This paper have collected the measured tides and certain tidal current data in different stages of many projects during past three to five years near the Aojiang River. The harmonic method is used to analyze tide and ...This paper have collected the measured tides and certain tidal current data in different stages of many projects during past three to five years near the Aojiang River. The harmonic method is used to analyze tide and tidal current data observed at five stations in the sea adjacent to Aojiang River. The results show that the tide is mainly regular and semidiumal in the sea near Aojiang of Wenzhou. The tidal amplitudes of M2 constituent are between 170 cm - 193 cm and the lags are between 260~ - 280~, According to the comparison of analytical results of harmonic constants of these stations in 2007, 2010 and 2011, the maximum change of tidal amplitudes and phase-lag range for the main semidiurnal tides (M2, $2, N2), the diurnal tide (K1, O1) and the shallow water tide (M4, MS4, M6) are 1.8 cm - 4.4 cm and 3~ - 7~, respectively. After analyzing the tide and tidal current characteristics of Aojiang River, this paper uses an unstructured grid and Finite-Volume Coastal Ocean Model (FVCOM) to test the results of simulation. The simulated results agree well with the measured data. The new shoreline and depth which are produced by the construction projects closed in important major years, and the tide and tidal current field for the new shoreline and depth are constructed, which describe the superimposed influences of construction engineering in Aojiang estuary.展开更多
AIM: To evaluate the predictive value of neutrophil in- filtration as a marker of Helicobacter pylori (H. pyloni) infection. METHODS: A total of 315 patients with dyspepsia symptoms who underwent upper gastrointes...AIM: To evaluate the predictive value of neutrophil in- filtration as a marker of Helicobacter pylori (H. pyloni) infection. METHODS: A total of 315 patients with dyspepsia symptoms who underwent upper gastrointestinal en- doscopy were enrolled in this study. Biopsies were evaluated using the updated Sydney system. The medication history of all patients in the preceding 4 wk was recorded. The diagnosis of H. pylori infection was based on 13C-urea breath test at least 4 wk after with- drawal of antisecretory drugs, antibiotics and related drugs. For the patients with subtotal gastrectomy, the diagnosis of H. pylori infection was based on anti-H. pylori immunoglobulin G (IgG) antibody. Serum anti-H. pylori IgG antibody was measured by enzyme-linked immunosorbent assays (Biohit, Finland). RESULTS: The sensitivity, specificity, positive predic- tive value and negative predictive value of neutrophil infiltration in the diagnosis ofH, pylorlinfection were 92.3%, 83.5%, 77.4% and 94.7%, respectively. Neu- trophil infiltration of gastric mucosa in the histological analysis was strongly associated withH, pylorlinfection (77.4% vs 5.3% in the neutrophil infiltration negative group, P = 0.000). Moderate neutrophil infiltration was more frequent in H. pylorl infection when compared to mild infiltration (81.8% and 75%, respectively), but did not reach statistical significance. For those patients with negative rapid urease test, H. pylori was detected in 73.2% of patients with positive neutrophil infiltration on histology. In patients with subtotal gastrectomy, the diagnostic accuracy of neutrophil infiltration in H. pylori infection was 50%. CONCLUSION: Neutrophil infiltration is closely associ- ated withH, pylori and may be recognized as a sign of this infection.展开更多
Sediment-water fluxes of N and P species in the Bohai Sea were investigated in Septem-ber-October 1998 and April-May 1999. The benthic fluxes of nutrient species were determined by incubating sediment core samples wit...Sediment-water fluxes of N and P species in the Bohai Sea were investigated in Septem-ber-October 1998 and April-May 1999. The benthic fluxes of nutrient species were determined by incubating sediment core samples with bottom seawater bubbled with air or nitrogen. -2NO,+4NH, dissolved organic nitrogen (DON) and phosphorus (DOP), total dissolved nitrogen (TDN) and phosphorus (TDP), and -34PO showed a net exchange flux from seawater to sediment, while -3NO, dissolved inorganic nitrogen (DIN) and -23SiO were released from sediment to seawater in the Bohai Sea. Sediment-water nutrient exchange increases DIN and reduces the phosphorus load in the Bohai Sea. The release of silicate from sediment to overlying seawater reduces potential silicate limitation of primary production resulted from decrease of riverine discharge. The exchange flux of nutrients showed no obvious seasonal variation. The present study showed that the concentrations and composition of nutrients in the water column were affected by suspended sediment, and that not all the exchangeable phosphate in sediment could be released via sediment resuspension.展开更多
