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Chinese Journal of Chemical Engineering 2019年第12期27卷 2917-2924页

作者： Zhaoyang Li Rongzong Li Zhaoxiang Zhong Ming Zhou Min Chen Weihong Xing State Key Laboratory of Materials-Oriented Chemical Engineering National Engineering Research Center for Special Separation MembraneNanjing Tech UniversityNanjing 211816China

Inefficient separation of inorganic salts and organic matters in crystallization mother liquor is still a problem to industrial wa stewater treatment since the high salinity significantly impedes organic pollutant degradation by oxidation or *** the study,acidification combined electrodialysis(ED)was attempted to effectively separate Cl-ions from organics in concentrate pulping ***’s rejection rate to total organic carbon(TOC)was 85%at wastewater intrinsic pH=9.8 and enhanced to 93%by acidifying it to pH=2 in ED ***-charged alkaline organic compounds(mainly lignin)could be liberated from their sodium salt forms and coagulated in acidification *** of the organic substances also made their electro-migration less effective under electric driving force and in particular improved separation efficiency of chloride and *** acid-ED coupled treatment(pH=2 and J=40 mA·cm-2)[TOC]remarkably reduced from 1.315 g·L-1 to 0.048 g·L-1 and[Cl-]accumulated to 130 g·L-1 in concentrate *** rate of NaCl was 89%and the power consumption was 0.38 kW·h·kg-1 *** fouling was not caused as electric resistance of membrane pile maintained *** conclusion,acidic-ED is a practical option to treat salinity organic wastewater when current techniques including thermal evaporation and pressure-driven membrane se paration present limitations.

关键词： Crystallization mother liquor acid precipitation Electrodialysis Chloride recovery

Decomposition mechanism of chromite in sulfuric acid–dichromic acid solution

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International Journal of Minerals,Metallurgy and Materials 2017年第12期24卷 1361-1369页

作者： Qing Zhao Cheng-jun Liu Bao-kuan Li Mao-fa Jiang Key Laboratory for Ecological Metallurgy of Multimetallic Ores(Ministry of Education) Northeastern UniversityShenyang 110819China School of Metallurgy Northeastern UniversityShenyang 110819China

The sulfuric acid leaching process is regarded as a promising, cleaner method to prepare trivalent chromium products from chromite; however, the decomposition mechanism of the ore is poorly understood. In this work, binary spinels of Mg–Al, Mg–Fe, and Mg–Cr in the powdered and lump states were synthesized and used as raw materials to investigate the decomposition mechanism of chromite in sulfuric acid–dichromic acid solution. The leaching yields of metallic elements and the changes in morphology of the spinel were studied. The experimental results showed that the three spinels were stable in sulfuric acid solution and that dichromic acid had little influence on the decomposition behavior of the Mg–Al spinel and Mg–Fe spinel because Mg^(2+), Al^(3+), and Fe^(3+) in spinels cannot be oxidized by Cr^(6+). However, in the case of the Mg–Cr spinel, dichromic acid substantially promoted the decomposition efficiency and functioned as a catalyst. The decomposition mechanism of chromite in sulfuric acid–dichromic acid solution was illustrated on the basis of the findings of this study.

关键词： hydrometallurgy chromite sulfuric acid leaching spinel decomposition mechanism

Ozonation as an efficient pretreatment method to alleviate reverse osmosis membrane fouling caused by complexes of humic acid and calcium ion

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Frontiers of Environmental Science & Engineering 2019年第4期13卷 89-100页

作者： Xuehao Zhao Yinhu Wu Xue Zhang Xin Tong Tong Yu Yunhong Wang Nozomu Ikuno Kazuki Ishii Hongying Hu Environmental Simulation and Pollution Control State Key Joint Laboratory State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC)School of EnvironmentTsinghua UniversityBeijing 100084China Collaborative Innovation Center for Advanced Nuclear Energy Technology Institute of Nuclear and New Energy TechnologyTsinghua UniversityBeijing 100084China Kurita Water Industries Ltd. Nakano-kuTokyo 164-0001Japan Shenzhen Environmental Science and New Energy Technology Engineering Laboratory Tsinghua-Berkeley Shenzhen InstituteShenzhen 518055China

