bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of Cryptosporidium with bovine faecal particles and implications for risk reduction by settling within water supply reservoirs
Authors: Brookes Justin D. , Davies Cheryl M. , Hipsey Matthew R. , Antenucci Jason P.
Published: May 2018

Artificial cow pats were seeded with Cryptosporidium oocysts and subjected to a simulated rainfall event. The runoff from the faecal pat was collected and different particle size fractions were collected within settling columns by exploiting the size-dependent settling velocities. Particle size and Cryptosporidium concentration distribution at 10 cm below the surface was measured at regular intervals over 24 h. Initially a large proportion of the total volume of particles belonged to the larger size classes (>17 μm). However, throughout the course of the experiment, there was a sequential loss of the larger size classes from the sampling depth and a predominance of smaller particles (<17 μm). The Cryptosporidium concentration at 10 cm depth did not change throughout the experiment. In the second experiment samples were taken from different depths within the settling column. Initially 26% of particles were in the size range 124–492 μm. However, as these large particles settled there was an enrichment at 30 cm after one hour (36.5–49.3%). There was a concomitant enrichment of smaller particles near the surface after 1 h and 24 h. For Pat 1 there was no difference in Cryptosporidium concentration with depth after 1 h and 24 h. In Pat 2 there was a difference in concentration between the surface and 30 cm after 24 h. However, this could be explained by the settling velocity of a single oocyst. The results suggested that oocysts are not associated with large particles, but exist in faecal runoff as single oocysts and hence have a low (0.1 m d−1) settling velocity. The implications of this low settling velocity on Cryptosporidium risk reduction within water supply reservoirs was investigated through the application of a three-dimensional model of oocyst fate and transport to a moderately sized reservoir (26 GL). The model indicated that the role of settling on oocyst concentration reduction within the water column is between one and three orders of magnitude less than that caused by advection and dilution, depending on the strength of hydrodynamic forcing.
PFGE analysis of enterococci isolates from recreational and drinking water in Greece
Authors: Grammenou Panagiota , Spiliopoulou Iris , Sazakli Eleni , Papapetropoulou Maria
Published: May 2018

Biotyping and DNA fingerprinting by pulsed-field gel electrophoresis were applied to a collection of enterococci recovered from recreational and drinking water, in order to identify possible genetic relationships. Clinical strains of hospital origin were compared to the environmental isolates. A total of 104 enterococci were isolated from 128 recreational water (94 marine and 34 river water) and 470 drinking water supplies (440 municipal and 30 natural spring water samples). Sixty-two isolates were characterised as Enterococcus faecium recovered from all sources, 32 E. faecalis (from all sources), 4 E. durans (from marine, river and municipal water), 4 E. gallinarum (from marine water) and 2 E. avium (from marine and municipal water). Biotypes, determined with API20Strep, among E. faecium were correlated with certain environmental sources, while antibiotypes, determined with Etest, did not reveal any relationship to the sample origin. Even though genetic diversity was observed among the studied strains, common clonal types were also identified in different sources, suggesting a possible common origin of the enterococci. Cluster analysis revealed a genetic relationship between certain environmental E. faecium and clinical strains.
Occurrence of Cryptosporidium oocysts in US wastewaters
Authors: McCuin Randi M. , Clancy Jennifer L.
Published: May 2018

Wastewater samples collected from ten wastewater facilities across the US were analyzed to determine the occurrence of indigenous Cryptosporidium oocysts using methods based on modifications of USEPA Method 1622. Wastewater facilities participating in this study ranged in size from 0.6 to 193 mgd average daily flow. A total of 289 wastewater samples were analyzed over a 15-month period. ColorSeed is a commercial product containing gamma-irradiated Cryptosporidium oocysts that have been permanently stained with a Texas Red dye. ColorSeed was used as an internal control with each sample to assess method performance. In 500 ml sample volumes, mean ColorSeed recoveries in raw influents and primary effluents were 26.1±17.7% and 33.0±17.9%, respectively. In 10 liter volumes of secondary effluent, mean ColorSeed recovery was 25.0±16.6%. Volumes analyzed for tertiary effluent samples ranged from 14.8 l to 131.3 l resulting in a mean ColorSeed recovery of 48.8±14.5%. Indigenous oocysts were detected in 30% of raw influents, 46% of primary effluents, 58% of secondary effluents and 19% of tertiary effluents analyzed. Indigenous oocyst concentrations ranged from <2 to 86 /liter across all wastewater matrices tested.
An attempt to estimate the global burden of disease due to fluoride in drinking water
Authors: Fewtrell Lorna , Smith Stuart , Kay Dave , Bartram Jamie
Published: May 2018

