Resource Type

Journal Article 623

Year

2024 1

2023 80

2022 61

2021 83

2020 43

2019 25

2018 23

2017 39

2016 24

2015 20

2014 27

2013 35

2012 41

2011 28

2010 24

2009 30

2008 5

2007 6

2006 5

2005 1

open ︾

Keywords

CO2 capture 19

PM2.5 16

TiO2 14

photocatalysis 10

CO2 9

CO2 emissions 7

Al2O3 6

Photocatalysis 6

adsorption 6

China 5

H2S 4

MnO2 4

N2O 4

biosorption 4

methane 4

2 3

Cr(VI) 3

MoS2 3

NOx 3

open ︾

Search scope:

排序： Display mode:

Assessment of toxicity of two nitroaromatic compounds in the freshwater fish

Hongyan SHEN, Jixi GAO, Jinsheng WANG

Frontiers of Environmental Science & Engineering 2012, Volume 6, Issue 4,   Pages 518-523 doi: 10.1007/s11783-012-0427-6

Abstract: This study was conducted to evaluate the toxicological response of -nitrotoluene and -nitroaniline to the key fish species, . A freshwater fish bioassay based on the 96 h was used to estimate the single and joint toxicity of the two chemicals. The toxicity of -nitrotoluene was greater than that of -nitroaniline based on 96 h values of 40.74 mg·L and 48.99 mg·L , respectively. Both compounds had moderate toxicity toward , and this toxicity increased with the exposure duration and concentration. Binary mixtures of the compounds were more toxic than the individual compounds at 96 h, and they acted upon partial addition. When the exposure time was longer, the toxicity increased for mixtures of compounds with the same concentration or toxicity. The results of this study suggest that exposure to a combination of these chemicals would result in a higher environmental risk in aquatic systems than exposure to either compound alone. Further research is needed to investigate the combined effects and sublethal toxicity of -nitrotoluene and -nitroaniline, since they are both still used in China.

Keywords： joint toxicity     <italic>Cyprinus carpioitalic>     <italic>LCitalic><sub>50sub>     <italic>pitalic>-nitrotoluene     <italic>pitalic>-nitroaniline     toxic unit    

HTML PDF Collect

Synthesis of

Lili ZHANG, Ming LIU, Shijun MA, Yaodong HUANG, Yongmei WANG

Frontiers of Chemical Science and Engineering 2013, Volume 7, Issue 4,   Pages 408-414 doi: 10.1007/s11705-013-1343-4

Abstract: Two new -symmetric primary-secondary diamines were synthesized via the reaction of ( , )-1,2-diphenyl ethylene diamine with 3,5-ditert-butyl salicylaldehyde and salicylaldehyde, respectively, followed by reduction with NaBH . The combination of the ligand from 3,5-ditert-butyl salicylaldehyde with CuBr could effciently catalyze the Henry reaction to afford -nitroalkanols in moderate to good yields (up to 87%) and high enantioselectivities (up to 88% ). A possible mechanism of the reaction was proposed.

Keywords： enantioselective Henry reaction     <italic>Citalic><sub>1sub>-symmetric diamines     asymmetric reaction    

HTML PDF Collect

Effects of different sediment fractions on sorption of galaxolide

Lixia JIN, Mengchang HE, Jinghuan ZHANG

Frontiers of Environmental Science & Engineering 2012, Volume 6, Issue 1,   Pages 59-65 doi: 10.1007/s11783-010-0259-1

Abstract: Sorption isotherms of galaxolide (HHCB) of different fractions from two sediments with different mineral and organic carbon contents were determined to compare HHCB sorption behavior and contribution to the total sorption. The HHCB sorption isotherms that used the batch equilibration method were studied on different sediments of different fractions. The sorption isotherms of 600°C heating fractions were detailed using the linear model, while the other fractions were nonlinear and fitted well with the Freundlich model. The dissolved organic carbon (DOC) removed, NaOH extracted, and 375°C heating fractions showed more nonlinear sorption than the original sediments, which suggested more heterogeneous sorption sites in these fractions. Compared to the original sediments, the 375°C heating fractions had higher carbon-normalized distribution coefficient ( ) values, indicating a higher sorption affinity for HHCB. Among the different sediment fractions, the contribution of the 600°C heating fractions to the overall sorption were the lowest (<20%), while the 375°C heating fractions were the highest (up to 85%).

