Water quality criteria for European freshwater fish: Report On Monohydric Phenols And Inland Fisheries

Phenolic wastes can contain monohydric phenols, including phenol, the three cresol isomers, and the six xylenol isomers, together with other substances. They may adversely affect freshwater fisheries by their direct toxicity to fish and fish-food organisms, by their high oxygen demand resulting in oxygen depletion of the receiving water, and by the production of undesirable flavours in the edible flesh of fish.Laboratory tests show that the toxicity of phenol is increased by decrease in dissolved-oxygen concentration, increase in salinity, and decrease in temperature. Salmonids and newly hatched fish are more sensitive than coarse fish and adults respectively. Cresols, xylenols, and phenols are of similar toxicity, and the toxicity of mixtures of phenols is apparently additive, although the toxicity of phenolic wastes may be greater than expected from chemical analyses, since these may not be equally sensitive to all phenols and may neglect the contribution from other poisons.Because of difficulties caused by inadequate chemical analysis there are few field observations which can be used to reinforce laboratory findings. For this reason, and also because of gaps in our knowledge of the effect of temperature on toxicity, only tentative criteria can be established, which may have to be modified in the light of further experience.These criteria are expressed as maximum concentrations which should not be exceeded but it should be appreciated that because of the natural fluctuation in the water quality found in rivers over a period of time, the average concentration will be lower to an extent depending on local circumstances.Salmonid fish. To ensure long-term survival of salmonids in the presence of phenolic wastes, the concentration of phenol, cresols or xylenols should not exceed 1·0 mg l⁻¹, either singly or collectively. Where 2,5-xylenol is the main constituent, the concentration should not exceed 0·5 mg l⁻¹. Where the temperature is lower than 5°C, concentrations may have to be halved to ensure the survival of fish.Coarse fish. Since laboratory data show that coarse fish are more resistant than salmonids to phenols, the concentration of phenol, cresol or xylenol should not exceed 2·0 mg l⁻¹, either singly or collectively, provided that oxidation of this concentration does not produce an adverse reduction in the dissolved-oxygen concentration of the water. In the absence of data on the effect of temperature on the toxicity of phenols to coarse fish it is proposed that the reduction in concentration of 50 per cent adopted for salmonids at temperatures below 5°C, should also apply to these species.Where other poisons are present in addition to phenols due allowance must be made for their contribution to the toxicity, particularly in the case of free chlorine.Commercial fisheries. There is no laboratory evidence to indicate that levels of phenol and cresols that are safe for fish cause their flesh to become tainted, but xylenols should not exceed 0·5 mg l⁻¹. Other phenolic substances, particularly the chlorophenols, are known to cause taint at very low concentrations; strictly these are outside the scope of this report, but the information that has been considered suggests that they should be excluded from waters supporting commerical fisheries.     

Water quality, nutrients and the European union's Water Framework Directive in a lowland agricultural region: Suffolk, south-east England

The water quality of 13 rivers in the lowland, agricultural county of Suffolk is investigated using routine monitoring data for the period 1981 to 2006 collected by the Environment Agency of England and Wales (EA), and its predecessors, with particular emphasis on phosphorus (as total reactive phosphorus, TRP) and total (dissolved and particulate) oxidised nitrogen (TOxN — predominantly nitrate NO₃). Major ion and flow data are used to outline fundamental hydrochemical characteristics related to the groundwater provenance of base-flow waters. Relative load contributions from point and diffuse sources are approximated using Load Apportionment Modelling for both TRP and TOxN where concurrent flow and concentration data are available. Analyses indicate a mixture of point and diffuse sources of TRP, with the former being dominant during low flow periods, while for TOxN diffuse sources dominate.Out of 59 sites considered, 53 (90%) were found to have annual average TRP concentrations greater than 0.05 mg P l^− 1, and 36 (61%) had average concentrations over 0.120 mg P l^− 1, the upper thresholds for ‘High’ and ‘Good’ ecological status, respectively. Correspondingly, for TOxN, most of the rivers are already within 70% of the 11.3 mg N l^− 1 threshold, with two rivers (Wang and Ore) being consistently greater than this.It is suggested that the major challenge is to characterise and control point-source TRP inputs which, being predominant during the late spring and summer low-flow period, coincide with the peak of primary biological production, thus presenting the major challenge to achieving ‘good’ ecological status under the Water Framework Directive. Results show that considerable effort is still required to ensure appropriate management and develop tools for decision-support.     

