The Danube Programme: The Challenge of International River-Basin Management

This paper highlights the key issues which affected the design and implementation of water policy within the first phase of the Environmental Programme for the Danube River Basin. The programme represents one of several regional environmental initiatives in Eastern Europe which were designed to control pollution through the coordinated actions of national governments, international organizations, international financial institutions and non-governmental organizations.
The paper identifies three key controversial findings. Firstly, although the programme has been a valuable tool for the skills and technology transfer which are necessary to enable the Danube states to control water pollution, it has failed to generate the anticipated levels of capital investment or establish itself as a cornerstone of Danube basin management. Secondly, the policy process has been beset by political, economic, social and historical conflicts and power struggles between the participating parties. Thirdly, valuable lessons for the strategic and sustainable management of international river basins can be learned from the operational experiences of the Danube programme.     

Occurrence of polar organic contaminants in the dissolved water phase of the Danube River and its major tributaries using SPE-LC-MS analysis

Polar water-soluble organic contaminants were analysed in the dissolved liquid water phase of river water samples from the Danube River and its major tributaries (within the Joint Danube Survey 2). Analyses were performed by solid-phase extraction (SPE) followed by triple-quadrupole liquid chromatography mass spectrometry (LC-MS²). In total, 34 different polar organic compounds were screened. Focus was given on pharmaceutical compounds (such as ibuprofen, diclofenac, sulfamethoxazole, carbamazepine), pesticides and their degradation products (e.g. bentazone, 2,4-D, mecoprop, atrazine, terbutylazine, desethylterbutylazine), perfluorinated acids (PFOS; PFOA), and endocrine disrupting compounds (nonylphenol, NPE₁C, bisphenol A, estrone). The most relevant polar compounds identified in the Danube River basin in terms of frequency of detection, persistency, and concentration levels were 1H-benzotriazole (median concentration 185 ng/L), caffeine (87 ng/L), tolyltriazole (73 ng/L), nonylphenoxy acetic acid (49 ng/L), carbamazepine (33 ng/L), 4-nitrophenol (29 ng/L), 2,4-dinitrophenol (19 ng/L), PFOA (17 ng/L), sulfamethoxazole (16 ng/L), desethylatrazine (11 ng/L), and 2,4-D (10 ng/L). The highest contamination levels were found in the area around Budapest and in the tributary rivers Arges (Romania), Timok (Bulgaria), Rusenski Lom (Bulgaria), and Velika Morava (Serbia).     

Investigation of the effects of multiple pressures in the lower Danube basin

The main scope of the paper is the implementation of future scenarios in the Lower Danube basin, supporting the development of River Basin Management Plans and future environmental policies. The 800 000 km² Danube River Basin extends across 19 countries, of which 14 are contracting parties of the ICPDR. The Lower Danube is occupied mostly by Romania, including the Danube Delta. The Danube Delta hydrological complex covers 5800 km² comprising over 300 lakes, three main branches and a vast network of channels. Changes impacting significant ecosystem services such as recreation, fishing, flows, ecotourism, flood regulation, navigation and reed/wood resources have to be evaluated and the quantification of those elements must be performed in order to incorporate them into the modelling process.     

Integrated analysis of water quality parameters for cost-effective faecal pollution management in river catchments