The adsorption characteristics and mechanisms of modified sepiolite as an adsorbent to recover Pd(Ⅱ) from acidic solutions were studied. The Pd(Ⅱ) adsorption properties were analyzed through isotherm, kinetic and th...The adsorption characteristics and mechanisms of modified sepiolite as an adsorbent to recover Pd(Ⅱ) from acidic solutions were studied. The Pd(Ⅱ) adsorption properties were analyzed through isotherm, kinetic and thermodynamic models. In addition, SEM-EDS, TEM and XPS were applied to investigating the Pd(Ⅱ) adsorption mechanisms onto modified sepiolite. The equilibrium data were well fitted to Langmuir isotherm model with maximum Pd(Ⅱ) adsorption capacity of 322.58 mg/g at 30 ℃. The kinetic data could be satisfactorily simulated by the pseudosecond order model, indicating that the rate-controlling step was chemical adsorption. 99% of Pd(Ⅱ) could be recovered using 1 g/L modified sepiolite when initial concentration of Pd(Ⅱ) was 100 mg/L. The results of reusability studies indicated the modified sepiolite had an acceptable stability and reusability. This study indicated that the modified sepiolite might be an efficient and cost-effective material for Pd(Ⅱ) recovery.展开更多
Acrochaete leptochaete, a species in Chaetophoraceae (Chlorophyta), was observed during our recent laboratory culture of the macroalgae Chaetornorpha that was originally collected from an intertidal pool in Rongchen...Acrochaete leptochaete, a species in Chaetophoraceae (Chlorophyta), was observed during our recent laboratory culture of the macroalgae Chaetornorpha that was originally collected from an intertidal pool in Rongcheng, Shandong Province, China. This is the first record of this species in China. Its morphology, taxonomy, and distribution were introduced and discussed in detail. Isolated culture experiments at different temperatures (9-29℃) and light intensities (36-108 μmol/m^2.s) were also carried out. The culture-based observations have extended our knowledge of growth morphology and general biology of the species.展开更多
The application of overgrowth microorganisms in ocean research was discussed,using the China National Knowledge Infrastructure(CNKI)network database to retrieve papers on the topic of symbiotic microbes(=198)and symbi...The application of overgrowth microorganisms in ocean research was discussed,using the China National Knowledge Infrastructure(CNKI)network database to retrieve papers on the topic of symbiotic microbes(=198)and symbiotic marine microorganisms(n=94).Bibliometric Analysis are conducted in terms of the published trends,subject headings and other aspects.The output of literature in this field has increased rapidly in the past15years.57.4%of the papers were published in the last five years.And the relevance of research topics has increased in recent years.The current research focuses on community diversity,secondary metabolites,biological activities and antibacterial activities.Literature analysis is helpful to understand the overall development trend of overgrowth microorganisms in ocean research.展开更多
The phosphate-embedded calcium alginate beads were successfully synthesized based on sodium alginate, calcium dihydrogen phosphate and sodium hydrogen carbonate. Scanning electron microscopy, Fourier transformed infra...The phosphate-embedded calcium alginate beads were successfully synthesized based on sodium alginate, calcium dihydrogen phosphate and sodium hydrogen carbonate. Scanning electron microscopy, Fourier transformed infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were conducted to characterize the morphology and structure of the phosphate-embedded calcium alginate beads. The effects of pH and the initial concentration of the metal ions on Pb(II) and Cd(II) sorption by the beads were investigated. The optimal pH values for Pb(II) and Cd(II) sorption are 4.0 and 5.5, respectively. The optimal initial concentrations of Pb(II) and Cd(II) are 200 mg/L and 25 mg/L, correspondingly, and the removal efficiencies are 94.2% and 80%,respectively. The sorption mechanism is that the heavy metal ions accessed the beads firstly due to the large surface area, combinedwith OH?, and then precipitated with phosphate radical, which was proven by FTIR and XRD. The sorption of Pb(II) and Cd(II) isfitted to Langmuir isotherm model with R2 values of 0.9957 and 0.988, respectively. The sorption capacities of Pb(II) and Cd(II) are263.16 mg/g and 82.64 mg/g, respectively. The results indicate that the phosphate-embedded calcium alginate beads could be appliedto treating Pb(II)/Cd(II)-containing wastewater and it could be implied that the synthesized beads also could be used as a kind of soil ameliorant for remediation of the heavy metal contaminated paddy soil.展开更多