Water quality and accelerated winter growth of European catfish using an enclosed recirculating system

Aquaculture of the European catfish Silurus glanis is impeded by the slow rate of growth at ambient water temperatures below 10°C, which are encountered during the winter months in many regions of Europe (such as central France). In an effort to increase water temperatures over this period, fish were held in an enclosed housing where the water quality was maintained using a low‐cost treatment plant. For comparison, some fish were held in a separate system that was not enclosed and where water treatment took place in an adjacent earth‐lined pond. Both systems were able to maintain good water quality during the winter months but the recirculating system achieved significantly higher water temperatures and rates of fish growth.     

Public values as essential criteria for public entrepreneurship: Water management in France

Historically, major private companies were the dominant players in urban water supply in France. However, a new era of water supply restructuring is underway, whereby formally private water corporations are being made public. Given that many such public water corporations adopt practices associated with private entities, it is essential to identify what is expected of “public” entities by virtue of the fact that they are public. In this article, we examine the foundational ideas behind the raison d'être of public entities, which engender priorities that differ from their private sector counterparts. Using a research-action methodology, water utility management, staff and consumers of Greater Nantes were asked to specify the meaning of “public” and how it should be operationalized in the case of publicly owned utilities. The research shows that the attainment of public values is what lends legitimacy to a public utility charged with the provision of essential services. In this case, even in a context of neoliberal governance, where private values of an economic nature conflict with public goals; public values take precedence in the management and the regulation of the service.     

Ag-PIE: a GIS-based screening model for assessing agricultural pressures and impacts on water quality on a European scale

Diffuse pollution of water resources from agricultural sources is a major environmental issue in the European Union, and has been dealt with by specific legislation: the Nitrate Directive of 1991 and the Water Framework Directive of 2000. These attempts to provide a coordinated approach to solving environmental problems require methods and tools for spatial analysis and modelling on a continental scale, with river basins being used as spatial units. This paper presents a screening model (Ag-PIE), developed in a GIS environment, for the assessment of pressures from agricultural land use and the consequent impacts on surface and groundwater. Ag-PIE has been applied at the European scale (EU15), with focus on nitrogen pollution from chemical fertilisers and manure. The model adopts a multi-criteria evaluation procedure applied to spatial data layers which represent the variety of factors affecting the pollution process. The DPSIR (Driving forces, Pressures, State, Impact, Responses) approach is applied to provide the modelling approach with a conceptual framework and to further analyse and communicate results. Ag-PIE is ultimately aimed at providing a tool making use of state-of-the-art geographical databases to support policy-makers at the European level. The scale of reference adopted is the river basin, in particular those that extend across national boundaries. The quality of the results obtained has been assessed against existing related studies and monitoring reports and by means of sensitivity analysis. Conclusions are driven by considering the potential of Ag-PIE in devising policy support and its strengths and weaknesses in view of identifying future research needs.     

Sorption of zinc by Lake Michigan sediments: Implications for zinc water quality criteria standards

A series of sorption and leaching tests were performed to investigate the uptake and release of zinc from Lake Michigan sediments. In general it was found that these sediments had a moderate affinity for zinc in the neutral to slightly alkaline pH range. If the pH of the sediment slurry was decreased to 6 or less, zinc release was found. Increasing the pH to 7 or greater did not result in the zinc being readsorbed. The sorption of zinc by the sediments was rapid, usually complete in 1–2 h. These results are in accord with the results of the other studies conducted with other waters and sediments. Field observations in Lake Michigan have shown that high concentrations of zinc in tributary waters rapidly decrease within a few kilometers of the tributary mouth to an essentially constant lake-wide concentration. This concentration ranged from 2 to 4 times the typical tributary concentrations. These results may be explained by the uptake of zinc by the suspended sediment in the river and nearshore waters, with settling to the quiescent sediment-water interfaces of the deeper areas of Lake Michigan, often far removed from the tributary input.The rapid, essentially irreversible sorption of zinc by aquatic sediments raises important questions concerning the appropriateness of using the US EPA water quality criterion for zinc as a state water quality standard. The US EPA criterion is based on the total zinc concentration. In many aquatic systems most of the zinc would be adsorbed by suspended sediment, and therefore unavailable to aquatic organisms. It is recommended that the US EPA criteria be used to indicate potential zinc water quality problems where “excessive” concentrations of zinc are investigated on a site-specific basis, using a hazard assessment approach designed to evaluate the actual impact of the zinc in impairing beneficial uses of the water.     

