bluuebunny/crossref_metadata_2025 huggingface dataset:
Phenotypic and genotypic identification of Aeromonas spp. isolated from a chlorinated intermittent water distribution system in Lebanon
Authors: Tokajian Sima , Hashwa Fuad
Published: May 2018

Aeromonas spp. were detected in samples collected from both untreated groundwater and treated drinking water in Lebanon. Aeromonas spp. levels ranged between 2 and 1,100 colonies per 100 ml in the intake underground well and between 3 and 43 colonies per 100 ml in samples from the distribution system. Samples positive for Aeromonas spp. from the network had a free chlorine level ranging between 0 and 0.4 mg l −1. Multiple antibiotic-resistance was common among the isolated aeromonads; all were resistant to amoxycillin while 92% showed resistance to cephalexin. Haemolysis on blood agar was detected in 52% of the isolates recovered from the distribution network and 81% of isolates from the untreated underground source. The Biolog microbial identification system assigned identities to all of the isolated presumptive aeromonads (at least at the genus level), which was not the case with the API 20NE strips. Differences at the species level were observed when results from the Biolog system were compared with identification based on the MicroSeq 500 16S rDNA sequence analysis. The presence of Aeromonas spp. in drinking water can be an important threat to public health, thus greater awareness of Aeromonas strains as potential enteropathogens is warranted.
Chlorination by-products (CBPs) in drinking water and adverse pregnancy outcomes in Italy
Authors: Aggazzotti Gabriella , Righi Elena , Fantuzzi Guglielmina , Biasotti Barbara , Ravera Gianbattista , Kanitz Stefano , Barbone Fabio , Sansebastiano Giuliano , Battaglia Mario Alberto , Leoni Valerio , Fabiani Leila , Triassi Maria , Sciacca Salvatore ,   Collaborative Group for the Study of Chlorinated Drinking Waters and Pregnancy
Published: May 2018

Chlorination by-products (CBPs) in drinking water have been associated with an increased risk of adverse pregnancy outcomes, including small for gestational age at term (term-SGA) and preterm delivery. Epidemiological evidence is weakened by a generally inaccurate exposure assessment, often at an ecological level.

A case control study with incident cases was performed in nine Italian towns between October 1999 and September 2000. A total of 1,194 subjects were enrolled: 343 preterm births (26th–37th not completed week of pregnancy), 239 term-SGA (from 37th completed week, and weight less than the lowest 10th percentile) and 612 controls. Exposure was assessed both by applying a questionnaire on mothers' personal habits during pregnancy and by water sampling directly at mothers' homes.

Levels of trihalomethanes (THMs) were low (median: 1.10 µg l−1), while chlorite and chlorate concentrations were relatively high (median: 216.5 µg l−1 for chlorites and 76.5 µg l−1 for chlorates). Preterm birth showed no association with CBPs, while term-SGA, when chlorite levels ≥200 µg l−1 combined with low and high levels of inhalation exposure are considered, suggested a dose-response relationship (adjusted-Odds Ratios (ORs): 1.52, 95%CI: 0.91–2.54 and 1.70, 95%CI: 0.97–3.0, respectively). A weak association with high exposure levels of either THMs (≥30 µg l−1), or chlorite or chlorate (≥200 µg l−1) was also found (adjusted-OR: 1.38, 95%CI: 0.92–2.07). Chlorine dioxide treatment is widespread in Italy; therefore, chlorite levels should be regularly and carefully monitored and their potential effects on pregnancy further evaluated and better understood.
The effectiveness of a multi-spark electric discharge system in the destruction of microorganisms in domestic and industrial wastewaters
Authors: Anpilov A. M. , Barkhudarov E. M. , Christofi N. , Kop'ev V. A. , Kossyi I. A. , Taktakishvili M. I. , Zadiraka Yu. V.
Published: May 2018

The aim of this work was to investigate the effectiveness of a high voltage multi-spark electric discharge, with pulse energy of 1 Joule, in killing microorganisms in wastewater. Wastewater from primary treated effluent arising from domestic and industrial sources was abstracted for continuous pulsed discharge disinfection. The wastewater contained a large mixed population of microorganisms (∼107 CFU ml−1 [109 CFU 100 ml−1] total aerobic heterotrophic bacteria) including vegetative cells and spores. The electrical conductivity of the wastewater ranged from 900–1400 μS cm−1 and it was shown that a specific energy of 1.25–1.5 J cm−3 was required to achieve 1 log reduction in bacterial (faecal coliforms/total aerobic heterotrophs) content. This is higher than that previously shown to reduce the population of E. coli in tap water of low conductivity, demonstrating the role of total wastewater constituents, including dissolved and particulate substances, water colour and the presence of microbial spores, in effective disinfection. The system can be engineered to eradicate microbial populations to levels governed by legislation by increasing treatment time or energy input.
Home water treatment by direct filtration with natural coagulant
Authors: Babu Raveendra , Chaudhuri Malay
Published: May 2018

