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Denitrification and the controlling factors in Yunnan Plateau Lakes(China): Exploring the role of enhanced internal nitrogen cycling by algal blooms

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Journal of Environmental Sciences 2019年第2期31卷 349-358页

作者： Sifeng Wu Zhen Wu Zhongyao Liang Yong Liu Yilin Wang College of Environmental Sciences and Engineering Key Laboratory of Water and Sediment Sciences (MOE)Peking University College of Environmental Sciences and Engineering Key Laboratory of Water and Sediment Sciences(MOE)Peking University

Denitrification plays an important role in nitrogen(N) removal in freshwater *** internal process regulates the fluctuations of N concentration, especially for lakes with high nutrients concentrations and long residence time. Lakes in Yunnan plateau(southwestern China) provide typical cases, while studies in this region have been ***, we studied denitrification of two lakes(Lake Dianchi in hypereutrophic state and Lake Erhai in mesotrophic) in this region. We used acetylene inhibition technique to quantify potential denitrification rate(PDR) of these lakes in April and August, 2015 and 2016. PDR of the sediments ranged 0–1.21 μmol/(N·m^2·hr), and that of overlying water ranged 0–0.24 μmol/(N·L·hr). Then, we used Least Angle Regression to determine the controlling factors for denitrification. Nutrients controlled PDR from two aspects: providing essential nitrogen sources; and affecting the richness and metabolism of denitrifying bacteria. In April, both aspects limited PDR; while only nitrogen sources limited PDR in August, due to depleted nitrate and enhanced denitrifying bacteria activity. Ammonia was most significant to denitrification, indicating that nitrate from nitrification transported to the bottom of wellmixed lake provide major N source by denitrification. The high PDR and low nitrate concentrate in August were evidence of an enhanced internal N cycling by algal blooms.

关键词： Denitrification Controlling factors Lake Dianchi Lake Erhai algal bloom Internal cycling

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Investigating the coagulation of non-proteinaceous algal organic matter: Optimizing coagulation performance and identification of removal mechanisms

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Journal of Environmental Sciences 2019年第5期31卷 25-34页

作者： Jana Naceradska Katerina Novotna Lenka Cermakova Tomas Cajthaml Martin Pivokonsky Institute of Hydrodynamics of the Czech Academy of Sciences Institute of Microbiology of the Czech Academy of Sciences

The removal of algal organic matter(AOM) is a growing concern for the water treatment industry worldwide. The current study investigates coagulation of non-proteinaceous AOM(AOM after protein separation), which has been minimally explored compared with proteinaceous fractions. Jar tests with either aluminum sulphate(alum) or polyaluminium chloride(PACl) were performed at doses of 0.2–3.0 mg Al per 1 mg of dissolved organic carbon in the p H range 3.0–10.5. Additionally, non-proteinaceous matter was characterized in terms of charge, molecular weight and carbohydrate content to assess the treatability of its different fractions. Results showed that only up to 25% of non-proteinaceous AOM can be removed by coagulation under optimized conditions. The optimal coagulation p H(6.6–8.0 for alum and 7.5–9.0 for PACl) and low surface charge of the removed fraction indicated that the prevailing coagulation mechanism was adsorption of non-proteinaceous matter onto aluminum hydroxide precipitates. The lowest residual Al concentrations were achieved in very narrow p H ranges, especially in the case of PACl. High-molecular weight saccharidelike organics were amenable to coagulation compared to low-molecular weight(< 3 k Da)substances. Their high content in non-proteinaceous matter(about 67%) was the reason for its low removal. Comparison with our previous studies implies that proteinaceous and nonproteinaceous matter is coagulated under different conditions due to the employment of diverse coagulation mechanisms. The study suggests that further research should focus on the removal of low-molecular weight AOM, reluctant to coagulate, with other treatment processes to minimize its detrimental effect on water safety.