In many parts of the world, microbial contamination of surface waters used for drinking, recreation, and shellfishery remains a pervasive risk to human health, especially in Less Economically Developed Countries (LEDC). However, the capacity to provide effective management strategies to break the waterborne route to human infection is often thwarted by our inability to identify the source of microbial contamination. Microbial Source Tracking (MST) has potential to improve water quality management in complex river catchments that are either routinely, or intermittently contaminated by faecal material from one or more sources, by attributing faecal loads to their human or non-human sources, and thereby supporting more rational approaches to microbial risk assessment. The River Ouse catchment in southeast England (U.K.) was used as a model with which to investigate the integration and application of a novel and simple MST approach to monitor microbial water quality over one calendar year, thereby encompassing a range of meteorological conditions. A key objective of the work was to develop simple low-cost protocols that could be easily replicated. Bacteriophages (viruses) capable of infecting a human specific strain of Bacteroides GB-124, and their correlation with presumptive Escherichia coli, were used to distinguish sources of faecal pollution. The results reported here suggest that in this river catchment the principal source of faecal pollution in most instances was non-human in origin. During storm events, presumptive E. coli and presumptive intestinal enterococci levels were 1.1-1.2 logs higher than during dry weather conditions, and levels of the faecal indicator organisms (FIOs) were closely associated with increased turbidity levels (presumptive E. coli and turbidity, r = 0.43). Spatio-temporal variation in microbial water quality parameters was accounted for by three principal components (67.6%). Cluster Analysis, reduced the fourteen monitoring sites to six representative ‘sentinel’ sites. The correlation coefficient between presumptive E. coli and phages of Bacteroides GB-124 was very small (r = 0.05) whilst that between turbidity and suspended solids was high (r = 0.62). Variations in climate, animal and anthropogenic interferences were all, either directly or indirectly, related to faecal contamination. The findings show the importance of meteorological conditions, such as storm events, on microbial water quality, and suggest that any future increases in the frequency of storm events (associated with climate change) are likely to result in a greater incidence of FIO/pathogen loads. This low-cost approach could help to predict spatio-temporal ‘hotspots’ of elevated waterborne disease risk. The work also represents an important step towards integrating novel MST tools into river catchment modelling.     

Contribution of treated wastewater to the microbiological quality of Seine River in Paris

Urban part of Seine River serving as drinking water supply in Paris can be heavily contaminated by Cryptosporidium spp. and Giardia duodenalis. In the absence of agricultural practice in this highly urbanized area, we investigated herein the contribution of treated wastewater to the microbiological quality of this river focusing on these two parasites. Other microorganisms such as faecal bacterial indicators, enteroviruses and oocysts of Toxoplasma gondii were assessed concurrently. Raw wastewaters were heavily contaminated by Cryptosporidium and Giardia (oo)cysts, whereas concentrations of both protozoa in treated wastewater were lower. Treated wastewater, flowed into Seine River, had a parasite concentration closed to the one found along the river, in particular at the entry of a drinking water plant (DWP). Even if faecal bacteria were reliable indicators of a reduction in parasite concentrations during the wastewater treatment, they were not correlated to protozoal contamination of wastewater and river water. Oocysts of T. gondii were not found in both raw and treated wastewater, or in Seine River. Parasitic contamination was shown to be constant in the Seine River up to 40 km upstream Paris. Altogether, these results strongly suggest that treated wastewater does not contribute to the main parasitic contamination of the Seine River usually observed in this urbanized area.     

Development of microbial and chemical MST tools to identify the origin of the faecal pollution in bathing and shellfish harvesting waters in France

The microbiological quality of coastal or river waters can be affected by faecal pollution from human or animal sources. An efficient MST (Microbial Source Tracking) toolbox consisting of several host-specific markers would therefore be valuable for identifying the origin of the faecal pollution in the environment and thus for effective resource management and remediation. In this multidisciplinary study, after having tested some MST markers on faecal samples, we compared a selection of 17 parameters corresponding to chemical (steroid ratios, caffeine, and synthetic compounds), bacterial (host-specific Bacteroidales, Lactobacillus amylovorus and Bifidobacterium adolescentis) and viral (genotypes I-IV of F-specific bacteriophages, FRNAPH) markers on environmental water samples (n = 33; wastewater, runoff and river waters) with variable Escherichia coli concentrations. Eleven microbial and chemical parameters were finally chosen for our MST toolbox, based on their specificity for particular pollution sources represented by our samples and their detection in river waters impacted by human or animal pollution; these were: the human-specific chemical compounds caffeine, TCEP (tri(2-chloroethyl)phosphate) and benzophenone; the ratios of sitostanol/coprostanol and coprostanol/(coprostanol+24-ethylcopstanol); real-time PCR (Polymerase Chain Reaction) human-specific (HF183 and B. adolescentis), pig-specific (Pig-2-Bac and L. amylovorus) and ruminant-specific (Rum-2-Bac) markers; and human FRNAPH genogroup II.     

