutical and chemical industries. Hence, it is important to develop green and efficient synthesis paths to organonitrogen chemicals for their use as new resources. Herein, we propose the preparation of organonitrogen chemicals from chitin biomass monomer N -acetyl- d -glucosamine (GlcNAc) promoted by natural deep eutectic solvents (NADESs). The selective generation of 3-acetamido-5-(1′,2′-dihydroxyethyl) furan (Chromogen III) and 3-acetamido-5-acetylfuran (3A5AF) from GlcNAc was achieved by the design of NADESs components. GlcNAc reacts in binary NADES proline-glycerol (Pro-Gly) to generate 26 % of Chromogen III and 39 % of 3A5AF in ternary NADES proline-glycerol-lactic acid (Pro-Gly-LA). In addition, the intermolecular hydrogen bonds in NADESs were confirmed through 1 H diffusion-ordered spectroscopy (DOSY) NMR technology. And the results of 13 C NMR chemical shift titration indicated interaction between NADESs and the C3 and C6 position of GlcNAc. Based on the NMR experiments a mechanism is proposed.
研究领域:
生物化学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2022
·
IF 8.91
Hui Wang,Yan Xiang,Wei Liu,Jiyang Li,Nanwen Zhu,Ziyang Lou
Low-molecular-weight dissolved organic nitrogen (LMW-DON) is an emerging issue in concentrated leachate (CL). Ozonation is crucial to remove LMW-DON, but selectivity mechanisms of different reactive oxygen species were unknown. Here, reactions of O 3 and • OH with LMW-DON at different dosages were determined from composition, unsaturation/redox potential, and precursor-product relationship. The molecular weight of LMW-DON in CL presented a normal distribution and 76.5% was below 450 Da. LMW-DON with 400–1000 Da increased to 55.6%–66.7% and O/C wa increased by over 40.0% due to electrophilic substitution of O 3 . LMW-DON with <400 Da and 550–1000 Da were preferentially degraded by • OH at the low and high O 3 dosage, respectively. O 3 preferred to remove lipid-like (69.1%), protein-like (58.2%), and amino sugars-like (72.8%) LMW-DON, whereas • OH preferred to the refractory LMW-DON, such as carbohydrates-like (71.1%), lignin-like (49.6%), and tannins-like (72.5%) LMW-DON. Forty-three transformation reactions were quantified using mass difference analysis, and O 3 preferred to oxygen addition (e.g., +2O) and conversed amino to nitro groups, and saturated LMW-DON increased via unsaturated bonds rupture. • OH attacked the carbon groups (e.g., –CH 2 ) and nitrogen groups (e.g., –NH 3 +O, –NO 2 +H). These findings provide molecular evidence for the selectivity of oxidants with LMW-DON and improve the ozonation application in wastewater treatment .
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
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