Water quality of arctic rivers in Finnish Lapland

The water quality monitoring data of eight rivers situated in the Finnish Lapland above the Arctic Circle were investigated. These rivers are icebound annually for about 200 days. They belong to the International River Basin District founded according to the European Union Water Framework Directive and shared with Norway. They are part of the European river monitoring network that includes some 3,400 river sites. The water quality monitoring datasets available varied between the rivers, the longest comprising the period 1975–2003 and the shortest 1989–2003. For each river, annual medians of eight water quality variables were calculated. In addition, medians and fifth and 95th percentiles were calculated for the whole observation periods. The medians indicated good river water quality in comparison to other national or foreign rivers. However, the river water quality oscillated widely. Some rivers were in practice in pristine state, whereas some showed slight human impacts, e.g., occasional high values of hygienic indicator bacteria.     

Statistical control of hygienic quality of bathing water

In Denmark the hygienic quality of the bathing water has been controlled, based on general guidelines since 1978. Today more than 1100 control sites in marine areas have been established to ensure safe bathing water quality. According to EEC directives and Danish tradition, the control is usually performed by measuring the content of the indicator bacteria Escherichia coli (E. coli) in 5 to 20 test samples each bathing season.In Denmark, control programmes and data are evaluated using basic statistical quality control principles. This paper presents general guidelines for bacterial control, their statistical background and practical application. Furthermore, the evaluation and application of a specific programme for control of Staphylococcus aureus (S. aureus) are presented. This programme was used in a Danish bay where the authorities prescribe direct control of these potentially harmful bacteria.     

Monitoring, assessment and modelling using water quality data in the Saale River Basin, Germany

The European Water Framework Directive (WFD) is the overall driver for this environmental study and currently requires the identification of patterns and sources of pollution (monitoring) to support objective ecological sound decision making and specific measures to enhance river water quality (modelling). The purpose of this paper is to demonstrate in a case study the interrelationship between (1) hydrologic and water quality monitoring data for river basin characterization and (2) modelling applications to assess resources management alternatives. The study deals with monitoring assessment and modelling of river water quality data of the main stem Saale River and its principal tributaries. For a period of 6 years the data, which was sampled by Environmental Agencies of the German states of Thuringia, Saxony and Saxony-Anhalt, was investigated to assess sources and indicators of pollution. In addition to the assessment a modelling exercise of the routing of different pollutants was carried out in the lower part of the test basin. The modelling is a tool to facilitate the evaluation of alternative measures to reduce contaminant loadings and improve ecological status of a water body as required by WFD. The transport of suspended solids, salts and heavy metals was modelled along a selected Saale reach under strong anthropogenic influence in terms of contaminants and river morphology between the city of Halle and the confluence with the Elbe River. The simulations were carried out with the model WASP5 which is a dynamic flood-routing and water quality model package developed by the US Environmental Protection Agency.     

袁河袁州区段溶解氧过饱和成因分析及防治

2020年8月15日袁河袁州区段(棚下-袁河水厂取水口)出现溶解氧过饱和现象,为了解该河段溶解氧的变化及提高河道流量前后对水生态环境的影响,将该段河道分为6个监测断面,于8月16—24日监测每个监测点的常规水质、浮游植物群落结构、溶解氧和实时流量.结果表明:自然状态下袁河袁州区段溶解氧沿水流方向从6.8 mg/L逐渐增...     

