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Optimization of phosphorus removal in uniFed SBR system for domestic wastewater treatment

Frontiers of Environmental Science & Engineering 2010年第4期4卷 475-481页

作者： xuguang tang Shuying WANG Yongzhen PENG Key Laboratory of Beijing Water Quality Science and Water Environment Recovery Engineering Beijing University of TechnologyBeijing 100124China

The characteristic of phosphorus removal andappropriate change of the traditional operation modes wereinvestigated in UniFed sequencing batch reactor (SBR)laboratory-scale apparatus (40 L), treating actual domesticwastewater with low ratios of C/N (2.57) and C/P (30.18),providing theoretical basis for actual application ofwastewater treatment plant. UniFed SBR system with itsunique operation mode had the distinct superiority ofphosphorus removal. On this occasion, the effect ofvolumetric exchange ratio (VER) and the method ofinfluent introduction for phosphorus removal were *** the carbon source became the limiting factor tophosphorus release, the higher the VER, the lower thephosphorus concentration in the effluent. Three differentinfluent patterns, including one-time filling, four-timefilling, and continuous filling with the same quantity ofwastewater could increase the release rate of anaerobicphosphorus from 0.082 to 0.143 mg·P·(L·min)-1. Appropriatechange of the traditional operation modes couldoptimize the efficiency of phosphorus removal. When thefeed/ decant time was extended from 2 h to 4 h, thephosphorous removal efficiency increased from 59.93% to88.45% without any external carbon source. In the mode ofalternation of anoxic-aerobic (A/O) condition, phosphorousremoval efficiency increased from 55.07% to 72.27%clearly. The carbon source in the influent can be usedadequately, and denitrifying phosphorus removal wascarried out in anoxic stage 2 (A2). This mode was optimalfor the treatment of actual domestic wastewater with lowC/N and C/P ratios.

关键词： UniFed sequencing batch reactor(SBR) phosphorus removal volumetric exchange ratio(VER) alternation of anoxic-aerobic(A/O) domestic wastewater

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The uncertainty analysis of the MODIS GPP product in global maize croplands

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Frontiers of Earth Science 2018年第4期12卷 739-749页

作者： Xiaojuan HUANG Mingguo MA Xufeng WANG xuguang tang Hong YANG Chongqing Engineering Research Center for Remote Sensing Big Data Application Southwest UniversityChongqing 400715China Research Base of Karst Eco-environments at Nanchuan in Chongqing Ministry of Natural ResourcesSchool of Geographical SciencesSouthwest UniversityChongqing 400715China Northwest Institute of Eco-environment and Resources Chinese Academy of SciencesLanzhou 730000China Department of Geography and Environmental Science University of ReadingReading RG66ABUK

Gross primary productivity (GPP) is very important in the global carbon cycle. Currently, the newly released estimates of 8-day GPP at 500 m spatial resolution (Collection 6) are provided by the Moderate Resolution Imaging Spectroradiometer (MODIS) Land Science Team for the global land surface via the improved light use efficiency (LUE) model. However, few studies have evaluated its performance. In this study, the MODIS GPP products (GPPMOD) were compared with the observed GPP (GPPEC) values from site-level eddy covariance measurements over seven maize flux sites in different areas around the world. The results indicate that the annual GPPMOD was underestimated by 6%‒58% across sites. Nevertheless, after incorporating the parameters of the calibrated LUE, the measurements of meteorological variables and the reconstructed Fractional Photosynthetic Active Radiation (FPAR) into the GPPMOD algorithm in steps, the accuracies of GPPMOD estimates were improved greatly, albeit to varying degrees. The differences between the GPPMOD and the GPPEC were primarily due to the magnitude of LUE and FPAR. The underestimate of maize cropland LUE was a widespread problem which exerted the largest impact on the GPPMOD algorithm. In American and European sites, the performance of the FPAR exhibited distinct differences in capturing vegetation GPP during the growing season due to the canopy heterogeneity. In addition, at the DE-Kli site, the GPPMOD abruptly produced extreme low values during the growing season because of the contaminated FPAR from a continuous rainy season. After correcting the noise of the FPAR, the accuracy of the GPPMOD was improved by approximately 14%. Therefore, it is crucial to further improve the accuracy of global GPPMOD, especially for the maize crop ecosystem, to maintain food security and better understand global carbon cycle.

