Journal of Environmental Sciences
·
2022
·
IF 6.796
Shuang Zhang,Yi-Li Lin,Tian-Yang Zhang,Chen-Yan Hu,Zhi Liu,Zheng-Yu Dong,Meng-Yuan Xu,Bin Xu
In this study, the formation of iodinated trihalomethanes (I-THMs) was systematically evaluated and compared for three treatment processes - (i) chlorination, (ii) monochloramine, and (iii) dichloramination - under different pH conditions. The results demonstrated that I-THM formation decreased in the order of monochloramination > dichloramination > chlorination in acidic and neutral pH. However, the generation of I-THMs increased in the dichloramination < chlorination < monochloramination order in alkaline condition. Specifically, the formation of I-THMs increased as pH increased from 5 to 9 during chlorination and monochloramination processes, while the maximum I-THM formation occurred at pH 7 during dichloramination. The discrepancy could be mainly related to the stability of the three chlor (am) ine disinfectants at different pH conditions. Moreover, in order to gain a thorough insight into the mechanisms of I-THM formation during dichloramination, further investigation was conducted on the influencing factors of DOC concentration and Br − /I − molar ratio. I-THM formation exhibited an increasing and then decreasing trend as the concentration of DOC increased from 1 to 7 mg-C/L, while the yield of I-THMs increased with increasing Br − /I − molar ratio from 5:0 to 5:10. During the three processes mentioned above, similar I-THM formation results were also obtained in real water, which indicates that the excessive generation of I-THMs should be paid special attention during the disinfection of iodide-containing water.
研究领域:
环境科学
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水处理工程
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DOI
PubMed
高影响因子
Agronomy-Basel
·
2024
·Vol. 14
·期 2
·352
·
IF 3.3
Zihao Ye,Dihao Xu,Jiawen Zhong,Shuang Gao,Jinjin Wang,Yulong Zhang,Huijuan Xu,Yongtao Li,Wenyan Li
The co-transport of contaminants by soil colloids can generate substantial environmental risk, and this behavior is greatly affected by environmental conditions. In this study, AF4-ICP-MS was used to investigate the size distribution and composition of Cd/Pb-bearing colloids; saturated sand column experiments were used to investigate the impact of soil colloids on the transport of Cd/Pb under different pH and ionic strength conditions. AF4-ICP-MS characterization showed that natural colloids were primarily associated with two sizes ranges: 0.3–35 KDa (F1, fine nanoparticles) and 280 KDa–450 nm (F2, larger nanoparticles), which mainly consisted of organic matter (OM), iron (Fe), and manganese (Mn) (oxy)hydroxides and clay minerals. Fine nanoparticles could strongly adsorb Cd and Pb under all environmental conditions. Mn and Fe (oxy)hydroxides generally formed under neutral to alkaline conditions and exhibited adsorption capabilities for Cd and Pb, respectively. Transport experiments were conducted under different pH and ionic strength conditions. At pH 3.0, soil colloids had little effect on the transport of Cd2+and Pb2+. At pH 5.0, soil colloids inhibited the transport of Cd2+by 16.1%, and Pb2+recovery was still 0.0%. At pH 7.0 and 9.0, soil colloids facilitated the transport of Cd2+by 15.6% and 29.6%, facilitated Pb2+by 1.3% and 6.4%. At an ionic strength of 0, 0.005, and 0.01 mol L−1NaNO3, soil colloids facilitated the transport of Cd2+by 77.7%, 45.8%, and 15.6%, only facilitated the transport of Pb2+by 46.2% at an ionic strength of 0 mol L−1NaNO3. At an ionic strength of 0.05 mol L−1NaNO3, soil colloids inhibited the transport of Cd2+and Pb2+by 33.1% and 21.0%, respectively. The transport of Cd2+and Pb2+facilitated by soil colloids was clearly observed under low ionic strength and non-acidic conditions, which can generate a potential environmental risk.