Relationship between F-specific RNA phage genogroups, faecal pollution indicators and human adenoviruses in river water

Recent studies have shown the increasing interest of F-specific RNA phage genotyping to identify major sources of faecal contamination in waters. This study, conducted in a river located in an urbanized watershed with recognized anthropogenic influences, was aimed at evaluating the relevance of direct phage genotyping by real-time RT-PCR. One hundred percent of positive results were obtained with a 5 mL aliquot of river water (n = 31). Phage distribution was modified after cultivation, since the ratio of the two most abundant genogroups (II and I) reached 1.51 log₁₀ by direct RT-PCR-based method versus 0.30 log₁₀ after cultivation (n = 8). For the first time, positive correlations between the concentrations of genogroup II, bacterial indicators and human adenoviruses were observed, which may indicate a human faecal pollution. No correlation between genogroups II and I has been revealed. The concentration of genogroup I was only correlated with water turbidity, suggesting an animal pollution coming from upstream after rainfall events. Among the microbiological parameters studied, only genogroup II/genogroup I ratio shows variations occurring in the major sources of faecal pollution.     

Perfluorinated alkylated substances in the aquatic environment: An Austrian case study

Perfluorinated alkylated substances (PFAS) are of global interest due to their occurrence and persistency in the environment. This study includes surface waters and sediments for the analysis of eleven PFAS. The PFAS studied can be grouped in perfluoroalkyl carboxylates (PFCAs), perfluoroalkyl sulfonates (PFS) and perfluoroalkyl sulfonamides (PFSA). The two most important compounds are perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS). These two substances showed the most significant values for surface water samples with maximum concentrations of 21 ng l⁻¹ for PFOA and 37 ng l⁻¹ for PFOS. Sediment samples from seven Austrian lakes and the river Danube were studied. Whereas PFSA and PFS were not detected in any sediment sample PFCAs were detected in most of the lake samples in concentrations up to 1.7 μg kg⁻¹ dry wt. PFOA, perfluorohexanoic acid (PFHxA) and perfluoroheptanoic acid (PFHpA) were detected in all Danube river sediment samples in concentrations varying from 0.1 up to 5.1 μg kg⁻¹ dry wt. For the various sampling points the proportional mass flows deriving from wastewater discharges were calculated. Whereas only up to 10% of the average flow is discharged wastewater up to more than 50% of the PFAS mass flows in the rivers can be attributed to wastewater discharges. Besides wastewater different other pathways as emissions from point sources, further degradation of precursor products, runoff from contaminated sites or surface runoff as well as dry and wet deposition have to be considered as relevant sources for PFAS contamination in surface waters.     

深圳河水体污染特征分析及整治措施

为提高深圳河的水环境,在水体污染特征分析及污染源解析的基础上,对污染物削减目标进行了估算,并提出了最大日负荷总量(TMDL)水质改善措施。结果表明,水体中DO浓度较低,71%的断面水体中氨氮和总氮浓度超出地表Ⅴ类水质标准,且氨氮和总氮浓度均沿河流方向升高。各行政区中生活和工业废水及河道底泥是水体污染的主要来源,福田区污染贡献占比最大,生活污水排放占比为33%,工业废水排放对河道COD、氨氮的贡献率分别达到42%、44%,是溯源截污的重点区域。通过截污清淤、海绵调蓄、生态修复及景观营造等措施,可以实现2020年全面消黑及2025年水质达到Ⅴ类水的目标。     

邯郸市沁河退污还清工程

为治理因大量工业废水和生活污水直排而造成的沁河水质污染状况，邯郸市通过建设西污水处理工程、铺设雨污水分流和污水截流管线、修建截流井、工业废水实现达标排放、对河道进行清淤、修建景观拦河坝、实施调水补水等工程，使沁河实现了退污还清。     