Seeds of the plant species Strychnos potatorum and Moringa oleifera contain natural polyelectrolytes which can be used as coagulants to clarify turbid waters. In laboratory tests, direct filtration of a turbid surface water (turbidity 15–25 NTU, heterotrophic bacteria 280–500 cfu ml−1, and fecal coliforms 280–500 MPN 100 ml−1), with seeds of S. potatorum or M. oleifera as coagulant, produced a substantial improvement in its aesthetic and microbiological quality (turbidity 0.3–1.5 NTU, heterotrophic bacteria 5–20 cfu ml−1, and fecal coliforms 5–10 MPN 100 ml−1). The method appears suitable for home water treatment in rural areas of developing countries. These natural coagulants produce a ‘low risk’ water; however, additional disinfection or boiling should be practised during localised outbreaks/epidemics of enteric infections.
Neurosensory effects of chronic exposure to arsenic via drinking water in Inner Mongolia: II. Vibrotactile and visual function
Authors: Otto David , Hudnell H. Kenneth , Mumford Judy , Geller Andrew , Wade Timothy , Li Yanhong , Xia Yajuan , Wu Kegong , He Linlin , Ning Zhixiong , Zhao Baixiao , Kwok Richard
Published: May 2018

This study was designed to assess the effects of exposure to arsenic in drinking water on visual and vibrotactile function in residents of the Bamen region of Inner Mongolia, China. Arsenic was measured by hydride generation atomic fluorescence. 321 participants were divided into three exposure groups– low (non-detectable-20), medium (100-300) and high (400-700 μg /l) arsenic in drinking water (AsW). Three visual tests were administered: acuity, contrast sensitivity and color discrimination (Lanthony's Desaturated 15 Hue Test). Vibration thresholds were measured with a vibrothesiometer. Vibration thresholds were significantly elevated in the high exposure group compared to other groups. Further analysis using a spline regression model suggested that the threshold for vibratory effects is between 150-170 μg /l AsW. These findings provide the first evidence that chronic exposure to arsenic in drinking water impairs vibrotactile thresholds. The results also indicate that arsenic affects neurological function well below the 1000 μg /l concentration reported by NRC (1999). No evidence of arsenic-related effects on visual function was found.
Effects of large-scale poultry farms on aquatic microbial communities: A molecular investigation
Authors: Ringbauer Joseph A. , James Joseph B. , Genthner Fred J.
Published: May 2018

The effects of large-scale poultry production operations on water quality and human health are largely unknown. Poultry litter is frequently applied as fertilizer to agricultural lands adjacent to large poultry farms. Run-off from the land introduces a variety of stressors into the surface waters including nutrients, antimicrobials and pathogenic bacteria. The Delaware, Maryland and Virginia (Delmarva) Peninsula has the highest concentration of broiler chickens per farm acre in the United States and provides an ideal location for studying the effects of stressors from poultry farms. We investigated potential effects by characterizing shifts in the structure of aquatic bacterial communities. DNA was isolated from microorganisms in water samples from streams and rivers at varying distances from, or having different frequencies of, litter applications. Fingerprints of 16S rDNA amplicons from bacteria in water samples collected during late summer 2001 to late spring 2002 were produced by denaturing gradient gel electrophoresis (DGGE). A statistical analysis of multiple fingerprints from each sampling location demonstrated that each site harboured a bacterial community significantly different from the communities at other sites. Similarly, the bacterial communities from each sampling time differed significantly from communities at other sampling times. Most importantly, a competitive, library-based analysis showed time of sampling (month) had a greater effect on community structure than did location.
Efficacy of oligodynamic metals in the control of bacteria growth in humidifier water tanks and mist droplets
Authors: Collart David , Kepner Bryan , Mehrabi Sharifeh , Robinson Liah , Mintz Eric A.
Published: May 2018

Antimicrobial capsules were evaluated for their effectiveness to control bacterial contamination of cool mist humidifiers. These capsules contain a mixture of silver and copper promoted alumina beads designed to release low concentrations of these oligodynamic metals into the reservoir water for bacteria control. The reservoir water and mist droplets from the humidifier units were tested for the presence of bacteria over a three-week period. A control unit (without capsule) showed significant bacterial contamination by day three, which increased throughout the three-week test period, in both the reservoir and mist droplets, whereas the antimicrobial capsules reduced contamination during the first week, and minimized the presence of bacteria, in both the reservoir water and mist droplets, to less than 2% of the control unit throughout the three-week test period. It was also observed that, after each inactive weekend, the initial discharge of bacteria via the mist droplets in the control unit was significantly higher than during daily use. However, initial bacterial discharge from the test unit following weekend inactivity never exceeded 0.5% of the control unit. In conclusion, these capsules containing oligodynamic metals are effective in controlling bacteria growth in humidifier water tanks and mist droplets.
Removal and transport mechanisms of arsenics in UF and NF membrane processes
Authors: Kim Do Hee , Kim Kyoung Woong , Cho Jaeweon
Published: May 2018