A heat pipe type adsorption ice maker with two adsorbers for fishing boats is designed by using ammonia as refrigerant and compound of activated carbon-CaCl2 as adsorbent. This type of heat pipe adsorber can solve the...A heat pipe type adsorption ice maker with two adsorbers for fishing boats is designed by using ammonia as refrigerant and compound of activated carbon-CaCl2 as adsorbent. This type of heat pipe adsorber can solve the problem of incompatibility between ammonia, copper, seawater and steel. The working process of the ice maker with 8.7kg adsorbent per bed is simulated. The results show that the optimal semi-cycle time is about 9 min at the evaporating temperature of -15℃, where the corresponding cooling power, specific cooling power per kilogram adsorbent SCP and coefficient of refrigerant performance COP are respectively 3.6kW, 217W·kg-1 and 0.404.展开更多
This work aims to investigate the efficiency of Fariman sepiolite from Iran as an adsorbent to remove Cd from aqueous solutions. The effects of different experimental factors such as the initial Cd concentration, cont...This work aims to investigate the efficiency of Fariman sepiolite from Iran as an adsorbent to remove Cd from aqueous solutions. The effects of different experimental factors such as the initial Cd concentration, contact time and the sorbent dose were investigated through a series of batch adsorption experiments. The results show that the adsorption capacity of sepiolite for Cd increases with the contact time, the initial concentration of Cd solutions and the sorbent dose. Sorption of Cd by Fariman sepiolite is rapid within the first hour of the experiment and then slowly increases until a pseudo equilibrium is approached at 8 h. The results also show that the time-dependent Cd sorption data are better described with pseudo second-order (7〉0.999) than that of pseudo first-order (r2〉0.971) kinetic model. Equilibrium isotherm studies show that the experimental data are better correlated by the Freundlich adsorption isotherm (7〉0.995) than the Langmuir (P〉0.825). It is suggested that both adsorption and cation exchange reactions are responsible for the sorption of Cd by the sepiolite, and the mineral has a very good potential to remove Cd from aqueous solutions.展开更多
Heavy metal pollution from industrial wastewater is a worldwide environmental issue. Biosorption of heavy metals by using biosorbents derived from various types of biomass has been shown to be effective for the uptake...Heavy metal pollution from industrial wastewater is a worldwide environmental issue. Biosorption of heavy metals by using biosorbents derived from various types of biomass has been shown to be effective for the uptake of heavy metal ions. In this study, biosorbents derived from the biomass of a group of marine macroalgae were used for the removal and recovery of heavy metal ions from aqueous solutions. Results indicated that the biosorbents have high uptake capacities and affinities for a number of heavy metal ions. The uptake capacities of the biosorbents were in the range of 1.0 to 1.5mmol·g-1 for divalent heavy metal ions. The kinetics of the uptake process was fast and the process can be used in both batch and fixed-bed operations. It appears that the biosorption process by using biosorbents from marine macroalgae can be an efficient and cost effective technology for the treatment of heavy metal containing wastewater.展开更多
To establish a theoretical foundation for simultaneous removal of multi-heavy metals,the adsorption of Cu(Ⅱ) and Pb(Ⅱ) ions from their single and binary systems by Ca-alginate immobilized activated carbon and Sa...To establish a theoretical foundation for simultaneous removal of multi-heavy metals,the adsorption of Cu(Ⅱ) and Pb(Ⅱ) ions from their single and binary systems by Ca-alginate immobilized activated carbon and Saccharomyces cerevisiae (CAS) was investigated.The CAS beads were characterized by Scanning electron microscope (SEM) and Fourier transformed infrared spectroscopy (FTTR).The effect of initial pH,adsorbent dosage,contact time and initial metal ions concentration on the adsorption process was systematically investigated.The experimental maximum contents of Cu(Ⅱ) and Pb(Ⅱ) uptake capacity were determined as 64.90 and 166.31 mg/g,respectively.The pseudo-second-order rate equation and Langmuir isotherm model could explain respectively the kinetic and isotherm experimental data of Cu(Ⅱ) and Pb(Ⅱ) ions in single-component systems with much satisfaction.The experimental adsorption data of Cu(Ⅱ) and Pb(Ⅱ) ions in binary system were best described by the extended Freundlich isotherm and the extended Langmuir isotherm,respectively.The removal of Cu(lⅡ) ions was more significantly influenced by the presence of the coexistent Pb(Ⅱ) species,while the Pb(Ⅱ) removal was affected slightly by varying the initial concentration of Cu(Ⅱ).The CAS was successfully regenerated using 1 mol/L HNO3 solution.展开更多