One-year weekly survey of noroviruses and enteric adenoviruses in the Tone River water in Tokyo metropolitan area, Japan

To investigate the actual fluctuations in the concentrations of noroviruses (NoVs) GI and GII, and enteric adenoviruses (EAdVs) in river water and its relationship with the number of acute infectious gastroenteritis patients, one-year weekly quantitative monitoring of NoVs GI and GII and EAdVs was performed in the Tone River in Japan where the surface water is utilized for the main production of drinking water for the Tokyo Metropolitan Area from October 2009 to September 2010. Noroviruses GI and GII and EAdVs were detected in 28 (54%), 33 (63%), and 23 (44%) of the 52 samples (1 L each), respectively. The concentrations of NoVs GI and GII and EAdVs fluctuated strongly and were more abundant in winter and early spring. The concentration of NoVs GI was transiently greater than 10,000 copies/L. The number of acute infectious gastroenteritis patients in the upper river basin was highly correlated with all the viral concentrations, while general microbial indicator data such as turbidity and heterotrophic plate count were independent of viral concentration as suggested in previous studies. To the best of our knowledge, this is the first study that clearly shows the strong correlation of the number of gastroenteritis with virus contamination in lower river basin.     

Evaluating the input and source of faecal contamination in the cattle farming and forested regions of the Oconee watershed

Sites along Sugar Creek and the Apalachee River were monitored to compare the water quality in cattle farming regions with the forested regions of the Oconee watershed. Dissolved oxygen (6.68 mg/L) and turbidity [23.91 nephelometric turbidity units (NTU)] in Sugar Creek and the Apalachee River were similar. Overall, cattle farming sites along Sugar Creek had higher levels of NO₃^? and PO₄^?3 during the summer months. In contrast, the forested sites on the Apalachee River had elevated concentrations of inorganic nutrients only during spring rain events. The concentration of faecal bacteria was greater in the cattle farming areas compared with the level of faecal bacteria in the forested areas, and microbial source tracking with the bovine‐associated Bacteroides (BoBac) DNA marker indicated that cattle were the major source of faecal bacteria in Sugar Creek.     

长江流域自然保护地体系优化路径研究： 基于国际大河流域对比分析

在“2020后全球生物多样性框架”制定和长江大保护国家重大战略需求下,有必要开展国际视野下的长江流域自然保护地体系优化研究。通过国际比较、空间荟萃分析、个案研究,基于“保护价值-人为干扰”分析框架,对全球大河流域自然保护优先度及自然保护地现状进行评价,筛选出亚马逊河、湄公河、育空河、多瑙河4个典型案例,剖析其自然保护地体系优化路径异同。研究发现:1)长江流域整体属于“高价值-高干扰”区域,局地存在较大空间差异;2)国际大河流域自然保护地体系的治理主体和途径存在普遍共性,但在空间优化模式和关键议题上存在显著差异。最后,从治理主体、驱动力、治理途径、空间优化模式、关键议题等方面提出长江流域自然保护地体系优化路径建议。     

Regional water quality management for the Karun–Dez River basin, Iran

To achieve water quality goals in a river basin, a water quality management model (WQMM) has been developed through the geographic information system (GIS) approach and a mathematical water quality model. The developed model has been applied to the Karun and Dez Rivers, where water quality has decreased due to heavy pollutant loads from Khuzestan province cities and surrounding areas. Pollution sources, land use, geographic features and measured water quality data of the river basin were incorporated into the Arc‐View GIS database. With the database, the management model calculated management type and management cost for each management project in the river basin. Until now, river management policy for polluted rivers in Iran first penalizes pollution sources and then constructs treatment plants for the pollution sources whose wastewater is released untreated and for which the wastewater quality goal of the Iranian Department of Environment is not met. Different management projects with a time programme were proposed and they were compared with the results of the river quality without any management approach. It became clear that the results based on the management approach were much better than those for the unmanaged condition from the viewpoint of the achievement of water quality goals and cost optimization.     