A Multi-Channel Continuous Water Toxicity Monitoring System: Its Evaluation and Application to Water Discharged from a Power Plant

A multi-channel continuous water toxicity monitoring system was, after confirming the systems' performance, implemented to samples of water discharged from power plants to detect and classify their toxicity using several recombinant bioluminescent bacteria. Each channel of the system is composed of a series of two mini-bioreactors to enable a continuous operation, i.e., without system interruption due to highly toxic samples. A different recombinant bacterial strain was present in each channel: DPD2540 (fabA::lux CDABE), DPD2794 (recA::luxCDABE), and TV1061 (grpE::luxCDABE), which are induced by cell membrane-, DNA-, and protein-damaging agents, respectively. GC2 (lac::luxCDABE) is a constitutive strain, whose bioluminescence is reduced by an increase in cellular toxicity. Phenol and mitomycin C (MMC) were used for evaluating the system's performance to detect toxic chemicals. These samples were injected into the second mini-bioreactor according to a step or bell-curve manner. The field samples used in this study were obtained from the water discharged from two different power plants in Korea – from a nuclear power plant and a thermo-electronic power plant, and were injected into the second mini-bioreactor to initiate the toxicity test. Each channel showed specific bioluminescent (BL) response profiles due to the toxic compounds present in the water samples. Comparing the BL signals between the standard toxic chemical samples and discharged water samples, the equivalent toxicity of the field water could be estimated. Finally, it was proved that this novel continuous toxicity monitoring system can be used as an alternative tool for the quick monitoring and control of water quality, as well as aid in the setting up of a new monitoring strategy to protect the source of tap water and in the prevention of polluted water discharge.     

萍水河水质监测点的优化

城市内河流水质监测点位的优化,是全面掌握河流水质状况的关键。文章采用贴近度法对萍乡市萍水河2005—2015年水质及监测点位变化进行分析评价,并提出优化建议。根据萍水河水质污染特征,选择化学需氧量、五日生化需氧量、氨氮、总磷、总氮和高锰酸钾盐指数作为评价指标,结果表明:2005—2015年,萍水河水环境质量整体情况较好,但在2010年后呈下降趋势;监测点布设方案的调整有一定合理性,也有欠妥之处;对目前监测点位进行删减,得到了水质优化监测布点方案。     

Evaluation of Water Quality Management Alternatives to Control Dissolved Oxygen and Un-ionized Ammonia for Ravi River in Pakistan

Different water quality management alternatives, including conventional wastewater treatment, transportation of wastewater, flow augmentation, low-cost treatment with reuse, and wetlands, are evaluated by using a verified dissolved oxygen (DO) model for the Ravi River. Biokinetic rate coefficients of the Ravi River for both the carbonaceous and nitrogenous oxygen-demanding wastes are adjusted, keeping in view the type and level of wastewater treatment. The conventional activated sludge process with nitrification comes out to be the most expansive alternative to meet the DO standard of 4 mg/L. Additional treatment cost is required to maintain un-ionized ammonia levels <0.02 mg/L, which corresponds to achieving treatment levels of 5 mg/L of DO in the river. Under critical low-flow conditions (i.e., minimum average seven consecutive days) of 9.2 m³/s, a flow augmentation of 10 m³/s can reduce 30 % of the cost with conventional wastewater treatment. Transportation of wastewater from the city of Lahore is a cost-effective alternative with 2.5 times less cost than the conventional process. Waste stabilization ponds (WSP) technology is a low-cost solution with 3.5 times less cost as compared to the conventional process. Further reduction in pollution loads to the Ravi River can be achieved by reusing WSP effluents for irrigation in the near proximity of Lahore along the Ravi River. The study results show that, for highly polluted rivers with such extreme flow variations as in case of the Ravi River, meeting un-ionized ammonia standards can reduce the efforts required to develop carbonaceous biochemical oxygen demand-based waste load allocations.     

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.     