In this study, the removal and transport mechanisms of ionized and non-ionized arsenics through NF and UF membranes were systemically investigated. The charge repulsion between the membrane surface and arsenic ions was an important mechanism for the rejection of ions by a charged membrane. In addition, the effect of J0/k ratio was dependent on the membrane and ion charge, but the cross-flow velocity was not significantly affected. Both diffusion and convection are proved to affect the transport of arsenic ions. The reflection coefficients (σ) of both UF and NF membranes increased with increasing pH; the reflection coefficients of arsenate were higher than those of arsenite under the same operating conditions. The spiral-wound module exhibited slightly higher arsenate removal than the flat-sheet module under the same operating conditions.
Toxic cyanobacteria and their toxins in standing waters of Kenya: implications for water resource use
Authors: Kotut Kiplagat , Ballot Andreas , Krienitz Lothar
Published: May 2018

Phytoplankton biodiversity studies in Kenya's standing waters were carried out between 2001 and 2003. Toxin producing cyanobacteria were recorded in twelve water bodies. Microcystis and Anabaena were the most common species in freshwaters while Anabaena and Anabaenopsis were common in alkaline saline lakes. Seven lakes with cyanobacteria blooms and a hot spring had detectable levels of microcystins and anatoxin-a. Cell bound microcystins (LR equivalents) concentration ranged from 1.6–19800 μg g−1 Dry Weight (DW) while anatoxin-a varied from below the limit of detection to 1260 μg g−1 DW. In alkaline-saline lakes, microcystins and anatoxin-a were also present in stomach contents and liver samples of dead flamingos. Monoculture strains of A. fusiformis from Lakes Sonachi and Bogoria had detectable levels of microcystins while anatoxin-a was present in strains isolated from Lakes Sonachi, Bogoria and Nakuru. Two freshwater sites, Nyanza Gulf (L. Victoria) and Lake Baringo recorded cyanotoxin concentration exceeding WHO's upper limit of 1.0 μg l−1 for drinking water. The results confirm that cyanotoxins could have played a role in the mortality of flamingos in Lakes Bogoria and Nakuru. The implications of these findings on water resource use, measures to be taken to reduce the risk of exposure and eutrophication control steps to reduce cyanobacteria bloom formation are considered in this paper.
Water consumption patterns in rural Bangladesh: are we underestimating total arsenic load?
Authors: Milton Abul Hasnat , Rahman Habibur , Smith Wayne , Shrestha Rupendra , Dear Keith
Published: May 2018

Risk related to the ingestion of any water contaminants depends on many factors, including the daily per capita amount of consumed water relative to body weight. This study explored the water consumption pattern of a rural arsenic-affected population in Bangladesh. The study findings are likely to contribute to the risk estimation attributable to ingestion of arsenic and other drinking water contaminants. A total of 640 individuals participated in this cross-sectional study carried out in an arsenic-affected rural population in Bangladesh. In this study daily per capita water consumption for drinking purposes was found to be 73.04 ml/kg/d (range = 71.24–74.84 ml/kg/d), which is higher than for both the US and Taiwan populations. This difference in per capita drinking water consumption might contribute to much higher lifetime cancer mortality and other morbidity risks from arsenic among the Bangladesh population compared to either the US or Taiwan populations. Arsenic is also ingested through cooking water which, if considered, might increase the risk further. The findings of this study highlight the urgent need for a holistic water supply programme for Bangladesh, with special emphasis on the arsenic-affected population.
Quantitative detection of E. coli, E. coli O157 and other shiga toxin producing E. coli in water samples using a culture method combined with real-time PCR
Authors: Heijnen Leo , Medema Gertjan
Published: May 2018

Recent water related outbreaks of shiga toxin producing E. coli O157 have resulted in increased attention of the water industry to this potentially deadly pathogen. Current methods to detect E. coli O157 and its virulence genes are laborious and time-consuming. Specificity, sensitivity and simple use of a real-time PCR method makes it an attractive alternative for the detection of STEC E. coli O157. This study describes the development and application of real-time PCR methods for the detection of E. coli O157, shiga toxin genes (Stx1 and Stx2) and E. coli. The specificity of the methods was confirmed by performing colony-PCR assays on characterized bacterial isolates, demonstrating the applicability of these assays as rapid tests to confirm the presence of E. coli or E. coli O157 colonies on culture plates. Sensitive culture-PCR methods were developed by combining culture enrichment with real-time PCR detection. This rapid method allowed detection of low concentrations of E. coli O157 in the presence of high concentrations of non-O157-E. coli (1:104). Culture-PCR methods were applied to 27 surface water and 4 wastewater samples. E. coli O157 and both Stx genes were detected in two wastewater samples, whereas only E. coli O157 was detected in two surface water samples. Culture-PCR methods were not influenced by matrix effects and also enabled quantitative (MPN) detection of E. coli in these samples.
Perspective: The unfinished agenda
Authors: Dieterich Bernd H.
Published: May 2018

