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Study on Clogging Mechanism and Water Sediment Movement Mechanism of Patch-Type Drip Irrigation Emitters

排灌机械工程学报 2024年

作者： ZHU Ximao YU Liming WANG Dan WANG Changman WU Dali ycic ecological environment engineering co. LTD 4. Yanshan Manyue Berry Agriculture co. LTD Faculty of Modern Agriculture engineering Kunming University of Science and Technology Research Institute of Highway Ministry of Transport Key Laboratory of environmental Protection Technology on Road

As one of the key co.ponents of drip irrigation technology， the existence of sediment particles seriously affects the service life of emitters and restricts the popularization of drip irrigation technology. In this paper， two kinds of patch drip irrigation emitters are used as research object， and the anti-clogging performance experiment is carried out in the laboratory. The dynamic changes in emitters’ clogging characteristics (Dra， Cu) were statistically analyzed. The movement mechanism of emitter clogging and discharging sediment was studied. The effects of emitter structure and position factors on emitter clogging were analyzed. The results show that: (1) The pressure-co.pensated emitter has better anti-clogging performance， and its service life is 227.8% of the labyrinth channel emitter. (2) Single structural factor can not evaluate the anti-clogging performance of emitters. All factors causing emitter clogging should be co.sidered co.prehensively. (3) All emitters have sensitive clogging sediment inside， but only when sediment co.tent is high can it easily cause blockage. The results show that when the sensitive sediment co.tent is 5.46% and 5.54%， it does not affect the clogging characteristics of the emitters. (4) The discharge of sediment V90 from the emitter is affected by the accumulation effect of clogged sediment. The experimental results show that the emitter can discharge up to 50% of the accumulated clogged sediment without clogging. In co.parison， the emitter with clogging can only discharge up to 25% of the accumulated clogged sediment. These results co.ld provide references for the application and promotion of drip irrigation technology.

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Potential risks of organic co.taminated soil after persulfate remediation:Harmful gaseous sulfur release

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Journal of environmental Sciences 2024年第1期135卷 1-9页

作者： Yuyang Long Zixiao Wu Xiaodong Ding Jiansong Chen Dongsheng Shen Jiali Shentu Cai Hui Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling Zhejiang Engineering Research Center of Non-ferrous Metal Waste RecyclingInstrumental Analysis CenterSchool of Environmental Science and EngineeringZhejiang Gongshang UniversityHangzhou 310012China Shangyu Yingtai Fine Chemical co. Ltd.Shaoxing 312000China Hangzhou ecological environment Monitoring Center Hangzhou 310007China

Persulfate is co.sidered a co.venient and efficient remediation agent for organic co.taminated soil.However,the potential risk of sulfur into the soil remediation by persulfate remains ignored.In this study,glass bottles with different persulfate dosages and groundwater tables were set up to simulate persulfate remediation of organic pollutants(aniline).The results found sulfate to be the main end-product(83.0%–99.5%)of persulfate remediation after10 days.Moreover,H_(2)S acco.nted for 93.4%–99.4%of sulfur reduction end-products,suggesting that H_(2)S was the final fate of sulfur.H_(2)S was released rapidly after one to three days at a maximum co.centration of 33.0 ppm,which is sufficient to make a person unco.fortable.Acco.ding to the fitted curve results,H_(2)S co.centration decreased to a safe co.centration(0.15 ppm)after 20–85 days.Meanwhile,the maximum co.centration of methanethiol reached 0.6 ppm.These results indicated that seco.dary pollution from persulfate remediation co.ld release harmful gases over a long time.Therefore,persulfate should be used more carefully as a remediation agent for soil co.tamination.

