共查询到20条相似文献，搜索用时 406 毫秒
1.
把城市污水净化处理为符合回灌标准的再生水并安全回灌补给地下水, 对于实现污水资源化、含水层恢复、缓解我国水资源供需矛盾和环境污染态势具有重要意义.针对再生水回灌地下水存在的水质安全问题, 通过理论分析、系列实验和技术集成形成了再生水地表回灌补给地下水的水质安全保障体系及关键技术.该安全保障体系包括场地选择与勘查、高效低成本的再生水处理技术、土壤—含水层系统数学模型和回灌方案设计技术、水质监控系统、安全评价技术以及回灌管理法规等.这些要素相互依赖、相互作用, 构成一个完整的体系.郑州郊区示范工程证实了该水质安全保障体系的可行性.2年示范工程表明, 处理的再生水水质达到《城市污水再生利用地下水回灌水质》(GB/T 19772-2005)标准, 优于场地背景地下水水质, 补给含水层后的地下水基本达到《地下水质量标准》(GB/T 14818-1993)Ⅲ类水标准.建议有关政府部门把再生水利用及回灌补给地下水, 纳入水资源开发利用及环境保护规划的整体框架中, 尽快制定或完善再生水回灌补给地下水的相关法律、法规和标准体系, 建立再生水回灌许可证制度, 有序推进再生水回灌工程. 相似文献
2.
A comparative study on nitrogen-concentration dynamics in surface water in a heterogeneous landscape 总被引：7，自引：0，他引：7
Liding Chen Bojie Fu Shurong Zhang Jun Qiu Xudong Guo Fulin Yang 《Environmental Geology》2002,42(4):424-432
With point-source pollution controlled effectively, nonpoint-source pollution, especially that resulting from agricultural land, has become the main factor affecting surface water. Much attention has been focused on the impact of fertilizer and pesticide application, wastewater irrigation, and land management on pollutant transport. However, landscape pattern also plays an important role in pollutant transport and detention. Landscape types may be classified into two parts: "source" and "sink" landscapes, based on their functions in pollutant transport and detention. As a major contributor to eutrophication of waterbodies, nitrogen loss with runoff has received particular attention when studying nonpoint-source pollution. In this study, four watersheds in the upper parts of the Yuqiao Reservoir Basin, Zuihua, Hebei Province, China, were chosen in order to study the relationship between landscape pattern and nitrogen-concentration dynamics. The results indicate that (1) nitrogen concentration in surface water within different seasons in the rainfall-normal year is higher than that in the rainfall-deficit year and (2) the variation of nitrogen concentration within different seasons in the rainfall-deficit year is smaller compared with that in the rainfall-normal year in which two types of seasonal variation on nitrogen concentration are presented. The first variation occurs when nitrogen concentration is lowest in the dry season, and rises rapidly from the dry season to rainy season and then declines quickly from the rainy season to mean-flow season. This mainly occurs in those areas where most "source" landscapes are close to the monitored waterbody. The second variation occurs when nitrogen concentration is low in the dry season, increases rapidly in the rainy season but does not reach its peak value until the mean flow season. The second variation occurs in those areas where "source" landscape types are spread over the whole watershed. There is no clear relationship between watershed shape, relative importance of landscape types, and nitrogen concentration; however, the spatial distribution of "source" and "sink" landscape types in the watershed has a strong impact on the nitrogen concentration in surface water. 相似文献
3.
4.
Correlations between algae and water quality: factors driving eutrophication in Lake Taihu, China 总被引：3，自引：0，他引：3
Y. P. Li C. Y. Tang Z. B. Yu K. Acharya 《International Journal of Environmental Science and Technology》2014,11(1):169-182
Rapid population increase and economic growth in eastern China has lead to the degradation of many water bodies in the region, such as Lake Taihu, the third largest freshwater lake in China. Using data from recent investigations, the correlations between algae (measured as chlorophyll-a) and water quality indices in Lake Taihu were described by multivariate statistical analyses, and the key driving factors for the lake eutrophication were identified by principal component analysis. Results revealed strong spatiotemporal variation in the correlations between algae and water quality indices, suggesting that the limiting factor for the dominant algae growth depends on seasonality and location and it is necessary to reduce both nitrogen and phosphorus inputs for a long-term eutrophication control in this hyper-eutrophic system. Water temperature was another important controlling factor for algal growth in the lake. Using principal component analysis, nutrient contaminations from anthropogenic and natural inputs were identified as the key driving factor for the water quality problems of the lake. Moreover, five principal components were extracted and characterized with high spatial and seasonal variations in Lake Taihu. The key driving factors were believed to influence spatial variations including heavily polluted areas located in the northern and northwestern parts of the lake, where many manufacturing factories were built and wastewater from domestic and industrial plants was discharged. Based on this analysis, attention should be paid to effective land management, industrial wastewater treatment, and macrophytic vegetation restoration to reduce the pollutant loads and improve water quality. Principal component analysis was found to be a useful and effective method to reduce the number of analytical parameters without notably impairing the quality of information in this study. 相似文献
5.