New targets for drinking water and sanitation were the prime water-related outcome of the World Summit on Sustainable Development in Johannesburg. They aimed at better health and development. The critical mass needed to implement them must be created, primarily at the local level involving the people, governments and non-governmental organizations but with responsive participation and large-scale contributions of the international community. Many issues still need resolution in the light of experience since the 1980s. Let us launch a second Water Decade in 2004, world-wide, but vastly different from the Decade of the 1980s; a new Decade that will ensure enduring commitment and maintain the momentum created in Johannesburg.
An opportunity to improve water trading in the South East Catchment of South Australia
Authors: Young Michael D. , Hatton MacDonald Darla
Published: May 2018

This paper outlines how an area-based water allocation system for irrigating crops could be converted to a system of shares, structured so as to allow the development of a low cost trading market for water and salinity shares. It stresses the need for separation of entitlements of water from land and the separation of water rights into their various components. By moving to this type of allocation system, combined with some safeguard provisions, trade in groundwater could be facilitated in the South East Water Catchment located in the State of South Australia. Separation of salinity and other environmental impacts from water volume trading will allow market assessment of highest and best use to include consideration of environmental impacts. Although the focus of the paper is on groundwater allocation and management, the principles and concepts outlined are applicable to surface water systems.
Laws, policy measures, standards and regulations in the water sector in Lebanon: a review and perspective
Authors: Chatila Jean G.
Published: May 2018

Lebanon is increasingly suffering from shortage and mismanagement of water, which is becoming a commodity of considerable value due to the inadequacy of supply to meet the needs of potential users. Efficient solutions for water-related problems necessitate the adoption of well-planned policies. These policies should concentrate on improving water management, rationalizing water consumption, and augmenting and protecting water supplies. Strict water policy, wastewater treatment and disposal criteria should be in effect in order to avoid contamination and achieve proper management of water resources systems. A system of laws and policies has been developed or under development, in which the government has framed comprehensive codes and regulations including health standards. In this instance, this paper describes different aspects of the laws and applicable policies in the water sector in Lebanon. A set of proposed regulations and recommendations has been developed.
Mapping global water projects: improving access to donor investment information on the web
Authors: Jorgensona J. Lisa
Published: May 2018

This paper discusses a series of discusses how web sites now report international water project information, and maps the combined donor investment in more than 6000 water projects, active since 1995.

The maps show donor investment:

 • has addressed water scarcity,

 • has improved access to improvised water resources,

 • correlates with growth in GDP,

 • appears to show a correlation with growth in net private capital flow,

 • does NOT appear to correlate with growth in GNI.

Evaluation indicates problems in the combined water project portfolios for major donor organizations:

•difficulties in grouping projects over differing Sector classifications, food security, or agriculture/irrigation is the most difficult.

 • inability to map donor projects at the country or river basin level because 60% of the donor projects include no location data (town, province, watershed) in the title or abstracts available on the web sites.

 • no means to identify donor projects with utilization of water resources from training or technical assistance.

 • no information of the source of water (river, aquifer, rainwater catchment).

 • an identifiable quantity of water (withdrawal amounts, or increased water efficiency) is not provided.

 • differentiation between large scale verses small scale projects.

Recommendation: Major donors need to look at how the web harvests and combines their information, and look at ways to agree on a standard template for project titles to include more essential information. The Japanese (JICA) and the Asian Development Bank provide good models.
Women and water: a policy assessment
Authors: Singh Nandita , Bhattacharya Prosun , Jacks Gunnar , Gustafsson Jan-Erik
Published: May 2018

Women and water are linked together in more than one way. They may be seen as “domestic water managers” with specific water-related needs and interests. They may also be seen as having the potential for more active involvement in the sector at the levels of policy making, planning and implementation. Drawing upon the background of such needs, interests and potentials of women in relation to water, different agencies at national and international levels have framed different kinds of policies. What is the nature of such policies? What do they aim at? How effective have these been in addressing the water-related needs of women as “beneficiaries”? How effective has been the involvement of women as “actors” in delivering the goods? This paper attempts to evaluate the existing policies using a microperspective analysis, and proposes “facilitation of role performance” as a suitable policy alternative.
Sharing the Incomati waters: cooperation and competition in the balance
Authors: van der Zaag Pieter , Carmo Vaz Álvaro
Published: May 2018