The environmental chemistry of Mahaweli river,Sri Lanka

The water pollution levels of Mahaweli River, the longest river in Sri Lanka, the basin of which covers one sixth of the Island, were monitored to probe the impacts of the urban environment in a developing country. It was observed the chemical quality is largely controlled by natural factors. From among the metals however, vanadium, zinc and copper showed higher concentrations. Pb and Cd showed a correlation co‐efficient of r = 0.58 for each other, and Co showed a highly significant correlation of r = 0.98 with Cu. The lack of correlation of Pb and Cd with the total dissolved solids (TDS) indicates an anthropogenic input of Pb and Cd into the aquatic environment. In general, the chemical quality of the water in the Mahaweli river is satisfactory for most purposes, none of the major dissolved constituents and nutrients exceeding the limit suggested by the WHO for potable water.     

Evaluation of selected ubiquitous contaminants in the aquatic environment and their transformation products. A pilot study of their removal from a sewage treatment plant

A simple method using direct sample injection combined with liquid chromatography tandem mass spectrometry has been developed for the simultaneous analysis of six alkaloid compounds in environmental samples. The target list includes two psychostimulants (nicotine and caffeine), three metabolites (cotinine, nicotinic acid and paraxanthine) and a coffee chemical (trigonelline). The analytical method was evaluated in three different matrices (surface water, influent and effluent wastewater). The method developed showed an adequate sensitivity, below 0.6 μg L⁻¹ for wastewater and 0.1 μg L⁻¹ for river matrices, without any prior treatment of the samples. Finally, the methodology was applied to real samples for evaluation of their removal from a sewage treatment plant and their persistence/fate in the aquatic environment. All compounds studied in this work were detected at all sampling points collected along the Henares River. However, nicotinic acid was only detected three times in treated sewage samples at levels above its detection limit.     

Use of watershed factors to predict consumer surfactant risk, water quality, and habitat quality in the upper Trinity River, Texas

Surfactants are high production volume chemicals that are used in a wide assortment of “down-the-drain” consumer products. Wastewater treatment plants (WWTPs) generally remove 85 to more than 99% of all surfactants from influents, but residual concentrations are discharged into receiving waters via wastewater treatment plant effluents. The Trinity River that flows through the Dallas-Fort Worth metropolitan area, Texas, is an ideal study site for surfactants due to the high ratio of wastewater treatment plant effluent to river flow (> 95%) during late summer months, providing an interesting scenario for surfactant loading into the environment. The objective of this project was to determine whether surfactant concentrations, expressed as toxic units, in-stream water quality, and aquatic habitat in the upper Trinity River could be predicted based on easily accessible watershed characteristics. Surface water and pore water samples were collected in late summer 2005 at 11 sites on the Trinity River in and around the Dallas-Fort Worth metropolitan area. Effluents of 4 major waste water treatment plants that discharge effluents into the Trinity River were also sampled. General chemistries and individual surfactant concentrations were determined, and total surfactant toxic units were calculated. GIS models of geospatial, anthropogenic factors (e.g., population density) and natural factors (e.g., soil organic matter) were collected and analyzed according to subwatersheds. Multiple regression analyses using the stepwise maximum R² improvement method were performed to develop prediction models of surfactant risk, water quality, and aquatic habitat (dependent variables) using the geospatial parameters (independent variables) that characterized the upper Trinity River watershed. We show that GIS modeling has the potential to be a reliable and inexpensive method of predicting water and habitat quality in the upper Trinity River watershed and perhaps other highly urbanized watersheds in semi-arid regions.     