Water Quality Assessment of an Untreated Effluent Impacted Urban Stream: The Bharalu Tributary of the Brahmaputra River, India

Guwahati, the lone city on the bank of the entire midstream of the Brahmaputra River, is facing acute civic problem due to severe depletion of water quality of its natural water bodies. This work is an attempt towards water quality assessment of a relatively small tributary of the Brahmaputra called the Bharalu River flowing through the city that has been transformed today into a city drainage channel. By analyzing the key physical, chemical and biological parameters for samples drawn from different locations, an assessment of the dissolved load and pollution levels at different segments in the river was made. Locations where the contaminants exceeded the permissible limits during different seasons were identified by examining spatial and temporal variations. A GIS developed for the watershed with four layers of data was used for evaluating the influence of catchment land use characteristics. BOD, DO and total phosphorus were found to be the sensitive parameters that adversely affected the water quality of Bharalu. Relationship among different parameters revealed that the causes and sources of water quality degradation in the study area were due to catchments input, anthropogenic activities and poor waste management. Elevated levels of total phosphorus, BOD and depleted DO level in the downstream were used to develop an ANN model by taking total phosphorus and BOD as inputs and dissolved oxygen as output, which indicated that an ANN based predictive tool can be utilized for monitoring water quality in the future.     

Optimal Expansion of Water Quality Monitoring Network by Fuzzy Optimization Approach

River reaches are frequently classified with respect to various mode of water utilization depending on the quantity and quality of water resources available at different location. Monitoring of water quality in a river system must collect both temporal and spatial information for comparison with respect to the preferred situation of a water body based on different scenarios. Designing a technically sound monitoring network, however, needs to identify a suite of significant planning objectives and consider a series of inherent limitations simultaneously. It would rely on applying an advanced systems analysis technique via an integrated simulation-optimization approach to meet the ultimate goal. This article presents an optimal expansion strategy of water quality monitoring stations for fulfilling a long-term monitoring mission under an uncertain environment. The planning objectives considered in this analysis are to increase the protection degree in the proximity of the river system with higher population density, to enhance the detection capability for lower compliance areas, to promote the detection sensitivity by better deployment and installation of monitoring stations, to reflect the levels of utilization potential of water body at different locations, and to monitor the essential water quality in the upper stream areas of all water intakes. The constraint set contains the limitations of budget, equity implication, and the detection sensitivity in the water environment. A fuzzy multi-objective evaluation framework that reflects the uncertainty embedded in decision making is designed for postulating and analyzing the underlying principles of optimal expansion strategy of monitoring network. The case study being organized in South Taiwan demonstrates a set of more robust and flexible expansion alternatives in terms of spatial priority. Such an approach uniquely indicates the preference order of each candidate site to be expanded step-wise whenever the budget limitation is sensitive in the government agencies.     

Assessment of river water quality during snowmelt and base flow periods in two catchment areas with different land use

River water quality was evaluated with respect to eutrophication and land use during spring snowmelt and summer base flow periods in Abashiri (mixed cropland-livestock farming) and Okoppe (grassland-based dairy cattle farming), eastern Hokkaido, Japan. Water from rivers and tributaries was sampled during snowmelt and summer base flow periods in 2005, and river flow was measured. Total N (TN), NO₃–N, and Si concentrations were determined using standard methods. Total catchment and upland areas for each sampling site were determined with ArcGIS hydrology modeling software and 1:25,000-scale digital topographic maps. Specific discharge was significantly higher during snowmelt than during base flow. In both areas, TN concentrations increased, whereas Si concentrations decreased, with increased specific discharge, and were significantly higher during snowmelt. The Si:TN mole ratio decreased to below or close to the threshold value for eutrophication (2.7) in one-third of sites during snowmelt. River NO₃–N concentrations during base flow were significantly and positively correlated with the proportion of upland fields in the catchment in both the Abashiri (r = 0.88, P < 0.001) and Okoppe (r = 0.43, P < 0.01) areas. However, the regression slope, defined as the impact factor (IF) of water quality, was much higher in Abashiri (0.025) than in Okoppe (0.0094). The correlations were also significantly positive during snowmelt in both areas, but IF was four to eight times higher during snowmelt than during base flow. Higher discharge of N from upland fields and grasslands during snowmelt and the resulting eutrophication in estuaries suggest that nutrient discharge during snowmelt should be taken into account when assessing and monitoring the annual loss of nutrients from agricultural fields.     