The water resources of the Incomati river basin, shared between South Africa, Swaziland and Mozambique, are intensively used. Moreover, the basin is situated in a part of Africa that over the last 40 years has experienced a dynamic, sometimes turbulent and volatile, political history. Both ingredients might have been sufficient for the emergence of confrontations over water. Tensions between Mozambique, South Africa and Swaziland over Incomati waters existed but never escalated. This case study attempts to explain why cooperation prevailed, by presenting information about the natural characteristics of the basin, its political history, water developments and the negotiations that took place during the period 1967–2002. The paper provides four explanations why tensions did not escalate and cooperation prevailed. It is concluded that the developments in the Incomati basin support the hypothesis that water drives peoples and countries towards cooperation. Increased water use has indeed led to rising cooperation. When the next drought comes and Mozambique, South Africa and Swaziland enforce their recently concluded agreement, and voluntarily decrease those water uses deemed less essential, then the hypothesis has to be accepted.
Visions of Nile basin development
Authors: Whittington Dale
Published: May 2018

This paper describes five alternative visions for cooperative Nile development in the hope that they will assist the Nile riparian countries in their search for both a consensus vision and sound development projects. These five alternate visions [(1) Century Storage Plus, (2) Water for Peace, (3) Southern Lights, (4) The Green Nile, and (5) Economic Partners on the Nile] are intentionally stylized to make them easy to understand and remember. There is a common thread tying all five of these alternative visions together: the desire of all riparian countries for peace and economic development. Each of the five visions describes a peaceful future in which its proponents believe economic prosperity will flourish. One of the advantages of thinking explicitly about these alternative visions is that comparisons can reveal surprising compromises - or coalitions - that may become possible between Nile riparian countries even though some members of the political leadership in the riparian countries may still hold quite different ideas about the way to achieve cooperative development.
Irrigation improvement projects in Tanzania; scale impacts and policy implications
Authors: Lankford Bruce
Published: May 2018

Observations in Tanzania indicate that the improvement of traditional smallholder irrigation does not necessarily result in improved water performance, greater equity and reduced conflict. The usual outcomes of such projects is a gain in water for the system being upgraded, especially if located upstream, accompanied by less ability to share water at the river basin scale. This paper concludes that these projects do not commonly understand, match and respond to the complexities of well-developed and evolving smallholder irrigation found in multi-user river basins. Without re-appraisal, the risk is that donors will be unsuccessful with smallholder irrigation and turn away from this sector, as they did with large-scale irrigation.
Public-private partnerships in watershed management - evidence from the Himalayan foothills
Authors: Kurian Mathew , Dietz Ton , Murali K. S.
Published: May 2018

Public-private partnerships have emerged in recent years as an important policy option to ensure service provision in the water resources sector. However, there is very little analysis of past experience of partnerships between the public sector and various arms of the private sector: water companies, NGOs or even farmer groups. Further, there is limited conceptualisation of what is meant by partnerships between the public and private sectors. This paper draws on a study of watershed management in Haryana to analyse the evolution of public-private partnerships in natural resource management. The paper finds that the public sector has an important role to play in facilitating design of an institutional contract that clarifies water rights and rules for benefit sharing and conflict resolution. Interestingly, the paper finds that when a proper institutional structure is in place, well-endowed individuals with sufficient interest in a common pool good (like an irrigation system) may emerge to provide irrigation services with positive equity and efficiency outcomes for the environment and rural communities. However, the paper argues that state parastatals have an important role to play in monitoring the impact of watershed management on traditionally marginalized groups like women and landless and coordinating inter-sectoral policy change to ensure that public-private partnerships can be sustained in the long term.
Water supply and sanitation sector of Karnataka, India: status, performance and change
Authors: Maria Saleth R. , Sastry G. S.
Published: May 2018

Although the water supply and sanitation sector of the state of Karnataka in India has made significant progress in terms of area coverage and, to some extent, meeting consumption targets, two tasks, i.e. fulfilling the unmet backlog demand and meeting the water needs of future population, continue to remain as its major challenges. Based on an analysis of the data and information pertaining to the sector during 1999–2001, this paper aims to assess the financial capacity and reform commitment of the state to meet these sectoral challenges successfully. Towards this end, this paper (a) describes the current status and recent performance of the sector, (b) reviews the financial health of the sector including an estimation of the magnitude of budgetary subsidy, (c) discusses the causes for and consequences of subsidy growth; (d) identi.es the issues and strategies for sectoral reforms including an evaluation of some recent reform initiatives and (e) concludes by highlighting the major implications for sectoral policy in the state in particular and India and other developing countries in general.
Catchment water deficits in the 21st century
Authors: Merrett Stephen
Published: May 2018

The objective of this paper is to provide a general theory of the manner in which the water resources of a catchment shift from surplus to deficit and the means by which water resource institutions can manage or reverse this shift. The approach combines the languages of hydrology and the social sciences. After defining the concepts of catchment water surplus and deficit, an account is given of how a river basin may shift from one to the other as its output per head and population expand. Twelve possible options to confront such a shift are reviewed. The paper discusses the global significance of these issues and ends with a general testable hypothesis as a basis for fieldwork.
Socio-economics and hydrological impacts of melamchi intersectoral and interbasin water transfer project, Nepal
Authors: Bhattarai Madhusudan , Pant Dhruba , Molden David
Published: May 2018