Algal organic materials (AOMs) are one critical factor affecting the efficiency of modified clays used for the mitigation of harrnful algal blooms (HABs). This study was conducted to develop a deeper understanding...Algal organic materials (AOMs) are one critical factor affecting the efficiency of modified clays used for the mitigation of harrnful algal blooms (HABs). This study was conducted to develop a deeper understanding of the mechanisms and factors affecting the adsorption of AOMs onto modified clays. Sodium alginate (polysaccharide) and kaolinite modified with polyaluminium chloride (PAC1) were used as AOMs and modified clay model substances, respectively, and the effects of modifier dosage, contact time, solution pH and ionic strength were investigated through batch adsorption experiments. Kinetics revealed that the alginate adsorption rate was described well by a pseudo-second order model. PACl effectively enhanced the adsorption capacity of kaolinite and increased the adsorption rate, and the optimum additive amount of PACl was 5%. The experimental data fitted both the Freundlich and Langmuir adsorption equations well. The adsorption thermodynamics for alginate onto modified clays suggests that alginate adsorption is a spontaneous process. The adsorption of alginate onto modified clays was highly dependent on pH, with a decrease in adsorption observed with increased pH to 9.48, but the opposite was true above pH 9.48. Finally, adsorption increased with increasing ionic strength.展开更多
Fouling diatoms are a main component of biofilm,and play an important role in marine biofouling formation. We investigated seasonal variations in fouling diatom communities that developed on glass slides immersed in s...Fouling diatoms are a main component of biofilm,and play an important role in marine biofouling formation. We investigated seasonal variations in fouling diatom communities that developed on glass slides immersed in seawater,on the Yantai coast,northern Yellow Sea,China,using microscopy and molecular techniques. Studies were conducted during 2012 and 2013 over 3,7,14,and 21 days in each season. The abundance of attached diatoms and extracellular polymeric substances increased with exposure time of the slides to seawater. The lowest diatom density appeared in winter and the highest species richness and diversity were found in summer and autumn. Seasonal variation was observed in the structure of fouling diatom communities. Pennate diatoms Cylindrotheca,Nitzschia,Navicula,Amphora,Gomphonema,and Licmophora were the main fouling groups. Cylindrotheca sp. dominated in the spring. Under laboratory culture conditions,we found that Cylindrotheca grew very fast,which might account for the highest density of this diatom in spring. The lower densities in summer and autumn might result from the emergence of fouling animals and environmental factors. The Cylindrotheca sp. was identified as Cylindrotheca closterium using18 S rDNA sequencing. The colonization process of fouling diatoms and significant seasonal variation in this study depended on environmental and biological factors. Understanding the basis of fouling diatoms is essential and important for developing new antifouling techniques.展开更多
This study investigates the heat and mass transfer mechanism of a marine engifie exhaust-powered adsorption refrigerating system by using irreversible thermodynamics. The equations of entropy-production rate and the l...This study investigates the heat and mass transfer mechanism of a marine engifie exhaust-powered adsorption refrigerating system by using irreversible thermodynamics. The equations of entropy-production rate and the linear phenomenological equations of thermodynamic flux and force are established. The conventional experimental facilities of unit tube are developed and the phenomenological coefficients are obtained by fitting the experimental data. It is concluded that the thermodynamic process in the adsorbent bed is determined by the coupling effect of the heat and mass transfer; furthermore, the mass transfer is determined by the heat transfer. Taking some measures to increase heat transfer can improve the performance of the adsorption refrigerating system. The conclusions presented in this paper may be of value to the engineering applications of the system.展开更多
A new species of deep-water barnacle that belongs to the family Scalpellidae is described from the South China Sea. A rcoscalpellum liui sp. nov. is morphologically similar to A rcoscalpellum gryllum Zevina,but differ...A new species of deep-water barnacle that belongs to the family Scalpellidae is described from the South China Sea. A rcoscalpellum liui sp. nov. is morphologically similar to A rcoscalpellum gryllum Zevina,but differs from the latter by the absence of longitudinal striae on the capitular plates and the presence of caudal appendages with few terminal setae.展开更多
Electrochemical behavior of 5083-H116 Al alloy with flow velocity of seachest material for Al ship was evaluated.To examine the electrochemical characteristics of flow velocity and its effects on the performance of th...Electrochemical behavior of 5083-H116 Al alloy with flow velocity of seachest material for Al ship was evaluated.To examine the electrochemical characteristics of flow velocity and its effects on the performance of the alloy,experiments were conducted at four flow velocity variables using static state with an agitator.An ultrasonic vibration generator using piezoelectric effect was used in cavitation test according to the requirements of in ASTM-G32.The results show that the corrosion current density and damage were increased by applying the flow velocity compared to static state.Therefore,it is determined that the case of applying flow velocity is weaker to the corrosion.展开更多