Artificial groundwater recharge to a semi-arid basin: case study of Mujib aquifer,Jordan 总被引：1，自引：1，他引：0
Mujib watershed is an important groundwater basin which is considered a major source for drinking and irrigation water in
Jordan. Increased dependence on groundwater needs improved aquifer management with respect to understanding deeply recharge
and discharge issues, planning rates withdrawal, and facing water quality problems arising from industrial and agricultural
contamination. The efficient management of this source depends on reliable estimates of the recharge to groundwater and is
needed in order to protect Mujib basin from depletion. Artificial groundwater recharge was investigated in this study as one
of the important options to face water scarcity and to improve groundwater storage in the aquifer. A groundwater model based
on the MODFLOW program, calibrated under both steady- and unsteady-state conditions, was used to investigate different groundwater
management scenarios that aim at protecting the Mujib basin. The scenarios include variations of abstraction levels combined
with different artificial groundwater recharge quantities. The possibilities of artificial groundwater recharge from existing
and proposed dams as well as reclaimed municipal wastewater were investigated. Artificial recharge options considered in this
study are mainly through injecting water directly to the aquifer and through infiltration from reservoir. Three scenarios
were performed to predict the aquifer system response under different artificial recharge options (low, moderate, and high)
which then compared with no action (recharge) scenario. The best scenario that provides a good recovery for the groundwater
table and that can be feasible is founded to be by reducing current abstraction rates by 20% and implementing the moderate
artificial recharge rates of 26 million(M)m3/year. The model constructed in this study helps decision makers and planners in selecting optimum management schemes suitable
for such arid and semi-arid regions. 相似文献
6.
沿海海—气界面的化学物质交换 总被引：18，自引：1，他引：18
沿海海－气界面化学物质的交换对生物地球化学循环起着十分重要的作用。大气沉降过程是化学物质进入沿海区域的重要途径之一。物质平衡估算的结果指出，在某些沿海区域，经由大气输入的若干痕量物质的总量几乎相当于河流的输入量，有的甚至更多。大气沉降作用是一些沿海区域氮化物的重要来源，并与富营养化有紧密关系。 相似文献
7.
Rituparna Bose Arnab De Subho Mozumdar Goutam Sen Ananda Deb Mukherjee 《Geochemistry International》2012,50(10):860-868
A thorough comprehension of relevant environmental parameters is a prerequisite to preventing coastal degradation and environmental balance in coastal zones. In this study, we correlate major physicochemical of two coastal rivers (Matla and Saptamukhi) in the Sunderban district, West Bengal. The parameters namely: pH, salinity, dissolved oxygen, suspended solids, nitrogen and phosphorus concentrations (inorganic and total) of these two rivers were studied in detail over the 90s decade. We hypothesized that both natural and anthropogenic activities during that time have contributed to the pollution and employed the above parameters to test our hypothesis. Our results reveal that the quality of waters in the rivers have been showed to be dependent on flood impacts, storm surge, eutrophication, domestic sewage, agricultural and industrial wastes. Thus, both natural and anthropogenic causes are the behind coastal pollution of river waters. We conclude that they have all contributed to pollution of these rivers in various ways and we calculate the differential effects of these parameters on coastal pollution. 相似文献
8.
Rowin J. van Lanen Menne C. Kosian Bert J. Groenewoudt Esther Jansma 《Geoarchaeology》2015,30(3):200-222
This study focuses on reconstructing landscape prerequisites for Roman and early‐medieval routes in the Netherlands. We applied spatial modeling to modern and paleogeographical landscape data in order to determine geographical obstacles for possible translocation in ca. A.D. 100 and 800 via land and water. Network‐friction values were calculated to produce a spatial model of possible movement corridors and to enable the integration of archaeological data. Results show that in geographically dynamic lowland regions such as the current Netherlands, landscape units such as water, peat, and levees must have had a high impact on route orientation. The lower parts of the western Netherlands were almost inaccessible by land, implying that its inhabitants largely must have depended on rivers and streams for transportation. In Dutch coastal and river areas, the landscape changed drastically between A.D. 100 and 800, the largest changes occurring along the coast. 相似文献
9.