Degradation of 1,2-dichloroethane by microbial communities from river sediment at various redox conditions

Insight into the pathways of biodegradation and external factors controlling their activity is essential in adequate environmental risk assessment of chlorinated aliphatic hydrocarbon pollution. This study focuses on biodegradation of 1,2-dichloroethane (1,2-DCA) in microcosms containing sediment sourced from the European rivers Ebro, Elbe and Danube. Biodegradation was studied under different redox conditions. Reductive dechlorination of 1,2-DCA was observed with Ebro and Danube sediment with chloroethane, or ethene, respectively, as the major dechlorination products. Different reductively dehalogenating micro-organisms (Dehalococcoides spp., Dehalobacter spp., Desulfitobacterium spp. and Sulfurospirillum spp.) were detected by 16S ribosomal RNA gene-targeted PCR and sequence analyses of 16S rRNA gene clone libraries showed that only 2-5 bacterial orders were represented in the microcosms. With Ebro and Danube sediment, indications for anaerobic oxidation of 1,2-DCA were obtained under denitrifying or iron-reducing conditions. No biodegradation of 1,2-DCA was observed in microcosms with Ebro sediment under the different tested redox conditions. This research shows that 1,2-DCA biodegradation capacity was present in different river sediments, but not in the water phase of the river systems and that biodegradation potential with associated microbial communities in river sediments varies with the geochemical properties of the sediments.     

Assessment of global nitrogen pollution in rivers using an integrated biogeochemical modeling framework

This study has analyzed the global nitrogen loading of rivers resulting from atmospheric deposition, direct discharge, and nitrogenous compounds generated by residential, industrial, and agricultural sources. Fertilizer use, population distribution, land cover, and social census data were used in this study. A terrestrial nitrogen cycle model with a 24-h time step and 0.5° spatial resolution was developed to estimate nitrogen leaching from soil layers in farmlands, grasslands, and natural lands. The N-cycle in this model includes the major processes of nitrogen fixation, nitrification, denitrification, immobilization, mineralization, leaching, and nitrogen absorption by vegetation. The previously developed Total Runoff Integrating Pathways network was used to analyze nitrogen transport from natural and anthropogenic sources through river channels, as well as the collecting and routing of nitrogen to river mouths by runoff. Model performance was evaluated through nutrient data measured at 61 locations in several major world river basins. The dissolved inorganic nitrogen concentrations calculated by the model agreed well with the observed data and demonstrate the reliability of the proposed model. The results indicate that nitrogen loading in most global rivers is proportional to the size of the river basin. Reduced nitrate leaching was predicted for basins with low population density, such as those at high latitudes or in arid regions. Nitrate concentration becomes especially high in tropical humid river basins, densely populated basins, and basins with extensive agricultural activity. On a global scale, agriculture has a significant impact on the distribution of nitrogenous compound pollution. The map of nitrate distribution indicates that serious nitrogen pollution (nitrate concentration: 10-50 mg N/L) has occurred in areas with significant agricultural activities and small precipitation surpluses. Analysis of the model uncertainty also suggests that the nitrate export in most rivers is sensitive to the amount of nitrogen leaching from agricultural lands.     

Spatial variation and source apportionment of water pollution in Qiantang River (China) using statistical techniques

Understanding the spatial distribution and apportioning the sources of water pollution are important in the study and efficient management of water resources. In this work, we considered data for 13 water quality variables collected during the year 2004 at 46 monitoring sites along the Qiantang River (China). Fuzzy comprehensive analysis categorized the data into three major pollution zones (low, moderate, and high) based on national quality standards for surface waters, China. Most sites classified as “low pollution zones” (LP) occurred in the main river channel, whereas those classified as “moderate and high pollution zones” (MP and HP, respectively) occurred in the tributaries. Factor analysis identified two potential pollution sources that explained 67% of the total variance in LP, two potential pollution sources that explained 73% of the total variance in MP, and three potential pollution sources that explained 80% of the total variance in HP. UNMIX was used to estimate contributions from identified pollution sources to each water quality variable and each monitoring site. Most water quality variables were influenced primarily by pollution due to industrial wastewater, agricultural activities and urban runoff. In LP, non-point source pollution such as agricultural runoff and urban runoff dominated; in MP and HP, mixed source pollution dominated. The pollution in the small tributaries was more serious than that in the main channel. These results provide information for developing better pollution control strategies for the Qiantang River.