文摘This paper have collected the measured tides and certain tidal current data in different stages of many projects during past three to five years near the Aojiang River. The harmonic method is used to analyze tide and tidal current data observed at five stations in the sea adjacent to Aojiang River. The results show that the tide is mainly regular and semidiumal in the sea near Aojiang of Wenzhou. The tidal amplitudes of M2 constituent are between 170 cm - 193 cm and the lags are between 260~ - 280~, According to the comparison of analytical results of harmonic constants of these stations in 2007, 2010 and 2011, the maximum change of tidal amplitudes and phase-lag range for the main semidiurnal tides (M2, $2, N2), the diurnal tide (K1, O1) and the shallow water tide (M4, MS4, M6) are 1.8 cm - 4.4 cm and 3~ - 7~, respectively. After analyzing the tide and tidal current characteristics of Aojiang River, this paper uses an unstructured grid and Finite-Volume Coastal Ocean Model (FVCOM) to test the results of simulation. The simulated results agree well with the measured data. The new shoreline and depth which are produced by the construction projects closed in important major years, and the tide and tidal current field for the new shoreline and depth are constructed, which describe the superimposed influences of construction engineering in Aojiang estuary.
基金Supported by The grant for Key Laboratory of Gastroenterology and Hepatology,Ministry of Health,Renji Hospital,Shanghai Jiao Tong University School of MedicineNational Natural Science Foundation of China,No.81170355
文摘AIM: To evaluate the predictive value of neutrophil in- filtration as a marker of Helicobacter pylori (H. pyloni) infection. METHODS: A total of 315 patients with dyspepsia symptoms who underwent upper gastrointestinal en- doscopy were enrolled in this study. Biopsies were evaluated using the updated Sydney system. The medication history of all patients in the preceding 4 wk was recorded. The diagnosis of H. pylori infection was based on 13C-urea breath test at least 4 wk after with- drawal of antisecretory drugs, antibiotics and related drugs. For the patients with subtotal gastrectomy, the diagnosis of H. pylori infection was based on anti-H. pylori immunoglobulin G (IgG) antibody. Serum anti-H. pylori IgG antibody was measured by enzyme-linked immunosorbent assays (Biohit, Finland). RESULTS: The sensitivity, specificity, positive predic- tive value and negative predictive value of neutrophil infiltration in the diagnosis ofH, pylorlinfection were 92.3%, 83.5%, 77.4% and 94.7%, respectively. Neu- trophil infiltration of gastric mucosa in the histological analysis was strongly associated withH, pylorlinfection (77.4% vs 5.3% in the neutrophil infiltration negative group, P = 0.000). Moderate neutrophil infiltration was more frequent in H. pylorl infection when compared to mild infiltration (81.8% and 75%, respectively), but did not reach statistical significance. For those patients with negative rapid urease test, H. pylori was detected in 73.2% of patients with positive neutrophil infiltration on histology. In patients with subtotal gastrectomy, the diagnostic accuracy of neutrophil infiltration in H. pylori infection was 50%. CONCLUSION: Neutrophil infiltration is closely associ- ated withH, pylori and may be recognized as a sign of this infection.
基金This study was funded by NSFC (Nos. 40036010 and 40206017) and the Special Funds from National Key Basic Research Program of P. R. China (No. 2001CB409703).
文摘Sediment-water fluxes of N and P species in the Bohai Sea were investigated in Septem-ber-October 1998 and April-May 1999. The benthic fluxes of nutrient species were determined by incubating sediment core samples with bottom seawater bubbled with air or nitrogen. -2NO,+4NH, dissolved organic nitrogen (DON) and phosphorus (DOP), total dissolved nitrogen (TDN) and phosphorus (TDP), and -34PO showed a net exchange flux from seawater to sediment, while -3NO, dissolved inorganic nitrogen (DIN) and -23SiO were released from sediment to seawater in the Bohai Sea. Sediment-water nutrient exchange increases DIN and reduces the phosphorus load in the Bohai Sea. The release of silicate from sediment to overlying seawater reduces potential silicate limitation of primary production resulted from decrease of riverine discharge. The exchange flux of nutrients showed no obvious seasonal variation. The present study showed that the concentrations and composition of nutrients in the water column were affected by suspended sediment, and that not all the exchangeable phosphate in sediment could be released via sediment resuspension.
