The Water Quality Of The CÉrtima River Basin (Central Portugal)

The aim of this study was to evaluate the water quality of the Cértima River basin (Central Portugal). For that purpose, surface water samples were collected in March, May and July 2003, at 10 selected sampling sites, and were analysed for physicochemical parameters, namely temperature, conductivity, pH, total suspended solids, dissolved oxygen, biochemical oxygen demand (BOD₅), Kjeldahl nitrogen and total phosphorus. Results revealed an acceptable water quality during the spring season. Maxima of 64 mg dm⁻³ for BOD₅, 39 mg dm⁻³ for Kjeldahl nitrogen, and 5.2 mg dm⁻³ for total phosphorus, were recorded during summer, indicating a significant degradation of the water quality in a river stretch located downstream of the town of Mealhada. These values, which did not comply with the objectives of minimum quality for surface waters prescribed by the Portuguese legislation, were related to domestic wastewater discharges and runoff waters from a cattle farm. Besides their effects on the middle stretch of the river, these pollution sources were the most likely cause of the high nutrient load in downstream waters, and thus may have a major impact on the trophic status of Pateira de Fermentelos, a sensitive wetland area located in the lower Cértima basin.     

Use of Stable Nitrogen Isotopes and Permeable Membrane Devices to Study what Factors Influence Freshwater Mollusk Survival in the Conasauaga River

Recent biological inventory data shows severe declines in freshwater mussel abundance and biodiversity in the Conasauga River Basin in Northwest Georgia, USA. Based on assessments of habitat conditions, mussel populations should be sustainable. We conducted a study of sediment and water quality to evaluate the impact of anthropogenic contamination on mussel populations. Permeable membrane devices (PMD), polar organic chemical integrative samplers (POCIS™), conventional water and sediment quality analyses, and stable nitrogen isotope ratio analyses (δ¹⁵N) of snails and sediments were used to assess sediment and water quality at target sites throughout the basin. Ambient concentrations of organic contaminants in water were well below any aquatic life criteria; concentrations of some nutrients were detected above aquatic life criteria levels. Most mussel species in the river are endangered or threatened; therefore, snails were collected for δ¹⁵N analyses. Mean δ¹⁵N values for snails collected at forested upper watershed sites (national forest areas) were significantly lower than δ¹⁵N values from snails in agricultural areas. δ¹⁵N values for raw cow manure and manure-treated soil were similar to δ¹⁵N values for snails collected in agricultural areas. Dissolved nitrate from water samples had elevated δ¹⁵N values similar to the upper range of δ¹⁵N values for snails in agricultural areas. Data, particularly stable nitrogen isotope data, indicates that a land use change from national forest land to agriculture alters nitrogen sources to the basin and snails. Implications of nutrient release on freshwater molluscan reproduction, growth, and survival are discussed.     

浑太河流域水质达标控制方法研究

结合浑太河流域水资源网络节点图,根据污染物来源、种类及其产生机理,针对计算单元水资源供需平衡预测数据、降雨径流值,分点源、非点源进行规划水平年污染物入河量的预测。根据浑太河流域地形特征、入河污染物降解特性,以水功能区水体纳污能力为计算单元污染物排放总量控制条件,给出基于规划水平年入河污染物变动特性的水质达标控制方法。运用该方法进行浑太河流域水质达标控制:2030年,流域总需水7.4亿立方米,缺水深度在1%以下,COD、NH3-N、TP、TN的入河量分别为28.5×104、2.8×104、3.1×104、4.6×104t,对应的入河控制量分别为9.3×104、0.6×104、0.8×104、0.9×104t,经控制后水功能区目标水质达标率100%。证实了该水质达标控制方法有效、可行。     

Effects of land use types on surface water quality across an anthropogenic disturbance gradient in the upper reach of the Hun River, Northeast China