Keywords： galaxolide (HHCB)     sorption     organic carbon     sediment     carbon-normalized distribution coefficient (<italic>Kitalic><sub>ocsub>)    

HTML PDF Collect

The effect of preparation conditions of Pt/Al

Lei YUAN, Xiang ZHENG, Kaijiao DUAN, Hao HU, Jinggang WANG, Seong Ihl WOO, Zhiming LIU

Frontiers of Environmental Science & Engineering 2013, Volume 7, Issue 3,   Pages 457-463 doi: 10.1007/s11783-013-0512-5

Abstract: Selective catalytic reduction of NO by H in the presence of oxygen has been investigated over Pt/Al O catalysts pre-treated under different conditions. Catalyst preparation conditions exert significant influence on the catalytic performance, and the catalyst pre-treated by H or H then followed by O is much more active than that pre-treated by air. The higher surface area and the presence of metallic Pt over Pt/Al O pre-treated by H or pretreated by H then followed by O can contribute to the formation of NO , which then promotes the reaction to proceed at low temperatures.

Keywords： NO<sub><italic>xitalic>sub> reduction     Pt/Al<sub>2sub>O<sub>3sub>     preparation condition     H<sub>2sub>-SCR    

HTML PDF Collect

H<sub>∞sub> control in the frequency domain for a semi-active floor isolation system

Yundong SHI, Tracy C BECKER, Masahiro KURATA, Masayoshi NAKASHIMA

Frontiers of Structural and Civil Engineering 2013, Volume 7, Issue 3,   Pages 264-275 doi: 10.1007/s11709-013-0214-x

Abstract: A floor isolation system installed in a single floor or room in a fixed base structure is designed to protect equipment. With this configuration, the input motions to the floor isolation from the ground motions are filtered by the structure, leaving the majority of the frequency content of the input motion lower than the predominant frequency of the structure. The floor isolation system should minimize the acceleration to protect equipment; however, displacement must also be limited to save floor space, especially with long period motion. Semi-active control with an control was adopted for the floor isolation system and a new input shaping filter was developed to account for the input motion characteristics and enhance the effectiveness of the control. A series of shake table tests for a semi-active floor isolation system using rolling pendulum isolators and a magnetic-rheological damper were performed to validate the control. Passive control using an oil damper was also tested for comparison. The test results show that the control effectively reduced acceleration for short period motions with frequencies close to the predominant frequency of the structure, as well as effectively reduced displacement for long period motions with frequencies close to the natural frequency of the floor isolation system. The control algorithm proved to be more advantageous than passive control because of its capacity to adjust control strategies according to the different motion frequency characteristics.

Keywords： semi-active     floor isolation     <italic>Hitalic><sub>∞sub> control     MR damper     shaping filter     shaking table    

HTML PDF Collect

Factors controlling

Chengkun WANG, Xiaojian ZHANG, Chao CHEN, Jun WANG

Frontiers of Environmental Science & Engineering 2013, Volume 7, Issue 2,   Pages 151-157 doi: 10.1007/s11783-013-0482-7

Abstract: The formation of cancinogenic nitrosamines, esp. -nitrosodimethylamine (NDMA) in water and wastewater treatment plants has drawn much attention in recent years. Dissolved organic matter from the transported Luan River water as water source of Tianjin was fractionated with different XAD resins and a series of ultra-filtration membranes with molecular weight (MW) cut-offs of 5k Da, 3k Da, and 1k Da, respectively. The NDMA yields from the raw water and each fraction were measured to investigate their role in NDMA yield. Results indicated that the hydrophilic fraction had a higher NDMA yield than those of hydrophobic fraction and transphilic fraction. The fraction with MW below 1k Da had a higher NDMA yield than that with larger MW. NDMA formation increased as the dissolved organic carbon (DOC) to dissolved organic nitrogen (DON) ratio decreased, which indicated that DON might serve as the real important precursor for NDMA. The correlation between NDMA yield and specific ultraviolet absorbance at 254 nm (SUVA ) suggested that the latter might not represent the specific precursors for NDMA in the water. Besides the water quality, the influences of pH, disinfectant dosage, and disinfection contact time on the formation of NDMA were also examined. These results will help water treatment plants establish measures to control this harmful disinfection by-product.