关键词： MODIS GPP eddy covariance maize cropland validation improvement

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Future variation of land surface temperature in the Yangtze River Basinbasedon CMIP6 model

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International Journal of Digital Earth 2023年第1期16卷 2776-2796页

作者： Jinlian Liu Hanya tang Fengqin Yan Shiwei Liu xuguang tang Zhi Ding Pujia Yu Chongqing Jinfo Mountain Karst Ecosystem National Observation and Research Station School of Geographical SciencesSouthwest UniversityChongqingPeople’s Republic of China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingPeople’s Republic of China Chongqing Key Laboratory of Karst Environment School of Geographical SciencesSouthwest UniversityChongqingPeople’s Republic of China

In recent years,past changes in global and regional land surface temperatures(LST)have been well studied,however,future LST changes have been largely ignored owing to data *** this study,three climate variables of CMIP6,namely air temperature(AT),precipitation(Pre),and leaf area index(LAl),were spatially corrected using the Delta downscaling *** this basis,by combining MODIS LST,elevation,slope and aspect,a random forest(RF)model was built to calculate the LST from 2022 to *** absolute variability(AV)and Mann-Kendall(M-K)tests were used to quantitatively detect interannual and seasonal LST changes in different Shared Socioeconomic Pathways(SSPs)*** results showed that the AV value increased successively from SSP1-2.6 to SSP2-4.5 and then to *** with the base period(2003-2021),the increment in interannual,spring,summer and autumn LST during 2022-2100 was mainly between 1 and 2°℃under *** interannual and seasonal LST were spatially characterized by significant warming over large areas,and the increasing was the fastest under *** results indicate that,in the future,LST will increase further over large areas,especially in winter.

关键词： Temporal and spatial changes Delta downscaling Random forest Global warming

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Feedback and contribution of vegetation, air temperature and precipitation to land surface temperature in the Yangtze River Basin considering statistical analysis

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International Journal of Digital Earth 2023年第1期16卷 2941-2961页

作者： Jinlian Liu Xinyao Zhou Hanya tang Fengqin Yan Shiwei Liu xuguang tang Zhi Ding Ke Jiang Pujia Yu Chongqing Jinfo Mountain Karst Ecosystem National Observation and Research Station School of Geographical SciencesSouthwest UniversityChongqingPeople’s Republic of China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingPeople’s Republic of China Chongqing Key Laboratory of Karst Environment School of Geographical SciencesSouthwest UniversityChongqingPeople’s Republic of China

Land surface temperature(LST),especially day-night LST difference(LSTd-LSTn),is a key variable for the stability of terrestrial ecosystems,affected by vegetation and climate *** the contribution and feedback of vegetation and climate to LST changes is critical to developing mitigation *** on LST,Normalized vegetation index(NDVI),land use(LU),air temperature(AT)and precipitation(Pre)from 2003 to 2021,partial correlation was used to analyze the response of LST to vegetation and *** feedback and contribution of both to LST were further quantifed by using spatial linear relationships and partial derivatives *** results showed that both interannual LST(LSTy)and LSTd-LSTn responded negatively to vegetation,and vegetation had a negative feedback effect in areas with significantly *** was also a major contributor to the decline of *** the advantage of positive partial correlation area of 94.99%,AT became the main driving factor and contributor to LSTy change *** contributed negatively to both LSTy and LSTd-LSTn,with contributions of-0.004℃/y and-0.022℃/y,*** played a decisive role in LST warming of YRB,which was partially mitigated by vegetation and *** present research contributed'to,the,detection,of LST changes and improved understanding of the driving mechanism.