A study was conducted to examine the feasibility of estimating the global burden of disease due to fluoride in drinking water. Skeletal fluorosis is a serious and debilitating disease which, with the exception of one area in China, is overwhelmingly due to the presence of elevated fluoride levels in drinking water. The global burden of disease due to fluoride in drinking water was estimated by combining exposure-response curves for dental and skeletal fluorosis (derived from published data) with model-derived predicted drinking water fluoride concentrations and an estimate of the percentage population exposed. There are few data with which to validate the output but given the current uncertainties in the data used, both to form the exposure-response curves and those resulting from the prediction of fluoride concentrations, it is felt that the estimate is unlikely to be precise. However, the exercise has identified a number of data gaps and useful research avenues, especially in relation to determining exposure, which could contribute to future estimates of this problem.
International waters: identifying basins at risk
Authors: Wolf Aaron T. , Yoffe Shira B. , Giordano Mark
Published: May 2018

Despite the growing literature on water and conflict in international river basins, little empirical work has been done to bolster common conclusions which are so widely reported. In order to address this gap, we set out to assess all reported events of either conflict or cooperation between nations over water resources during the last 50 years and to use these events to inform the identification of basins at greatest risk of political stress in the near future (5-10 years). The study is divided into three components:Compilation and assessment of relevant biophysical, socio-economic and geopolitical data in a global Geographic Information System (GIS), and use of these factors to determine history-based indicators for future tensions along international waterways.Using these indicators, identification of basins at risk for the coming decade.Identification and assessment of the potential for mitigating factors and new technologies resulting in a future different than that predicted by history-based indicators.

In general, we find that most of the parameters regularly identified as indicators of water conflict are actually only weakly linked to disputes, but that institutional capacity within a basin, whether defined as water management bodies or treaties, or generally positive international relations are as important, if not more so, than the physical aspects of a system. It turns out then that very rapid changes, either on the institutional side or in the physical system, which outpace the institutional capacity to absorb that change, are at the root of most water conflict, as reflected in two sets of indicators: 1) “internationalized” basins, i.e. basins which include the management structures of newly independent states, and 2) basins which include unilateral development projects and the absence of cooperative regimes. By taking our parameters of rapid change as indicators-internationalized basins and major planned projects in hostile and/or institution-less basins-we are able to identify the basins with settings which suggest the potential for political stresses in the coming five to ten years. These basins include: the Ganges-Brahmaputra, Han, Incomati, Kunene, Kura-Araks, Lake Chad, La Plata, Lempa, Limpopo, Mekong, Ob (Ertis), Okavango, Orange, Salween, Senegal, Tumen and Zambezi.

We then identify “red flags,” or markers related to these indicators, which might be monitored in the future. Finally, recognizing that history-based indicators may lose validity over time in a rapidly changing world, we ask, “what about the future, which may look nothing like the past,” and focus on four topics: new technologies for negotiation and management; globalization, privatization and the WTO; the geopolitics of desalination; and the changing sources of water and the changing nature of conflict.
A role for GIS-based simulation for empowering local stakeholders in water resources negotiations in developing countries: case studies for two rural hillside watersheds in Honduras and Colombia
Authors: Luijten J. C. , Knapp E. B. , Sanz S. I. , Jones J. W.
Published: May 2018

Water security for those living in poverty is a concern for a broad range of policy makers. Identifying appropriate policy options, however, means coping with complexity and uncertainty inherent in natural and human systems. This paper demonstrates how geographical information systems and simulation modeling can facilitate scenario analysis of water availability and water security. The result is policy development with a strong human context that can empower stakeholders in water resources negotiations and the design of a science-based, community-supported water resources management plans. We applied these tools to two hillside watersheds in Honduras and Colombia to generate basic information about the “state of water resources”, and how they may change over space and time, for the present situation and under alternatives futures. Stakeholder participation in creating and analyzing scenarios is a critical part of the overall policy development methodological framework, so that what might otherwise be only lines on a graph is put into more concrete human terms. The analyses showed that, among others, stream water availability and the location of streams strongly vary throughout the year and over space; that different parts of the watersheds do not equally contribute to stream water; that inequalities exist in household accessibility to streams; and that dams could help supply sufficient irrigation water under alternative development scenarios without endangering water supply to downstream communities. These results are helpful for better understanding landscape processes at a watershed scale, for identifying desired future conditions and negotiating tradeoffs that are required to reach them, and for supporting water policy development.
How can stakeholder participation improve European watershed management: the Water Framework Directive, watercourse groups and Swedish contributions to Baltic Sea eutrophication
Authors: Blomqvist Anna
Published: May 2018