基金Projects(51871250,51504106)supported by the National Natural Science Foundation of ChinaProject(SKL-SPM-201809)supported by the State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals,China+2 种基金Projects(502211852,502211906)supported by the Fundamental Research Funds for the Central Universities of Central South University,ChinaProject(SKYAM005-2016)supported by State Key Laboratory of Applied Microbiology Southern ChinaProjects(2015FB204,2016BA006,2017FA030)supported by the Yunnan Science and Technology Plan Project of China。
文摘The adsorption characteristics and mechanisms of modified sepiolite as an adsorbent to recover Pd(Ⅱ) from acidic solutions were studied. The Pd(Ⅱ) adsorption properties were analyzed through isotherm, kinetic and thermodynamic models. In addition, SEM-EDS, TEM and XPS were applied to investigating the Pd(Ⅱ) adsorption mechanisms onto modified sepiolite. The equilibrium data were well fitted to Langmuir isotherm model with maximum Pd(Ⅱ) adsorption capacity of 322.58 mg/g at 30 ℃. The kinetic data could be satisfactorily simulated by the pseudosecond order model, indicating that the rate-controlling step was chemical adsorption. 99% of Pd(Ⅱ) could be recovered using 1 g/L modified sepiolite when initial concentration of Pd(Ⅱ) was 100 mg/L. The results of reusability studies indicated the modified sepiolite had an acceptable stability and reusability. This study indicated that the modified sepiolite might be an efficient and cost-effective material for Pd(Ⅱ) recovery.
基金Supported by the National Natural Science Foundation of China(Nos.40876081,30570125)the Knowledge Innovation Program of Chinese Academy of Sciences(No.KSCX2-YW-Z-018)
文摘Acrochaete leptochaete, a species in Chaetophoraceae (Chlorophyta), was observed during our recent laboratory culture of the macroalgae Chaetornorpha that was originally collected from an intertidal pool in Rongcheng, Shandong Province, China. This is the first record of this species in China. Its morphology, taxonomy, and distribution were introduced and discussed in detail. Isolated culture experiments at different temperatures (9-29℃) and light intensities (36-108 μmol/m^2.s) were also carried out. The culture-based observations have extended our knowledge of growth morphology and general biology of the species.
文摘The application of overgrowth microorganisms in ocean research was discussed,using the China National Knowledge Infrastructure(CNKI)network database to retrieve papers on the topic of symbiotic microbes(=198)and symbiotic marine microorganisms(n=94).Bibliometric Analysis are conducted in terms of the published trends,subject headings and other aspects.The output of literature in this field has increased rapidly in the past15years.57.4%of the papers were published in the last five years.And the relevance of research topics has increased in recent years.The current research focuses on community diversity,secondary metabolites,biological activities and antibacterial activities.Literature analysis is helpful to understand the overall development trend of overgrowth microorganisms in ocean research.
基金Project(51504299)supported by the National Science Found for Young Scientists of ChinaProject(2012GS430101)supported by the National Science and Technology Program for Public Wellbeing,China
文摘The phosphate-embedded calcium alginate beads were successfully synthesized based on sodium alginate, calcium dihydrogen phosphate and sodium hydrogen carbonate. Scanning electron microscopy, Fourier transformed infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were conducted to characterize the morphology and structure of the phosphate-embedded calcium alginate beads. The effects of pH and the initial concentration of the metal ions on Pb(II) and Cd(II) sorption by the beads were investigated. The optimal pH values for Pb(II) and Cd(II) sorption are 4.0 and 5.5, respectively. The optimal initial concentrations of Pb(II) and Cd(II) are 200 mg/L and 25 mg/L, correspondingly, and the removal efficiencies are 94.2% and 80%,respectively. The sorption mechanism is that the heavy metal ions accessed the beads firstly due to the large surface area, combinedwith OH?, and then precipitated with phosphate radical, which was proven by FTIR and XRD. The sorption of Pb(II) and Cd(II) isfitted to Langmuir isotherm model with R2 values of 0.9957 and 0.988, respectively. The sorption capacities of Pb(II) and Cd(II) are263.16 mg/g and 82.64 mg/g, respectively. The results indicate that the phosphate-embedded calcium alginate beads could be appliedto treating Pb(II)/Cd(II)-containing wastewater and it could be implied that the synthesized beads also could be used as a kind of soil ameliorant for remediation of the heavy metal contaminated paddy soil.