关键词： Land surface temperature vegetation dynamics climate change land use contribution feedback

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Sensitivity of Near Real-time MODIS Gross Primary Productivity in Terrestrial Forests Based on Eddy Covariance Measurements

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Chinese Geographical Science 2015年第5期25卷 537-548页

作者： tang xuguang LI Hengpeng LIU Guihua LI Xinyan YAO Li XIE Jing CHANG Shouzhi Key Laboratory of Watershed Geographic Sciences Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Key Laboratory of Poyang Lake Wetland and Watershed Research (Jiangxi Normal University) Ministry of Education Department of Geography University of Zurich Jilin University College of Geo Exploration Science and Technology

As an important product of Moderate Resolution Imaging Spectroradiometer(MODIS), MOD17A2 provides dramatic improvements in our ability to accurately and continuously monitor global terrestrial primary production, which is also significant in effort to advance scientific research and eco-environmental management. Over the past decades, forests have moderated climate change by sequestrating about one-quarter of the carbon emitted by human activities through fossil fuels burning and land use/land cover change. Thus, the carbon uptake by forests reduces the rate at which carbon accumulates in the atmosphere. However, the sensitivity of near real-time MODIS gross primary productivity(GPP) product is directly constrained by uncertainties in the modeling process, especially in complicated forest ecosystems. Although there have been plenty of studies to verify MODIS GPP with ground-based measurements using the eddy covariance(EC) technique, few have comprehensively validated the performance of MODIS estimates(Collection 5) across diverse forest types. Therefore, the present study examined the degree of correspondence between MODIS-derived GPP and EC-measured GPP at seasonal and interannual time scales for the main forest ecosystems, including evergreen broadleaf forest(EBF), evergreen needleleaf forest(ENF), deciduous broadleaf forest(DBF), and mixed forest(MF) relying on 16 flux towers with a total of 68 site-year datasets. Overall, site-specific evaluation of multi-year mean annual GPP estimates indicates that the current MOD17A2 product works highly effectively for MF and DBF, moderately effectively for ENF, and ineffectively for EBF. Except for tropical forest, MODIS estimates could capture the broad trends of GPP at 8-day time scale for all other sites surveyed. On the annual time scale, the best performance was observed in MF, followed by ENF, DBF, and EBF. Trend analyses also revealed the poor performance of MODIS GPP product in EBF and DBF. Thus, improvements in the

关键词： MOD 17A2 FLUXNET community eddy covariance (EC) gross primary productivity (GPP) forest ecosystem evaluation

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Characterization of Water Constituents Spectra Absorption in Chagan Lake of Jilin Province, Northeast China

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Chinese Geographical Science 2011年第3期21卷 334-345页

作者： WANG Yuandong LIU Dianwei SONG Kaishan DU Jia WANG Zongming ZHANG Bai tang xuguang LEI Xiaochun WU Yanqing Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

Research on the optical characteristics of water color constituents in Chagan Lake of Jilin Province,Northeast China was carried out in order to investigate the variability of the spectra absorption parameters as inputs to bio-optical models and remote sensing algorithms for converting observed spectral signals into water quality *** of total particulates,non-algal particles and colored dissolved organic matter (CDOM) were first prepared by quantitative filter technique (QFT) and then absorption coefficients of these color producing agents were determined by *** characteristics of absorption coefficients by total particulate matter,spectral specific absorption dependency on chlorophyll concentration (Chl-a) of phytoplankton,spectral absorption slopes variation for CDOM and non-algal particles and their corresponding reasons were examined and clarified over five months of 2009 and 2010 in this *** suggest that total particulate spectral absorption in Chagan Lake is mainly dominated by non-algal particles in most cases,but phytoplankton could be the dominant contributor when chlorophyll concentration is high (up to 84.48 mg/m3 in autumn 2010).The specific absorption coefficients of phytoplankton particulate (a*ph(λ)) dependency on Chl-a is significantly variable due to relative contributions of package effect and accessory pigments,and the parameters of power function are clearly biased on a long time *** sources of variability in spectral absorption slopes of CDOM and non-algal particles are mainly attributed to the changing proportions of high molecular weight humic acids and mineral suspended sediments in waters,respectively.