To mitigate the drinking water crisis in Kathmandu city, the Government of Nepal has recently initiated the Melamchi project, which will divert water from the Melamchi River to Kathmandu city's water supply network. In the first phase, the project will divert 170,000 cubic metres of water per day (at 1.97 m3/s). There is a plan to triple the volume of water using the same infrastructure as city water demand increases. This paper illustrates the complexities involved in planning and implementing the intersectoral (interbasin) water transfer project, and the socio-economic and hydrological implications of the project in the basin of water supply. This project potentially generates huge economic benefits, mostly accrued to the urban sector. An already a resource-poor water-supplying basin bears all the opportunity costs of the water transfer. The project compensation scheme has focused more on local public goods and has not much considered third party effects such as traditional water mill owners and tenant farmers who may unduly bear the brunt of the project. Effective participation of stakeholders and early negotiation for compensation could minimize such third party effects. The absence of such negotiation has raised some concerns about the effectiveness of the Melamchi project to meet the social obligations in the basin of water origin.
Water framework directive: exploring policy design issues for irrigated systems in Italy
Authors: Bazzani G. , Pasquale S. Di , Gallerani V. , Viaggi D.
Published: May 2018

Today the EU must deal with a new legal framework: the new water framework directive (WFD) (60/2000/EC). This directive sets up new criteria for water management and promotes the need for policy changes in sectors using water, such as agriculture. This paper deals with the problem of water regulation in agriculture by testing the results of innovative policy instruments, such as the joint regulation of water use and water pollution. The methodology—based on a simulation model that integrates a mathematical programming model and an optimal regulation model—makes it possible to quantify water demand and optimal regulation from the policy makers' point of view. The results show that, to meet the increasing social value attributed to water resources and pollution, major changes are needed in crop mix and policy design. However, changes in the economic role of farming and in the (cultural) attitudes of local populations towards agricultural work may have an even greater weight than water policy in the use of this resource.
Water and sanitation policies for improving health in South Africa: overcoming the institutional legacy of apartheid
Authors: Sinanovic Edina , Mbatsha Sandi , Gundry Stephen , Wright Jim , Rehnberg Clas
Published: May 2018

The burden of water-related disease is closely related to both the socio-economic situation and public health issues like access to clean water, sanitation and hygiene services. Poverty eradication, through improved access to water and sanitation, is the South African government's major priority. This is partly achieved through subsidising the cost of water and sanitation provision to the poor in rural areas. Whilst the new policies have made a remarkable impact on improved access to water and sanitation services, a general problem since the new approach in 1994 has been the lack of integration of policies for water and sanitation and health. This paper analyses the policies concerning rural water supply and sanitation in South Africa. It considers the structure of institutions, the division of responsibilities and legislated and financial capacity of the South Africa's water sector. A more integrated approach for the policies aiming at water access, sanitation and health is needed. In addition, as the local government's capacity to implement different programmes is limited, a review of the financing system is necessary.
The French model of water supply management challenged by users' empowerment
Authors: Pflieger Géraldine
Published: May 2018

Since the early 1990s, in France, the increase in water prices and the denunciation of public–private partnerships have encouraged the state, water companies and local authorities to enhance management transparency and develop their relationships with consumer groups. The opening to user representatives is challenging the French model of water supply management. These transformations are resulting in tensions between different representations of users as consumers or citizens. Between consumer and citizen, which representation is actually emerging and how is the user's status affected?

At the national level, the state and consumer groups tend to develop a pro-consumerist policy involving reflection on price levels, the efficiency of utilities and consumer information. On the other hand, companies are trying to highlight the representation of the citizen concerned about the environment and water quality. At the local level, user status varies with context. The user can be perceived either as a simple consumer or as a citizen–consumer hybrid. The examples of Grenoble and Ardèche show that consumption issues can be open to debate about public choices, investment strategies or drinking water quality. This opening up of debate depends on local authorities' competence and communication strategies, consumer groups' agendas and specific local issues (e.g. resource scarcity, corruption).
Using constructed wetland systems to remove solids from highly polluted river water
Authors: Jing S.R. , Lin Y.F. , Lee D.Y. , Wang T.W.
Published: May 2018

The Erh-Ren River is located in southern Taiwan and is one of the most polluted rivers in Taiwan. A pilot-scale constructed wetlands (ERRCW) system containing a free surface flow wetland (FSF) followed by a subsurface flow wetland (SSF) was set up to treat the polluted river water. The system was designed to include solids removal. A removal efficiency of suspended solids (SS) in the ERRCW system that was greater than in a control system indicates that the existence of macrophytes in wetlands could enhance solids removal. The results of this study also showed that SS were removed mainly through the SSF in the ERRCW system. The poor removal of SS, or even an increase in SS, that occurred in the FSF was found to be caused by the growth of algae. Although the macrophytes reduced the penetration of sunlight into the water in the FSF portion of the ERRCW system, the residue of nutrients in water and a low flushing rate still induced the growth of algae on some open water surfaces. From this study, it may be concluded that the roles played by macrophytes in solids removal include providing barriers for filtration, reducing sunlight penetration, supplying oxygen to enhance biodegradation of organic solids, and absorbing nutrients to limit the growth of algae.
Development of a bio-monitoring system for toxicants in water with fish
Authors: Lee Y.-H. , Lee H.-K. , Chang C.-H. , Kim W.-H.
Published: May 2018