关键词： algal organic matter Chlorella vulgaris Coagulation Flocculation Non-proteinaceous matter Water treatment

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Performance and microbial community analysis of an algal-activated sludge symbiotic system: Effect of activated sludge concentration

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Journal of Environmental Sciences 2019年第2期31卷 121-132页

作者： Li Sun Wei Zuo Yu Tian Jun Zhang Jia Liu Ni Sun Jianzheng Li State Key Laboratory of Urban Water Resource and Environment (SKLUWRE) School of EnvironmentHarbin Institute of Technology

It was focused on the effect of different sludge concentrations on the performances of an algal-activated sludge symbiotic system in terms of wastewater treatment, algal-activated sludge characteristics and community structure. The results showed that the highest nutrient removal efficiencies were obtained in the reactor R^2 with soluble chemical oxygen demand(sC OD), ammonia nitrogen(NH_4^+-N) and phosphate(PO_4^(3-)-P) removal efficiencies of(90.6 ± 2.3)%,(97.69 ± 2.6)% and(83.81 ± 2.3)%, respectively. Further investigation exhibited that sludge concentration has a great effect on the dissolved oxygen(DO) concentration, the pH, the growth of algae and the extracellular polymeric substance(EPS) production, which resulted in influencing the settleability and the performance of symbiotic system. The denaturing gradient gel electrophoresis(DGGE) analysis demonstrated that the sludge concentration had a selective power for particular members of algae. Meantime, the stimulated algal population would selectively excite the members of bacteria benefited for the formation of algal-bacterial *** variation of microbial compositions, which was influenced by the different sludge concentrations, might be ultimately responsible for the different treatment performances.

关键词： algal-activated sludge symbiotic system Sludge concentration Wastewater treatment algal and bacterial communities

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Spatio-temporal variations of harmful algal blooms along the coast of Guangdong,Southern China during 1980–2016

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Journal of Oceanology and Limnology 2019年第2期37卷 535-551页

作者： LI Li Lü Songhui CEN Jingyi College of Life Science and Technology Jinan University Guangzhou 510632 China Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes Jinan University Guangzhou 510632 China

Harmful algal blooms (HABs) have become a recurring problem, posing severe impacts on marine ecosystems, fisheries, mariculture industry, and even public health. In this study, the geographic information system (GIS) was utilized to determine spatial and temporal characteristics of HAB events in the coastal waters of Guangdong from 1980–2016. We analyzed distribution patterns and characteristics of HABs by dividing the coast of Guangdong into well-known bays, estuary and coastal waters. Results showed that there were a total of 337 HABs recorded in Guangdong coastal waters. Spatial and temporal distributions varied among diff erent regions. Most HABs occurred in the Mirs Bay, followed by the west coast of Daya Bay, while a few occurred in the west and east coasts of Guangdong but with an increasing trend in the past two decades. HABs occurred mostly in warmer months of March to May in the western coast of Guangdong, March and April in Mirs Bay, April in Zhujiang (Pearl) River estuary, November in eastern coast of Guangdong. For Daya Bay, most HABs were reported between March and September. The most frequently occurring HABs species were Noctiluca scintillans , Phaeocystis globosa , Skeletonema costatum and Scrippsiella trochoidea , occurring mostly in Mirs Bay, western Guangdong coast area, eastern Guangdong coast area and Zhujiang River estuary and Daya Bay, respectively. Ichthyotoxic blooms were more common than toxic blooms, and Heterosigma akashiwo , Chattonella marina , Karenia mikimotoi and P haeocystis globosa were the most common ichthyotoxic species. Our results provide baseline information useful for policy making and management of HABs in the region.

关键词： harmful algal blooms Guangdong Province distribution geographic information system (GIS) kernel density estimation

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Identification of dissolved and particulate carbonyl compounds produced by marine harmful algal bloom species

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Journal of Oceanology and Limnology 2019年第5期37卷 1566-1581页

作者： SHANG Lixia HU Zhangxi TANG Yingzhong Key Laboratory of Marine Ecology and Environmental Sciences Institute of OceanologyChinese Academy of SciencesQingdao 266071China Laboratory for Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China