Humic acid has been considered as one of the most significant sources in feed water causing organic fouling of reverse osmosis (RO) membranes, but the relationship between the fouling behavior of humic acid and the change of its molecular structure has not been well developed yet. In this study, the RO membrane fouling behavior of humic acid was studied systematically with ozonation as a pretreatment method to control RO membrane fouling. Furthermore, the effect of ozone on the structure ofhumic acid was also explored to reveal the mechanisms. Humic acid alone (10-90 mg/L, in deionized water) was found not to cause obvious RO membrane fouling in 45-h operation. However, the presence of Ca^2+ aggravated significantly the RO membrane fouling caused by humic acid, with significant flux reduction and denser fouling layer on RO membrane, as it was observed by scanning electron microscope (SEM) and atomic force microscope (AFM). However, after the pretreatment by ozone, the influence of Ca^2+ was almost eliminated. Further analysis revealed that the addition of Ca^2+ increased the particle size of humic acid solution significantly, while ozonation reduced the SUVA254, particle size and molecular weight of the complexes of humic acid and Ca^2+(HA-Ca^2+ complexes). According to these results and literature, the bridge effect of Ca^2+ aggregating humic acid molecules and the cleavage effect of ozone breaking HA-Ca^2+ complexes were summarized. The change of the structure of humic acid under the effect of Ca^2+ and ozone is closely related to the change of its membrane fouling behavior.

关键词： Reverse osmosis Membrane fouling Humic acid Ca^2+ Ozone

Optimizational production of phenyllactic acid by a Lactobacillus buchneri strain via uniform design with overlay sampling methodology

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Chinese Journal of Chemical Engineering 2019年第2期27卷 418-425页

作者： Jintao Guan Chaofei Han Yixin Guan Songhong Zhang Junxian Yun Shanjing Yao College of Chemical and Biological Engineering Zhejiang University State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology College of Chemical Engineering Zhejiang University of Technology

A Lactobacillus buchneri GBS3 strain isolated from the traditional Chinese pickles was used for the production of 3-phenyllactic acid(PLA), an important compound with antimicrobial activities against a wide species of grampositive and gram-negative bacteria and some fungi. The growth performance of this strain in the de Man, Rogosa and Sharpe(MRS) medium, the production of metabolites of valuable organic acids, and the biosynthesis of PLA using this strain as the whole-cell biocatalyst and phenylpyruvic acid(PPA) as the precursor, were investigated experimentally. The uniform design method with overlay sampling was developed for the optimization of the biotransformation conditions. The results showed that although it produced naturally lactic acid with the maximum concentration of 1.84 g·L^(-1) and PLA with the concentration of 0.015 g·L^(-1) after 66 to 72 h cultivation in MRS broth by fermentation, the present strain displayed an effective utilization ability by transforming PPA to PLA. By the uniform design method with overlay sampling for the design and optimization of transformation conditions, a maximum yield of 10.93 g·L^(-1) PLA with the mole conversion ratio of 83.07% from PPA to PLA was achieved under the optimized condition, i.e., 20 g·L^(-1) glucose, 270 g·L^(-1) cells, 13 g·L^(-1) PPA, pH 8.0 and the reaction time of 15 h, indicating that Lactobacillus buchneri GBS3 was an interesting strain for the biosynthesis of PLA via the microbial transformation. The prediction of PLA yield under different conditions was achieved successfully based on the limited information of only a small number of experiments by the uniform design with overlay sampling. Therefore, the present methodology is effective and helpful for the optimization of the biosynthesis processes of PLA.

关键词： Phenyllactic acid Biotransformati on Lactobacillus Buchneri Uniform Design Overlap Sampling

Chlorine-free emission disposal of spent acid etchant in a three-compartment ceramic membrane reactor

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Chinese Journal of Chemical Engineering 2020年第1期28卷 271-278页

作者： Fanglu Yuan Lele Cui Peipei Ding Wenheng Jing State Key Laboratory of Materials-Oriented Chemical Engineering National Engineering Research Center for Special Separation MembraneCollege of Chemical EngineeringNanjing Tech UniversityNanjing 211800China

Electrochemical technologies for the on-site treatment of spent acid etchant have received great attention due their ease of operation and economic benefits. On the other hand, a large amount of Cl2 is generated during the electrolysis process, which leads to potential environmental risks. In the present work, a novel threecompartment ceramic membrane flow reactor, including a cathode chamber, an anode chamber, and a gas absorption chamber was developed. The three chambers were divided by an Al2O3 ceramic membrane and a breathable hydrophobic anode diffusion electrode(ADE). The Cl2 evolution onset potential of the ADE was increased to 1.19 V from 1.05 V of the graphite felt, effectively inhibiting the chlorine evolution reaction(CER).The anode-generated Cl2 diffused into the gas absorption chamber through the ADE and was eventually consumed by the H2O2 adsorbent. Cu could be recovered without emitting chlorine due to the special structure of reactor. The current efficiency of copper precipitation and cathode reduction from Cu2+to Cu+reached 97.7%at a working current of 150 m A. These results indicated that the novel membrane reactor had high potential for application in the copper recovery industry.

