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Natural marmatite photocatalyst for treatment of mineral processing wastewater to help zero wastewater discharge

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Journal of Environmental Sciences 2024年第8期142卷 83-91页

作者： Meirong Wu Wei Sun Xiangsong Meng Jianhua Kang Yue Yang School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources Central South UniversityChangsha 410083China

Mineral processing wastewater(MPW)with large discharge and high toxicity affects environmental safety,and the realizing zero discharge of MPW is of great significance for reducing environmental pollution,saving water resources,and promoting the sustainable development of the mining industry.In this study,we reported natural marmatite(NM)as a low-cost and efficient photocatalyst for the treatment of MPW to help zero wastewater discharge.The photocatalytic activity of NM was evaluated by the removal of total organic carbon(TOC)from MPW under visible-light illumination,and the optimal degradation conditions were discussed.Results showed that superoxide free radicals(^(·)O_(2)^(-))were the dominant active species responsible for organic pollutants degradation,and 74.25%TOC removal was obtained after 120 min reaction under the optimum treatment conditions.Meanwhile,the wastewater treated by NM photocatalysis can be reused in the flotation system without adverse impact on the product index.Based on these findings,a model of zero wastewater discharge for flotation with the help of photocatalytic treatment was established,it indicated that the water of the whole system can be balanced without affecting the ore dressing index,which showed that visible light-driven photocatalyst has a promising application prospect in the treatment and recycling of industrial wastewater.

关键词： Natural mineral Photocatalysis Industrial wastewater Wastewater recycling water balance

Estimating the optimal vegetation coverage for the dominant tree and shrub species over China's northwest drylands

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Science China Earth Sciences 2024年第5期67卷 1500-1517页

作者： Zhongdian ZHANG Xiaoxu JIA Ping ZHU Mingbin HUANG Lidong REN Ming’an SHAO School of Geographic Sciences Xinyang Normal UniversityXinyang 464000China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100190China Yellow River Delta Modern Agricultural Engineering Laboratory Chinese Academy of SciencesBeijing 100101China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationNorthwest A&F UniversityYangling 712100China

Anthropogenic revegetation is an effective way to control soil erosion and restore degraded ecosystems in China's northwest drylands(NWD).However,excessive vegetation cover expansion has long been known to increase evapotranspiration,leading to reduced local water availability,which can in turn threaten the health and services of restored ecosystems.Determining the optimal vegetation coverage(OVC)is critical for balancing the trade-off between plant growth and water consumption in water-stressed areas,yet quantitative assessments over the entire NWD are still lacking.In this study,a modified Biome BioGeochemical Cycles(Biome-BGC)model was used to simulate the long-term(1961–2020)dynamics of actual evapotranspiration(ET_(a)),net primary productivity(NPP),and leaf area index(LAI)for the dominant non-native tree(R.pseudoacacia and P.sylvestris)and shrub(C.korshinkii and H.rhamnoides)species at 246 meteorological sites over NWD.The modified model incorporated the Richards equation to simulate transient unsaturated water flow in a multilayer soil module,and both soil and eco-physiological parameters required by the model were validated using field-observed ETadata for each species.Spatial distributions of OVC(given by the mean maximum LAI,LAI_(max))for the dominant species were determined within three hydrogeomorphic sub-areas(i.e.,the loess hilly-gully sub-area,the windy and sandy sub-area,and the desert sub-area).The modified Biome-BGC model performed well in terms of simulating ET_(a) dynamics for the four plant species.Spatial distributions of mean ET_a,NPP,and LAI_(max)generally exhibited patterns similar to mean annual precipitation(MAP).In the loess hilly-gully sub-area(MAP:210 to 710 mm),the OVC respectively ranged from 1.7 to 2.9 and 0.8 to 2.9 for R.pseudoacacia and H.rhamnoides.In the windy and sandy sub-area(MAP:135 to 500 mm),the OVC ranged from 0.3 to 3.3,0.5 to 2.6 and 0.6 to 2.1for P.sylvestris,C.korshinkii and H.rhamnoides,respectively.In the desert sub-area(MAP:90 to 500 mm),the OVC ranged from 0.4 t