Keywords： <italic>Nitalic>-nitrosodimethylamine (NDMA)     disinfection by-product     dissolved organic nitrogen (DOC)     hydrophilic     molecular weight (MW)     specific ultraviolet absorbance at 254 nm (SUVA<sub>254sub>)    

HTML PDF Collect

Experimental investigations on combustion characteristics of syngas composed of CH

Qingwei FAN, Shien HUI, Qulan ZHOU, Qinxin ZHAO, Tongmo XU

Frontiers of Chemical Science and Engineering 2010, Volume 4, Issue 4,   Pages 404-410 doi: 10.1007/s11705-010-0513-x

Abstract: The residual gas and remained raw gas in dual gas resources polygeneration system are quite complex in components (mainly CH , CO, and H ), and these results to the distinguished differences in combustion reaction. Experimental investigations on basic combustion characteristics of syngas referred above are conducted on a laboratory-scale combustor with flame temperature and flue gas composition measured and analyzed. Primary air coefficient (PA), total air coefficient (TA), and components of the syngas (CS) are selected as key factors, and it is found that PA dominates mostly the ignition of syngas and NO formation, while TA affects the flue gas temperature after high temperature region and NO formation trend to be positive as H /CO components increase. The results provide references for industrial utilization.

Keywords： dual gas resources polygeneration     lean premixed combustion     residual gas     remained raw gas     NO<sub><italic>xitalic>sub> emission    

HTML PDF Collect

Numerical simulation and experimental verification of chemical reactions for SCR DeNO

Qiang ZHANG, Yonglin FAN, Wenyan LI

Frontiers of Chemical Science and Engineering 2010, Volume 4, Issue 4,   Pages 523-528 doi: 10.1007/s11705-010-0520-y

Abstract: Selective catalytic reduction (SCR) is a major commercial technology for NO removal in power plants. There are a lot of complex chemical reactions in SCR reactors, and it is of great significance to understand the internal process of chemical reactions for SCR DeNO and study the impact of various factors on NO removal efficiency. In this paper, the impact of reaction temperature, ammonia-nitrogen molar ratio and resident time in the catalyst bed layer on NO removal efficiency were studied by simulation of chemical reactions. Then calculated results were compared with catalyst activity test data in a power plant, which proved that the simulated results were accurate. As a result, the reaction conditions were optimized in order to get the best removal efficiency of NO, so that we can provide a reference for optimal running of SCR in power plants.

Keywords： SCR     NO<sub><italic>xitalic>sub>     removal efficiency     chemical reactions     simulation    

HTML PDF Collect

A combined experimental and theoretical study of micronized coal reburning

Hai ZHANG, Jiaxun LIU, Jun SHEN, Xiumin JIANG

Frontiers in Energy 2013, Volume 7, Issue 1,   Pages 119-126 doi: 10.1007/s11708-012-0226-6

Abstract: Micronized coal reburning (MCR) can not only reduce carbon in fly ash but also reduce NO emissions as compared to the conventional coal reburning. However, it has two major kinetic barriers in minimizing NO emission. The first is the conversion of NO into hydrogen cyanide (HCN) by conjunction with various hydrocarbon fragments. The second is the oxidation of HCN by association with oxygen-containing groups. To elucidate the advantages of MCR, a combination of Diffuse Reflection Fourier Transform Infrared (FTIR) experimental studies with Density Functional Theory (DFT) theoretical calculations is conducted in terms of the second kinetic barrier. FTIR studies based on Chinese Tiefa coal show that there are five hydroxide groups such as OH-π, OH-N, OH-OR , self-associated OH and free OH. The hydroxide groups increase as the mean particle size decreases expect for free OH. DFT calculations at the B3LYP/6-31 G(d) level indicate that HCN can be oxidized by hydroxide groups in three paths, HCN+OH→HOCN+H (path 1), HCN+OH→HNCO+H (path 2), and HCN+OH→CN+H O (path 3). The rate limiting steps for path 1, path 2 and path 3 are IM2→P1+H (170.66 kJ/mol activated energy), IM1→IM3 (231.04 kJ/mol activated energy), and R1+OH→P3+H O (97.14 kJ/mol activated energy), respectively. The present study of MCR will provide insight into its lower NO emission and guidance for further studies.

