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Oxidant or catalyst for oxidation? The role of manganese oxides in the activation of peroxymonosulfate (PMS)

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Frontiers of Environmental Science & Engineering 2019年第5期13卷 1-3页

作者： Jianzhi Huang huichun zhang Department of Civil Engineering Case Western Reserve UniversityClevelandOH 44106USA

Manganese oxides(MnOv)have been demonstrated to be effective materials to activate Oxone(i.e.,PMS)to degrade various ***,the contribution of direct oxidation by MnOx to the total contaminant degradation under acidic conditions was often neglected in the published work,which has resulted in different and even conflicting interpretations of the reaction ***,the role of MnOx(as both oxidants and catalysts)in the activation of Oxone was briefly *** findings offered new insights into the reaction mechanisms in PMS-MnOr and provided a more accurate approach to examine contaminant degrada?tion for water/wastewater treatment.

关键词： oxides manganese catalyst

Predicting non-carcinogenic hazard quotients of heavy metals in pepper (Capsicum annum L.) utilizing electromagnetic waves

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Frontiers of Environmental Science & Engineering 2020年第6期14卷 237-249页

作者： Marzieh Mokarram Hamid Reza Pourghasemi huichun zhang Depatment of Range and Watcrshed Managemcent Cllge of Ariculut and Naturel Resures of Darab Shiraz UnivrsityShiraz 71946-84471Iran Depatment of Natural Resources and Enionmental Enginerng Cllge of Agicuture Shiraz UniversityShirz 7141-6586 Iran Depatment of Civil and Environmental Engiccrin Case Westem Reseve Univrsit Cleveland0H 44106USA

Given the tendency of heavy metals to accumulate in soil and plants,the purpose of this study was to determine the *** of Cd,Ni,Pb,and Zn on peppers(*** fruit),grown in contaminated soils in industral *** this purpose,we measured the uptake of the four heavy metals by peppers grown in the heavy metal contaminated soils throughout the four growth stages:two-leaf,growth,fiowering,and fruiting;and calculated various vegetation indices to evaluate the heavy metal contamination *** waves were also applied for analyzing the responses of the target plants to various heavy *** on the relevant spectral bands identified by principal component analysis(PCA)and random search methods,a regression method was then *** determine the most *** bands for estimating,the target hazard quotient(THQ).The THQ was found to be the highest in the plants contaminated by Pb(THQ=62)and Zn(THQ=5.07).The results of PCA and random search indicated that the spectra at the bands of b570,b650,and b760 for Pb,b400 and b880 for Ni,b560 and b880 for Cd,and b560 b910,and b1050 for Zn were the most optimal spectra for assessing ***,in future studies,instead of examining the amount of heavy metals in plants by chemical analysis in the laboratory,the responses of the plants to the electromagnetic waves in the identified bands can be redily investigated in the field based on the established correlations.

关键词： Heavy metals Plants Target Hazard Quotient(THQ) Principal Component Analysis(PCA) Random search Electromagnetic wave

A Note on Gradient Estimates for Elliptic Equations with Discontinuous Coefficients

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Chinese Annals of Mathematics,Series B 2024年第1期45卷 1-10页

作者： Yu PENG Xiandong SUN huichun zhang Department of Mathematics Sun Yat-Sen UniversityGuangzhou 510275China.

The authors will use a method in metric geometry to show an L^(P)-estimate for gradient of the weak solutions to elliptic equations with discontinuous coefficients,even the BMO semi-norms of the coefficients are not *... 详细信息

关键词： L^(p)-Estimate Elliptic equation Discontinuous coefficients

Evolution of humic substances in polymerization of polyphenol and amino acid based on non-destructive characterization

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Frontiers of Environmental Science & Engineering 2021年第1期15卷 91-100页

作者： Jianmei Zou Jianzhi Huang huichun zhang Dongbei Yue School of Environment Tsinghua UniversityBeijing 100084China Department of Civil and Environmental Engineering Case Western Reserve UniversityClevelandOH 44106USA