Water affordability across and within European countries: a microdata analysis

We analyze water affordability in 23 European countries using the latest microdata from the European Household Budget Survey.Average affordability ratios vary considerably across countries, from 0.85% (Ireland) to 4.7% (Poland).The prevalence of affordability problems is highest in Poland (60%), while intensity is greatest in Finland (families with problems spend, on average, 9% of their income). The analysis by income deciles shows a gradient, with affordability problems generally concentrated in bottom deciles, though they are not exclusive to the poorest. This variation in affordability problems occurs within countries regardless of their high or low average affordability ratio.     

空调系统水质及水处理问题探讨

介绍了空调系统的水质标准及其项目含义,以及常见的水处理方法和换热管清洗方法,指出了水处理的必要性,探讨了水质的管理方法,提出水质管理可结合水处理,溢流、换热管清洗来进行。     

重视外墙外保温系统质量问题

目前,在我国外墙外保温技术中主要有EPS、XPS和胶粉聚苯颗粒外墙外保温系统等。这当中,EPS板和胶粉聚苯颗粒外墙外保温是我国目前应用较多的建筑保温技术。该技术是将保温隔热体系置于外墙外侧,从而使主体结构所受温差作用下降,温度变形减小,对结构墙体起到保护作用并可有效阻断冷(热)桥。     

Water quality modeling for load reduction under uncertainty: a Bayesian approach

A Bayesian approach was applied to river water quality modeling (WQM) for load and parameter estimation. A distributed-source model (DSM) was used as the basic model to support load reduction and effective water quality management in the Hun-Taizi River system, northeastern China. Water quality was surveyed at 18 sites weekly from 1995 to 2004; biological oxygen demand (BOD) and ammonia (NH(4)(+)) were selected as WQM variables. The first-order decay rate (k(i)) and load (L(i)) of the 16 river segments were estimated using the Bayesian approach. The maximum pollutant loading (L(m)) of NH(4)(+) and BOD for each river segment was determined based on DSM and the estimated parameters of k(i). The results showed that for most river segments, the historical loading was beyond the L(m) threshold; thus, reduction for organic matter and nitrogen is necessary to meet water quality goals. Then the effects of inflow pollutant concentration (C(i-1)) and water velocity (v(i)) on water quality standard compliance were used to demonstrate how the proposed model can be applied to water quality management. The results enable decision makers to decide load reductions and allocations among river segments under different C(i-1) and v(i) scenarios.     

Chemical drinking water quality in Ghana: Water costs and scope for advanced treatment

To reduce child mortality and improve health in Ghana boreholes and wells are being installed across the country by the private sector, NGO's and the Ghanaian government. Water quality is not generally monitored once a water source has been improved. Water supplies were sampled across Ghana from mostly boreholes, wells and rivers as well as some piped water from the different regions and analysed for the chemical quality. Chemical water quality was found to exceed the WHO guidelines in 38% of samples, while pH varied from 3.7 to 8.9. Excess levels of nitrate (NO₃⁻) were found in 21% of the samples, manganese (Mn) and fluoride (F⁻) in 11% and 6.7%, respectively. Heavy metals such as lead (Pb), arsenic (As) and uranium (U) were localised to mining areas. Elements without health based guideline values such as aluminium (Al, 95%) and chloride (Cl, 5.7%) were found above the provisional guideline value.Economic information was gathered to identify water costs and ability to pay. Capital costs of wells and boreholes are about £1200 and £3800 respectively. The majority of installation costs are generally paid by the government or NGO's, while the maintenance is expected to be covered by the community. At least 58% of the communities had a water payment system in place, either an annual fee/one-off fee or “pay-as-you-fetch”. The annual fee was between £0.3-21, while the boreholes had a water collection fee of £0.07-0.7/m³, many wells were free. Interestingly, the most expensive water (£2.9-3.5/m³) was brought by truck. Many groundwater sources were not used due to poor chemical water quality. Considering the cost of unsuccessful borehole development, the potential for integrating suitable water treatment into the capital and maintenance costs of water sources is discussed. Additionally, many sources were not in use due to lack of water capacity, equipment malfunction or lack of economic resources to repair and maintain equipment. Those issues need to be addressed in combination with water quality, coordinated water supply provision and possible treatment to ensure sustainability of improved water resources.     