研究领域:
环境科学
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土壤学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Feihui Li,Ruiru Zhao,Bingye Yang,Wei Wang,Yu Liu,Jianping Gao,Yunlan Gong
Nowadays, energy shortage is one of the major problems in the world. Photocatalytic hydrogen production is a new type of energy technology with good application prospect. As a new type of photocatalytic semiconductor material, g-C 3 N 4 has attracted much attention as a photocatalyst . By ultrasonic treatment of a mixed solution of g-C 3 N 4 and bovine serum albumin, followed by adding a certain amount of silver nitrate solution and then directly hydrothermal treatment , a special dandelion-like g-C 3 N 4 /Ag (D-g-C 3 N 4 /Ag) was prepared. The scanning electronic microscopy, transmission electronic microscopy , X-ray diffraction, Fourier transform infrared, fluorescence and physicochemical adsorption methods were used to characterize the morphology and structure of D-g-C 3 N 4 /Ag. In addition, the photocatalytic H 2 production of D-g-C 3 N 4 /Ag with different Ag loadings or in different sacrificial agents and different pH conditions were investigated. The results indicated that when triethanolamine was used as sacrificial agent, photocatalytic hydrogen efficiency was the best, and the rate of photocatalytic hydrogen production reached 862 μmol g −1 h − 1 as the Ag loading was 4%.
研究领域:
材料科学
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能源技术
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Lei Yu,Kuibao Zhang,Kui Liu,Baozhu Luo
In this study, the chemical durability of Gd 2 Zr 2 O 7 transparent ceramics was investigated under different pH environments. The influence of acidic and alkaline environments on the leaching behavior of Gd 2 Zr 2 O 7 immobilization matrix were studied to simulate the disposal of nuclear waste forms in deep geological landfills. The measured results demonstrate that the normalized leaching rates in acidic environments are higher than those in alkaline and neutral environments. The macroscopic color of all samples fades after leaching, and the visible range in-line transmittance of the leached transparent ceramics decreases slightly at pH ≤ 9. The leaching behavior leads decrement of lattice volume and increment of surface roughness, but it exhibits no significant effect on the surface elemental distribution. Never the less, Gd 2 Zr 2 O 7 transparent ceramic exhibits excellent chemical durability in weak alkaline environment, and the leaching process leads to the discoloration of Gd 2 Zr 2 O 7 transparency.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2016
·
IF 2.848
Wenyu Wang,Qinyan Yue,Baoyu Gao,Ruihua Li
In this study, the tendency of coagulation performances, floc characteristics and membrane resistances under different pH conditions in coagulation–ultrafiltration hybrid process was investigated by different Al species and chitosan (CS). Results indicated that CS as coagulation aid was independent of aluminum species. Coagulation efficiencies of three Al species (Al a , Al b and Al c ) combined with CS were enhanced comparing with Al species used alone and shown similar variation tendencies during the pH range. The values of floc size and strength/recovery factor were relatively high at pH 6, and the maximum fractal dimension was achieved under alkaline conditions generally due to adsorption sweeping. Al a /Al b /Al c combined with CS contributed to larger flocs, higher recovery factors and smaller fractal dimension values than those without CS. The results of ultrafiltration experiments shown that membrane resistances during alkaline ranges were higher than those of acidic conditions, which indicated membrane fouling was more serious in alkaline range. In addition, the total membrane resistance was decreased significantly by CS addition.
