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Classification of marine diatoms using pigment ratio suites

Chinese Journal of Oceanology and Limnology 2011年第5期29卷 1075-1085页

作者：姚鹏于志刚邓春梅刘淑霞甄毓 key laboratory of marine Chemistry Theory and Technology Ministry of Education key laboratory of marine Spill Oil Identification and Damage Assessment Technology State Oceanic Administration key laboratory of marine Environment and Ecology Ministry of Education

Diatoms are widely distributed in many temperate areas and some species frequently form extensive blooms in spring. Hence, monitoring the variations of specific genera or species of diatoms is necessary for studying phytoplankton population dynamics in marine ecosystems. To test whether pigment ratios can be used to identify diatoms at a below-class taxonomic level, we analyzed 14 species/strains of diatoms isolated from Chinese seas using high performance liquid chromatography （HPLC）. We normalized all pigment concentrations to total chlorophyll a to calculate the ratios of pigment to chlorophyll a, and calculated the ratios between accessory pigments （or pigment sums）. Cluster analysis indicated that these diatoms could be classified into four clusters in terms of three accessory pigment ratios： chlorophyll c2： chlorophyll Cl, fucoxanthin：total chlorophyll c and diadinoxanthin：diatoxanthin. The classification results matched well with those of biological taxonomy. To test the stability of the classification, pigment data from one species, cultured under different light intensities, and five new species/strains were calculated and used for discriminant analysis. The results show that the classification of diatom species using pigment ratio suites was stable for the variations of pigment ratios of species cultured in different light intensities. The introduction of new species, however, may confuse the classification within the current scheme. Classification of marine diatoms using pigment ratio suites is potentially valuable for the fine chemotaxonomy of phytoplankton at taxonomic levels below class and would advance studies on phytoplankton population dynamics and marine ecology.

关键词： diatoms classification pigment ratio suites statistical analysis HPLC chemotaxonomy

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Interannual variation of nutrients along a transect across the Kuroshio and shelf area in the East China Sea over 40 years

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Journal of Oceanology and Limnology 2018年第1期36卷 62-76页

作者：胡莹英郭新宇赵亮 Center for marine environmental Studies Ehime University key laboratory of marine Environment and Ecology Ministry of Education Ocean University of China College of environmental science and Engineering Ocean University of China College of marine and environmental sciences Tianjin University of Science and Technology

Long-term datasets of water temperature,salinity,dissolved oxygen,phosphate and nitrate from 1973 to 2013 were used to study interannual variations of these parameters along a transect(section PN)across the Kuroshio and shelf area in the East China *** temperature and salinity at depths of 0–200 m showed a low-high-low-high pattern over the 40-year *** temperature and salinity at 500 m were relatively high from 1985 to 1990 and decreased continuously *** at 800 m was lowest around 1993 and increased *** were highest between 1980 and *** 1985,nutrients at 500 m were *** range of variation in nutrients was large before 1985 and the magnitude increased with greater *** oxygen utilization at 500 m depth was decreasing before 1990 and started to increase after *** changes after 1990 at 500 m depth may be due to the upward trend of the upper boundary of Kuroshio intermediate *** variation of water temperature,salinity,dissolved oxygen,phosphate and nitrate along section PN has a significant correlation with the Pacific Decadal Oscillation index.

关键词： Kuroshio East China Sea interannual variation nutrient phosphate nitrate

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Study on Soil Salinization Information in Arid Region Using Remote Sensing Technique

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Agricultural sciences in China 2011年第3期10卷 404-411页

作者： Tashpolat Tiyip key laboratory of Oasis Ecology Ministry of Education/College of Resources and Environmental Science Xinjiang University

Extracting information about saline soils from remote sensing data is useful, particularly given the environmental significance and changing nature of these areas in arid environments. One interesting case study to consider is the delta oasis of the Weigan and Kuqa rivers, China, which was studied using a Landsat Enhanced Thematic Mapper Plus （ETM＋） image collected in August 2001. In recent years, decision tree classifiers have been successfully used for land cover classification from remote sensing data. Principal component analysis （PCA） is a popular data reduction technique used to help build a decision tree; it reduces complexity and can help the classification precision of a decision tree to be improved. A decision tree approach was used to determine the key variables to be used for classification and ultimately extract salinized soil from other cover and soil types within the study area. According to the research, the third principal component （PC3） is an effective variable in the decision tree classification for salinized soil information extraction. The research demonstrated that the PC3 was the best band to identify areas of severely salinized soil; the blue spectral band from the ETM＋ sensor （TM1） was the best band to identify salinized soil with the salt-tolerant vegetation of tamarisk （Tamarix chinensis Lour）; and areas comprising mixed water bodies and vegetation can be identified using the spectral indices MNDWI （modified normalized difference water index） and NDVI （normalized difference vegetation index）. Based upon this analysis, a decision tree classifier was applied to classify landcover types with different levels of soil saline. The results were checked using a statistical accuracy assessment. The overall accuracy of the classification was 94.80%, which suggested that the decision tree model is a simple and effective method with relatively high precision.