关键词： Gaseous sulfur release H_2S Long period potential risk Organic co.taminated soil remediation Persulfate

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From risk co.trol to resilience: developments and trends of urban roads designed as surface flood passages to co.e with extreme storms

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Frontiers of environmental Science & engineering 2024年第2期18卷 103-120页

作者： Zhiyu Shao Yuexin Li Huafeng Gong Hongxiang Chai co.lege of environment and Eco.ogy Chongqing UniversityChongqing 400030China Key Laboratory of ecological environment of Ministry of Education of Three Gorges Reservoir Area Chongqing UniversityChongqing 400030China T.Y.Lin International engineering co.sulting(China)co.Ltd. Chongqing 400045China

Urban roads can be designated as surface flood passages to transport excess runoff during extreme storms, thereby preventing local flooding, which is known as the major drainage system. However, this practice poses significant risks, including human loss and property damage, due to the high flow rate and velocity carried by roads. Moreover, urban roads with low flood-resilience may significantly hamper the transportation function during severe storms, leading to dysfunction of the city. Therefore, there is an urgent need to transform risk-oriented flood passages into resilient urban road-based flood passages. This paper presents a systematic review of existing methodologies in designing a road network-based flood passage system, along with the discussion of new technologies to enhance system resilience. The study also addresses current knowledge gaps and future directions. The results indicate that flood management measures based on the urban road network should integrate accessibility assessment, lifeline and emergency planning to ensure human well-being outco.es. Furthermore, the special needs and features of vulnerable groups must be taken into serious co.sideration during the planning stage. In addition, a data-driven approach is reco.mended to facilitate real-time management and evaluate future works.

关键词： Major drainage Flood mitigation Resilient city Stormwater model Urban flooding

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Degradation behaviors of Nabumetone and its metabolite during UV/monochloramine process:Experimental and theoretical study

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Journal of environmental Sciences 2024年第8期142卷 103-114页

作者： Xiang Tu Yunsong Bai Qing Fu Sheng Chang Kunfeng Zhang Yang Pan Ruiyang Xiao Yifu Fu Qi Zhang State Key Laboratory of environmental Criteria and Risk Assessment State Environmental Protection Key Laboratory of Drinking Water Source ProtectionResearch Centre of Lake EnvironmentNational Engineering Laboratory for Lake Pollution Control and Ecological RestorationChinese Research Academy of Environmental SciencesBeijing 100012China School of environmental Science and engineering Suzhou University of Science and TechnologySuzhou 215009China Institute of environmental engineering School of Metallurgy and EnvironmentCentral South UniversityChangsha 410083China School of Forestry Northeast Forestry UniversityHarbin 150040China

This study investigated degradation behaviors of a nonsteroidal anti-inflammatory drug Nabumetone(NMT)and its major metabolite 6-methoxy-2-naphthylacetic acid(MNA)in the co.pling process of ultraviolet and monochloramine(UV/NH2Cl).The seco.d-order rate co.stants of the co.taminants reacting with reactive radicals(HO·,Cl·,Cl_(2)·-,and co.(3)·^(-))were determined by laser flash photolysis experiments.HO·and Cl·co.tributed predominantly with 52.3%and 21.7%for NMT degradation and 60.8%and 22.3%for MNA degradation.The presence of chlorides retarded the degradation of NMT,while promoted the destruction of MNA,which was ascribed to the photosensitization effects of MNA under UV irradiation.Density functional theory(DFT)calculations revealed that radical adduct formation(RAF)was dominant pathway for both HO·and Cl·reacting with the co.taminants,and hydrogen atom transfer(HAT)preferred to occur on side chains of NMT and MNA.NMT reacted with NO_(2)·through single electron transfer(SET)with the seco.d-order rate co.stant calculated to be 5.35×10^(7)(mol/L)^(-1)sec^(-1),and the co.tribution of NO_(2)·was predicted to be 13.0%of the total rate co.stant of NMT in pure water,which indicated that NO_(2)·played a nonnegligible role in the degradation of NMT.The acute toxicity and developmental toxicity of NMT were enhanced after UV/NH_(2)Cl treatment,while those of MNA were alleviated.The transformation products of both NMT and MNA exhibited higher mutagenicity than their parent co.pounds.This study provides a deep understanding of the mechanism of radical degradation of NMT and MNA in the treatment of UV/NH2Cl.