Keywords： transform infrared spectroscopy (FTIR)     density functional theory (DFT)     homogeneous reaction mechanism     NO<sub><italic>xitalic>sub>    

HTML PDF Collect

Design and operational considerations for selective catalytic reduction technologies at coal-fired boilers

Jeremy J. SCHREIFELS, Shuxiao WANG, Jiming HAO

Frontiers in Energy 2012, Volume 6, Issue 1,   Pages 98-105 doi: 10.1007/s11708-012-0171-4

Abstract: By the end of 2010, China had approximately 650 GW of coal-fired electric generating capacity producing almost 75% of the country’s total electricity generation. As a result of the heavy reliance on coal for electricity generation, emissions of air pollutants, such as nitrogen oxides (NO ), are increasing. To address these growing emissions, the Ministry of Environmental Protection (MEP) has introduced new NO emission control policies to encourage the installation of selective catalytic reduction (SCR) technologies on a large number of coal-fired electric power plants. There is, however, limited experience with SCR in China. It is therefore useful to explore the lessons from the use of SCR technologies in other countries. This paper provides an overview of SCR technology performance at coal-fired electric power plants demonstrating emission removal rates between 65% and 92%. It also reviews the design and operational challenges that, if not addressed, can reduce the reliability, performance, and cost-effectiveness of SCR technologies. These challenges include heterogeneous flue gas conditions, catalyst degradation, ammonia slip, sulfur trioxide (SO ) formation, and fouling and corrosion of plant equipment. As China and the rest of the world work to reduce greenhouse gas emissions, carbon dioxide (CO ) emissions from parasitic load and urea-to-ammonia conversion may also become more important. If these challenges are properly addressed, SCR can reliably and effectively remove up to 90% of NO emissions at coal-fired power plants.

Keywords： nitrogen oxides (NO<sub><italic>xitalic>sub>)     coal     selective catalytic reduction (SCR)     air pollution    

HTML PDF Collect

Effect of K and Ca on catalytic activity of Mn-CeO

Boxiong SHEN, Lidan DENG, Jianhong CHEN

Frontiers of Environmental Science & Engineering 2013, Volume 7, Issue 4,   Pages 512-517 doi: 10.1007/s11783-013-0519-y

Abstract: Mn-CeO /Ti-pillared clay (PILC) is an attractive catalyst for selective catalytic reduction of NO at low temperature because of its low cost. The poisoning of K and Ca on the catalyst of Mn-CeO /Ti-PILC is an important problem because K and Ca are always in presence in flue gas. To investigate the effect of K and Ca on the physicochemical characters of the catalysts, the techniques of NH -temperature programmed desorption (TPD), H -temperature programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS) were used to analyze the fresh and deactivated catalysts of Mn-CeO /Ti-PILC. (Ca)Mn-CeO /Ti-PILC and (K)Mn-CeO /Ti-PILC are denoted for the dopes of the catalyst of Mn-CeO /Ti-PILC with Ca and K, respectively. The activities of Mn-CeO /Ti-PILC, (Ca)Mn-CeO /Ti-PILC and (K)Mn-CeO /Ti-PILC for NH -selective catalytic reduction (SCR) reaction at low temperature were investigated. The results showed that with the dopes of K and Ca on the catalysts, the SCR activities of the catalysts decreased greatly, and K exhibited more poisoning effect than Ca. With the dopes of K and Ca, the acidity, the redox property and chemisorbed oxygen on the surfaces of the catalysts were decreased, which resulted in a decreasing in SCR activity.