Surface water quality is vulnerable to pollution due to human activities. The upper reach of the Hun River is an important water source that supplies 52 % of the storage capacity of the Dahuofang Reservoir, the largest reservoir for drinking water in Northeast China, which is suffering from various human-induced changes in land use, including deforestation, reclamation/farming, urbanization and mine exploitation. To investigate the impacts of land use types on surface water quality across an anthropogenic disturbance gradient at a local scale, 11 physicochemical parameters (pH, dissolved oxygen [DO], turbidity, oxygen redox potential, conductivity, biochemical oxygen demand [BOD₅], chemical oxygen demand [COD], total nitrogen [TN], total phosphorus [TP], NO ₃ ^? -N, and NH ₄ ⁺ -N) of water from 12 sampling sites along the upper reach of the Hun River were monitored monthly during 2009–2010. The sampling sites were classified into four groups (natural, near-natural, more disturbed, and seriously disturbed). The water quality exhibited distinct spatial and temporal characteristics; conductivity, TN, and NO ₃ ^? -N were identified as key parameters indicating the water quality variance. The forest and farmland cover types played significant roles in determining the surface water quality during the low-flow, high-flow, and mean-flow periods based on the results of a stepwise linear regression. These results may provide incentive for the local government to consider sustainable land use practices for water conservation.     

闽江入海断面溶解无机氮长时间序列分析及入海通量估算

为深入研究闽江口富营养化机制,于1985—2021年在闽江入海断面开展了水质监测。采用结合局部加权回归散点平滑法(LOWESS)的季节性肯达尔检验(SK检验)对断面溶解无机氮(DIN)及其各组分浓度变化趋势进行分析,同时结合水文资料对入海通量进行估算。结果表明:DIN浓度范围为0.728~3.140 mg/L,在37年间整体呈上升趋势,但不显著。各组分中NO₂-N和NH₃-N浓度分别呈显著和极显著下降趋势,而NO₃-N浓度呈极显著上升趋势。DIN组分中NO₂-N和NH₃-N比重不断减小,而NO₃-N比重不断增大,目前已成为DIN的主要组成部分。DIN入海通量范围为3.59×10⁴~14.85×10⁴ t,在37年间缓慢增加,其各组分入海通量长期变化趋势同浓度变化类似。从长期来看,DIN及其各组分浓度的变化趋势主要受流域环境变化及下游福州市含氮废水排放影响,而在短期则受台风、降水等一些突发环境事件的影响较大。     

2001-2015年松花江流域水污染变化特征研究

利用2001-2015年松花江流域国家监测网30个可比断面监测数据,从流域和断面水质变化、各项指标超标情况和浓度变化、污染负荷等方面分析了松花江流域水质变化情况。结果表明,松花江流域水质总体呈好转趋势,特别是2007年以来有比较明显的改善。该流域长期以来主要污染指标为高锰酸盐指数、石油类、五日生化需氧量和氨氮。高锰酸盐指数、石油类和五日生化需氧量污染均有明显改善,但氨氮污染改善不明显。在继续加强COD排放总量控制的基础上,有效削减氨氮排放是促进松花江水质改善的重点。     

Assessment of water pollution in the Antuã River basin (Northwestern Portugal)

The Antuã River, located in northwestern Portugal, drains a region with a high population density and a strong economic dynamism. These factors, together with a lack of facilities for appropriate treatment of domestic and industrial sewage, are putting increasing pressure on water resources. In this context, the aim of the present study was to identify point sources of pollution and to assess the surface water quality in the Antuã basin by monitoring physicochemical variables. A total of 40 point sources of wastewater, including some with a high pollution load, were detected in the most populated and industrialized areas of the São João da Madeira and Oliveira de Azeméis municipalities. These sources explained the strong degradation of water quality observed in the upper and medium Antuã River and in one of its tributaries, where maxima of 49 mg l^?1 for biochemical oxygen demand, 29 mg l^?1 for Kjeldahl nitrogen and 3.7 mg l^?1 for total phosphorus, were found after five surface water monitoring campaigns. Despite the relevance of pollution problems, a considerable water quality improvement, promoted by favourable reaeration conditions, was observed in the final stretch of the river, giving evidence of a great self-depuration capacity. However, the Antuã is a significant contributor of nutrients to the Ria de Aveiro, the coastal lagoon where the river meets the Atlantic Ocean.     