基金Supported by State Key Fundamental Research Program (No. G2000026309) Natural Science Fund for Distinguished Young Scholars of China (No. 50225621)Shanghai Shuguang Training Program for the Talents, the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of MOE, P.R.C.
文摘A heat pipe type adsorption ice maker with two adsorbers for fishing boats is designed by using ammonia as refrigerant and compound of activated carbon-CaCl2 as adsorbent. This type of heat pipe adsorber can solve the problem of incompatibility between ammonia, copper, seawater and steel. The working process of the ice maker with 8.7kg adsorbent per bed is simulated. The results show that the optimal semi-cycle time is about 9 min at the evaporating temperature of -15℃, where the corresponding cooling power, specific cooling power per kilogram adsorbent SCP and coefficient of refrigerant performance COP are respectively 3.6kW, 217W·kg-1 and 0.404.
基金Shahid Chamran University of Ahvaz and Isfahan University of Technology for the financial supports they provided for this study
文摘This work aims to investigate the efficiency of Fariman sepiolite from Iran as an adsorbent to remove Cd from aqueous solutions. The effects of different experimental factors such as the initial Cd concentration, contact time and the sorbent dose were investigated through a series of batch adsorption experiments. The results show that the adsorption capacity of sepiolite for Cd increases with the contact time, the initial concentration of Cd solutions and the sorbent dose. Sorption of Cd by Fariman sepiolite is rapid within the first hour of the experiment and then slowly increases until a pseudo equilibrium is approached at 8 h. The results also show that the time-dependent Cd sorption data are better described with pseudo second-order (7〉0.999) than that of pseudo first-order (r2〉0.971) kinetic model. Equilibrium isotherm studies show that the experimental data are better correlated by the Freundlich adsorption isotherm (7〉0.995) than the Langmuir (P〉0.825). It is suggested that both adsorption and cation exchange reactions are responsible for the sorption of Cd by the sepiolite, and the mineral has a very good potential to remove Cd from aqueous solutions.
基金Supported in part by the Australian Research Council (Small Grant Scheme) and a Royal Thai Government Scholarship.
文摘Heavy metal pollution from industrial wastewater is a worldwide environmental issue. Biosorption of heavy metals by using biosorbents derived from various types of biomass has been shown to be effective for the uptake of heavy metal ions. In this study, biosorbents derived from the biomass of a group of marine macroalgae were used for the removal and recovery of heavy metal ions from aqueous solutions. Results indicated that the biosorbents have high uptake capacities and affinities for a number of heavy metal ions. The uptake capacities of the biosorbents were in the range of 1.0 to 1.5mmol·g-1 for divalent heavy metal ions. The kinetics of the uptake process was fast and the process can be used in both batch and fixed-bed operations. It appears that the biosorption process by using biosorbents from marine macroalgae can be an efficient and cost effective technology for the treatment of heavy metal containing wastewater.
基金Project(11JJ2031)supported by the Key Project of Natural Science Foundation of Hunan Province,China
文摘To establish a theoretical foundation for simultaneous removal of multi-heavy metals,the adsorption of Cu(Ⅱ) and Pb(Ⅱ) ions from their single and binary systems by Ca-alginate immobilized activated carbon and Saccharomyces cerevisiae (CAS) was investigated.The CAS beads were characterized by Scanning electron microscope (SEM) and Fourier transformed infrared spectroscopy (FTTR).The effect of initial pH,adsorbent dosage,contact time and initial metal ions concentration on the adsorption process was systematically investigated.The experimental maximum contents of Cu(Ⅱ) and Pb(Ⅱ) uptake capacity were determined as 64.90 and 166.31 mg/g,respectively.The pseudo-second-order rate equation and Langmuir isotherm model could explain respectively the kinetic and isotherm experimental data of Cu(Ⅱ) and Pb(Ⅱ) ions in single-component systems with much satisfaction.The experimental adsorption data of Cu(Ⅱ) and Pb(Ⅱ) ions in binary system were best described by the extended Freundlich isotherm and the extended Langmuir isotherm,respectively.The removal of Cu(lⅡ) ions was more significantly influenced by the presence of the coexistent Pb(Ⅱ) species,while the Pb(Ⅱ) removal was affected slightly by varying the initial concentration of Cu(Ⅱ).The CAS was successfully regenerated using 1 mol/L HNO3 solution.