关键词： Optimal vegetation coverage water balance Leaf area index Biome-BGC model Dryland

Effect of glaciers on the annual catchment water balance within Budyko framework

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Advances in Climate Change Research 2022年第1期13卷 51-62页

作者： Shi-Wei LIU Xiaoming WANG Lu ZHANG Wei-Ming KONG Hong-Kai GAO Cun-De XIAO State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou730000China University of Chinese Academy of Sciences Beijing100049China CSIRO Land and water CanberraACT 2601Australia Key Laboratory of Geographic Information Science(Ministry of Education) East China Normal UniversityShanghai200241China State Key Laboratory of Earth Surface Processes and Resources Ecology Beijing Normal UniversityBeijing100875China

The effects of catchment characteristics and climate variables on water partitioning into evapotranspiratio n and runoff can be evaluated using the Budyko framework.However,the influence of glaciers on catchment characteristics within the framework has yet been adequately investigated.Here we extend the Budyko framework and apply the elasticity method to examine the effects of glaciers on runoff between 2001 and 2010 in 25 upstream catchments of the Tarim River Basin in western China.The consideration of glacier mass balance and glacier fraction improves the performance of the Budyko framework,especially for the catchments with a high glacier fraction.We found that the catchment characteristic parameterwas strongly affected by glacier fraction,and it changes from 1.15 to 2.09 when glacier fraction decreases from 0.4191 to 0.0005.This also reflects the change in water-energy partitioning that eventually effects on evapotranspiration and runoff.We further assessed the average runoff responses to changes in precipitation,potential evapotranspiration,glacier mass balance,and glacier fraction in the 25 catchments.Although the runoff appears most sensitive to precipitation in average,its sensitivity to glacier mass balance and glacier area in fact rises from-0.07%to 0.17% and about 0-0.54%,respectively,when the glacier fraction increases from 0.0005 to 0.4191,further demonstrating the increasing influence of glaciers when the fraction becomes larger.After all,the inclusion of glacier factors in the Budyko framework allows us to understand more about the impacts and contributions of glaciers to runoff at a catchment scale.

关键词： Budyko framework Glacier water balance water resource Runoff elasticity

Numerical Study of water Transport and Operating Strategy for Fuel Cells with Segmented water Management Flow Fields

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Journal of Thermal Science 2024年第4期33卷 1577-1589页

作者： CHEN Chengdai WANG Changhong ZHENG Zijun School of Materials and Energy Guangdong University of Technology

The effective cathode flow field design can realize the internal water balance and higher current density output of proton exchange membrane fuel cells(PEMFC).Therefore,a segmented water management flow field is proposed in this study,i.e.a half separated-half coupled cathode(HSHC) flow field which has two inlets but just one outlet.A 3D numerical PEMFC model is applied to study the effect of the HSHC flow field on PEMFC performance and its operating strategy in terms of operating conditions.The study results are shown as follows:Compared with the two conventional cathode flow fields,the HSHC flow field improves the water balance along the channel and increases the current density by 17.1% at a cathode stoichiometry of 3.25.It is because the HSHC flow field can overcome the water loss at channels upstream and the water accumulation at channels downstream.The draw water phenomenon(DWP) in the HSHC flow field is observed,which is mainly affected by the water vapor pressure of channel.Based on the DWP,cooling channel inlet flow rates can be used to adjust water balance,but severe water loss should be avoided.In addition,the inlet temperature control in HSHC flow field should be that cell temperature>cathode channel inlet temperature>cooling channel inlet temperature> ambient temperatures for better water balance.