关键词： soil salinization information arid region remote sensing

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Simulating the responses of a low-trophic ecosystem in the East China Sea to decadal changes in nutrient load from the Changjiang(Yangtze) River

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Journal of Oceanology and Limnology 2018年第1期36卷 48-61页

作者：王玉成郭新宇赵亮 Center for marine environmental Studies Ehime University key laboratory of marine Environment and Ecology Ministry of Education Ocean University of China College of environmental science and Engineering Ocean University of China College of marine and environmental sciences Tianjin University of Science and Technology

Using a three-dimensional coupled biophysical model,we simulated the responses of a lowtrophic ecosystem in the East China Sea(ECS)to long-term changes in nutrient load from the Changjiang(Yangtze)River over the period of 1960–*** major factors aff ected changes in nutrient load:changes in river discharge and the concentration of nutrients in the river *** or decreasing Changjiang discharge induced different responses in the concentrations of nutrients,phytoplankton,and detritus in the *** in dissolved inorganic nitrogen(DIN),silicate(SIL),phytoplankton,and detritus could be identified over a large area of the ECS shelf,but changes in dissolved inorganic phosphate(DIP)were limited to a small area close to the river *** high DIN:DIP and SIL:DIP ratios in the river water were likely associated with the diff erent responses in DIN,DIP,and *** DIP is a candidate limiting nutrient,perturbations in DIP resulting from changes in the Changjiang discharge are quickly consumed through primary *** is interesting that an increase in the Changjiang discharge did not always lead to an increase in phytoplankton levels in the *** decreases could be found in some areas close to the river mouth.A likely cause of the reduction in phytoplankton was a change in the hydrodynamic field associated with the river plume,although the present model is not suitable for examining the possibility in *** in DIN and DIP concentrations in the river water primarily led to increases in DIN,DIP,phytoplankton,and detritus levels in the ECS,whereas decreases in the SIL concentration in river water led to lower SIL concentrations in the ECS,indicating that SIL is not a limiting nutrient for photosynthesis,based on our model results from 1960 to *** both of the above-mentioned cases,the sediment accumulation rate of detritus exhibited a large spatial variation near the river mouth,suggesting that core sample data should be carefull

关键词： East China Sea Changjiang(Yangtze) River low-trophic ecosystem

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Performance and microbial community analysis of bioaugmented activated sludge for nitrogen-containing organic pollutants removal

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Journal of environmental sciences 2021年第3期33卷 373-381页

作者： Xuwang Zhang Zhaojian Song Qidong Tang Minghuo Wu Hao Zhou Lifen Liu Yuanyuan Qu key laboratory of Industrial Ecology and environmental Engineering(ministry of education) School of Ocean Science and TechnologyDalian University of TechnologyPanjin 124221China key laboratory of Industrial Ecology and environmental Engineering(ministry of education) School of Environmental Science and TechnologyDalian University of TechnologyDalian 116024China

Nitrogen-containing organic pollutants(quinoline,pyridine and indole)are widely distributed in coking wastewater,and bioaugmentation with specific microorganisms may enhance the removal of these recalcitrant *** bioaugmented system(group B)was constructed through inoculation of two aromatics-degrading bacteria,Comamonas sp.Z1(quinoline degrader)and Acinetobacter ***(indole degrader),into the activated sludge for treatment of quinoline,indole and pyridine,and the non-bioaugmented activated sludge was used as the control(group C).Both groups maintained high efficiencies(>94%)for removal of nitrogen-containing organic pollutants and chemical oxygen demand(COD)during the long-term operation,and group B was highly effective at the starting period and the operation stage fed with raw ***-throughput sequencing analysis indicated that nitrogen-containing organic pollutants could shape the microbial community structure,and communities of bioaugmented group B were clearly separated from those of non-bioaugmented group C as observed in non-metric multidimensional scaling(NMDS)*** the inoculants did not remain their dominance in group B,bioaugmentation could induce the formation of effective microbial community,and the indigenous microbes might play the key role in removal of nitrogen-containing organic pollutants,including Dokdonella,Comamonas and *** Investigation of Communities by Reconstruction of Unobserved States(PICRUSt)analysis suggested that bioaugmentation could facilitate the enrichment of functional genes related to xenobiotics biodegradation and metabolism,probably leading to the improved performance in group *** study indicated that bioaugmentation could promote the removal of nitrogen-containing organic pollutants,which should be an effective strategy for wastewater treatment.