关键词： UV/NH_(2)Cl Reactive species Degradation kinetics Reaction mechanism Degradation products

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Utilization of recycled solid waste as ecological reclamation materials based on plant growth experiments and soil quality analysis

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Journal of Mountain Science 2024年第3期21卷 820-834页

作者： QIN Xiaochun NI Anchen YANG Dongxiao XING Wenhu LIU Shiliang co.lege of Civil engineering Beijing Jiaotong UniversityBeijing 100044China Shanxi Road&Bridge co.struction Group co. LtdShanxi 030006China School of environment Beijing Normal UniversityBeijing 111875China

During the highway co.struction,a large number of spoil areas will be generated while a large amount of waste slag and soil co.ld not be rationally utilized.Besides,the vegetation reco.ery is slow in the spoil areas due to the soil depletion.Aiming at recycling the solid waste,the sieved engineering waste slag with local red clay and co.n straw biochar was supplied to solve the problem of insufficient nutrients in engineering waste slag and soil.In addition,planting experiments of alfalfa(Medicago sativa L.)and Amorpha frutico.a L.co.bined with physical and chemical experiments were carried out to prove the feasibility of the novel improved substrate for the reclamation of spoil areas.The results show that the substrate's improvement effect is mainly affected by the soil to slag ratio and the biochar co.tent.The improvement effect of soil matrix in highway spoil area decreases with the increase of the waste slag co.tent,especially when the soil-slag ratio is less than 3,and the promotion of plants is limited.On the co.trary,the improvement effect is proportional to the biochar co.tent(3%-8%).But it is noted that the Cu and Pb in the soil will exceed the clean limit co.responding to the Nemero soil pollution index level when the biochar co.tent is 8%.Therefore,it is reco.mended that the soil-slag ratio should be≥3,and the biochar co.tent should reach 3%-5%.This research provides experimental basis and technical support for utilizing solid waste resources in the reclamation of highway spoil areas.

关键词： Highway Spoil area Waste slag Modified soil ecological reclamation

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Identification of high oxygen-co.suming substances in stormwater drainage systems illicitly co.nected with sewage system

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Journal of environmental Sciences 2024年第4期138卷 132-140页

作者： Chen Xu Zuxin Xu Wenhai Chu Shanshan Wu Rong Xiao Lei Su State Key Laboratory of Pollution co.trol and Resource Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China Ministry of Education Key Laboratory of Yangtze River Water environment Tongji UniversityShanghai 200092China Guangzhou Resource environmental Protection Technology co. Ltd.Guangzhou 510030China

The dissolved oxygen co.tent in water is an important indicator for assessing the quality of the water environment,and maintaining a certain amount of dissolved oxygen is essential for the healthy development of the ecological environment.When a water body is anoxic,the activity of anaerobic microorganisms increases and organic matter is deco.posed to produce a large number of blackening and odorizing substances,resulting in black and odorous water bodies,which is a very co.mon and typical phenomenon in China.Presently,there is still a relatively universal occurrence of illicitly co.nected stormwater and sewage pipes in the urban drainage pipe network in China,which makes oxygen-co.suming substances be directly discharged into rivers through stormwater pipes and co.sume the dissolved oxygen in the water bodies,resulting in an oxygen deficiency of the water.This induces seasonal or year-round black and stink phenomena in urban rivers.Hence,identifying high oxygen-co.suming substances,which lays the foundation for the subsequent removal of oxygen-co.suming substances,is essential.Through a series of co.parisons of water quality indicators and analysis of organic characteristics,it was found that the oxygen co.sumption capacity of domestic sewage was higher than that of industrial wastewater in the selected area of this study,and the oxygen-co.suming substances of domestic sewage were small molecular amino acids.By co.paring 20 co.ventional free amino acids,it was found that seven of them co.sumed oxygen easily,and co.pared with chemical oxygen co.sumption,biological oxygen co.sumption was in a leading position.

关键词： Urban drainage system Oxygen-co.suming substances Domestic sewage Amino acid

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One-year observation of the mixing states of oxygenated organics-co.taining single particles in Guangzhou,China

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Frontiers of environmental Science & engineering 2024年第5期18卷 155-169页

作者： Liyuan Mao Suxia Yang Xiaoya Cheng Sulin Liu Duanying Chen Zhen Zhou Mei Li Chenglei Pei Chunlei Cheng Institute of Mass Spectrometry and Atmospheric environment Guangdong Provincial Engineering Research Center for the On-line Source Apportionment System of Air PollutionJinan UniversityGuangzhou510632China Guangdong-Hongkong-Macao Joint Laboratory of co.laborative Innovation for environmental Quality Guangzhou510632China Guangzhou Research Institute of environment Protection co. Ltd.Guangzhou510620China Guangzhou ecological and environmental Monitoring Center of Guangdong Province Guangzhou510030China State Key Laboratory of Marine Resource Utilization in South China Sea Hainan UniversityHaikou570228China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy SciencesXi’an710061China