Nutrient losses from agricultural land constitute an important part of the total flow of nutrients to lakes and seas in Sweden and the Baltic region. With the Water Framework Directive, to be implemented shortly throughout Europe, emphasis is increasing on the role of stakeholder participation and decentralisation of various responsibilities from authorities to groups in the civil society. This paper investigates a Swedish case where local watercourse groups (WCGs) have formed in order to be involved more actively in the efforts to reduce nutrient losses from agricultural lands. This paper presents a qualitative analysis of the institutional landscape surrounding WCGs, goals, goal formulation and space of action.
Resilience and flood risk management
Authors: de Bruijn K.M.
Published: May 2018

Since flood disasters still occur and even increase in frequency and severity, flood risk management must be reconsidered. This paper describes a new way of looking at flood risk management by applying a systems approach. This approach may result in flood risk management that is better suited to the socio-economic context in which this flood risk management occurs. The systems approach allows the definition of resilience and resistance strategies for flood risk management. Resistance strategies aim at flood prevention, while resilience strategies aim at minimising flood impacts and enhancing the recovery from those impacts. A resilience strategy is supposed to be able to better cope with uncertainties than a resistance strategy. To enable the evaluation of resilience and resistance strategies under different conditions the concepts of resilience and resistance must first be sufficiently understood. This paper discusses the meaning of resilience and resistance and applies the concepts to flood risk management systems. This discussion is exemplified by The Netherlands' flood risk management.
International efforts to improve access to water and sanitation in the developing world: a good start, but more is needed
Authors: Hecht Alan D.
Published: May 2018

Considerable international efforts are underway to address water and sanitation needs in developing countries. The 2003 G8 Action Plan on water sets the right tone, but more is needed. Three activities deserve additional support and greater cooperation between government and non-government organizations. These are: immediate steps to improve health and sanitation, multilateral efforts to foster good governance, and the development of innovative financial mechanisms to make local and investment capital available for water infrastructure development. Public understanding of these three approaches is often misunderstood, as evinced by the Stakeholder Dialogue at the 2003 World Water Forum. Achieving the Millennium goals on water and sanitation requires greater public and private sector cooperation in these three areas. A significant accomplishment for the next G8 meeting would be to strengthen partnerships between public and private sectors in these areas.
Perspective: Positive experiences from Africa in water, sanitation and hygiene
Authors: Lane Jon
Published: May 2018

Nowhere in the world is poverty more visible, more destructive and more pervasive than in Africa. Too often, Africa is associated with stories of failure and pessimism, of wars and famines, floods and unrest. Africa appears to be slipping back on many development indicators, even as other parts of the world move ahead.

In 2003, however, there are prospects of achieving progress in water, sanitation and hygiene in Africa. Across the continent, there is a strong sense of the need for peace, democracy and co-operation. Through the Highly Indebted Poor Countries initiative, industrialised countries are finally proposing to write off a significant part of the debt into which the poorest countries have fallen. Many African countries have written Poverty Reduction Strategy Papers, which give clarity and direction to the development work in those countries. Within the water sector itself, the African Ministerial Conference on Water (AMCOW) has been formed to share ideas and lessons and to provide mutual support and active direction. Recent meetings, especially the World Summit on Sustainable Development (August 2002), are giving fresh political impetus to this work.

This paper suggests five priorities for achieving the water and sanitation Millennium Development Goals in Africa. It relates them to practical examples of inspiring and positive initiatives in water and sanitation from across the continent. These examples have worked, or have the potential to work, at a large scale, are demonstrably sustainable, and do not benefit from too many unique local conditions. These characteristics enable the lessons from these examples to be useful for other people in, and indeed outside, Africa.
In pursuit of the millennium development goals in water and sanitation
Authors: Brown Casey , Holcombe Arthur
Published: May 2018

In recognition of the United Nations designating 2003 as the “Year for Fresh Water” and the endorsement of the Millennium Development Goals (MDG) in water and sanitation, the United Nations Association of Greater Boston (UNA-GB) convened speakers to address strategies for meeting these goals. Water professionals from the public sector, private sector and non-governmental organizations shared their experiences and recommendations. Over the course of the discussions, three themes emerged that appear critical for implementing successful water initiatives. First, the water and sanitation. nancing gap requires mobilization of local capital through innovative financial tools. Second, public institutions that manage water must be focused and enabled to carry out their mandate effectively. Private sector collaboration can only succeed when coupled with strong public partners. Third, the MDG cannot be met with conventional technological approaches. Technology must be appropriate to the. nancial and technical context to which it is applied and must engender ef.cient use of water resources.
Targeting the water-poor through water poverty mapping
Authors: Cullis James , O Regan Dermot
Published: May 2018