Assessment of anthropogenic influences on surface water quality in urban estuary, northern New Jersey: multivariate approach

Concentrations of selected heavy metals (Cd, Cr, Cu, Pb, Ni, Fe, and Zn), nutrients (NO ₃ ^? and NH₃), fecal coliform colonies, and other multiple physical–chemical parameters were measured seasonally from 12 locations in an urban New Jersey estuary between 1994 and 2008. Stepwise regression, principal component analysis, and cluster analysis were used to group water quality results and sampling locations, as well as to assess these data’s relationship to sewage treatment effluents and the distance to the mouth of the river. The BOD₅, NH₃, NO ₃ ^? and fecal coliform counts clustered as one group and positively correlated to the distances from treated effluent and the measures of magnitude at the discharge points. Dissolved solids and most metal species scored high along a single principal component axes and were significantly correlated with the proximity to the industrialized area. From these data, one can conclude that the effluent discharge has been a main source of anthropogenic input to the Hackensack River over the past 15 years. Therefore, the greatest improvement to water quality would come from eliminating the few remaining combined sewer overflows and improving the removal of nutrients from treated effluents before they are discharged into the creeks and river.     

Environmental assessment of water-courses of the Turvo Limpo River basin at the Minas Gerais State, Brazil

A study was performed to evaluate the environmental contamination in the Turvo Limpo River basin which receives effluent discharges from domestic (residential and commercial) activities. The watercourses examined were the São Bartolomeu Stream, Turvo Sujo River, and Turvo Limpo River, located in the Minas Gerais State, Brazil. Water samples were collected at the river-side and analyzed for evaluation of pollutant inputs. The pH, temperature, electrical conductivity, redox potential (Eh), dissolved oxygen (DO), total and settleable solids, visual color, hardness, chemical oxygen demand (COD), biochemical oxygen demand (BOD), chloride, total phosphate, total nitrogen, ammonia nitrogen, nitrate, total coliforms and E. coli, as well as the Cd, Pb, Cu, and Zn speciation were determined in the watercourses. The data obtained were compared with those of the Brazilian Environmental Standards and with data from non-contaminated areas. River water characteristics in some sites were far from the limit values established for superficial waters with satisfactory quality. For instance, the BOD values reached 411 mg L^?1 for a maximum limit of 10.0 mg L^?1, while the ammonia nitrogen concentration reached 28 mg L^?1 for a maximum limit of 13.3 mg L^?1. Some sites showed E. coli values above those of non-contaminated regions. Besides the effects of sewage discharges into the water-courses, agriculture activities and the use of the area for cattle husbandry influenced the quality of the river waters, for instance, the pH of a spring-water sample reached the value of 4.3. The São Bartolomeu Stream has been contributing to the deterioration of the water quality of the Turvo Sujo River, while the Turvo Limpo River has also been affected by anthropogenic discharges in the Turvo Sujo River. The speciation of Cd, Cu and Pb showed that these metals were mainly found in the particulate fraction (i. e., associated with the suspended material). Fifty five percent of the water samples showed labile Zn concentrations greater than that of the nonlabile Zn.     

黄河流域甘肃段面源污染估算与空间分析

采用遥感分布式面源污染评估模型（DPeRS）,对2018年黄河流域(甘肃段)面源污染空间分布特征进行分析,具体包括多类型污染量产排特征解析和流域优先管控单元识别。结果表明,污染量上,2018年黄河流域（甘肃段）总氮(TN)、总磷(TP)、氨氮(NH₃^-N)、化学需氧量(COD_Cr)的面源污染排放负荷分别为65.6,11.8,19.1和77.2 kg/km²,入河量分别为836.7,33.3,220.2和1 353.3 t;空间分布上,氮型(TN和NH₃^-N)排放负荷高值区主要分布在流域中部和东部局部地区,流域大部分地区TP排放负荷均较高,COD_Cr面源污染排放负荷高值区分布较为零散。与排放负荷相比,黄河流域（甘肃段）面源污染入河负荷并不突出,这与该地区水资源量少有密切关系。筛选出黄河流域（甘肃段）面源污染优先控制单元15个,面积占比为85.2%,I类优控单元主要分布在庆阳市、天水市、兰州市和白银市等地区,II类优控单元主要分布在甘南藏族自治州,且TN、TP、NH₃^-N和COD_Cr面源污染优控单元识别结果的平均精度达到80%。     