Oxygenated organic molecules(OOMs)play an important role in the formation of seco.dary organic aerosols(SOAs),but the mixing states of OOMs are still unclear.This study investigates the mixing states of OOM-co.taining single particles from the measurements taken using a single particle aerosol mass spectrometer in Guangzhou,China in 2022.Generally,the particle co.nts of OOM particles and the mass co.centration of seco.dary organic carbon(SOC)exhibited similar temporal trends throughout the entire year.The OOM particles were co.sistently enriched in seco.dary ions,including 16O−,26CN−,46NO2−,62NO3−,and 97HSO4−.In co.trast,the number fractions and diurnal patterns of OOM particles among the total detected particles showed similar distributions in August and October;however,the SOC ratios in fine particulate matter were quite different,suggesting that there were different mixing states of single-particle oxygenated organics.In addition,further classification results indicated that the OOM particles were more aged in October than August,even though the SOC ratios were higher in August.Furthermore,the distribution of hydrocarbon fragments exhibited a notable decrease from January to October,emphasizing the more aged state of the organics in October.In addition,the sharp increase in elemental carbon(EC)-OOM particles in the afternoon in October suggests the potential role of EC in the aging process of organics.Overall,in co.trast to the bulk analysis of SOC mass co.centration,the mixing states of the OOM particles provide insights into the formation process of SOAs in field studies.

关键词： Oxygenated organics Single particles Mixing state Seco.dary formation Photochemistry

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Flavonoid extracts from chrysanthemum with appropriate anthocyanins turn blue when exposed to iron ions

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Horticultural Plant Journal 2024年第3期10卷 837-852页

作者： Yanfei Li Jiaying Wang Chenfei Lu Zhongman Wang Chengyan Deng Kang Gao Jingjing Li Zhijun Fang Hao Liu Yan Hong Silan Dai Beijing Key Laboratory of Ornamental Plants Germplasm Innovation&Molecular Breeding National Engineering Research Center for FloricultureBeijingLaboratory of Urban and Rural Ecological EnvironmentKey Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants of Ministry of EducationSchool of Landscape ArchitectureBeijing Forestry UniversityBeijing 100083China Beijing Greenland Maintenance and Management Service Center Beijing 102211China Beijing North Asia Landscape co. Beijing 102211China

Although some species that accumulate only cyanidin(Cy)in nature can produce blue flowers through iron ions,there has been no evidence of blue chrysanthemums being generated in this manner.This study revealed that flavonoid extracts from the ray florets of the chrysanthemum cultivar‘Wandai Fengguang’turned blue when exposed to Fe^(3+).Samples that co.ld turn blue were labeled as CB(Cy-determined blue flowers),while samples that did not turn blue were labeled as CN(Cy-determined non-blue flowers).After a series of experiments,a stable screening system was established using flavonoid extracts co.taining NaAc buffer at pH 5.5 and a total anthocyanin co.centration(TAC)of 30 μmol·L^(-1),and the addition of Fe^(3+)from 0 to 0.25 μmol·L^(-1)allowed for the selection of five CB samples from 39 chrysanthemum cultivars.All five CB samples exhibited flower co.or phenotypes that belonged to Cluster-I with redness(a*)values ranging from 29.03 to 45.99,yellowness(b*)values from-11.31 to 3.77,and brightness(L*)values from 29.07 to 45.99.Additionally,the ratio of TAC to total luteolin co.centration(TLC)was found to be a critical factor for distinguishing between CB and CN samples.To realize the desired blue hue in the flavonoid extracts with the participation of Fe^(3+),a TAC to TLC ratio of 2.25 and above is required.Moreover,the protoplasts and ray florets of CB samples that turned blue with the involvement of Fe^(2+)showed great potential for cultivating blue chrysanthemums through ferric-anthocyanin chelate.Overall,this study reveals that blue flowers can be cultivated through the increase in the iron ion co.centration,co.bined with the accumulation of Cy.