Sensitivity analysis of water quality for Delhi stretch of the River Yamuna,India

Simulation models are used to aid the decision makers about water pollution control and management in river systems. However, uncertainty of model parameters affects the model predictions and hence the pollution control decision. Therefore, it often is necessary to identify the model parameters that significantly affect the model output uncertainty prior to or as a supplement to model application to water pollution control and planning problems. In this study, sensitivity analysis, as a tool for uncertainty analysis was carried out to assess the sensitivity of water quality to (a) model parameters (b) pollution abatement measures such as wastewater treatment, waste discharge and flow augmentation from upstream reservoir. In addition, sensitivity analysis for the “best practical solution” was carried out to help the decision makers in choosing an appropriate option. The Delhi stretch of the river Yamuna was considered as a case study. The QUAL2E model is used for water quality simulation. The results obtained indicate that parameters K ₁ (deoxygenation constant) and K ₃ (settling oxygen demand), which is the rate of biochemical decomposition of organic matter and rate of BOD removal by settling, respectively, are the most sensitive parameters for the considered river stretch. Different combinations of variations in K ₁ and K ₂ also revealed similar results for better understanding of inter-dependability of K ₁ and K ₂. Also, among the pollution abatement methods, the change (perturbation) in wastewater treatment level at primary, secondary, tertiary, and advanced has the greatest effect on the uncertainty of the simulated dissolved oxygen and biochemical oxygen demand concentrations.     

基于GIS的河流污染应急监测方案自动生成研究

通过对河流污染事故应急监测工作流程的分析,研究了基于GIS的河流污染应急监测方案中所涉及的关键技术问题,包括对事故发生地点的空间定位、事故发生地周围应急监测单位及专家组分布信息的查询、应急监测队伍及仪器设备到达事发地最短路径的确定,以及重点研究的一维水质模型与GIS的集成技术。以昆山市河流突发性污染事故为例,探讨了基于GIS的河流污染应急监测优化方案的自动生成原型系统。     

Simulations of groundwater-surface water interaction and particle movement due to the effect of weir construction in the sub-watershed of the river Labe in the town of Děčín

Steady- and transient-state simulations of groundwater flow and particle movement in the sub-watershed of the river Labe in Dě?ín town was carried out using Visual MODFLOW software. The simulations were performed for calibration and for the scenarios that the change in the water level of the river Labe was undergoing. Steady-state simulation was carried out for the sake of calibration of model outputs. For transient simulation, two different scenarios were considered in order to investigate the response of the aquifer system to the stresses applied on surface water of the river. The simulation results have shown that the surface water and groundwater interactions, and the subsequent particle movement were affected by the stresses applied on the surface water in the river Labe. The first scenario involved the rapid recharge of surface water to the aquifer in the vicinity of the river while particles still move towards the river at the places far away from the river. At the end of the second scenario, particles still tend to move towards the river slowly and finally tend to stay within the aquifer as equilibrium of hydraulic gradient is reached between the surface and groundwater levels. The time series graphs of hydraulic heads at all observation wells show that the groundwater level in the surrounding aquifer rises significantly as a result of recharges from the river. The local water balance of the study area was calculated and expressed as the rates of water entering and leaving the system. At the end of the second scenario, the difference between the rate of flow into and out of the model area was 0.73 m³ day^?1.     

Design of on-line river water quality monitoring systems using the entropy theory: a case study

The design of a water quality monitoring network is considered as the main component of water quality management including selection of the water quality variables, location of sampling stations and determination of sampling frequencies. In this study, an entropy-based approach is presented for design of an on-line water quality monitoring network for the Karoon River, which is the largest and the most important river in Iran. In the proposed algorithm of design, the number and location of sampling sites and sampling frequencies are determined by minimizing the redundant information, which is quantified using the entropy theory. A water quality simulation model is also used to generate the time series of the concentration of water quality variables at some potential sites along the river. As several water quality variables are usually considered in the design of water quality monitoring networks, the pair-wise comparison is used to combine the spatial and temporal frequencies calculated for each water quality variable. After selecting the sampling frequencies, different components of a comprehensive monitoring system such as data acquisition, transmission and processing are designed for the study area, and technical characteristics of the on-line and off-line monitoring equipment are presented. Finally, the assessment for the human resources needs, as well as training and quality assurance programs are presented considering the existing resources in the study area. The results show that the proposed approach can be effectively used for the optimal design of the river monitoring systems.     