Abiotic humification is important in the formation and evolution of organic matter in soil and compost maturing ***,the roles of metal oxides in abiotic humification reactions under micro-aerobic remain *** aim of this study was to use non-destructive measurement methods to investigate the role of MnO_(2) in the evolution of humic substances(HSs)during oxidative polymerization of polyphenol-amino *** results suggested a synergistic effect between MnO_(2) and O_(2) in promoting the polymerization reaction and identified that MnO_(2) alone had a limited ability in accelerating the transformation of fulvic acid(FA)to humic acid(HA),whereas O_(2) was the key factor in the ***-dimensional correlation spectroscopy(2D-COS)showed that the evolution in the UV-vis spectra followed the order of 475–525 nm>300–400 nm>240–280 nm in the humification process,indicating the formation of simple organic matter followed by FA and then HA.13C nuclear magnetic resonance(13C NMR)analysis revealed that the products under both air and N2 conditions in the presence of MnO_(2) had greater amounts of aromatic-C than in the absence of MnO_(2),demonstrating that MnO_(2) affected the structure of the humification *** results of this study provided new insights into the theory of abiotic humification.

关键词： Two-dimensional correlation spectroscopy(2D-COS) Humic substances(HSs) Humification Manganese dioxide Polyphenol

Enhanced dewaterability of waste activated sludge by UV assisted ZVI-PDS oxidation

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Journal of Environmental Sciences 2022年第3期34卷 152-164页

作者： Yanping zhang Tiantian Li Jiayu Tian huichun zhang Fen Li Jiahua Pei School of Civil Engineering and Transportation Hebei University of TechnologyTianjin 300401China Department of Civil and Environmental Engineering Case Western Reserve UniversityClevelandOH 44106USA College of Chemical and Environmental Engineering Harbin University of Science and TechnologyHarbin 150000China

Ultraviolet(UV)assisted zero-valent iron(ZVI)-activated sodium persulfate(PDS)oxidation(UV-ZVI-PDS)was used to treat waste activated sludge(WAS)in this *** dewaterability performance and mechanism of WAS dewatering were *** results showed that UV-ZVI-PDS can obtain better sludge dewatering performance in a wide pH range(2.0-8.0).When the molar ratio of ZVI/PDS was 0.6,UV was 254nm,PDS dosage was 200 mg/g TS(total solid),pH was 6.54,reaction time was 20 min,the CST(capillary suction time)and SRF(specific resistance to filtration)were decreased by 64.0%and 78.2%,*** molar ratio of ZVI/PDS used in this paper is much lower than that of literatures,and the contents of total Fe and Fe^(2+) in sludge supernatant remained at a low level,as 3.7 mg/L and 0.0 mg/*** analysis of extracellular polymeric substances(EPS),scanning electron microscope(SEM)and particle size distribution showed that the EPS could be effectively destroyed by UV-ZVI-PDS,the sludge flocs broken down into smaller particles,cracks and holes appeared,and then the bound water was *** the same time,the highly hydrophilic tightly bound-EPS(TB-EPS)were converted into loosely bound EPS(LB-EPS)and soluble EPS(S-EPS).During sludge pretreated by UV-ZVI-PDS,positively charged ions,such as Fe^(2+),Fe^(3+) and H^(+),produced in the reaction system could reduce the electronegativity of sludge surface,promote sludge particles aggregation,and then enhanced the sludge dewaterability.

关键词： Sludge dewatering Persulfate Zero-valent iron UV Extracellular polymeric substances

High-throughput phenotyping of plant leaf morphological, physiological,and biochemical traits on multiple scales using optical sensing

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The Crop Journal 2023年第5期11卷 1303-1318页

作者： huichun zhang Lu Wang Xiuliang Jin Liming Bian Yufeng Ge College of Mechanical and Electronic Engineering Nanjing Forestry UniversityNanjing 210037JiangsuChina Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources Nanjing Forestry UniversityNanjing 210037JiangsuChina Institute of Crop Sciences Chinese Academy of Agricultural Sciences/Key Laboratory of Crop Physiology and EcologyMinistry of AgricultureBeijing 100081China College of Forestry Nanjing Forestry UniversityNanjing 210037JiangsuChina Co-Innovation Center for Sustainable Forestry in Southern China and Key Laboratory of Forest Genetics&Biotechnology of the Ministry of Education Nanjing Forestry UniversityNanjing 210037JiangsuChina Department of Biological Systems Engineering University of Nebraska-LincolnNE 68583USA

Acquisition of plant phenotypic information facilitates plant breeding, sheds light on gene action, and can be applied to optimize the quality of agricultural and forestry products. Because leaves often show the fastest responses to external environmental stimuli, leaf phenotypic traits are indicators of plant growth,health, and stress levels. Combination of new imaging sensors, image processing, and data analytics permits measurement over the full life span of plants at high temporal resolution and at several organizational levels from organs to individual plants to field populations of plants. We review the optical sensors and associated data analytics used for measuring morphological, physiological, and biochemical traits of plant leaves on multiple scales. We summarize the characteristics, advantages and limitations of optical sensing and data-processing methods applied in various plant phenotyping scenarios. Finally, we discuss the future prospects of plant leaf phenotyping research. This review aims to help researchers choose appropriate optical sensors and data processing methods to acquire plant leaf phenotypes rapidly,accurately, and cost-effectively.