Keywords： Mn-CeO<sub><italic>xitalic>sub>/Ti-pillared clay (PILC)     low-temperature selective catalytic reduction    

HTML PDF Collect

The abatement of major pollutants in air and water by environmental catalysis

Junhua LI, Hong HE, Chun HU, Jincai ZHAO

Frontiers of Environmental Science & Engineering 2013, Volume 7, Issue 3,   Pages 302-325 doi: 10.1007/s11783-013-0511-6

Abstract: This review reports the research progress in the abatement of major pollutants in air and water by environmental catalysis. For air pollution control, the selective catalytic reduction of NO (SCR) by ammonia and hydrocarbons on metal oxide and zeolite catalysts are reviewed and discussed, as is the removal of Hg from flue gas by catalysis. The oxidation of Volatile organic compounds (VOCs) by photo- and thermal- catalysis for indoor air quality improvement is reviewed. For wastewater treatment, the catalytic elimination of inorganic and organic pollutants in wastewater is presented. In addition, the mechanism for the procedure of abatement of air and water pollutants by catalysis is discussed in this review. Finally, a research orientation on environment catalysis for the treatment of air pollutants and wastewater is proposed.

Keywords： air pollution control     wastewater treatment     DeNO<sub><italic>xitalic>sub>     selective catalytic reduction    

HTML PDF Collect

Identification and ecotoxicity assessment of intermediates generated during the degradation of clofibric acid by advanced oxidation processes

Wenzhen LI, Yu DING, Qian SUI, Shuguang LU, Zhaofu QIU, Kuangfei LIN

Frontiers of Environmental Science & Engineering 2012, Volume 6, Issue 4,   Pages 445-454 doi: 10.1007/s11783-012-0419-6

Abstract: The aim of this study was to identify the intermediates in clofibric acid degradation under various advanced oxidation processes, namely ultraviolet (UV), UV/H O , vacuum ultraviolet (VUV), VUV/H O , and solar/TiO processes, as well as to assess the toxicity of these intermediates. Eleven intermediates have been detected by gas chromatography-mass spectrometer, most of which were reported for the first time to our best knowledge. Combining the evolution of the dissolved organic carbon, Cl and specific ultraviolet absorption at 254 nm, it could be deduced that cleavage of aromatic ring followed by dechlorination was the mechanism in solar/TiO process, while dechlorination happened first and accumulation of aromatic intermediates occurred in the other processes. Different transformation pathways were proposed for UV-, VUV-assisted and solar/TiO processes, respectively. The acute toxicity was evaluated by means of T spp. bioassay. It was believed that aromatic intermediates increased the toxicity and the ring-opening pathway in solar/TiO process could relieve the toxicity.

Keywords： clofibric acid     advanced oxidation processes     intermediates     toxicity     <italic>Photobacterium phosphoreumitalic> T<sub>3sub> spp    

HTML PDF Collect

The <italic>rpoSitalic> deficiency suppresses acetate accumulation in glucose-enriched culture of <italic>Escherichia coliitalic> under an aerobic condition

Prayoga SURYADARMA, Yoshihiro OJIMA, Yuto FUKUDA, Naohiro AKAMATSU, Masahito TAYA

Frontiers of Chemical Science and Engineering 2012, Volume 6, Issue 2,   Pages 152-157 doi: 10.1007/s11705-012-1287-0

Abstract: The role of on the central carbon metabolism was investigated through analyzing the deficiency of this regulon gene under aerobic and glucose-enriched culture conditions. The experimental results showed that while the wild type cells exhibited an overflow metabolism effect, the -deleting mutation alleviated this effect with the significant suppression of acetate accumulation under a high glucose condition. This gene deletion also induced the twofold upregulation of and one-tenth downregulation of , respectively. The overflow metabolism effect was confirmed to be recovered by re-introducing gene into the mutant. These results demonstrated changed the central carbon metabolism toward acetate overflow through dehydrogenation of pyruvate and reduction of TCA cycle activity.