Design of River Water Quality Monitoring Networks: A Case Study

Karoon River, from Gotvand Dam to Persian Gulf with more than 450 km in length and an annual discharge of 11,891 million cubic meters, is the largest river in Iran. Increasing water withdrawal from and wastewater discharge to the river has endangered the aquatic life of this important ecosystem. Furthermore, the drinking and in-stream water quality standards have been violated in many instances. In this paper, a river water quality monitoring network is designed, including determination of sampling frequencies as well as location of water quality monitoring stations. In this regard, two models are developed. The first model is a Genetic Algorithm-based optimization model and the second one is a combination of Kriging method and Analytical Hierarchy Process. The temporal variation of the concentration of water quality variables along Karoon and Dez Rivers are evaluated and the main water quality indicators are selected. Then, thirty five stations are selected and the application of Entropy Theory in calculating the sampling frequency is demonstrated. The results show the significant value of the proposed methodology in the design of monitoring network.     

Analysis of long-term water quality for effective river health monitoring in peri-urban landscapes—a case study of the Hawkesbury–Nepean river system in NSW, Australia

The Hawkesbury–Nepean River (HNR) system in South-Eastern Australia is the main source of water supply for the Sydney Metropolitan area and is one of the more complex river systems due to the influence of urbanisation and other activities in the peri-urban landscape through which it flows. The long-term monitoring of river water quality is likely to suffer from data gaps due to funding cuts, changes in priority and related reasons. Nevertheless, we need to assess river health based on the available information. In this study, we demonstrated how the Factor Analysis (FA), Hierarchical Agglomerative Cluster Analysis (HACA) and Trend Analysis (TA) can be applied to evaluate long-term historic data sets. Six water quality parameters, viz., temperature, chlorophyll-a, dissolved oxygen, oxides of nitrogen, suspended solids and reactive silicates, measured at weekly intervals between 1985 and 2008 at 12 monitoring stations located along the 300 km length of the HNR system were evaluated to understand the human and natural influences on the river system in a peri-urban landscape. The application of FA extracted three latent factors which explained more than 70 % of the total variance of the data and related to the ‘bio-geographical’, ‘natural’ and ‘nutrient pollutant’ dimensions of the HNR system. The bio-geographical and nutrient pollution factors more likely related to the direct influence of changes and activities of peri-urban natures and accounted for approximately 50 % of variability in water quality. The application of HACA indicated two major clusters representing clean and polluted zones of the river. On the spatial scale, one cluster was represented by the upper and lower sections of the river (clean zone) and accounted for approximately 158 km of the river. The other cluster was represented by the middle section (polluted zone) with a length of approximately 98 km. Trend Analysis indicated how the point sources influence river water quality on spatio-temporal scales, taking into account the various effects of nutrient and other pollutant loads from sewerage effluents, agriculture and other point and non-point sources along the river and major tributaries of the HNR. Over the past 26 years, water temperature has significantly increased while suspended solids have significantly decreased (p?<?0.05). The analysis of water quality data through FA, HACA and TA helped to characterise the key sections and cluster the key water quality variables of the HNR system. The insights gained from this study have the potential to improve the effectiveness of river health-monitoring programs in terms of cost, time and effort, particularly in a peri-urban context.     