A bio-monitoring system for toxicants in water has been developed and verified for actual applications. This system is based on the motionality of five Acheilognathus lanceolata, a fish known to be very sensitive to toxic substances, moving around in an aquarium. Their movements are continuously monitored with a charge coupled device (CCD) camera and analyzed to find and quantify any abnormal behavior in their motional characteristics in comparison with the pre-acquired data. That is, the images of fish captured by a CCD camera are digitalized to identify the location of fish in a constant time interval and the locations of each fish were then analyzed mathematically with a personal computer using the equations proposed to determine the motional characteristics such as floatness, fledness and mobility(agility). These data are then converted by means of fuzzy estimation to an index value, defined as the contamination index (CI), by which the system provides the information about the overall toxic strength of the toxicant in the water flowing into the aquarium. If the fish are exposed to toxicant(s), the CI value will be proportional to the strength of its toxicity. The pilot test was performed in a water treatment plant for six months in order to verify the reproducibility of the system over the unstable conditions such as highly turbid water after rainfall as well as in normal conditions. The test results revealed that this monitoring system has good reproducibility and sensitivity, proving our approach, described in this paper, is reliable. As a result, this approach seems to enable us to make a quick and easy detection of toxic substances contained in water, therefore, this system can be applied to a source of water supply as a toxicant watching system.
Removal of tetrachloroethylene in an anaerobic fixed-bed reactor immobilized with Clostridium bifermentans DPH-1
Authors: Chang Y.C. , Asanuma K. , Hatsu M. , Takamizawa K.
Published: May 2018

An upflow fixed-bed reactor was evaluated for the removal of tetrachloroethylene (PCE) by a strictly anaerobic, PCE dechlorinating bacterium, Clostridium bifermentans DPH-1 immobilized on sterile ceramic beads. The ceramic beads provide a large surface area for development of cell mass in the column. For kinetic experiments, the conventional first-order reaction kinetics was applied to evaluate the batch and continuous immobilized reactors. Velocity constants (KB and KC) under the batch culture and continuous culture were determined to be 1.9 × 10–2 (mg protein–1h–1) and 1.4 × 10–2 (mg protein–1h–1), respectively. Maximum specific degradation rate of PCE was calculated as 0.16 (10–3 μmol mg protein–1h–1 from average influent concentration of PCE (12 μM) in the bioreactor. Simultaneously maximum volumetric degradation rate was also computed as 10.2 μmol l–1h–1. The volumetric degradation rate was relatively higher than those of other reactors. In order to maintain the efficiency of PCE dechlorination, 20 h or more HRT in the reactor system was required.
From basic investigations to pilot plant tests of depth filtration with permeable synthetic collectors
Authors: Nahrstedt A. , Esperschidt K. , Gimbel R.
Published: May 2018

Permeable Synthetic Collectors (PSCs) are bodies of some millimetres consisting of a highly porous arrangement of fixed fibres or open-porous plastic foam. The advantages of the application of this media in deep bed filtration were studied. The theoretical analysis of the particle transport efficiency was based on the numerical solution of the flow field and on trajectory calculations for non-Brownian particles. Investigations with an endoscope allowed the consideration of the particle adhesion on the surface of the inner fibres. The resulting filter coefficients are compared with experimental data. The application of PSC filtration in a pilot scale unit for wastewater treatment performs much better in contrast to conventional filter grains (sand, anthracite etc.), especially under high rate conditions. In the future, the deep filtration can be applied to new fields of the topic of solid liquid separation with smaller units, lower pressure drop and higher filtration rates.
Integrated modelling of ozonation processes in water treatment
Authors: Zhou Hongde , Smith Daniel W.
Published: May 2018

This paper presents the formulation of an integrated Back Flow Cell Model (IBFCM) for ozonation processes by incorporating together the contactor hydrodynamics, mass transfer, ozone decay in water, microbial inactivation, and disinfection by-products formation to describe the significance of their interrelated nature in determining the overall process performance. It also summarizes the experimental procedures that could be used to quantify the characteristic parameters for each process component. The model applicability was then illustrated by comparing the predictions with the experimentally observed dissolved ozone profiles. Further analysis was made to demonstrate the model application for predicting the disinfection efficiency and disinfection by-products formation simultaneously. From these analyses, it was also found that during the ozonation of natural waters, the ozone decay could not be described by the simple first order rate expression.
State of the art in organic piping systems: alternative solutions for avoiding internal corrosion
Authors: Rigal S. , Baron J.
Published: May 2018