关键词： proton exchange membrane fuel cells channel design segmented water management water balance operating strategy

Understanding the impact of mountain landscapes on water balance in the upper Heihe River watershed in northwestern China

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Journal of Arid Land 2013年第3期5卷 366-383页

作者： Jia QIN YongJian DING JinKui WU MingJie GAO ShuHua YI ChuanCheng ZHAO BaiSheng YE Man LI ShengXia WANG State Key Laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences Division of Hydrology water-Land Resources in Cold and Arid Regions Chinese Academy of Sciences

Estimating the impact of mountain landscape on hydrology or water balance is essential for the sus- tainable development strategies of water resources. Specifically, understanding how the change of each landscape influences hydrological components will greatly improve the predictability of hydrological responses to mountain landscape changes and thus can help the government make sounder decisions. In the paper, we used the VIC （Variable Infiltration Capacity） model to conduct hydrological modeling in the upper Heihe River watershed, along with a frozen-soil module and a glacier melting module to improve the simulation. The improved model performed satisfactorily. We concluded that there are differences in the runoff generation of mountain landscape both in space and time. About 50% of the total runoff at the catchment outlet were generated in mid-mountain zone （2,900-4,000 m asl）, and water was mainly consumed in low mountain region （1,700-2,900 m asl） because of the higher requirements of trees and grasses. The runoff coefficient was 0.37 in the upper Heihe River watershed. Barren landscape produced the largest runoff yields （52.46% of the total runoff） in the upper Heihe River watershed, fol- lowed by grassland （34.15%）, shrub （9.02%）, glacier （3.57%）, and forest （0.49%）. In order to simulate the impact of landscape change on hydrological components, three landscape change scenarios were designed in the study. Scenario 1, 2 and 3 were to convert all shady slope landscapes at 2,000-3,300 m, 2,000-3,700 m, and 2,000-4,000 m asl respectively to forest lands, with forest coverage rate increased to 12.4%, 28.5% and 42.0%, respectively. The runoff at the catchment outlet correspondingly declined by 3.5%, 13.1% and 24.2% under the three scenarios. The forest landscape is very important in water conservation as it reduced the flood peak and increased the base flow. The mountains as ＂water towers＂ play important roles in water resources generation and the impact of mountain landscapes on hydrology is significant.

关键词： mountain landscape runoff modeling water balance VIC model Heihe River watershed

Impacts of forestation on the annual and seasonal water balance of a tropical catchment under climate change

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Forest Ecosystems 2021年第4期8卷 856-871页

作者： Hero Marhaento Martijn J.Booij Noorhadi Rahardjo Naveed Ahmed Faculty of Forestry Universitas Gadjah MadaYogyakarta 55281Indonesia water Engineering and Management Group Faculty of Engineering TechnologyUniversity of TwenteP.O.Box 2177500 AE Enschedethe Netherlands Faculty of Geography Universitas Gadjah MadaYogyakarta 55281Indonesia Key Laboratory of Mountain Surface Process and Ecological Regulations Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China

Background:This study aims to assess the effects of a forestation program and climate change on the annual and seasonal water balance of the Bogowonto catchment(597 km^(2))in Java,Indonesia.The catchment study is rare example in Indonesia where forestation has been applied at the catchment level.However,since the forestation program has been initiated,evaluations of the program only focus on the planting area targets,while the environmental success e.g.,impacts on the hydrological processes have never been assessed.This study used a calibrated Soil and water Assessment Tool(SWAT)model to diagnose the isolated and combined effects of forestation and climate change on five water balance components,namely streamflow(Q),evapotranspiration(ET),surface runoff(Q_(s)),lateral flow(Q_(l))and base flow(Q_(b)).Results:The results show that from 2006 to 2019,forest cover has increased from 2.7% to 12.8% of the total area,while in the same period there was an increase in the mean annual and seasonal temperature,rainfall,and streamflow.Results of SWAT simulations show that changes in the mean annual and seasonal water balance under the forestation only scenario were relatively minor,while changes were more pronounced under the climate change only scenario.Based on the combined impacts scenario,it was observed that the effects of a larger forest area on the water balance were smaller than the effects of climate change.Conclusions:Although we found that forestation program has minor impacts compared to that of climate change on the hydrological processes in the Bogowonto catchment,seasonally,forestation activity has decreased the streamflow and surface runoff during the wet season which may reduce the risk of moderate floods.However,much attention should be paid to the way how forestation may result in severe drought events during the dry season.Finally,we urge the importance of accounting for the positive and negative effects in future forestation programs.