This paper shows how water poverty mapping using census data and the Water Poverty Index can be used to identify effectively the most water-poor households in a region for the targeting of water supply development policies and projects. The main findings come from a case study conducted in the Estcourt municipal district in South Africa where simple water poverty maps were developed using readily available data sources at three different scales: enumerator area, place names and sub-catchment. The efficiency of targeting the most water-poor households using the different scales of water poverty maps were measured by comparing both the inclusion and exclusion rates of targeting and comparing them with other similar targeting studies. The distribution of water poverty within a community was also compared with the results of a detailed household questionnaire conducted as part of the broader development of the water poverty index (WPI). The main conclusion from the study is that water poverty mapping is a strong visual extension of the WPI that has great potential for providing a practical way for water management authorities and decision makers to identify and target the most water poor households and monitoring the impacts and tangible benefits of water supply development policies.
Assessing customer preferences for water supply options using mixed methodology choice experiments
Authors: Powe N. A. , Garrod G. D. , McMahon P. L. , Willis K. G.
Published: May 2018

A range of alternatives are available to water companies in the UK for reducing future water supply deficits, each having different implications in terms of environmental impacts (both positive and negative), level of service provided to customers and associated costs. This paper presents the results of two choice experiment valuation studies in the south east of England, in which water supply problems are considered. Further to the specifics of the individual scenarios, these studies lead to more general observations relevant to the future evaluation of water supply options, namely: at the current level of supply reliability, there is a reluctance to pay for any improvement in reliability; where future increases in supply reliability are required, water customers are generally willing to pay more in water charges in order to prevent negative environmental impacts; and, to a lesser extent, customers are willing to pay for water supply operations that would bring about environmental improvements, although this depends on the type of improvements considered and may require greater efforts on the part of water companies to gain consumer acceptance. In order to explore the meaning and validity of these principles further, a more generic choice experiment was designed and studied using post-questionnaire focus group analysis. Although the qualitative results provide further support for these principles, they also illustrate the difficulties inherent in asking the general public to value unfamiliar goods and the challenges that this raises for future design and analysis.
Integrated coastal zone and river basin management: a review of the literature, concepts and trends for decision makers
Authors: Massoud May A. , Scrimshaw Mark D. , Lester John N.
Published: May 2018

River management has frequently been associated with water supply and resource management, whereas coastal zone management has been more concerned with marine resource management and physical planning. Recognizing the close connection between the river and its catchment area has led to a more integrated approach to river basin management, taking into account water quality along with quantity. Similarly, recognition of the importance of integrated management of the coastal zone as a move towards achieving sustainable development, has led to integrated coastal zone management, with expansion of the domain in both landward and seaward directions. Considering the intrinsic link through physical and ecological structure as well as related physical and biological processes, any modification in a river basin will ultimately affect the coastal zone. Land-based activities, rivers, estuaries, coastal zones and marine environments are all inherently interlinked. As such, an integrated approach to the concomitant management of coastal zones and river basins is crucial. This paper provides an overview of various concepts, approaches and strategies to integrated coastal zone and river basin management. It points out lessons that could be learned from previous and ongoing projects. The paper provides a starting point for investigating how changes in land use and management of river basins might have an impact on the quality of river water and the corresponding coastal zone through scrutinization of management tools and implementation instruments. The paper identifies a requirement further to develop tools which will assist in evaluating current and future environmental conditions at a river/estuary/sea interface within a rigorous framework.
The benefits of combining lay and expert input for water-management planning at the watershed level
Authors: Rinaudo Jean Daniel , Garin Patrice
Published: May 2018

With the promulgation of the EC Water Framework Directive (WFD), stakeholders’ involvement in water management planning and public consultation has become mandatory for member states. This paper investigates the case of France, where water management has been based on a distinctive form of “participatory democracy” for over 40 years. It first analyses how public participation and expert opinion fit into the water-management planning procedure and compares this to what occurs elsewhere in Europe and the United States. It then proposes an operational method for initiating the participatory process with an analysis of the stakeholders' viewpoint at the watershed level. The method, which relies on interviews, is applied to two watersheds located in southern France. The results of the two case studies illustrate how the stakeholders' viewpoint analysis can give access to practical knowledge and experience and to a wider range of perspectives and options. The case studies highlight the idea that the mobilisation of non-scientific (or lay) knowledge, values and preferences can improve the quality of the identification of the issues at stake, the formulation of a generally complex and unstructured problem and the identification of a large panel of alternative solutions. The paper then proposes some recommendations for implementing the provisions of the WFD.
Exporting fresh water: is there an economic rationale?
Authors: Dore Mohammed H.I.
Published: May 2018

With a growing world population and changing patterns of global precipitation, researchers are examining a number of options in the management and supply of fresh water to areas where the demand for fresh water is outstripping local availability. These options include bulk water exports as well as the establishment of desalination plants. This paper argues that three key factors will determine the possibility of such trade. These factors are: (a) the travelling distance of the marine vessels from the fresh water source to the population, (b) the cost of capital and (c) the average expected utilization rate of local desalination plant. It concludes that the supply of bulk water transported by single hulled marine vessels is economically viable if the distance is less than 548 miles (884 km). For greater distances, the cost of drinking water production using desalination technology is cost effective. In any case the supply of these single hulled marine vessels is limited, as new ones are unlikely to be built for water only. Thus local communities are unlikely to lose control over water resources owing to export trade.
Temporary water trading trends in northern Victoria, Australia
Authors: Zaman Asif M. , Davidson Brian , Malano Hector M.
Published: May 2018