Carbonyl compounds, especially polyunsaturated aldehydes (PUAs), are increasingly reported as teratogenic to grazers and deleterious to phytoplankton. While PUAs have been considered to be mainly produced by diatoms after cell wounding, little is known about whether microalgae other than diatoms, particularly harmful algal bloom (HAB)-forming species, produce carbonyl compounds. In this study, we analyzed the carbonyl compounds from eight common HAB-forming species ( Akashiwo sanguinea , Karenia mikimotoi , Karlodinium venefi cum , Margalefi dinium polykrikoides , Prorocentrum donghaiense , P . minimum , Scrippsiella trochoidea , and Heterosigma akashiwo ) using gas chromatography-mass spectrometry in full scan and selected ion monitoring (SIM) modes. Our results show a ubiquitous presence of carbonyl compounds in both dissolved and particulate forms in all species we examined. In the full scan mode, 133 chromatographic peaks were detected from 51 samples altogether. Both the varieties of carbonyl compounds and their quantities were algal species dependent, although most of the carbonyl compounds could not be fully identifi ed according to the mass spectral database only due to the unavailability of enough standards for all analytes. Aided with nine standards in SIM mode, we further identifi ed and quantifi ed all nine aldehydes (2-methyl-2-pentenal, trans-2-nonenal, cis-6-nonenal, 2,6-dimethyl-5-heptenal, trans-2-hexenal, trans-2- decenal, 2,4-heptadienal, trans-trans-2,4-octadienal, and trans-trans-2,4-decadienal). Four of these nine aldehydes were detected in particulate form, which confi rmed that trans-2-nonenal could be produced by K . mikimotoi , Karl . venefi cum , P . donghaiense , P . minimum , S . trochoidea , and H . akashiwo , 2,4-heptadienal and trans-trans-2,4-decadienal by A . sanguinea , M . polykrikoides , and S . trochoidea , and trans, trans-2,4- octadienal by S . trochoidea , respectively. We proved that some dinofl agellate and raphidophyte spe

关键词： aldehyde dinofl agellate harmful algal blooms (HABs) heptadienal octadienal decadienal

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The Distribution of Green algal Micro-Propagules and Macroalgae at the Early Stage of Green Tide in the Coastal Area of South Jiangsu Province in 2014

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Journal of Ocean University of China 2017年第1期16卷 81-86页

作者： LIU Xiangqing WANG Zongling FAN Shiliang ZHANG Xuelei LI Ruixiang LI Yan College of Environmental Science and Engineering Ocean University of China The First Institute of Oceanography State Oceanic Administration Laboratory of Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and Technology

An integrated investigation was carried out during late April to late May of 2014 in the coastal area of South Jiangsu Province to understand the early development of green tide in the Yellow Sea and discover the temporal and spatial distribution of green algal micro-propagules and macroalgae at the early stage of green tide. The results showed that green algal micro-propagules distributed in all stations from late April to late May, and micro-propagules of high density(> 300 ind. L^(-1)) concentrated in the adjacent Porphyra aquaculture area. Floating macroalgae were initially observed in the northern survey areas, and increased gradually. The dominant species was U. prolifera in the floating macroalgae, ranging between 90% and 100%. The seawater surface temperature and salinity in the above mentioned time period were suitable for the growth of macroalgae. This work can help government to strengthen management to reduce the blooms of macroalgae in the coastal area of South Jiangsu Province and also facilitate the decision-making for managers at the early stage of green tide.

关键词： distribution green tide green algal micro-propagules macroalgae

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Variations in Dissolved Methane in the Yellow Sea During the Spring algal Blooms of 2009

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Journal of Ocean University of China 2019年第4期18卷 896-912页

作者： YE Wangwang ZHANG Guiling LI Peipei ZHOU Feng LIU Chenggang Key Laboratory of Marine Chemistry Theory and Technology Ministry of Education Ocean University of China Qingdao 266100 China Laboratory for Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and Technology Qingdao 266071 China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of Oceanography Ministry of Natural Resources Hangzhou 310012 China

Methane (CH4) is an important greenhouse gas and oceans are net sources of atmospheric CH4. The effects of environ- mental factors on the CH4 variation during different phases of the spring algal blooms were examined during two cruises conducted in the Yellow Sea (YS) from February to April of 2009. During the pre-bloom period from February to March, low CH4 saturation (< 134%) was observed in the surface water, except at two nearshore stations where the CH4 levels were above 140% in March due to mixing with the coastal water. During the bloom period, CH4 increased obviously at two bloom-tracking stations, especially at the surface with mean saturations of 140% and 170%. The increase in CH4 concentration/saturation is thought to be the result of in situ CH4 production. The particulate organic carbon (POC) and chlorophyll a contents were believed to be important factors that influ- enced the CH4 production. In addition, the presence of different dominant phytoplankton species and the grazing pressure may have stimulated the CH4 production by supplying potential methanogenic substrates (such as dimethylsulphoniopropionate (DMSP)). Both the incubation data and the in situ estimations further evidenced the significant influence of the spring blooms on the CH4 production. The calculated sea-to-air CH4 fluxes during the bloom period were not significantly higher than those during the pre-bloom period despite the bloom-increased CH4 saturation. This is due to the variation in physical forcing (such as wind speed), which is the main driver for determining the CH4 flux. Finally, we estimated the annual CH4 flux in the YS as 9.0 μmol m 2 d 1;the findings suggest that the YS is a natural source of atmospheric CH4.