关键词： Bioaugmentation Indigenous microbes Microbial community Nitrogen-containing organic pollutants Wastewater treatment

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Lake microbiome composition determines community adaptability to warming perturbations

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Ecological Processes 2024年第2期13卷 177-191页

作者： Xiaotong Wu Qixing Zhou Hui Zeng Xiangang Hu key laboratory of Pollution Processes and environmental Criteria (ministry of education) Carbon Neutrality Interdisciplinary Science Centre/College of Environmental Science and Engineering Nankai University

Background Microbial communities are crucial for ecosystems. A central goal of microbial ecological research is to simplify the biodiversity in natural environments and quantify the functional roles to explore how the ecosystems respond under different environmental conditions. However, the research on the stability and dynamics of lake microbes in response to repeated warming stress is *** To exclude confounding environmental factors, we conducted a 20-day repeated warming simulation experiment to examine the composition and function dynamics of lake microbial *** Experimental warming significantly altered the community structure of bacteria instead of fungi. Microbial community structure, together with microbial biomass, jointly regulated the function of microbial communities. The plummeting of aerobic denitrifiers Pseudomonadaceae decreased by 99%(P < 0.001) after high temperature, leading to reduced microbial nitrogen metabolism on nitrogen respiration and nitrate respiration. Under warming conditions, the microbial community with higher adaptability showed more positive correlations and less competitive relationships in co-occurrence networks to acclimate to *** Microbiome composition controlled carbon and nitrogen metabolism, thus determining lake microbial communities' adaptability to heat stress. This study extended our insights on the lake microbial community response and adaptability under warming drivers.

关键词： Temperature environmental stress Bacteria Fungi Freshwater ecosystem

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Colloid-facilitated release of polybrominated diphenyl ethers at an e-waste recycling site: evidence from undisturbed soil core leaching experiments

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Frontiers of environmental science & Engineering 2024年第2期18卷 91-101页

作者： Zebin Huo Mengjun Xi Lianrui Xu Chuanjia Jiang Wei Chen College of environmental science and Engineering Ministry of Education Key Laboratory of Pollution Processes and Environmental CriteriaTianjin Key Laboratory of Environmental Remediation and Pollution ControlNankai UniversityTianjin 300350China

Polybrominated diphenyl ethers (PBDEs), a class of persistent organic pollutants, have been frequently detected in soil at e-waste recycling sites. However, the key factors controlling the transport of PBDEs from surface soil to the vadose zone and groundwater are unclear. Here, colloid-enhanced leaching of PBDEs from undisturbed soil cores collected at an e-waste recycling site in Tianjin, China, is reported. Spatially heterogeneous release of colloids and PBDEs was observed in all the tested soil cores under chemical and hydrodynamic perturbations, indicating the presence of preferential flow paths. Colloid concentration in the effluent significantly increased as ionic strength decreased (from 10 to 0.01 mmol/L), probably due to the stronger electrostatic repulsion between colloidal particles and the soil matrix at lower ionic strength. In contrast, colloid mobilization was not significantly affected by the changes in pH of the influent (from 4.0 to 10.0) and flow rate (from a Darcy velocity of 1.5 to 6.0 cm/h). The concentrations of 2,2′,3,3′,4,4′,5,5′,6,6′-decabromodiphenyl ether (BDE-209), the predominant PBDE congener at the site, detected in the leachate (ranging from 1.09 to 3.43 ng/L) were much lower than previously reported results from packed column leaching tests, and were positively correlated with colloid concentrations. This indicates that remobilization of colloids at e-waste recycling sites can promote the leaching and downward migration of PBDEs from surface soil. The findings highlight the potential risk of surface soil PBDE contamination to groundwater quality and call for further understanding of colloid-facilitated transport for predicting the fate of PBDEs at e-waste recycling sites.