研究领域:
环境科学
·
水处理技术
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DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2019
·
IF 5.714
Wen Yang,Tongtong Feng,Markus Flury,Baoguo Li,Jianying Shang
Antibiotics are contaminants of emerging concern due to their potential effect on antibiotic resistance and human health. Antibiotics tend to sorb strongly to organic materials, and biochar, a high efficient agent for adsorbing and immobilizing pollutants, can thus be used for remediation of antibiotic-contaminated soil and water. The effect of ionizable antibiotics on surface characteristics and transport of biochar colloids (BC) in the environment is poorly studied. Column experiments of BC were conducted in 1 mM NaCl solution under three pH (5, 7, and 10) conditions in the presence of sulfamethazine (SMT). Additionally, the adsorption of SMT by BC and the zeta potential of BC were also studied. The experimental results showed that SMT sorption to BC was enhanced at pH 5 and 7, but reduced at pH 10. SMT sorption reduced the surface charge of BC at pH 5 and 7 due to charge shielding, but increased surface charge at pH 10 due to adsorption of the negatively charged SMT species. The mobility of BC was inhibited by SMT under acidic or neutral conditions, while enhanced by SMT under alkaline conditions, which can be well explained by the change of electrostatic repulsion between BC and sand grains. These findings imply that pH conditions played a crucial role in deciding whether the transport of BC would be promoted by SMT or not. Biochar for antibiotics remediation will be more effective under acidic and neutral soil conditions, and the mobility of BC will be less than in alkaline soils.
研究领域:
环境科学
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土壤学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Zuyue Li,Jiaojiao Chen,Mahmoud Abou-Elsoud,Long Sheng,Dong Uk Ahn,Dewei Shu,Meiyu Liu,Xi Huang
Storage of shell eggs converts natural ovalbumin (N-OVA) into its more thermostable forms (S-OVA). This conversion may be associated with deterioration in the foaming properties of the stored shell egg. Thus, the foaming behavior of N-OVA and S-OVA, especially their performance at different pH conditions, was conducted. Compared with N-OVA, S-OVA improved foaming ability by 29.04 % at pH 3.0 and exhibited rough foam. Regarding foaming stability, the conversion of N-OVA to S-OVA had a pronounced reduction effect, with foaming stability significantly decreasing by 28.48 %–100.00 % in pH 3.0–9.0. The spectroscopic analysis revealed that the alteration in the foaming properties of OVA was fundamentally attributed to its conformational change. Thermostable conformational transition provided S-OVA with smaller particle sizes, more flexible conformations, higher surface charge, and higher surface hydrophobicity. S-OVA at pH 3.0 showed a higher surface activity, indicating superior foaming ability. Moreover, N-OVA and S-OVA formed stiff and solid-like interfaces. Notably, N-OVA exhibited higher dilatational and elastic modulus, indicating a more compact and stable adsorption layer at air-water interface. Overall, thermostable conformational transition improved the interfacial activity of OVA and enhanced its foaming ability; however, overactive proteins were detrimental to the stabilization of its interfacial films.
研究领域:
食品科学
·
蛋白质化学
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Ruisong Li,Feng-Yi Zheng,Xiaohan Zhang,Jiadan Hu,Congying Xu,Yucang Zhang
Various catalysts were synthesized by incorporating phosphorus and iron into nitrogen-containing carbon derived from shrimp shell with pyrolysis . These catalysts had high specific surface area, uniform atomic doping and various active sites, which resulted in the high kinetics activity towards oxygen reduction reaction (ORR) under various pH conditions . Based on different doping sources to analyse ORR activity, phosphorus-doped catalyst was suitable for alkaline medium and iron doping for acidic medium, while their synergistic effect induced the highest ORR activity in neutral medium. Besides, the stability measurements investigated their abilities for application. Introducing iron into nitrogen-containing carbon could gradually strengthen the long-term stability for different catalysts in various pH conditions. Especially, phosphorus doping promoted the best ORR performance in alkaline condition with an extremely poor stability, which could be overcome by further adding iron. This work provides a strategy for the doped biomass-based carbon to accommodate different fuel cells.