关键词： Leaf traits Optical sensing Image processing Machine learning Artificial intelligence

MONOTONICITY FORMULAS FOR PARABOLIC FREE BOUNDARY PROBLEMS ON CONES

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Acta Mathematica Scientia 2022年第6期42卷 2193-2203页

作者： Chung-Kwong CHAN huichun zhang Xiping ZHU Department of Mathematics Sun Yat-sen UniversityGuangzhou 510275China

Monotonicity formulas play a central role in the study of free boundary *** this note,we develop a Weiss-type monotonicity formula for solutions to parabolic free boundary problems on metric measure cones.

关键词： smonotonicity formula parabolic free boundary problem RCD-spaces

Contamination of Phthalate Esters in Vegetable Agriculture and Human Cumulative Risk Assessment

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Pedosphere 2017年第3期27卷 439-451页

作者： CHEN Ning SHUAI Wenjuan HAO Xinmei zhang huichun ZHOU Dongmei GAO Juan Key Laboratory of Soil Environment and Pollution Remediation Institute of Soil Science Chinese Academy of Sciences University of Chinese Academy of Sciences College of Water Resources and Civil Engineering China Agricultural University Department of Civil and Environmental Engineering Temple University

Phthalate esters （PAEs）, which can disturb human endocrine system, have been widely detected in vegetable greenhouse agriculture in China. To investigate the effects of environmental factors on PAEs in soils, pollution sources were identified, and the cumulative risks of PAEs to humans through vegetables in the diet were evaluated in this study. Ninety-eight vegetable samples were collected from 10 markets along with 128 vegetable and 111 soil samples from agricultural greenhouses and open field. All soil and vegetable samples were contaminated with PAEs, and the total concentrations of the 5 PAEs, including dimethyl phthalate （DMP）, diethyl phthalate （DEP）, di-iso-butyl phthalate （DiBP）, di-n-butyl phthalate （DnBP）, and di-2-ethylhexyl phthalate （DEHP）, were in the ranges of 0.26-2.53 mg kg-1 for soils and 0.95-8.09 mg kg-1 for vegetables. Three components extracted from principle component analysis could explain 51.2%, 19.8%, and 15.3% of the total variance of the 5 PAEs in soils, which may represent three major sources of PAEs, i.e., wastewater irrigation, application of fertilizers and pesticides, and plastic film. Long-term greenhouse cultivation could accumulate DEHP in soils, and a higher soil FeOx content reduced the DnBP concentration. Based on a survey of vegetables in the diet, the hazard index of PAEs was 〈 0.15 for individuals in different cities. The exposure of PAEs through vegetable intake was higher than the total exposure from other food stuffS, inhalation, and dermal absorption. More attention should be g!ven to controlling PAEs in greenhouse vegetables.

关键词： average daily intake dietary survey environmental factors greenhouse agriculture hazard index

Evaluating the environmental impact of selected chemical de-icers

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Transportation Safety and Environment 2019年第3期1卷 220-229页

作者： Xiang Li Benoit Van Aken Erica Mckenzie huichun zhang Bechara Abboud William Davenport Civil&Environmental Engineering Department Temple UniversityPhiladelphiaPAUSA Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijingChina Department of Civil Engineering Case Western Reserve UniversityClevelandOHUSA Department of Transportation PhiladelphiaPAUSA

In this study,the environmental impacts of six commercial chloride-based de-icer products,including Rock Salt and Salt Brine,were *** nutrients,oxygen demand,heavy metal concentration,corrosion and toxicity of all six de-icers were *** an assumed 500-fold dilution,the test results were compared to the public water-quality *** results show that the selected chemical de-icers have little chance of severely damaging the environment and ecosystem under a normal dilution ***,attention needs to be paid to small water bodies and sensitive receiving water.

关键词： chemical de-icer environmental impact corrosion test toxicity