关键词： Forestation Land use change Climate change SWAT model water balance Bogowonto catchment

Antecedent Precipitation Index to Estimate Soil Moisture and Correlate as a Triggering Process in the Occurrence of Landslides

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International Journal of Geosciences 2024年第1期15卷 70-86页

作者： Marcio Augusto Ernesto De Moraes Walter Manoel Mendes Filho Rodolfo Moreda Mendes Cassiano Antonio Bortolozo Daniel Metodiev Marcio Roberto Magalhães De Andrade Harideva Marturano Egas Tatiana Sussel Gonçalves Mendes Luana Albertani Pampuch CEMADEN - National Centre for Monitoring and Early Warnings of Natural Disasters General Coordination of Research and Development S&#227o José dos Campos Brazil Faculty of Science and Technology Goias Federal University Aparecida de Goi&#226nia Brazil Institute of Science and Technology S&#227o Paulo State University (Unesp) S&#227o José dos Campos Brazil

Landslides are highly dangerous phenomena that occur in different parts of the world and pose significant threats to human populations. Intense rainfall events are the main triggering process for landslides in urbanized slope regions, especially those considered high-risk areas. Various other factors contribute to the process;thus, it is essential to analyze the causes of such incidents in all possible ways. Soil moisture plays a critical role in the Earth’s surface-atmosphere interaction systems;hence, measurements and their estimations are crucial for understanding all processes involved in the water balance, especially those related to landslides. Soil moisture can be estimated from in-situ measurements using different sensors and techniques, satellite remote sensing, hydrological modeling, and indicators to index moisture conditions. Antecedent soil moisture can significantly impact runoff for the same rainfall event in a watershed. The Antecedent Precipitation Index (API) or “retained rainfall,” along with the antecedent moisture condition from the Natural Resources Conservation Service, is generally applied to estimate runoff in watersheds where data is limited or unavailable. This work aims to explore API in estimating soil moisture and establish thresholds based on landslide occurrences. The estimated soil moisture will be compared and calibrated using measurements obtained through multisensor capacitance probes installed in a high-risk area located in the mountainous region of Campos do Jordão municipality, São Paulo, Brazil. The API used in the calculation has been modified, where the recession coefficient depends on air temperature variability as well as the climatological mean temperature, which can be considered as losses in the water balance due to evapotranspiration. Once the API is calibrated, it will be used to extrapolate to the entire watershed and consequently estimate soil moisture. By utilizing recorded mass movements and comparing them with API and soil moisture, it will be possible to dete

关键词： Landslides Antecedent Precipitation Index Soil Moisture Threshold water balance

Transformation of surface water and groundwater and water balance in the agricultural irrigation area of the Manas River Basin,China

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International Journal of Agricultural and Biological Engineering 2017年第4期10卷 107-118页

作者： Yang Guang He Xinlin Li Xiaolong Long Aihua Xue Lianqing College of water&Architectural Engineering Shihezi UniversityShihezi 832003China Xinjiang Production&Construction Group Key Laboratory of Modern Water-Saving IrrigationShihezi 832003XinjiangChina China Institute of water Resources and Hydropower Research Beijing 100038China