Temporary water trading is now well established in the Goulburn-Broken Catchment irrigation sector, which is located in northern Victoria, Australia. The operation of the Victorian water exchange (Watermove) has, for the past five years, facilitated this trade. In this paper a review of the market activities over this period is provided. Data from Watermove is analysed to determine the main annual and monthly trends in the trade. It is shown empirically that the water market is displaying signs of maturity and a distinct seasonal pattern for the volumes traded and the market water price has developed.
Watershed management: review of Canadian diversity
Authors: Senecal Catherine , Madramootoo Chandra A.
Published: May 2018

Watershed management combines the concept of the watershed as the most appropriate spatial management unit for water resources and the concept of integrated water resources management. The movement toward this form of management has resulted in the emergence of new forms of governance in Canada. The Canadian water management context has resulted in various forms of river basin management organizations co-existing within the same country. Four examples are presented of river basin management organizations as they have evolved in Ontario, British Columbia, Quebec and the Prairies, with emphasis on government policy, organizational structure, roles and responsibilities, sources of funding and implementation of integrated watershed management programs and policies. These case studies are selected because they range from government institutions to organizations partially supported by government, to grass roots and stakeholder involvement models, reflecting different levels of funding and stakeholder participation.
Empowering communities to carry out drought contingency planning
Authors: Durley Jennifer L. , de Loë Rob C.
Published: May 2018

Drought is a pervasive natural hazard, even in relatively water rich areas such as the Province of Ontario, Canada. A common response to drought in many jurisdictions has been crisis management, especially involving drought relief during or after a drought event. Proactive drought contingency planning, which takes a risk management approach to reduce vulnerability, is much more appropriate. Unfortunately, the extent to which local communities have the capacity to participate effectively in this activity is highly variable. This paper explores factors that facilitate and constrain locally led drought contingency planning and highlights several that relate to management capacity, or the ability of local actors to accomplish their objectives and participate effectively in implementing appropriate drought responses. Drought planning experiences in Australia and the United States are used to frame an evaluation of Ontario's new drought contingency planning approach. We conclude that while Ontario's approach has many desirable features (e.g. organized around watersheds; locally driven), it also has several shortcomings, relating especially to the way in which droughts are understood, coordination of roles and responsibilities and community disempowerment during severe droughts.
Water in the economy of Tamil Nadu, India: more flexible water allocation policies offer a possible way out of water-induced economic stagnation and will be good for the environment and the poor
Authors: Bhatia Ramesh , Briscoe John , Malik R. P. S. , Miller Lindy , Misra Smita , Palainisami K. , Harshadeep N.
Published: May 2018

The state of Tamil Nadu, India, is in the grips of a water crisis, with demand far outstripping supply. As the economy of the state grows, this crisis is going to become ever more serious. To date the focus of state water policy has been on trying to augment supplies, from within the state (even from desalinization) and from neighboring states. In addition, the water use is regulated in a way that does not encourage the highest value uses. International experience shows that supply-side measures must be complemented by demand-side measures and that practice must move away from fixed, command-and-control allocation policies towards flexible allocation mechanisms, which facilitate the voluntary movement of water from low to high-value uses.

This study addresses the question of whether such a change in allocation policies is worth doing. It addresses this question by developing optimization models for each of the 17 river basins in Tamil Nadu (including an assessment of the economic value of water in different end-uses – agriculture, domestic and industry), then using an input–output model embedded in a social accounting matrix (SAM), to assess the impact of these changes on the state economy and on different rural and urban employment groups.

The results suggest that a shift to a flexible water allocation system would bring major environmental, economic and social benefits to the state. Compared with the current “fixed sectoral allocation” policy, a flexible allocation policy would, in 2020, result in 15% less overall water used; 24% less water pumped from aquifers; 20% higher state income; with all strata, rich and poor, benefiting similarly, with one important exception, that of agricultural laborers.
Limits to donor-driven water sector reforms: insight and evidence from Pakistan and Sri Lanka
Authors: Bandaragoda D. J.
Published: May 2018