Heavy metals: confounding factors in the response of New Zealand freshwater fish assemblages to natural and anthropogenic acidity

Acidification of freshwaters is a global phenomenon, occurring both through natural leaching of organic acids and through human activities from industrial emissions and mining. The West Coast of the South Island, New Zealand, has both naturally acidic and acid mine drainage (AMD) streams enabling us to investigate the response of fish communities to a gradient of acidity in the presence and absence of additional stressors such as elevated concentrations of heavy metals. We surveyed a total of 42 streams ranging from highly acidic (pH 3.1) and high in heavy metals (10 mg L⁻¹ Fe; 38 mg L⁻¹ Al) to circum-neutral (pH 8.1) and low in metals (0.02 mg L⁻¹ Fe; 0.05 mg L⁻¹ Al). Marked differences in pH and metal tolerances were observed among the 15 species that we recorded. Five Galaxias species, Anguilla dieffenbachii and Anguillaaustralis were found in more acidic waters (pH< 5), while bluegill bullies (Gobiomorphus hubbsi) and torrentfish (Cheimarrichthys fosteri) were least tolerant of low pH (minimum pH 6.2 and 5.5, respectively). Surprisingly, the strongest physicochemical predictor of fish diversity, density and biomass was dissolved metal concentrations (Fe, Al, Zn, Mn and Ni) rather than pH. No fish were detected in streams with dissolved metal concentrations > 2.7 mg L⁻¹ and nine taxa were only found in streams with metal concentrations < 1 mg L⁻¹. The importance of heavy metals as critical drivers of fish communities has not been previously reported in New Zealand, although the mechanism of the metal effects warrants further study. Our findings indicate that any remediation of AMD streams which seeks to enable fish recolonisation should aim to improve water quality by raising pH above ≈ 4.5 and reducing concentrations of dissolved Al and Fe to < 1.0 mg L⁻¹.     

Cooperative research on water quality and health parameters in the European community

Research programmes planned and sponsored by the Commission of the European Communities (CEC) are executed by the Joint Research Centre which belongs to the Community (direct action) and through the collaboration of research institutions of the member countries (indirect action). In the tatter case national laboratories carry out investigations under contract with the CEC thus providing scientific and technological data needed in the implementation of Community policies in various fields such as Agriculture, Industrial Affairs, Energy, Environment.To sustain the Community policy on the environment, adopted in 1973, the CEC proposed and the Council of the EC approved, in parallel with direct action programmes, the first Environmental Research Programme of indirect action for the period 1973–1975 and the second Environmental Research Programme of indirect action for the period 1976–1980. Both programmes have contributed to improve the understanding of problems concerning the presence of pottutants in the environment and their ecological and health effects.     

Water quality of Scottish rivers: spatial and temporal trends

The Harmonised Monitoring Scheme (HMS) was initiated in 1974 and represents the best-organised source of temporal and spatial data describing water quality for the major mainland rivers of Scotland, England and Wales. This paper presents the first detailed analysis of HMS data for Scotland, and identifies temporal changes in water quality from 1974 to 1995. From a concomitant analysis of catchment land cover characteristics, water quality indices have been linked with potential 'drivers' of change, influencing both point and diffuse sources. Nitrate concentrations between rivers are highly correlated with the amount of arable land, and relationships exist between grassland cover, orthphosphate-P and suspended solids concentrations. Similarly, urban catchments are highly correlated with ammonium-N, orthophosphate-P and suspended solids. Spatial and temporal trends in water quality for the rivers of Scotland are discussed.     

三维水质模拟、预测及应用

本文主要讨论了三维区域上的水污染质运移模型及其计算机辅助解法 ,并以北京密云水库三氮污染质运移为例 ,阐述了借助计算机处理手段 ,通过水平层面间逐点线性插值成功求解三维水污染质运移模型的数学方法、可靠性分析和程序设计方案