根据2004年4个季度2、5、8、11月的调查资料,选择化学耗氧量、溶解氧、活性磷酸盐、溶解无机氮和叶绿素a作为评价因子,利用人工神经网络模型对长江口及其邻近海域的营养水平进行评价。结果表明,富营养化区域主要集中在口门附近,富营养化程度由口门向东和东北方向递减。富营养化范围几乎均分布在盐度小于20的一侧,并随着长江冲淡水的变化而发生季节性的变化。5月和8月的富营养化比较严重,且都有转向东北的趋势,可能与5月进入丰水期长江冲淡水转向有关。断面分布表明,各个季度月由河口向东,富营养化评价等级由高到低,垂直方向则呈现复杂的变化。分析表明影响富营养化的主要评价指标是溶解无机氮。 相似文献
10.
R. H. Meade N. N. Bobrovitskaya V. I. Babkin 《International Journal of Earth Sciences》2000,89(3):461-469
Of the world's great rivers, the Ob and Yenisey rank among the largest suppliers of fresh water and among the smallest suppliers of suspended sediment to the coastal ocean. Sediment in the middle reaches of the rivers is mobilized from bordering terraces and exchanged between channels and flood plains. Sediment in the lower reaches of these great rivers is deposited and stored (permanently, on a millennial time scale) in flood plains. Sediment discharges, already small under natural conditions, are diminished further by large manmade reservoirs that trap significant proportions of the moving solids. The long winter freeze and sudden spring breakup impose a peakedness in seasonal water runoff and sediment discharge that contrasts markedly with that in rivers of the tropics and more temperate climates. Very little sediment from the Ob and Yenisey rivers is being transported to the open waters of the Arctic Ocean under present conditions. 相似文献
11.
Francisco J. Flores-Verdugo John W. Day Laurence Mee Raquel Briseño-Dueñas 《Estuaries and Coasts》1988,11(1):51-56
Plankton metabolism andRuppia maritima biomass were measured seasonally during 1982–83 in El Verde Lagoon, a small coastal lagoon with an ephemeral inlet on the Pacific Coast of Mexico. Total net aquatic primary production was 521 g C m?2 y?1. The water column was slightly heterotrophic, with an annual P/R ratio of 0.89. Our analysis indicates that tropical and subtropical coastal lagoons with restricted or seasonal inlets have generally higher net aquatic primary productivity levels than lagoons with permanently open inlets. We hypothesize that this is due to retention of nutrients and plankton stocks during the dry season. The seasonal pattern of water column metabolism was related to rainfall and riverflow, with higher values generally occurring during the wet season. Net production and respiration were about three times lower during the 1982 dry season as compared to the 1983 dry season which received considerable rains due to abnormal climatic conditions. The biomass ofR. maritima ranged from zero to 620 g dry wt m?2. Growth occurred only during the dry season and there were two distinct biomass peaks representing two separate crops. The second crop was heavily epiphytized with nitrogen-fixing algae. There was an apparent succession in dominance of water column productivity over the year, withRuppia dominating during the dry season and phytoplankton more important during the wet season. 相似文献
12.
Impact of reservoir impoundment-caused groundwater level changes on regional slope stability: a case study in the Loess Plateau of Western China 总被引：3，自引：1，他引：2
This paper reports the results of the in situ application of diffusive gradients in thin-films (DGT) passive samplers for
trace metals (Cd, Co, Cr, Cu, Ni, Pb and Zn) monitoring in transboundary Udy and Lopan rivers of the Seversky Donets watershed
in the Kharkiv region (Ukraine), which has a long history of industrial development. The research discusses potential sources
of DGT-measured labile metals in water and seasonal variations. Our results demonstrate the application of DGT for identifying
and measuring labile metal concentrations in contrasted climate conditions (cold snowy winter and hot summer) and appropriateness
of such a tool for continuous water monitoring with the presence of an ice cover. Results show that DGT-measured concentrations
of most of trace metals were much higher downstream of the wastewater treatment plants discharges than upstream; thus wastewater
treatment plants seemed not able to reduce or to remove trace metals’ contaminations and become major sources of pollutants
in the studied rivers. The calculation of the average metal fluxes based on the DGT-measured concentrations confirmed that
the urban wastewater discharges significantly contribute to the metal fluxes into the Udy and the Lopan rivers during both
low-flow and high-flow periods. Compared to the wastewaters inputs to the rivers, the transboundary effect is limited, but
should be taken into account as the origin of some metals is from sources located on the adjacent Russian territory. 相似文献
13.