成都府南河叶绿素a和氮、磷的分布特征与富营养化研究

通过对成都市府南河上中下游共21个断面叶绿素a和总溶解态氮(TDN)、总溶解态磷(TDP)含量的测定,绘制时空分布图,并应用SPSS 13.0统计软件分析了3个指标之间的相关性,初步评价了府南河的富营养化状况。结果表明,府南河叶绿素a含量不高,磷污染较为严重;相关性分析显示叶绿素a和TDP含量呈显著正相关关系,氮是河水富营养化的主要限制因子;按照叶绿素a的含量判定府南河基本属于贫营养化型,但按照氮、磷含量评价已达到富营养化水平。这对评价城市河流的富营养化状态及生态环境整治和恢复有着积极意义。     

松花江流域水生态环境中生物与生境和化学要素间的关联 性研究

利用2012年松花江流域生物、生境和水质的调查数据,采用生物完整性指数(IBI)评价松花江流域的水生态环境质量,并着重对IBI评价结果与生境质量、水质间的关系及生物与生境和化学参数间的相关关系进行了分析。结果表明,松花江流域IBI评价结果与其生境质量存在显著正相关,与水质评价结果基本一致。生境质量及大多数生境参数均与多项生物参数间存在显著/极显著的相关关系;其次,COD、CODMn、BOD5、TN、TP等超标化学因子也与多项生物参数存在显著/极显著的相关关系,说明生境受损和有机污染压力是引起松花江流域水生态环境质量变化的主要压力。为恢复和改善松花江流域的水生态质量,研究建议针对流域生境质量和超标化学污染开展相应的保护和控制措施。     

Chemical water quality gradients in the Mongolian sub-catchments of the Selenga River basin

Even though the Selenga is the main tributary to Lake Baikal in Russia, the largest part of the Selenga River basin is located in Mongolia. It covers a region that is highly diverse, ranging from almost virgin mountain zones to densely urbanized areas and mining zones. These contrasts have a strong impact on rivers and their ecosystems. Based on two sampling campaigns (summer 2014, spring 2015), we investigated the longitudinal water quality pattern along the Selenga and its tributaries in Mongolia. While headwater regions typically had a very good water quality status, wastewater from urban areas and impacts from mining were found to be main pollution sources in the tributaries. The highest nutrient concentrations in the catchment were found in Tuul River, and severely elevated concentrations of trace elements (As, Cd, Cu, Cr, Fe, Mn, Ni, Pb, Zn), nutrients (NH₄ ⁺, NO₂ ^?, NO₃ ^?, PO₄ ^3?), and selected major ions (SO₄ ^2?) were found in main tributaries of Selenga River. Moreover, trace element concentrations during spring 2015 (a time when many mines had not yet started operation) were markedly lower than in summer 2014, indicating that the additional metal loads measured in summer 2014 were related to mining activities. Nevertheless, all taken water samples in 2014 and 2015 from the main channel of the Mongolian Selenga River complied with the Mongolian standard (MNS 1998) for the investigated parameters.     

Water quality in Minho/Miño River (Portugal/Spain)