研究领域:
材料科学
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能源化学
·
催化科学
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DOI
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Pei Gao,Zhijie Liang,Zhiwei Zhao,Wenhao Wang,Chun Yang,Bibo Hu,Fuyi Cui
In this study, the phenyl-modified mesoporous materials were successfully synthesized using phenyl-organosilanes (trimethoxyphenylsilane and triethoxyphenylsilanea) by one-pot co-condensation method for the removal of estrone (E1), 17β-estradiol (E2), and 17α-ethinyl estradiol (EE2). Both the triethoxyphenylsilane-modified material (20%EtPh-MCM-41) and trimethoxyphenylsilane-modified material (20%MePh-MCM-41) could rapidly achieve equilibrium in 30 min at low adsorbent dosage of 0.025 g L −1 . But the different hydrolysable groups of trimethoxyphenylsilane and triethoxyphenylsilane led to the discrepancies in physicochemical properties of the 20%EtPh-MCM-41 and 20%MePh-MCM-41, and thus affected adsorption performance. The 20%EtPh-MCM-41 exhibited the faster estrogen adsorption rates expressed in pseudo-second-order kinetic constant than the 20%MePh-MCM-41 due to the more hydrophobicity . Conversely, the 20%MePh-MCM-41 had much more estrogen adsorption capacities than the 20%EtPh-MCM-41 because of the more available adsorption sites. The addition of the phenyl-organosilane improved estrogen adsorption by π-π and hydrophobic interactions, and the Langmuir-model-based maximum adsorption amounts could reach 99.02, 83.47, and 53.60 mg g −1 for EE2, E2, and E1, respectively. But excessive concentration of phenyl-organosilane decreased adsorption capacities due to poor pore structure. Alkaline solution, which induced estrogen deprotonation and negative surface charge of absorbents, inhibited estrogen adsorption by electrostatic repulsion and the decreased hydrophobic interaction, but acidic and neutral solutions, ionic strength, and humic acid did not significantly affect estrogen removal. This work not only showed the high potential of trimethoxyphenylsilane-modified MCM-41 used in water purification for steroid estrogens, but also demonstrated the suitable selection of organosilane precursors was key in producing favorable materials with designed functionality.
研究领域:
环境科学
·
材料科学
·
生物学
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DOI
高影响因子
JOURNAL OF FOOD SCIENCE
·
2021
·Vol. 86
·期 3
·677-686
·
IF 3.167
Yuanyuan Chen,Yu Tang,Qiming Wang,Lin Lei,Jichun Zhao,Yuhao Zhang,Lin Li,Qiang Wang,Jian Ming
Absract The interaction between gluten and hydrocolloid additive, as well as the pH condition during dough formation is very important in making flour products. In this study, the influence of different pH conditions on the interactions between gluten proteins (including glutenin and gliadin) and carboxymethylcellulose (CMC), and on the rheological and microstructure changes of gluten proteins was investigated. The dynamic frequency sweep indicated CMC-gluten displayed more solid-like behavior under alkaline conditions than that under acidic conditions. The creep-recovery experiment suggested acidic conditions were not conducive to maintain the elasticity of CMC-gluten. Microstructural changes of various glutens with CMC showed that a higher ratio of β-sheets was observed in the CMC-gluten and CMC-glutenin under alkaline conditions. Total free sulfhydryl contents and changes in tryptophan microenvironment showed glutenin played a key role in the G polymerization with the addition of CMC. Lower surface hydrophobicity of CMC-gluten was displayed under acidic conditions. Scanning electron microscopy images showed that neutral and alkaline conditions were conducive to the network structure formation of CMC-gluten and CMC-glutenin. Practical Application This study investigated the interaction of CMC with gluten, gluten, and gliadin under different pH conditions, providing a basis for expanding dough quality improvement, and extending the in-depth application of CMC in the food industry.