基于潮白河流域再生水的场地回灌,为提高抗生素甲氧苄氨嘧啶（TMP）的去除率,降低其进入地下水的风险,选用价格低廉对TMP有高效去除性能的黏土陶粒作为吸附剂,构建去除TMP的人工复合土柱。吸附实验研究结果显示黏土陶粒对TMP吸附容量达到151.824 μg/g,具有去除再生水中TMP能力;TMP在黏土陶粒解吸过程中存在解吸滞后性的现象。柱实验研究结果表明此人工复合土柱能够有效地去除再生水中TMP,去除率高于95%,其去除机制主要是吸附与生物降解协同作用。本研究建立的人工复合土层系统能有效地去除再生水中TMP,对实际场地回灌工程具有指导性作用。 相似文献
14.
Sustaining the human ecological benefits of surface water requires carefully planned strategies for reducing the cumulative
risks posed by diverse human activities. Municipal governments in Aksaray City play a key role in developing solutions to
surface water management and protection problems. The responsibility to provide drinking water and sewage works, regulate
the use of private land, and protect public health provides the mandate and authority to take action. A large part of Aksaray
City uses Mamasın dam water as its primary source for drinking water. Several point sources of contamination may result from
direct wastewater discharges from Melendiz and Karasu rivers, which recharge the Mamasın dam watershed. Relevant studies were
carried out for monitoring the eutrophication process, which usually occurs in the static water mass of the Mamasın dam lake.
This process may be caused by the continual increase in nutrients and decrease of O2 levels, causing anaerobic conditions. Stimulated algae growth in these water bodies consequently reduces water quality. Hydrochemical
parameters were evaluated to estimate the types of pollution sources, the level of pollution, and its environmental impacts
on the Mamasın dam drinking water reservoir. 相似文献
15.
Liang Mingchao Wang Tianzhi Li Yunkai Yang Peiling Liu Chengcheng Li Pengxiang Zhao Wei 《Environmental Earth Sciences》2013,70(5):2319-2333
Reusing reclaimed wastewater from lakes has become one of the most effective measures to relieve the urban ecological crisis. However, reclaimed wastewater still contains large amounts of nutrient salts, trace organic pollutants, suspended solid particles and microorganisms, which may significantly affect the aquatic ecosystems. The health of aquatic ecosystems can be directly and effectively monitored by evaluating the biofilms in them, because the structures of biofilms are directly affected by multiple environmental factors. Therefore, it is important to study the structures of biofilms attached on multiple medium surfaces in river-lake systems that contain reclaimed wastewater. In this study, the paper applied scanning electron microscope (SEM) technology and fractal theory to quantitatively describe the structural characteristics of biofilms attached on the medium surfaces of aquatic plants and gravels in the Lianshi Lake of Beijing Yongding River and other two kinds of reclaimed water of the river-lakes, whose sewage treatment processes were the combined process of deposit and sand filtration and UF membrane filtration, plus anaerobic-anoxic-oxic process, respectively. The paper found that these two types of biofilms were typical porous media and their basic skeletons were mainly composed of inorganic particles, microorganisms, and algae. Furthermore, most areas between the particles were filled with extracellular polymers (EPS) secreted by bacteria. At the same time, these biofilms showed obvious fractal and multifractal characteristics, but the fractal dimensions alone failed to effectively describe the complexity of biofilm structures. The multifractal spectra were able to quantitatively characterize the biofilms’ heterogeneity. In addition, the number of microorganism species, the quantity and the heterogeneity of aquatic plants’ surface biofilms were all higher than those of gravel surface biofilms, most likely due to the effects of light. In addition, the heterogeneity of biofilms in reclaimed water treated by the combined process of deposit and sand filtration and UF membrane filtration plus anaerobic-anoxic-oxic process was higher than that of biofilms in reclaimed water treated by traditionally activated sludge process (Lianshi Lake’s water). Besides, the non-uniformity of biofilms in reclaimed water treated by combined process of deposit and sand filtration was higher than that of biofilms in reclaimed water treated by UF membrane filtration plus anaerobic-anoxic-oxic process. 相似文献
16.
17.