Keywords： <italic>Escherichia coliitalic>     <italic>rpoSitalic>     aerobic and glucose-enriched culture     overflow    

HTML PDF Collect

Synthesis of depsipeptides from

Hongfei CAO, Yakai FENG, Heyun WANG, Li ZHANG, Musammir KHAN, Jintang GUO

Frontiers of Chemical Science and Engineering 2011, Volume 5, Issue 4,   Pages 409-415 doi: 10.1007/s11705-011-1141-9

Abstract: By using the corresponding -amino acid sodium as initiator, -caprolactone-depsipeptides CL-Ala and CL-Leu were prepared by the reactions of -caprolactone (CL) with -alanine and -leucine, respectively, and -dioxanone-depsipeptide (PDO-Leu) was prepared by the reaction of -dioxanone (PDO) with -leucine. Two poly( -caprolactone) oligomers (PCL-Ala and PCL-Leu) of different molecular weights with depsipeptide unit were synthesized by controlling the feed ratio of -amino acid sodium and CL. The presence of the depsipeptide structure in these obtained products was confirmed by H NMR spectra and the molecular weight of the poly( -caprolactone) oligomers was measured by gel permeation chromatography (GPC). These products contain a hydroxyl group and a carboxyl group in one molecule, which means they could act as bifunctional monomers for further polymerization to prepare high molecular weight polymers. By this way, the depsipeptide unit could be introduced into the polymers and the biodegradation rates of the novel polymers could be well controlled in vivo by the tailored molecular structures.

Keywords： <italic>?italic>-caprolactone     <italic>pitalic>-dioxanone     <italic>Litalic>-alanine     <italic>Litalic>-leucine    

HTML PDF Collect

Title Author Date Type Operation

Assessment of toxicity of two nitroaromatic compounds in the freshwater fish

Hongyan SHEN, Jixi GAO, Jinsheng WANG

Journal Article

Synthesis of

Lili ZHANG, Ming LIU, Shijun MA, Yaodong HUANG, Yongmei WANG

Journal Article

Effects of different sediment fractions on sorption of galaxolide

Lixia JIN, Mengchang HE, Jinghuan ZHANG

Journal Article

The effect of preparation conditions of Pt/Al

Lei YUAN, Xiang ZHENG, Kaijiao DUAN, Hao HU, Jinggang WANG, Seong Ihl WOO, Zhiming LIU

Journal Article

H<sub>∞sub> control in the frequency domain for a semi-active floor isolation system

Yundong SHI, Tracy C BECKER, Masahiro KURATA, Masayoshi NAKASHIMA

Journal Article

Factors controlling

Chengkun WANG, Xiaojian ZHANG, Chao CHEN, Jun WANG

Journal Article

Experimental investigations on combustion characteristics of syngas composed of CH

Qingwei FAN, Shien HUI, Qulan ZHOU, Qinxin ZHAO, Tongmo XU

Journal Article

Numerical simulation and experimental verification of chemical reactions for SCR DeNO

Qiang ZHANG, Yonglin FAN, Wenyan LI

Journal Article

A combined experimental and theoretical study of micronized coal reburning

Hai ZHANG, Jiaxun LIU, Jun SHEN, Xiumin JIANG

Journal Article

Design and operational considerations for selective catalytic reduction technologies at coal-fired boilers

Jeremy J. SCHREIFELS, Shuxiao WANG, Jiming HAO

Journal Article

Effect of K and Ca on catalytic activity of Mn-CeO

Boxiong SHEN, Lidan DENG, Jianhong CHEN

Journal Article

The abatement of major pollutants in air and water by environmental catalysis

Junhua LI, Hong HE, Chun HU, Jincai ZHAO

Journal Article

Identification and ecotoxicity assessment of intermediates generated during the degradation of clofibric acid by advanced oxidation processes

Wenzhen LI, Yu DING, Qian SUI, Shuguang LU, Zhaofu QIU, Kuangfei LIN

Journal Article

The <italic>rpoSitalic> deficiency suppresses acetate accumulation in glucose-enriched culture of <italic>Escherichia coliitalic> under an aerobic condition

Prayoga SURYADARMA, Yoshihiro OJIMA, Yuto FUKUDA, Naohiro AKAMATSU, Masahito TAYA

Journal Article

Synthesis of depsipeptides from

Hongfei CAO, Yakai FENG, Heyun WANG, Li ZHANG, Musammir KHAN, Jintang GUO

Journal Article