基金Supported by the National Natural Science Foundation of China for Young Scholars(No.40906055)the National Natural Science Foundation of China for Creative Research Groups(No.41121064)the National Basic Research Programof China (973 Program) (No.2010CB428706)
文摘Algal organic materials (AOMs) are one critical factor affecting the efficiency of modified clays used for the mitigation of harrnful algal blooms (HABs). This study was conducted to develop a deeper understanding of the mechanisms and factors affecting the adsorption of AOMs onto modified clays. Sodium alginate (polysaccharide) and kaolinite modified with polyaluminium chloride (PAC1) were used as AOMs and modified clay model substances, respectively, and the effects of modifier dosage, contact time, solution pH and ionic strength were investigated through batch adsorption experiments. Kinetics revealed that the alginate adsorption rate was described well by a pseudo-second order model. PACl effectively enhanced the adsorption capacity of kaolinite and increased the adsorption rate, and the optimum additive amount of PACl was 5%. The experimental data fitted both the Freundlich and Langmuir adsorption equations well. The adsorption thermodynamics for alginate onto modified clays suggests that alginate adsorption is a spontaneous process. The adsorption of alginate onto modified clays was highly dependent on pH, with a decrease in adsorption observed with increased pH to 9.48, but the opposite was true above pH 9.48. Finally, adsorption increased with increasing ionic strength.
基金Supported by the National Natural Science Foundation of China(No.41206154)the Yantai Science and Technology Development Project(No.2011063)the National Marine Project(No.XDA11020403)
文摘Fouling diatoms are a main component of biofilm,and play an important role in marine biofouling formation. We investigated seasonal variations in fouling diatom communities that developed on glass slides immersed in seawater,on the Yantai coast,northern Yellow Sea,China,using microscopy and molecular techniques. Studies were conducted during 2012 and 2013 over 3,7,14,and 21 days in each season. The abundance of attached diatoms and extracellular polymeric substances increased with exposure time of the slides to seawater. The lowest diatom density appeared in winter and the highest species richness and diversity were found in summer and autumn. Seasonal variation was observed in the structure of fouling diatom communities. Pennate diatoms Cylindrotheca,Nitzschia,Navicula,Amphora,Gomphonema,and Licmophora were the main fouling groups. Cylindrotheca sp. dominated in the spring. Under laboratory culture conditions,we found that Cylindrotheca grew very fast,which might account for the highest density of this diatom in spring. The lower densities in summer and autumn might result from the emergence of fouling animals and environmental factors. The Cylindrotheca sp. was identified as Cylindrotheca closterium using18 S rDNA sequencing. The colonization process of fouling diatoms and significant seasonal variation in this study depended on environmental and biological factors. Understanding the basis of fouling diatoms is essential and important for developing new antifouling techniques.
文摘This study investigates the heat and mass transfer mechanism of a marine engifie exhaust-powered adsorption refrigerating system by using irreversible thermodynamics. The equations of entropy-production rate and the linear phenomenological equations of thermodynamic flux and force are established. The conventional experimental facilities of unit tube are developed and the phenomenological coefficients are obtained by fitting the experimental data. It is concluded that the thermodynamic process in the adsorbent bed is determined by the coupling effect of the heat and mass transfer; furthermore, the mass transfer is determined by the heat transfer. Taking some measures to increase heat transfer can improve the performance of the adsorption refrigerating system. The conclusions presented in this paper may be of value to the engineering applications of the system.
基金Supported by the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA1103040102)the National Natural Science Foundation of China(No.31172054)
文摘A new species of deep-water barnacle that belongs to the family Scalpellidae is described from the South China Sea. A rcoscalpellum liui sp. nov. is morphologically similar to A rcoscalpellum gryllum Zevina,but differs from the latter by the absence of longitudinal striae on the capitular plates and the presence of caudal appendages with few terminal setae.
基金Project supported by the Cooperative Promotion Center of Science & Technology of JEONNAM TECHNOPARK and Ministry of Education,Science and Technology (MEST) through the Research & Development support project of JEONNAM southwest science park,Korea
文摘Electrochemical behavior of 5083-H116 Al alloy with flow velocity of seachest material for Al ship was evaluated.To examine the electrochemical characteristics of flow velocity and its effects on the performance of the alloy,experiments were conducted at four flow velocity variables using static state with an agitator.An ultrasonic vibration generator using piezoelectric effect was used in cavitation test according to the requirements of in ASTM-G32.The results show that the corrosion current density and damage were increased by applying the flow velocity compared to static state.Therefore,it is determined that the case of applying flow velocity is weaker to the corrosion.