关键词： Polybrominated diphenyl ether Colloid-facilitated transport E-waste recycling site Undisturbed soil core Groundwater quality

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Citrate-promoted dissolution of nanostructured manganese oxides:Implications for nano-enabled sustainable agriculture

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Journal of environmental sciences 2023年第3期125卷 492-498页

作者： Di Fu Lin Duan Xiaoyan Li Chuanjia Jiang Tong Zhang Wei Chen ministry of education key laboratory of Pollution Processes and environmental Criteria Tianjin Key Laboratory of Environmental Remediation and Pollution ControlCollege of Environmental Science and EngineeringNankai UniversityTianjin 300350China

Nanostructured manganese oxides (nano-MnO_(x)) have shown great promises as versatile agrochemicals in nano-enabled sustainable agriculture,owing to the coupled benefits of controlled release of dissolved Mn2+,an essential nutrient needed by plants,and oxidative destruction of environmental organic ***,we show that three δ-MnO_(2)nanomaterials consisting of nanosheet-assembled flower-like nanospheres not only exhibit greater kinetics in citrate-promoted dissolution,but also are less prone to passivation,compared with three α-MnO_(2)nanowire *** better performance of the δ-MnO_(2)nanomaterials can be attributed to their higher abundance of surface unsaturated Mn atoms–particularly Mn(Ⅲ)–that is originated from their specific exposed facets and higher abundance of surface defects *** results underline the great potential of modulating nanomaterial surface atomic configuration to improve their performance in sustainable agricultural applications.

关键词： Nano-enabled sustainable agriculture Nanostructured manganese oxides Controlled release Unsaturated Mn atoms Mn(III)

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Effects of natural organic matter on cadmium mobility in paddy soil: A review

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Journal of environmental sciences 2021年第6期33卷 204-215页

作者： Chaolei Yuan Qi Li Zhaoyang Sun Hongwen Sun ministry of education key laboratory of Pollution Processes and environmental Criteria Tianjin Key Laboratory of Environmental Remediation and Pollution ControlCollege of Environmental Science and EngineeringNankai UniversityTianjin 300350China

Cadmium(Cd) contamination in paddy soil has caused public concern. The uptake of Cd by rice plants depends on soil Cd mobility, which is in turn substantially influenced by organic matter(OM). In this review, we first summarize the fate of Cd in soil and the role of OM. We then focus on the effects of OM on Cd mobility in paddy soil and the factors influencing the remedial effectiveness of OM amendments. We further discuss the performance of straw incorporation in the remediation of Cd-contaminated paddy soils reported in laboratory and field studies. Considering the huge production of organic materials(such as straw) in agriculture, the use of natural OM for soil remediation has obvious appeal due to the environmental benefits and low cost. Although there have been successful application cases, the properties of OM amendments and soil can significantly affect the remedial performance of the OM amendments. Importantly, straw incorporation alone does not often decrease the mobility of Cd in soil or the Cd content in rice grains. Careful evaluation is required when considering natural OM amendments, and the factors and mechanisms that influence their remedial effectiveness need further investigation in paddy soil with realistic Cd concentrations.

关键词： Cadmium Mobility Organic matter Paddy soil Remediation

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Novel approach to control adsorbent aggregation： iron fixed bentonite-fly ash for Lead （Pb） and Cadmium （Cd） removal from aqueous media

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Frontiers of environmental science & Engineering 2018年第2期12卷 17-28页

作者： Teza Mwamulima Xiaolin Zhang Yongmei Wang Shaoxian Song Changsheng Peng The key laboratory of marine environmental science and Ecology Ministry of Education Ocean University of China Qingdao 266100 China School of Resource and environmental Engineering Wuhan University of Technology Wuhan 430070 China

In the present study, a novel approach was used to control zero valent iron aggregation and separation problems by fixing zero valent iron （ZVI） on bentonite-fly ash pellets. For this purpose, porous low cost bentonite-fly ash （BFA） pellets with size of 2.00 cm in length and 0.35 cm in diameter were prepared and fixed with ZV1 to manufacture zero valent iron bentonite-fly ash （ZVI-BFA） pellets. Importantly, unlike powdered adsorbents, ZVI-BFA can easily be separated from final effluents when exhausted without any disintegration. The performance of the developed novel adsorbent was investigated for the removal of Pb2＋ and Cd2＋ from aqueous media. At 100 mg.L I and 1 g adsorbent, a maximum of 89.5% ofCd2＋ and 95.6% ofPb2＋ was removed by ZVI-BFA as compared to 56% and 95% removal by BFA. At 200 mg.L 10 Cd2＋ and Pb2＋ removal by ZVI-BFA was 56% and 99.8% respectively as compared to only 28% and 96% by BFA. Further, the removal kinetics was best fitted for pseudo-second order model. The study provides the basis for improving the removal capacity of porous materials by iron fixation while taking separation ability into consideration.

关键词： Zero valent ironBentoniteFly ashHeavy metals removalSynthesis

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