Minho River, also called Miño (in Spain), extends to about 300 km from Spain to Portugal. The source of the river lies in Spain and in the last 75 km, the river defines the border between Portugal and Spain. Under the scope of a cooperation project between North Portugal and Galicia region of Spain, titled: “Valorization of the natural resources of the Minho/Miño drainage basin”, seven water-sampling campaigns were carried out during the last 2 years in Minho River basin. Seven sampling sites were selected along the international stretch, and five were chosen in the main Portuguese and Spanish tributaries of Minho River. Water quality based on the physicochemical and microbial parameters was assessed. According to the Portuguese legislation for surface waters, the international section of Minho River presents a reasonably good water quality (BOD₅ <5 mg/L, TNK <2 mg/L, and total phosphorous <1 mg P/L). Valença and Louro were found to be the most polluted sampling sites and Louro the most polluted tributary (maximum values observed: TSS?=?26 mg/L, BOD₅?=?6.6 mg O₂/L, COD?=?20.8 mg O₂/L, total nitrogen?=?9.9 mg N/L; minimum value observed: OD?=?1.3 mg O₂/L). A one-dimensional stream water quality model QUAL2Kw was calibrated using data measured in field surveys along the international stretch of Minho River. QUAL2Kw was also used to predict the impact of flow conditions, discharges, and tributaries on the water quality of international stretch of Minho River, essential to establish proposals for management and planning of Minho River Basin.     

高纬区阿什河面源氮和磷污染输出特征

基于阿什河2008—2010年水质监测和流量监测结果,利用改进的埃特金和相关性拟合插值法,补全监测条件限制造成的缺失数据,再利用基流分割法,估算阿什河面源氮和磷污染输出量,分析其污染特征。结果显示:阿什河进入松花江的污染负荷峰值一般出现在3—5月或者7—9月,主要由春汛或夏汛造成,峰值出现时污染来源以面源污染为主。2008—2010年阿什河面源污染输出量表现出TP减少,TN和NH_4~+-N增加的趋势。阿什河年均输出量TN约为5 436.6 t,NH_4~+-N约为3 057.8 t,TP约为554.8 t,其中,点源污染为2 775.8、1 440.7、250.8 t,面源污染为2 660.7、1 630.7、304.1 t,面源污染占总量的50%左右。     

Metal and nutrient dynamics in a eutrophic coastal lagoon (Óbidos, Portugal): the importance of observations at different time scales

Water and sediment quality was monitored at four sites of Óbidos coastal lagoon (Portugal) in February, May, July and October 2006, covering different hydrological conditions. Concentrations of nutrients and metals increased in autumn/winter, particularly in an inner branch with symptoms of eutrophication that receives a small tributary contaminated by agro-industrial activities. Moreover, concentrations of PO₄ ^3?, Si(OH)₄ and Mn (diffusive gradients of thin films (DGT)-measured) varied inversely with salinity. Additionally, that branch was monitored over 26-h in July 2006 to assess variations of water quality parameters, nutrients and metals on short timescale. During the night, O₂ in water reached a minimum of 40% saturation followed by a pronounced increase of DGT-measured metals and nutrients in water column: Fe and Mn (ten times); Cr, Co, PO₄ ^3? and Si(OH)₄ (six times). Enhancements were also registered for metal/Al ratios in suspended particulate matter: Mn, Cr and Cd (four to six times); Fe, Ni and Co (1.5 times). The metal distribution coefficients calculated along the 26-h survey showed a maximum at daylight suggesting a preferential association of metals with suspended particles. Data recorded under different hydrological conditions and over the 26-h survey allowed to address the influence of external and internal sources on water quality. The results of this study highlight the importance of day/night cycles on the availability of nutrients and metals in eutrophic environments.     

Modelling nutrient loads to Sydney estuary (Australia)

Sydney estuary (Australia) catchment is substantially urbanised (80%) and small (480 km²) with a large population (2.5 million) and is therefore highly sensitive to anthropogenic influence. The Model for Urban Stormwater Improvement Conceptualisation used to model nutrient export to the estuary determined an average annual load of 475 t total nitrogen, 63.5 t total phosphorus and 343,000 t total suspended solids. Model verification included intense, short-term water sampling and analysis undertaken in the current project and use of published data spanning 10 years. Under high-rainfall conditions (>50 mm day^???1), the estuary becomes stratified and nutrients are either removed from the estuary directly in a plume or indirectly by advective/dispersive remobilisation. The majority of the nutrient load is delivered during moderate rainfall (5–50 mm day^???1) conditions and accumulates close to discharge points and remains in the estuary. To significantly reduce nutrient load, management strategies should aim to minimise low and moderate rainfall pollutant loads.     