Two countries in South Asia, Pakistan and Sri Lanka, have embarked upon innovative measures for restructuring their institutional framework for water resources management. Both of these countries have a colonial heritage. Most of their current institutional arrangements for water resources management, particularly in the irrigation sub-sector, are greatly influenced by the laws and administrative procedures introduced during the British colonial period. In the wake of massive investment programmes sponsored by international development aid after independence, each of the two countries has collaborated with donor agencies in designing new institutional development packages. Despite similarities in terms of donor interests, the two countries seemed to be proceeding along different reform paths. Pakistan experimented with an overall change in the irrigation institutions, whereas, Sri Lanka focused on coordinating mechanisms for integrated water resources management at both river basin and national levels. In both of these cases, the progress of reform attempts seems to be grinding to a halt owing to lack of an internally generated demand for reforms.
Gender and water management: some policy reflections
Authors: Singh Nandita , Jacks Gunnar , Bhattacharya Prosun , Gustafsson Jan-Erik
Published: May 2018

The importance of gender concern in water sector is paramount, being seen as the harbinger of greater efficiency and effectiveness as well as equity. Consequently, there has been a continuing trend of designing water management policies with emphasis ranging from promoting participation of women in management of water projects in particular to supporting “gender-balanced” development of the water sector in general. How effective have these policies been in addressing such basic concerns? What are the local water users' perceptions about effectiveness of the policies in addressing their realistic gendered needs and priorities? While “women” have received much attention, how well does the gender concern in the policies integrate “men”? Do “effectiveness” and “equity” as underlying policy goals reflect the water users' perceptions as well? The paper attempts to evaluate the existing policies within the context of local communities where these are operational and proposes “facilitation of gender role performance” as a suitable policy alternative.
Enhanced coagulation: a viable option to advance treatment technologies in the South African context
Authors: Freese S. D. , Nozaic D. J. , Pryor M. J. , Rajagopaul R. , Trollip D. L. , Smith R. A.
Published: May 2018

Laboratory and pilot scale tests were conducted to compare the effectiveness of enhanced coagulation with the more advanced technologies of ozone and granular activated carbon in treating a range of clean, eutrophic and industrially polluted waters. Particular attention was paid to the removal of disinfectant by-product precursors, organics and micropollutants that could be achieved using the various types of treatment. Reductions of up to 50% trihalomethane formation potential and between 40 and 70% organic carbon and colour were obtained using enhanced coagulation, which compared favourably with the advanced treatment processes. The more sophisticated processes were especially effective in the removal of micropollutants, this generally being in excess of 70%, which was not achievable using enhanced coagulation. pH depression using acid addition allowed for increases in organics removal at lower coagulant doses and inorganic coagulants were found to be more effective than the polymeric coagulants for organic matter removal. It was shown that the advanced treatment processes became more cost effective for larger plants and as water quality deteriorates, but for smaller water works, enhanced coagulation is cheaper.
Determination of cadmium and lead in water - new recommended way of evaluating the limits of detection and quantification
Authors: Mocak J. , Bobrowski A.
Published: May 2018

Traditional and the new IUPAC recommended calculation methods for determining the limit of detection and the limit of quantification are applied to the trace determination of cadmium and lead in water. The new method is based on the upper limit approach (ULA), which utilises the one-sided confidence band around the calibration line. The residual standard deviation of the calculated calibration line as well as the t-distribution critical value are used for the calculation of both limits. An appropriate design of the calibration experiment is described. The calculation of both limits in the new way is extremely easy when the calibration experiment is equidistantly designed.
Phosphorus mass-quantity change in Lake Biwa
Authors: Nagare H. , Somiya I. , Fujii S. , Morita M.
Published: May 2018

To understand the eutrophication phenomena in Lake Biwa, Japan, a research project for the water quality formation processes was executed. This paper presents phosphorus mass changes in water body in Lake Biwa from April 1995 to January 2000 and discusses the main factors of the change. Phosphorus mass ranged from 190 to 350 t, with an average of 260 t. DP mass in 1995, '97 and '98 showed seasonal change patterns, while non-periodical phenomena seemed to control the PP mass. Phosphorus mass was increased about 15 t in epilimnion from April to July while nitrogen showed a 50 t decrease. This disagreement suggests that some processes selectively accumulated phosphorus in epilimnion during this period. However, such an increase in phosphorus was not observed in 1996 and '99. Air temperature was lower and much snowfall was recorded in 1996 and '99, suggesting that coldness in winter season weakened the phosphorus accumulation process to depress the mass in epilimnion in summertime. Water temperature increase seemed to be delayed in proportion to total snowfall, but thermocline was formed independently of coldness. Hence, the idea was abandoned that the delay of thermocline formation encouraged the sedimentation process, and biological activities were considered to be the main factor controlling phosphorus mass in the epilimnion in Lake Biwa.
Effects of the H2O2 concentration and spectral distribution of the UV lamp output power on the photooxidation of a water pollutant
Authors: Alfano O.M. , Martínez M.J. , Brandi R.J. , Cassano A.E.
Published: May 2018