The Quality of Water Resources in Dalmatia

The purpose of this study was to monitor and record the specific characteristics and properties of most of the important water resources in Dalmatia located in Southern Croatia for a period of 5 years (1998–2002) according to established standards for drinking water. The paper presents a detailed account of their chemical content, the classification and the concentration of salts. The bacteriological pollution levels are indicated by the total coliform bacterial levels (MPN coli/100 mL). The water characteristics are expressed by coefficients, which represent the ratios between water ingredients. The Ca/Mg eq ratio, SO₄/Cl eq ratio and K₁, K₂ for bicarbonate hardness were calculated. The hygienic characteristics of the water samples were expressed by the total coliform bacteria estimation (MPN coli/100 mL), the permanganate consumption (KMnO₄) and biological oxygen demand (BOD₅). Karst waters in Dalmatia are moderately hard, the SO₄/Cl ratio is 0.38–1.6, non-corrosive (K₁ lower than 0.2) and not significantly mineralised (< 500 mg/L minerals). Sulphate waters are generally hard, the SO₄/Cl ratio is higher than 1.6, K₁ is 0.2–0.65. Marine waters are quite hard or hard, particularly at the river estuaries, the SO₄/Cl ratio is lower than 0.38, and K₁ is higher than 0.65. The groundwater and springs in Dalmatia are less polluted than surface waters. A majority of these have a geometric average value of MPN coli < 150/100 mL of water observed in 24 of 42 locations studied. The highest bacteriological pollution was found in nine locations where MPN coli > 1000/100 mL and moderate pollution was found in nine locations where MPN coli is between 150 and 1000/100 mL of water. The physical and chemical parameters determined for the most sources in Dalmatia are safe below the international permissible limits.     

近岸海域水质自动监测规范化研究

为规范近岸海域水质自动监测,基于近岸海域水质监测要求和质控要求、近岸海域水质自动监测系统特点和近岸海域水质自动监测运行的经验,开展了近岸海域水质自动监测规范化研究,编制了《近岸海域水质自动监测技术规范》(HJ 731—2014),规范了近岸海域水质自动监测系统建设、设备选择、系统验收、日常管理、维护和校准、质量保证和质量控制、数据有效性和上报、监测报告等方面的工作。有利于在标准方法基础上,使中国近岸海域水质自动监测系统的监测数据准确、可靠、可比,有利于近岸海域水质自动监测系统在日常监测中更好地发挥作用。     

Optical Resilience of the Paraíba do Sul River (Brazil) during a Toxic Spill of a Wood-Pulping Factory: The Cataguazes Accident

This study investigates the inherent optical properties (IOP) of a Brazilian river during a non-natural, anthropogenically mediated, toxic spill of a wood-pulping factory (the ‘Cataguazes accident’). The results indicated an outstanding transformation in the river water chromophoric dissolved organic matter (CDOM) pools. For instance, increases in CDOM absorption coefficients, a _CDOM (λ), which were averaged at specific spectral intervals, , ranged from 58-fold at the UV-B and UV-A ranges to 95-fold at the PAR range. As a result, the water color expressed as CDOM absorption at 440 nm, a _CDOM (440), varied from 4.16 to 365.03 m^-1. For S-coefficient, the variations ranged from ∼1.1 to 5.6-fold, respectively, at the 300–650 nm and UV-B range. The variability of S as a proxy of dissolved chromophores was thus clearly influenced by the spectral range used. Optical proportions were also investigated through the use of and S ratios at the UV-B, UV-A, and PAR ranges and, in the case of , also at the NIR range. This approach also showed clear variations between the water samples, likely reflecting changes in the composition of optically active substances in the river system. As a whole, the findings obtained here indicated that both the quantity and quality of the chromophoric material dissolved in the river water were greatly altered by the toxic spill. The changes in the optical properties of the river water, although extreme and likely with no parallel in the literature, were quite rapid as indicated by the optical resilience of the system. Overall, this study indicates that IOP might be thought, and possibly used, as a metric tool for monitoring the state of waters and aquatic ecosystems.