关键词： Spent acid etchant Chlorine evolution reaction Anode diffusion electrode Three-compartment reactor Ceramic membrane

acid/Alkali Gated Photochromism of Diarylethenes with Quinoline Derivatives

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Chinese Journal of Chemistry 2012年第7期30卷 1393-1398页

作者：宋波李海霞杨琳张复实向军辉 College of Chemistry and Chemical Engineering Graduate University of Chinese Academy of SciencesBeijing 100049China The Key Lab of Organic Photoelectrons&Molecular Engineering of Ministry of Education Department of ChemistryTsinghua UniversityBeijing 100084China

Three new diarylethenes 1--3 combined with quinoline derivatives have been synthesized. Through controlled chemical condition of deprotonation/protonation, they presented some new irreversible photochromic phenomenons under UV/Vis light irradiation in chloroform solution. It was found that 1--3 had well photoisomerization upon UV/Vis light irradiation in neutral chloroform solution. Addition of acid to the solution of the ring-opening isomers of 1--3 produced 1 oa--3oa, which performed reversible photochromic behavior under UV/Vis light irradiation and reversed back to 1--3 under neutralizing with adding lewis base. However, addtion of base to neutral soluton of the ring-opening isomers of 1--3 produced lob--3ob, which could not change to the deprotonated ring-closing isomers under UV light irradiation.

关键词： diarylethene photochromism quinoline acid alkali

Facile oxalic acid-assisted construction of laminated porous N-deficient graphitic carbon nitride: Highly efficient visible-light-driven hydrogen evolution photocatalyst

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Journal of Energy Chemistry 2019年第6期28卷 1-8页

作者： Fengli Yang Jia Ren Qianqian Liu Lu Zhang Yuanyuan Chai Wei-Lin Dai Department of Chemistry & Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Fudan University

The laminated porous N-deficient g-C3N4(CN–H)is successfully synthesized by a facile two-step hydrothermal calcination method using oxalic acid-assisted melamine as the *** with pristine g-C3N4(224μmol g-1h-1),the CN–H shows superior photocatalytic hydrogen production activity(up to 728μmol g-1h-1),which is three times higher than the unmodified *** draw out the multifaceted influences of oxalic acid modification on the visible-light-induced photocatalytic activity,various techniques are utilized to investigate the formation mechanism,structural characteristics and photoelectrical properties of CN–*** results indicate that the addition of a trace amount of oxalic acid to the precursor melamine results in a g-C3N4 structure possessing the advantage of both nitrogen defects and laminated *** properties can enlarge specific surface areas of g-C3N4,enhance an efficient separating of photogenerated electron-hole pairs and extend the range of spectral response,all contributing to the enhancement of the visible-light-induced photocatalytic activity.

关键词： Oxalic acid Melamine Laminated porous N-deficient g-C3N4 Visible-light-induced photocatalytic activity for H2 generation

Zinc-substituted hemoglobin with specific drug binding sites and fatty acid resistance ability for enhanced photodynamic therapy

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Nano Research 2019年第8期12卷 1880-1887页

作者： Yiting Xu Jiamei Xu Xiaoxiao Hu Xin Xia Qian Dong Zhangkun Liu Zhuo Chen Weihong Tan Molecular Science and Biomedicine Laboratory State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringCollege of Life SciencesAptamer Engineering Center of Hunan ProvinceHunan Provincial Key Laboratory of Biomacromolecular Chemical BiologyHunan UniversityChangsha 410082China Department of Chemistry Departments of Physiology and Functional GenomicsCenter for Research at the Bio/Nano InterfaceUF Health Cancer CenterUF Genetics Institute and McKnight Brain InstituteUniversity of FloridaGainesvilleFlorida 32611USA