Corrosion can lead to degradation of water quality and affect the mechanical characteristics of drinking water piping systems. Alternative solutions consist of replacing traditional inorganic materials by plastic materials. A review of the organic materials used in drinking water distribution systems is presented in relation to their specific application. Future aspects of the European Regulation for Drinking Water Construction Products and the next European Approval Scheme (EAS) are developed.
Corrosion control measures in Sweden and the effect of succession order
Authors: Berghult B. , Elfström Broo A. , Hedberg T.
Published: May 2018

Corrosion control actions for drinking water distribution in Sweden are discussed. Several different processes are used. The water quality goals vary over a wide range both with respect to pH and alkalinity. None of the waters are supersaturated with respect to calcium carbonate. The results of the corrosion control action on copper and iron corrosion product release are calculated and discussed in terms of possibilities for improvements. The effect of water quality changes due to pipe material succession order is shown.
Water treatment to reduce internal corrosion in the drinking water distribution system in Oslo
Authors: Hem L.J. , Vik E.A. , Bjørnson-Langen A.
Published: May 2018

In 1995 the new Skullerud water treatment plant was put into operation. The new water treatment includes colour removal and corrosion control with an increase of pH, alkalinity and calcium concentration in addition to the old treatment, which included straining and chlorination only. Comparative measurements of internal corrosion were conducted before and after the installation of the new treatment plant. The effect of the new water treatment on the internal corrosion was approximately a 20% reduction in iron corrosion and a 70% reduction in copper corrosion. The heavy metals content in standing water was reduced by approximately 90%. A separate internal corrosion monitoring programme was conducted, studying the effects of other water qualities on the internal corrosion rate. Corrosion coupons were exposed to the different water qualities for nine months. The results showed that the best protection of iron was achieved with water supersaturated with calcium carbonate. Neither a high content of free carbon dioxide or the use of the corrosion inhibitor sodium silicate significantly reduced the iron corrosion rate compared to the present treated water quality. The copper corrosion rate was mainly related to the pH in the water.
Application of large volume injection GC/MS to the picogram analysis of chlorinated and brominated anisoles in “earthy-musty” off-flavor water samples
Authors: Malleret L. , Bruchet A.
Published: May 2018

This paper summarizes the most commonly used methods to identify the origins of taste and odor episodes. An innovative analytical tool which allows the identification of odorous compounds at levels as low as 25 pg/L by injecting a large volume of extracts, is described. This large volume on-column technique was employed to investigate real “earthy-musty” cases which remained unsolved using traditional chromatographic methods. “Musty” odor causative agents could be identified in each sample studied, proving the efficiency of this new method. Estimated concentrations were well correlated with taste intensities. The relative importance of haloanisoles when dealing with musty odors was highlighted, and 2,4,6-tribromoanisole was detected for the first time in water samples. Finally, analysis of the corresponding halophenols for some of the samples studied gave insights concerning the origin of the odorous anisoles.
Effect of bromide ions on formaldehyde formation during ozonation of drinking waters
Authors: Can Z.S. , Gurol M.D.
Published: May 2018

The effect of bromide ions on formaldehyde formation during ozonation was studied by ozonating solutions of Suwannee River humic acids at three different bromide ion concentrations in a semi-batch system. No significant effect was observed during the initial 20 minutes of ozonation in the presence of 1 mg/l of bromide and during 10 minutes of ozonation in the presence of 10 mg/l bromide ions in solution. However, upon further ozonation, formaldehyde formation was significantly slower in the humic acid solution containing 10 mg/l of bromide. The effect of bromide ions at the later stages of ozonation was due to the formation of oxidized bromide species, which act as efficient hydroxyl radical scavengers in the system. The presence of 10 mg/l chloride ions in solution did not affect formaldehyde formation during 50 minutes of ozonation.
Uncertainty in air stripping tower design: implications of the air-to-water ratio
Authors: Dvorak B.I. , Schauble J.W.
Published: May 2018

Environmental engineers are frequently faced with uncertainty in making design decisions because the true value of many process parameters is unknown. In this study, the design of countercurrent air stripping towers was modeled using fuzzy numbers, taking into account uncertainties in mass transfer and Henry's constant. It was found that, in addition to cost, the risk of failure is an important design consideration for stripping tower design. A significant over-design is both cost-effective and results in less risk of design failure. The air-to-water ratio that yielded the least risk of failure switched from low to high as the removal efficiency of the tower increased. An important result is that at lower removal efficiencies, tower design and operation is most sensitive to uncertainties in mass transfer and at higher removal efficiencies, tower design and operation is most sensitive to uncertainties in Henry's constant . The implication is that low air-to-water ratios are best when the regulatory target removal efficiency is low and/or when the uncertainty in the value of the contaminant's Henry's constant is larger than the uncertainty in the mass transfer coefficient value. Otherwise a high air-to-water ratio results in the least risk of process failure.