典型陆源入海排污对邻近海域富营养化及生物毒性的影响

主要采用等标污染负荷、营养状态指数、生物综合毒性指标和GIS手段,通过对秦皇岛海域3个陆源入海排污口及邻近海域水质因子调查,考察典型陆源入海排污对邻近海域富营养化及生物毒性的影响。结果表明,大蒲河、人造河和洋河入海污染物的等标污染负荷比分别为36.9%、61.1%和2.0%,其中大蒲河和人造河对该海域污染负荷比的贡献达98%,为主要污染源;邻近海域主要超标污染物为PO3-4和DIN,PO3-4浓度与NQI相关分析(r=0.76,P=0.004 6)和GIS空间对比表明,PO3-4可能是造成该海域富营养化的主要因子。NQI和发光细菌发光抑制率的空间分布特征表明,该海域受陆源排污的影响比较明显。     

Nutrient spatial pattern of the upstream,mainstream and tributaries of the Three Gorges Reservoir in China

A comprehensive monitoring program was conducted to investigate the nutrient spatial pattern in the mainstream of the Yangtze River from the Baihetan Dam down to the Three Gorges Dam located at the upper region of the Yangtze River in China. Samples were taken from 33 different sites from July 30 to August 19, 2011. The nutrient patterns of the three representative tributaries of the Three Gorges Reservoir (TGR)—the Modao, the Daning, and the Xiangxi Rivers—were also investigated. The results show that the mainstream of the TGR has a higher concentration of nitrogen and a lower concentration of phosphorus than that of the upper mainstream before the TGR. Moreover, it was found that nitrate-nitrogen (NO₃-N) is the main nitrogen component, while particulate phosphorus predominates the total phosphorus (TP). It was found that the three representative tributaries of the TGR have lower total nitrogen (TN) concentrations compared to the corresponding sections of the mainstream TGR. Based on the nutrient spatial pattern, the nutrient flux was calculated. The total fluxes of TN, NO₃-N, TP, and orthophosphate (PO₄-P) from the upstream reach into the TGR are 2,155.06, 1,674.97, 212.98, and 83.42 t day^?1, respectively. The amount of nutrients imported from the TGR into its tributaries is more than the amount exported. It was determined that the Xiangxi River has the largest net rate of imported nitrogen at 7.66 t day^?1, whereas the Daning River has the largest net rate of imported phosphorus at 1.75 t day^?1. In addition, compared with the nutrients imported from the TGR into its tributaries, the nutrient flux from the upstream reach into the TGR contributes approximately less than 3 %.     

Developing an environmental water quality monitoring program for Haraz River in Northern Iran

Water quality management plans are an indispensable strategy for conservation and utilization of water resources in a sustainable manner. One common industrial use of water is aquaculture. The present study is an attempt to use statistical analyses in order to prepare an environmental water quality monitoring program for Haraz River, in Northern Iran. For this purpose, the analysis of a total number of 18 physicochemical parameters was performed at 15 stations during a 1-year sampling period. According to the results of the multivariate statistical methods, the optimal monitoring would be possible by only 3 stations and 12 parameters, including NH₃, EC, BOD, TSS, DO, PO₄, NO₃, TDS, temperature, turbidity, coliform, and discharge. In other words, newly designed network, with a total number of 36 measurements (3 stations × 12 parameters = 36 parameters), could achieve exactly the same performance as the former network, designed based on 234 measurements (13 stations × 18 parameters = 234 parameters). Based on the results of cluster, principal component, and factor analyses, the stations were divided into three groups of high pollution (HP), medium pollution (MP), and low pollution (LP). By clustering the stations, it would be possible to track the water quality of Haraz River, only by one station at each cluster, which facilitates rapid assessment of the water quality in the river basin. Emphasizing on three main axes of monitoring program, including measurement parameters, sampling frequency, and spatial pattern of sampling points, the water quality monitoring program was optimized for the river basin based on natural conditions of the study area, monitoring objectives, and required financial resources (a total annual cost of about US $2625, excluding the overhead costs).