关键词： CH4 Yellow Sea algal bloom sea-to-air flux CH4 production

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Potential effect of sedimentary iron-phosphorus accumulation on frequent algal bloom in the Pearl River Estuary

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Science China Earth Sciences 2007年第3期50卷 453-461页

作者： WENG HuanXin SUN XiangWei CHEN JingFeng CHEN JianFang CHEN LiHong CHEN XiangHua QIN YaChao Institute of Environment&Biogeochemistry Zhejiang UniversityHangzhou 310027China Second Institute of Oceanography State Oceanic AdministrationHangzhou 310027China

Based on laboratory culture of harmful alga on iron and phosphorus uptake, and the study of accu-mulation of iron-phosphorus in cores and release of iron and phosphorus from surficial sediments collected in the Pearl River Estuary, the reasons of the high frequency of phytoplankton bloom therein are discussed. The results show that Fe starvation can make algal growth rate slow down and the peak of cell number decrease. Fe and P contents in algal cell bear a significant correlation and the molar ratio of P:Fe is ~356:1, suggesting that algal uptake of Fe and P is synergistic. Total Fe and total P in sediments are positively correlated and Fe-P is the main species of inorganic sedimentary P. Through continuous leaching with agitation, 34.26%―80.21% of exchangeable P and 4.04%―22.52% of ex-changeable Fe are released from surficial sediments, implying that the accumulation of Fe-P in sedi-ments is available for providing nutrients (P and essential Fe) for the demand of phytoplankton bloom. These factors might be responsible for a higher frequency of red tides than other marine regions.

关键词： sedimentary Fe-P iron limitation harmful algal bloom Pearl River Estuary

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The “Fingerprint” of a freshwater microalga Scenedesmus sp. LX1:Visualizing the composition of its soluble algal products

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Chinese Chemical Letters 2019年第5期30卷 1126-1128页

作者： Yinhu Wu Yin Yu 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 State Key Laboratory of Environmental Criteria and Risk Assessment Research Center of Water Pollution Control TechnologyChinese Research Academy of Environmental SciencesBeijing 100012China Shenzhen Environmental Science and New Energy Technology Engineering Laboratory Tsinghua-Berkeley Shenzhen InstituteShenzhen 518055China

In this study,a fingerprint analysis method along with the EEM fluorescence spectra was used to characterize the SAPs released by Scenedesmus ***1 during the growth *** fractionation was used firstly to divide the SAPs into six resin fractions,and then size exclusion chromatography(SEC)was performed to separate each resin fraction into several subfractions with different molecular weights(MW).The fingerprint graph integrated the information revealed by resin fractionation as well as that by SEC,showing that main components of SAPs changed from the hydrophilic subfractions with MW of 10~2-10~3 Da to the hydrophobic subfractions with MW of 10~3-10~4 *** these results with the EEM fluorescence spectra of different resin fractions,the change of the main matters within SAPs could be inferred.

关键词： Microalgae Soluble algal products Fingerprint analysis Resin fractionation Molecular weight distribution

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Cementing mechanism of algal crusts from desert area

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Chinese Science Bulletin 2002年第16期47卷 1361-1368页

作者： HU Chunxiang LIU Yongding ZHANG Delu HUANG Zebo B.S.Paulsen College of Life Sciences Northwest Normal UniversityLanzhou 730070China Institute of Hydrobiology Chinese Academy of SciencesWuhan 430072China School of Pharmacy University of Oslo1068 BlindemN-0316 OsloNorway

34-, 17-, 4-, 1.5-year old natural algal crusts were collected from Shapotou Scientific Station of the Chinese Academy of Sciences, 40-day old field and greenhouse artificial algal crusts were in situ developed in the same sandy soil and the same place (37°27’N, 104°57’E). Their different cohesions both against wind force and pressure were measured respectively by a sandy wind-tunnel experiment and a penetrometer. On the basis of these algal crusts, the cementing mechanism was revealed from many subjects and different levels. The results showed that in the indoor artificial crusts with the weakest cohesion bunchy algal filaments were distributed in the surface of the crusts, produced few extracellular polymers (EPS), the binding capacity of the crusts just accomplished by mechanical bundle of algal filaments. For field crusts, most filaments grew toward the deeper layers of algal crusts, secreted much more EPS, and when organic matter content was more than 2.4 times of chlorophyll a, overmuch organic

关键词： algal crust cohesion cementing structure gluing sub-stance cementing mechanism EPS.

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