Precisely designed protein-based nanodrugs, as a kind of colloidal drug system, have attracted significant attention in tumor therapy because of their refined drug loading ratio, controlled delivery efficacy and natural biocompatibility. However, most drugs are conjugated to the protein carriers randomly without specific binding sites. Moreover, such sites could easily be replaced by lipophilic molecules in the physiological environment and result in low delivery efficiency. With strong and specific binding locations especially comparatively narrow spatial binding sites and nonflexible structure, hemin (FePPIX)-free hemoglobin or apohemoglobin (apoHb), as a natural metalloporphyrin protein carrier, represents great potential in bioapplication. Therefore, we herein introduce a folate acid (FA) modified, zinc-substituted hemoglobin (ZnPHb-FA) as a naturally occurring protein matrix-based photosensitizer for cancer photodynamic therapy (PDT). Noncovalent inserted ZnPPIX molecules in apoHb possess an extremely stable property and significant recovered photoproperties with superior biocompatibility and phototoxicity, both in vitro and in vivo. This stability was verified by molecular docking analysis and calculation of binding constant, representing a total of five drug binding sites of apoHb for ZnPPIX molecules, four of which are energetically favorable (△G value of -11.9 kcal/mol), and one which is energetically acceptable (△G value of -9 kcal/mol). Folate acid modification has been shown to efficiently enhance the internalization and retention time of ZnPHb nanodrug. ZnPHb-FA is also an efficient depressor of hemin oxygenase-1 (HO-1), which could, in turn, lower the antioxidant ability of cancer cells by decreasing the production of biiirublin. Results in vitro and in vivo both indicated that the firmly combination of apoHb and ZnPPIX described here represents a novel and efficient protein nanodrug systems for cancer therapy.

关键词： natural metalloporphyrin protein carrier specific drug binding sites fatty acid resistance ability photodynamic therapy hemin oxygenase-1 (HO-1)

Trithiocyanuric acid derived g-C3N4 for anchoring the polysulfide in Li-S batteries application

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Journal of Energy Chemistry 2020年第4期29卷 71-77页

作者： Ziyang Jia Hongzhang Zhang Ying Yu Yuqing Chen Jingwang Yan Xianfeng Li Huamin Zhang Division of Energy Storage Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina University of Chinese Academy of Sciences Beijing 100049China Dalian National Laboratory for Clean Energy Dalian 116023LiaoningChina Collaborative Innovation Center of Chemistry for Energy Materials(iChEM) Dalian 116023LiaoningChina

Lithium-sulfur (Li-S) batteries have great potential as an electrochemical energy storage system because of the high theoretical energy density and acceptable cost of financial and ***,the shuttle effect leads to severe capacity fading and low coulombic ***,graphitic carbon nitride(g-C3N4) is designed and prepared via a feasible and simple method from trithiocyanuric acid (TTCA) to anchor the polysulfides and suppress the shuttle *** obtained g-C3N4 exhibits strong chemical interaction with polysulfides due to its high N-doping of 56.87 at%,which is beneficial to improve the cycling stability of Li-S ***,the novel porous framework and high specific surface area of g-C3N4 also provide fast ion transport and broad reaction interface of sulfur cathode,facilitating high capacity output and superior rate performance of Li-S *** a result,Li-S batteries assembled with g-C3N4 can achieve high discharge capacity of 1200 mAh/g at 0.2 C and over 800 mAh/g is remained after 100 cycles with a coulombic efficiency more than 99.5%.When the C-rate rises to 5 C,the reversible capacity of Li-S batteries can still maintain at 607mAh/g.

关键词： Lithium sulfur batteries g-C3N4 Cathode material Polarity interaction Trithiocyanuric acid

Enhancing General Corrosion Resistance of Biomedical High Nitrogen Nickel-Free Stainless Steel by Nitric acid Passivation

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Acta Metallurgica Sinica(English Letters) 2020年第2期33卷 307-312页

作者： Yixun Yang Qingchuan Wang Jun Li Lili Tan Ke Yang Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

A systematic study of nitric acid passivation was investigated to enhance the general corrosion resistance of biomedical high-nitrogen nickel-free stainless steels(HNSs).After passivation,the corrosion rate of HNS could dramatically reduce to 1/20 of the untreated in 37℃0.9 wt% NaCl ***,the passive film on HNS was analyzed by X-ray photoelectron *** was found that chromium enrichment in the passive film and nitrogen enrichment in the film/metal interface contributed to the improvement in general corrosion resistance of HNS.

关键词： Stainless steel Nitric acid passivation General corrosion Passive film