Hassen Ouelhazi Fethi Lachaal Abdelkrim Charef Bilel Challouf Habib Chaieb Faten Jarraya Horriche 《Arabian Journal of Geosciences》2014,7(10):4407-4421
Korba aquifer is one of the most typical examples of overexploited coastal aquifer in the Mediterranean countries. In fact, from 1985, a considerable piezometric level drop, water salinization, and seawater intrusion were registered in the aquifer. In December 2008, Tunisian authorities initiated a general plan to groundwater management in order to augment groundwater resources, restore the piezometric levels, and improve water quality. The plan consists of artificial recharge of groundwater used treated wastewater through three infiltration basins. During the first 4 years (from December 2008 to December 2012), 1.41 Mm3 of treated wastewater was injected to the Korba aquifer. This study presents a hydrogeological assessment of groundwater evolution during the recharge processes. In this study, 32 piezometric and chemical surveys of 70 piezometers and observed wells are used to present hydrogeological investigation and water quality evolution of wastewater reuse through artificial recharge in Korba coastal aquifer. The piezometric evolution maps are used to specify the positive effect in groundwater level that exceeding 1.5 m in some regions. The interpretation of salinity evolution maps are used to indicate the improving of groundwater quality. 相似文献
18.
湖泊是地球关键带的重要组成部分,是水循环、物质循环和能量循环的重要环节。为了解我国湖泊分布现状,依托中国地质调查局“生态地质调查工程”及其所属二级项目“全国地球关键带遥感地质调查”,利用Landsat8 OLI 等卫星影像数据,通过遥感解译等技术方法,识别了2018年我国境内(不包括香港、澳门与台湾地区)面积大于1.0 km2的湖泊2 780个,总面积78 727.9 km2; 研究统计并分析了我国各省/自治区、五大湖区、主要流域的湖泊数量、面积和分布特征; 针对典型区域的湖泊存在的生态问题进行分析,提出相关湖泊生态保护修复的相关建议。其中,北方农牧交错带湖泊大量萎缩干涸,主因是农业和畜牧业的发展,地下水超采严重,应着力减少地下水开采; 黄河流域人工湖建设存在无序发展、过度追求景观水面扩张等问题,应遵从水循环与水平衡自然规律,针对全流域水资源配置进行调控; 长江源区湖泊水面整体处于扩张状态,应以自然因素为主、人类活动干扰触发为辅,加强冻土变化过程以及主要河流的水生态、水环境监测,综合提高源区整体监测水平。研究成果为后续湖泊生态保护修复研究工作提供了参考。 相似文献
19.
Based on the characteristics of land use and drainage network of the upper watershed of the Miyun Res-ervoir, Beijing, 26 monitoring and sampling sites were selected in different sub-catchments. Temporal and spatial variations in nutrient loss were dealt with in this paper in terms of the monitoring data on the water quality of the main tributaries flowing into the Miyun Reservoir. In combination with the monitoring data on water quality, the impacts of watershed characteristics including land-use type, landscape pattern, and drainage density were assessed, The concentrations of nutrients in the rainy season are higher than those in other seasons, and the concentrations of NO3--N are linearly related to those of total N which is the main form of nitrogen present in the fiver water. The concentrations of nitrogen become higher toward the reservoir along the main rivers. The seasonal variation of ni-trogen in the watershed affected by intensive human activities is very obvious; in the watershed with steady or low water flow, the seasonal variation of nitrogen is less obvious. Forest land and grassland can trap and filter nitrogen effectively. Land-use pattern also has important impacts on the loss of nitrogen. The concentrations of nitrogen and phosphorus in the water bodies show great temporal and spatial variations. On a temporal scale, the concentrations of TN and TP in the rainy reason are higher than those in other seasons. On a spatial scale, the concentrations of TN and NO3--N in the Qingshui River and Chaohe River are highest all the time. The spatial variation of TP is distinct, being obvious at sampling sites near villages. The form of nitrogen and phosphorus loss varies in different hydrological seasons. Dissolved nitrogen and phosphorus are the main forms in streams in non-rainy seasons, the dissolved nitro-gen and total nitrogen decrease in percentage in the rainy season. Particulate nitrogen and phosphorus are the main forms in some rivers. The concentrations of TN and NO3--N from orchards and villages are high whereas those from forest land are lowest. Land-use pattern has impacts on TN and NO3--N losses, at the sampling sites near the source landscape, the concentrations are higher than those at the sampling sites near the sink landscape. Water quality of the rivers which flow into the Miyuan Reservior is influenced by the composition of adjacent soils. 相似文献