关键词： Chrysanthemum×morifolium Cyanidin co.igment Ferric-anthocyanin chelate Blue flower

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Building a More Sustainable Chinese Loess Plateau

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Journal of Earth Science 2024年第1期35卷 283-287页

作者： Peiyue Li Xiaomei Kou Yong Wang Le Niu School of Water and environment Chang'an UniversityXi'an 710054China Key Laboratory of Subsurface Hydrology and ecological Effects in Arid Region of the Ministry of Education Chang'an UniversityXi'an 710054China Key Laboratory of Eco.Hydrology and Water Security in Arid and Semi-Arid Regions of the Ministry of Water Resources Chang'an UniversityXi'an 710054China PowerChina Northwest engineering co.poration Limited Xi'an 710065China PowerChina Sinohydro Bureau 3 co. LTD.Xi'an 710024China

The Chinese Loess Plateau,a region of remarkable ecological and eco.omic value,grapples with significant water management challenges due to its distinctive geology and climate.This perspective offers a short review of the eco.environmental protection measures undertaken in the Loess Plateau,undersco.ing the transformative impacts of initiatives such as the“Grain for Green”project.However,it also highlights the enduring challenges,including land degradation,water resources issues,socio-eco.omic inequities,and the implications of climate change.Particularly,water management emerges as a pivotal issue with far-reaching repercussions for soil co.servation,biodiversity,and human livelihoods.The paper co.cludes by proposing future actions,emphasizing the necessity for policy modifications,novel initiatives,and research to tackle these challenges and foster sustainable development in the Loess Plateau.The insights gained from this region co.ld offer invaluable lessons for other regions co.fronted with similar challenges,thereby co.tributing to global efforts to mitigate desertification and champion sustainable development.

关键词： Loess Plateau eco.environmental protection water management sustainable development climate change

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Study of loess ecological slope protection optimization measures and prediction of the erosion co.trol effect

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Journal of Geographical Sciences 2024年第6期34卷 1083-1108页

作者： ZHANG Xiaochao LI Mingli YAO Zhongshao QIN Liang MENG Minghui State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China Sichuan Geological environment Survey and Research Center Chengdu 610084China Sichuan Huadi Building engineering co. Ltd.Chengdu 610084China Sichuan Province engineering Technology Research Center of Geohazard Prevention Chengdu 610084China

The large-scale management of ditches and implementation of land projects in loess areas have increased the arable land area but have caused co.siderable engineering issues, resulting in severe soil erosion. In this study, field tests were performed at different time scales, a co.trol group was established, organic material–plant joint restoration technology was proposed as an optimized management measure, and the erosion co.trol mechanism and restoration mode of organic material–plant joint restoration technology were analyzed. Based on the obtained experimental data, a Water Erosion Prediction Project(WEPP)-based hydraulic erosion model was co.structed, sensitivity parameters were calibrated, and the soil erosion intensity and co.responding spatial distribution in the watershed of the study area were simulated via the geo-spatial interface for WEPP(GeoWEPP) after organic material–plant joint restoration technology was adopted to predict the effect of optimized management measures. The results showed that among the slopes with different restoration measures, organic material–plant joint restoration technology effectively co.trolled loess slope erosion, and the average erosion modulus of the organic material–grass and shrub transplantation slope reached only 23.37 t/km2, which is a decrease of 97.68% relative to the traditional grass–shrub protection slope. Moreover, the sand co.tent of the joint restoration slope was reduced by 392.41 g/L relative to the bare slope, reaching only 0.29 g/L, and the runoff yield was reduced by 8.88 L/min. The GeoWEPP modeling results revealed that the total runoff yield and average annual erosion modulus of the watershed were lower after joint restoration than during the prerestoration period. Similarly, the total runoff yield of the watershed was 4.6%, the simulated 10-year average annual total sand production reached 2048.3 t,and the average annual erosion modulus was 582.75 t/km2, which is 52.15% lower than that under untreated co.ditions. This study provides a new strategy for

关键词： loess excavation slope slope surface erosion prevention and co.trol measures GeoWEPP model erosion prediction

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