Calculation of the water balance is very important to relieve the pressure on water resources in arid agricultural irrigation areas.This research focused on irrigation water balance calculations in the Manas River Basin of the southern margin of the Junggar Basin of China,and aimed to analyze the groundwater level dynamic trend and response characteristics of the basin water cycle under water-saving irrigation measures.The surface water and groundwater coupling model of MIKE 11-Visual MODFLOW was used to simulate rainfall runoff in mountainous areas,and quantify the contribution of water balance components in the plain irrigation area.Convergence of the delayed watershed in the mountain area was obvious,and when the river runoff exceeded 200 m^(3)/s,the error in the runoff simulation was large.The water balance in the plain agricultural irrigation area was in a negative equilibrium state,and the difference between recharge and discharge was−2.65 billion m^(3).The evapotranspiration was 24.49 billion m^(3) under drip irrigation,accounting for only approximately 51%of the total discharge.The lateral discharge of the unsaturated and saturated aquifers was 15.38 billion m^(3),accounting for approximately 32%of the total discharge.The main reason for the groundwater decline in the irrigation area was closely related to the extraction of groundwater,because the amount of recharge and discharge in the natural state was approximately identical.The MIKE 11-Visual MODFLOW model produced accurate results,and the research method provided a new exploration technique to quantify the effect of water supply mode on the groundwater table.The model is suitable for the management of water resources in arid areas.

关键词： water balance coupling model surface water and groundwater water saving irrigation Manas River Basin

Hydrologic balance, net primary productivity and water use efficiency of the introduced exotic Eucalyptus grandis × Eucalyptus urophylla plantation in south-western China

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Journal of Plant Ecology 2019年第6期12卷 982-992页

作者： Yanting Hu Ping Zhao Yuqing Huang Liwei Zhu Guangyan Ni Xiuhua Zhao Zhihong Huang Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems South China Botanical GardenChinese Academy of Sciences723 Xingke RoadTianhe DistrictGuangzhou 510650China Guangdong Provincial Key Laboratory of Applied Botany South China Botanical GardenChinese Academy of Sciences723 Xingke RoadTianhe DistrictGuangzhou 510650China Key Laboratory of Beibu Gulf Environment Change and Resource Use Ministry of Education and Guangxi Key Laboratory of Earth Surface Processes and Intelligent SimulationNanning Normal University175 Mingxiu East RoadNanningGuangxi 530001China Department of Forest Ecology College of Life Science and TechnologyCentral South University of Forestry and Technology498 Shaoshan South RoadChangshaHunan 410004China

Aims Land cover changes can disrupt water balance and alter the partitioning of precipitation into surface runoff,evapotranspiration and groundwater recharge.The widely planted Eucalyptus trees in south-western China have the potential to bring about hydrologic impacts.Our research aims to elucidate the hydrologic balance characteristics of the introduced exotic Eucalyptus grandis×Eucalyptus urophylla plantation and to assess whether its high productivity results from high water use efficiency(WUE)or large water consumption.Methods A 400-m^(2) experimental plot was established in an E.grandis×E.urophylla plantation in south-western China.water balance components,including stand transpiration(T_(r)),evapotranspiration(E_(t))and runoff(R)were obtained as follows:T_(r) was estimated based on sap flow measurements,E_(t) was estimated as the average of surface transpiration and evaporation weighted by the fractional green vegetation cover using a modeling approach,and R was collected using the installed metal *** primary productivity(NPP)was obtained from allometric equation and annual diameter at breast height(DBH)increment determination.Important Findings Annual E_(t) and T_(r) were 430±31 and 239±17 mm,respectively.Annual T_(r) accounts for 56±8%of total evapotranspiration on average.WUE(NPP/T_(r))of the E.grandis×E.urophylla was estimated to be 3.3–3.9 mmol·mol^(−1).Based on the comparative analysis of T_(r) and WUE,E.grandis×E.urophylla had a high productivity due to its high WUE without exhibiting prodigal water use.Meteorological factors including vapor pressure deficit and global solar radiation(R_(s))were key factors regulating E_(t) and T_(r) in our research site.Annual surface runoff,E_(t) and canopy interception occupied 7%,27–30%and 16%of total precipitation,while the remaining 46–50%of precipitation was used for sustaining groundwater recharge and altering soil water storage.The higher runoff coefficient(7.1%)indicated the weaker capability of E.grandis×E.urophylla to reserve water resource than natural

关键词： water balance evapotranspiration water use efficiency sap flow runoff