关键词： colored dissolved organic matter spectra absorption water constituents spectral slope Chagan Lake

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Whether human-induced activities could change the gradient pattern of coastal land use along the sea-land direction:a case study in Manila Bay,Philippines

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Acta Oceanologica Sinica 2023年第2期42卷 163-174页

作者： Zhi Ding Fenzhen Su Yanan Chen Ying Liu Xue Feng Wenqiu Hu Fengqin Yan He Li Pujia Yu xuguang tang Chongqing Jinfo Mountain Karst Ecosystem National Observation and Research Station School of Geographical ScienceSouthwest UniversityChongqing400715China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101ChinaState Key Laboratory of Resources and Environmental Information SystemInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101China Key Laboratory of Reservoir Aquatic Environment Chongqing Institute of Green and Intelligent TechnologyChinese Academy of SciencesChongqing400714China

Increasing intense human activities have largely changed the coastal landscape and caused many environmental ***,whether human-induced activities could change the coastal land use gradient pattern,an important coastal zonal characteristic along the sea-land direction,remains *** Bay was selected as the study area in this *** to the distance of the land use and land cover(LULC)to the coastline,we clustered the typical coastal land use sequence patterns(CLUSPs)along the sea-land direction between 1988 and 2016 in Manila Bay and found the following.(1)Four typical CLUSPs,including the natural CLUSP dominated by forest land and grassland,the agricultural CLUSP dominated by dry farm and paddy field,the urbanised CLUSP dominated by construction land and the fishery CLUSP dominated by fishing farm,were mined in *** typical CLUSPs(a natural CLUSP,an intermediate CLUSP between the agricultural and urbanised CLUSPs,and a fishery CLUSP)were mined in 2016.(2)Affected by the dominant LULC,these typical CLUSPs showed a regular spatial pattern along the sea-land *** example,the typical natural CLUSP showed a landward pattern due to the long distance between the forest land and grassland and the coastline.(3)However,influenced by urban and aquaculture expansion,the land intensification of the CLUSP exhibited an obvious increase and caused the decrease of the CLUSP diversity from 1988 to *** increase in the area of LULC coverage showed no obvious correlation with its distance from the coastline(DFC),but the net increase rate of LULC coverage had a significant negative correlation with the ***,human-induced activities have a large impact on the gradient pattern of coastal land use along the sea-land direction.

关键词： coastal zone land use gradient sea-land human activities Manila Bay

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温度变化对生物除磷系统的影响

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化工学报 2011年第4期62卷 1103-1109页

作者：唐旭光王淑莹张婧倩北京工业大学北京市水质科学与水环境恢复工程重点实验室北京100124

以厌氧/好氧交替运行的SBR系统为研究对象,母反应器运行温度控制在15℃,采用实际生活污水,考察了温度（5、10、20、25、30、35℃）对EBPR系统的冲击影响。结果表明,温度较低（〈10℃）情况下,由于对微生物生理活性产生抑制而使系统除磷... 详细信息

以厌氧/好氧交替运行的SBR系统为研究对象,母反应器运行温度控制在15℃,采用实际生活污水,考察了温度（5、10、20、25、30、35℃）对EBPR系统的冲击影响。结果表明,温度较低（〈10℃）情况下,由于对微生物生理活性产生抑制而使系统除磷效率大幅度下降,由20℃时出水磷浓度为0 mg.L-1升高至5℃时的6.95 mg.L-1,而且胞内聚合物PHB的降解量下降,使系统内PHB处于累积状态。温度较高（25~30℃）时,系统能保持高效运行,并保持良好除磷效果,但当温度高于30℃时,出水磷浓度开始恶化,出水磷浓度为3.33mg.L-1,吸磷效率下降。根据在不同温度条件下,厌氧PHB合成速率RPHB-produced与磷释放速率RP-release的比值R1和好氧条件下PHB降解速率RPHB-degradation与磷吸收速率RP-uptake的比值R2可以得出结论,在环境温度为20℃的条件下,更有利于系统内EBPR高效稳定的运行。

关键词：生活污水温度冲击 PHB

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制革排污管盐结晶区混凝土硫酸盐侵蚀的研究

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腐蚀科学与防护技术 2016年第2期28卷 103-108页