Previous kinetics studies have been extended to analyze some practical issues concerning this process. Hence, in this work we have studied additional aspects of the H2O2 enhanced, UV degradation of 2,4-dichlorophenoxyacetic acid (2,4-D), namely: (i) the effect of the H2O2/2,4-D initial molar ratio and (ii) the effect of the irradiation power and, particularly, the characteristics of the wavelength distribution of the lamp output emission. The work was done on a well stirred, discontinuously operated tank reactor irradiated from its bottom. A UV, tubular lamp and a cylindrical reflector of parabolic cross section were used [actually, two germicidal lamps (254 nm) of different output power per unit lamp length and a medium pressure, mercury arc lamp with polychromatic emission between 220 and 760 nm]. 2,4-D concentration and TOC were the main variables used to investigate the degradation rate. There is an optimal initial concentration ratio for each 2,4-D initial concentration. It was also observed that increasing the lamp output power at 254 nm (output from 0.08 W/cm to 0.6 W/cm) favors the reaction rate. However, much more significant is the effect produced by employing a polychromatic lamp with some emission below 254 although this photonic contribution is relatively small (just 0.21 W/cm below 250 nm). A kinetic model, having parameters independent of the reactor configuration and derived from mechanistic considerations was used to analyze the experimental data.
The use of nanofiltration for the removal of pesticides from groundwater: an evaluation
Authors: Van der Bruggen B. , Everaert K. , Wilms D. , Vandecasteele C.
Published: May 2018

This study explores the combined removal of four pesticides (atrazine, simazine, diuron, isoproturon) and hardness from groundwater with nanofiltration (NF). Four NF membranes were used: NF45 and NF70 (Dow/FilmTec), and UTC-20 and UTC-60 (Toray Ind. Inc.). Each pesticide was added to groundwater samples in a concentration of 1 μg/l, representative for contaminated sources. For the determination of pesticides in such low concentrations, an analytical method using solid-phase extraction and high performance liquid chromatography was elaborated.

The retentions with NF were compared and explained by means of molecular size and dipole moment. Molecular size, expressed as an effective diameter representing the projection of the molecule on the membrane surface, was calculated by determining the energetically most favourable molecular configuration. The largest molecules had the highest retentions, when all other properties are comparable. A high dipole moment decreases retentions because of charge interactions with the membrane.

The hardness retentions were high. For drinking water production, it might be necessary to add hardness after filtration.

The groundwater flux was approximately 5% lower compared to the distilled water flux. This relatively small flux decline indicates pore blocking due to adsorption in the membrane pores. The flux decline was proved reversible; no membrane fouling occurred.
Removal of arsenate from drinking water with a natural manganese oxide in the presence of competing anions
Authors: Ouvrard S. , Simonnot M.-O. , Sardin M.
Published: May 2018

The efficiency of arsenic removal from drinking water in adsorption processes using natural oxides may be influenced by the presence of other adsorbable anions. The present paper focuses on the study of arsenate adsorption by a natural manganese oxide. The objective is to determine which of the anions usually present in drinking water may be adsorbed: hydrogen carbonate, sulfate, chloride, nitrate, phosphate and arsenate. A kinetic batch experiment was conducted with a natural drinking water, leading to a first qualitative selection: nitrate and chloride have little interaction with the adsorbent, sulfate and hydrogen carbonate are adsorbed while phosphate and arsenate are strongly adsorbed. Then column experiments were run with aqueous solutions containing either chloride, sulfate, etc. The previous trends were confirmed and the equilibrium isotherms of the adsorbable anions were built by integration of the breakthrough curves. The isotherms fitted with a Langmuir model showed that the capacitieswere low (a few μmol.g-1). The affinity order was determined from the isotherm initial slopes: arsenate ≫ phosphate > hydrogen carbonate ≌ sulfate. Given the strong affinity of the adsorbent for arsenate and the low arsenate concentration in drinking water, the process selectivity for As traces from drinking water is ensured.
Trihalomethane (THM) reduction in Istanbul water treatment plants
Authors: Saatçı A.M. , Eroğlu V.
Published: May 2018

This paper describes trihalomethane reduction in an Istanbul drinking water plant. The total THM levels (TTHM) could be controlled by decreasing the post-chlorination doses. After the commencement of the pre-ozonation process, pre-chlorination was terminated and a sudden drop of THM values in the effluent of the plant was observed. A predictive model that gives a good fit to the observed TTHM levels during the 7 months operation of the plant with and without the pre-ozonation process was presented.
Model of leak inspection and repair of water distribution network
Authors: Hosoi Y.
Published: May 2018