研究领域:
食品科学
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生物化学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 121
·100030-100038
·
IF 3.84
Ruihua Li,Baoyu Gao,Shenglei Sun,Hui Wang,Yingxue Liu,Qinyan Yue,Yan Wang
To recycle papermaking sludge, a novel lignin-based flocculant with high cationic degree and molecular weight was introduced. The product, lignin–diallyl dimethyl ammonium chloride–acrylamide (LDA) was combined with polyferric chloride (PFC) to treat simulated humic acid (HA) solution. To identify its flocculation mechanisms, coagulation efficiencies and floc properties under different dosing methods and pH conditions were studied. Results showed that LDA was superior to polyacrylamide, poly diallyldimethylammonium chloride as well as lignin–acrylamide with regards to dissolved organic carbon (DOC) and turbidity removal efficiencies, which demonstrated its significant flocculating efficiency. Compared with single PFC, the addition of LDA enhanced the coagulation performance and floc properties, including floc size, growth rate and the recovery ability within the investigated pH range. The dosing sequence also had an effect on the coagulation mechanism and performance. When PFC was dosed first, negatively charged Fe(III) hydrolysates-colloids were neutralized and bridged by LDA. On the contrary, colloids–LDA complexes with slight negative charge were destabilized by the entrapment and sweeping effect of Fe(III) hydrolysates. As a result, coagulation efficiencies were in the following order: PFC dosed firstly (PFC + LDA) > LDA dosed firstly (LDA + PFC) > PFC. PFC + LDA achieved the maximum floc size and growth rate, whereas flocs with the most open structure was formed by LDA + PFC. Moreover, the effect of solution pH on coagulation behavior was noteworthy due to the variance of hydrolyzed Fe species. PFC was more sensitive to pH with regards to coagulation efficiencies and flocs structure. The variations caused by different pH values decreased after the addition of LDA. Regardless of the coagulant types, the optimal coagulation performance and floc characteristics were achieved under acidic conditions, especially at pH 6. Overall, LDA could introduce strong charge neutralization and adsorption bridging effect within a relatively wider pH range and offer a positive effect on coagulation behavior and flocs properties.
研究领域:
环境科学
·
化学工程
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产品关联
DOI
高影响因子
Food & Function
·
2019
·Vol. 10
·期 10
·6568-6581
·
IF 3.241
Jinyu Chen,Yunxia Ren,Kunsheng Zhang,Jinping Qu,Fangyang Hu,Yijun Yan
Formation of a gel matrix, involving interactions between proteins, lipids, and water, plays an essential role in the textural properties of processed meats. This study investigated the effects of sodium pyrophosphate (SPP) on the textural properties and oxidative stability of myofibrillar protein (MP)-stabilized emulsion gels under different pH conditions (5.0–9.0). The SPP-modified MP emulsion gels showed an improved elasticity, strength, water-holding capacity, and oxidative stability at pH 6.0 and 7.0. This improvement should be mainly attributed to the enhanced protein–protein crosslinks via ionic interaction between phosphate groups and –NH3+ of amino acids, which were homogeneously formed among adsorbed and/or unadsorbed proteins, entrapping fractions of MPs (myosin heavy chain, actin, and troponin T) within the network. Therefore, the oil droplets were better adherent to the gel matrix. Nevertheless, increased electrostatic repulsion between protein molecules due to excessive phosphates attached to MPs at pH 8.0 and 9.0, as well as protein precipitation at pH 5.0, caused the collapse of the MP-stabilized emulsion gel structure, and thus, overall decreased the gel properties and oxidative stability. LC-MS/MS results confirmed that phosphate groups were successfully introduced to MPs through C–O–P bonds at pH 6.0, and the phosphorylation sites were found to be on serine residues (Ser14, Ser79, Ser96, Ser148, Ser2427, and Ser5272), threonine residues (Thr118 and Thr926), and tyrosine residues (Tyr215 and Tyr425). The results provided a new aspect for better understanding the effect of polyphosphates in meat protein/oil composite systems.
研究领域:
食品化学
·
蛋白质科学
·
食品加工技术
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生物物理化学
·
食品胶体与界面科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）