作者：唐旭光谢友均龙广成马昆林中南大学土木建筑学院长沙410075 湖南科技大学土木工程学院湘潭411201

基于对制革工业园排污混凝土管破坏特征的现场调查和对混凝土的微观形貌及腐蚀产物的测试分析,探讨了污水对制革排污管混凝土的硫酸盐侵蚀破坏机理。结果表明,埋于地下的排污混凝土管,污水含有的硫酸盐对管内壁混凝土为半浸泡的盐侵蚀作... 详细信息

基于对制革工业园排污混凝土管破坏特征的现场调查和对混凝土的微观形貌及腐蚀产物的测试分析,探讨了污水对制革排污管混凝土的硫酸盐侵蚀破坏机理。结果表明,埋于地下的排污混凝土管,污水含有的硫酸盐对管内壁混凝土为半浸泡的盐侵蚀作用,内壁混凝土受化学腐蚀与物理侵蚀的双重复合作用。污水对管壁混凝土的化学腐蚀主要是低SO_4^(2-)浓度下的钙矾石型侵蚀(EA)、碳硫硅钙石型硫酸盐侵蚀(TSA)、高钙硅比C-S-H凝胶向低钙硅比C-S-H凝胶转化、钙矾石和碳硫硅钙石向石膏转化等。物理结晶侵蚀劣化则与盐的种类、环境温湿度及变动情况、混凝土的渗透性等因素相关。

关键词：制革综合污水埋地混凝土硫酸盐侵蚀盐结晶区侵蚀机理

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基于三维生态足迹的长江经济带生态安全动态评价

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地理科学进展 2024年第6期43卷 1184-1202页

作者：徐秋怡颜凤芹丁智汤旭光姚丽西南大学地理科学学院重庆400715 中国科学院地理科学与资源研究所北京100101 杭州师范大学遥感与地球科学研究院杭州311121 浙江外国语学院文化和旅游学院杭州310023

长江经济带是新时代中国重大战略发展区域之一,其生态建设对长江流域的社会经济发展和生态屏障建设起着重要作用,开展生态安全动态评价十分重要。论文选取多源数据,采用改进的三维生态足迹模型,模拟2000—2020年长江经济带的足迹深度、... 详细信息

长江经济带是新时代中国重大战略发展区域之一,其生态建设对长江流域的社会经济发展和生态屏障建设起着重要作用,开展生态安全动态评价十分重要。论文选取多源数据,采用改进的三维生态足迹模型,模拟2000—2020年长江经济带的足迹深度、足迹广度以及三维生态足迹,而后进一步构建生态压力指数、生态经济协调指数、流量资本占用率和存量资本流量利用比等指标量化生态安全变化,最后利用偏最小二乘回归分析法研究了三维生态足迹的驱动要素。结果表明:(1)在时间上,研究期间长江经济带足迹广度呈上升趋势但整体利用水平不高,足迹深度较大且表现出明显上升趋势(长江三角洲除外),通过消耗资本存量来满足自然资源需求;在空间上,地类足迹广度呈“西高东低”格局,足迹深度则相反;在地类组分构成上,足迹广度、足迹深度各地类占比不平衡,耕地对足迹广度、足迹深度的贡献率最大,林地生态可持续性较好。(2)长江经济带各地区生态安全状况差异较大。长江三角洲地区过度消耗存量资本,生态安全形势严峻。长江中游、成渝双城地区生态环境相对安全,但生态环境与经济发展可能存在逐渐失衡的趋势。云贵地区自然禀赋优越,生态安全状况较好。(3)驱动力分析表明,能源消耗、经济发展、城市扩张是导致区域生态资本占用增加的重要因素,而科技水平、生态建设在目前阶段对自然资源利用的影响程度较小。研究为长江经济带各地区生态环境保护与经济、城市建设协调发展提供了理论依据和实践指引,可为长江经济带整体发展规划提供参考,助力区域社会、经济与生态环境的协调发展。

关键词：三维生态足迹生态安全动态评价长江经济带驱动分析

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