Theories and policies for the maintenance and renewal of water supply systems are required. The occurrence of water distribution pipe breakage and water leakage is influenced by pipe material, size and age as well as soil characteristics and transportation. The water leakage has to be discovered as soon as possible from the viewpoint of minimizing water loss. However, it costs more to increase inspections for water leakage. In this study, the model to determine the optimal inspection interval for water leakage of the water distribution network was examined. The optimal inspection interval was estimated to minimize the total cost of inspection, pipe repair and lost water. The developed model was applied to a water distribution area whose water main is 486 kilometres long. The area was divided into sub-area of 250 metres square. Those sub-areas were classified into 6 groups according to pipe break rate. The optimal inspection interval was obtained for each group and its validity examined by numerical simulation.
Incorporation of advection and adsorption in modeling ground water quality
Authors: Aniszewski A.
Published: May 2018

A one-dimensional model of groundwater flow, incorporating advection and adsorption of conservative pollutants has been presented. Based on earlier laboratory experiments on physical models and adopting the numerical solution of the presented mathematical model, the adsorption parameters k1 and n have been calculated for a non-linear function describing this process. Empirical relationships for the adsorption parameters characteristic of the aquifer and the ground water flow have been developed. These relationships should allow for better forecasting and estimation of groundwater quality at the intake.
The influence of drinking water quality on the corrosion of stainless steel EN 1.4401 (SS 2347)
Authors: Elfström Broo A. , Berghult B. , Hedberg T.
Published: May 2018

The corrosion and heavy metal release of stainless steel EN1.4401 (SS 2347) into drinking water was studied using potentiodynamic sweeps and chronoamperometry together with test rigs located in four Swedish municipalities. The influence of the drinking water quality on the corrosion was found to be very low. The corrosion increased with increasing total carbonate content and increasing content of natural organic matter. The results imply the action of surface complexation. Heavy metal release in stagnant water was in the vicinity of the detection limit. Nickel leaching was observed on some occasions shortly after installation. The nickel release disappeared after a few weeks. Surface analysis of the internal pipe surface after 9-12 months of exposure revealed no indication of local corrosion.
Metallic materials in Danish supply water systems
Authors: Nielsen K.
Published: May 2018

Characteristic corrosion phenomena and materials selection in hard supply water areas in Denmark are reviewed. Both corrosion failures and metal release are described. Even though good protective layers can be formed in the majority of cast iron pipes, the ease of installation and the corrosion resistance of plastic pipes result in the use of medium- and high-density polyethylene and polyvinylchloride (PEM, PEH and PVC) for new pipes. Corrosion is problematic in domestic pipes. Due to localised corrosion, selective attack of the zinc-layer and zinc release, galvanised steel gives too many problems. The copper release from copper pipes is too high after stagnation. The tendency is to preferentially use the more resistant materials such as stainless steel and crosslinked polyethylene (PEX), for domestic pipes. Possible higher microbial growths in plastic pipes are under investigation.
Direct coagulation pretreatment in nanofiltration of waters rich in organic matter and calcium
Authors: Schäfer A. I. , Fane A.G. , Waite T.D.
Published: May 2018

Nanofiltration (NF) can remove natural organic matter (NOM) and multivalent ions from surface waters. Large hydrophobic organics and calcium ions are responsible for irreversible fouling of nanofiltration membranes and thus a decrease of process efficiency and increase in cleaning requirements. Fouling due to the precipitation of organic-calcium complexes and the impact of colloids and coagulant (FeCl3) on the precipitation of these species was investigated. Coagulation in solution (as opposed to in the boundary layer) did not cause significant flux decline and was able to prevent irreversible fouling under conditions which were previously determined as detrimental. The rejection was varied if a strongly charged solid was deposited on the membrane.
Polar and non-polar aromatic micropollutants in water (drinking-water) resources
Authors: Literathy P.
Published: May 2018

Aromatic compounds are important contaminants that limit the intended uses of water resources. Both polar and non-polar substances, such as phenols, aromatic sulfonates, lignin-sulfonic acids, humic and fulvic substances (acids) and mono- and poly-aromatic hydrocarbons, their alkyl-substituted derivatives, respectively, are among the potential aromatic micropollutants. During the last 5 - 10 years, an analytical approach has been developed on the basis of total fluorescence measurement of the original water sample and its organic solvent (cyclohexane) extract. It has been demonstrated and verified that polar aromatic compounds fluoresce only in the original water sample, whereas non-polar (hydrophobic) compounds fluoresce in an organic solvent (e.g. cyclohexane) extract. During extraction, polar compounds remain in the water sample. This method has been used in a country-wide survey in drinking water aquifers, as well as in several environmental impact assessment studies, particularly for petroleum-related pollution. It is a very convenient method to determine the naturally occurring humic and fulvic substances in water and has proved to be an appropriate substitute of the infrared spectrophotometric method for oil pollution assessment in the environment, also having the advantage of signalling more harmful, toxic aromatic petroleum hydrocarbons.