bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydraulic Modelling of Suspended Sediment Deposition in an Inundated Floodplain of the Nemunas Delta
Authors: Vaikasas Saulius , Rimkus Alfonsas 
Published: May 2018

Floods of meadows in the delta of the river Nemunas contribute to the deposition and retention of sediments and nutrient that would otherwise deposit in the Curonian Lagoon. In grassland area of the Nemunas delta the formation of alluvial soil occurs according to the flood dynamic rules: water discharging into the valley leaves suspended sediments on the soil surface. By mathematical modelling it was established that about 35% of suspended sediments inflow deposited there. Due to sand particles deposited during the study period (1950-1991), the natural river bank levee rose by 0.3 m. Fine clay and silt particles deposited uniformly within the entire model area and formed a 4-6 mm thick layer there. It contained about 50-60 t/ha of silt deposits. The valley soils were naturally fertilized with 250 t of potassium, 950 t of phosphorus, 38,000 t of calcium, and even 147,000 t of organic matter saturated with nitrogen. Certain amount of heavy metals also deposited there.
The deposition process has not yet been adequately investigated under the conditions of flow bed covered by grass. It was established that grass cover intensified the sediment deposition in the floodplain. Considering calculation results and measurement data, the process of suspended sediment deposition was analysed and new formulas were derived. It was established that in order to increase sedimentation in the valley, it would be necessary to increase water discharge overflowing from river bed into the delta valley.
Nutrient Losses and N & P Balances in Small Agricultural Watersheds in Estonia
Authors: lital Arvo , Loigu Enn , Vagstad Nils 
Published: May 2018

The paper deals with nutrient runoff monitoring results and calculated nutrient budgets on catchment level in small agricultural watersheds in Estonia. A special programme for monitoring of nutrient losses was initiated and a network of monitoring stations, equipped with data-loggers and suitable devices for continuous flow measurement and flow-proportional automatic water sampling were established in Estonia in the mid-1990s. The research methodology is harmonized with the Nordic countries as well as with the other Baltic countries. The results indicate that nutrients losses are relatively low (generally below 11 kg N/ha and 0.9 kg P/ha). It can be partly explained by drastic changes in the Estonian agricultural practice in the 1990s but also by differences in runoff regime.
Nutrient balances were calculated for two catchments, based on the data collected from the farms, some special studies and water quality monitoring results in two watersheds in 1995 (1999) - 2001. The nutrient balances for the catchments turned positive after being negative both for nitrogen and phosphorus in the mid-1990s.
Mesoscale Circulations and Surface Energy Balance During Snowmelt in a Regional Climate Model
Authors: Mac Kay Murray D. , Szeto Kit , Verseghy Diana , Chan Ed , Bussières Normand 
Published: May 2018

The Canadian Regional Climate Model has recently been coupled with an advanced, second generation land surface model - the Canadian Land Surface Scheme. In addition, high resolution land cover and soils data sets have been assembled on a 1 km horizontal resolution grid over North America. These data sets, along with the coupled model, provide a powerful tool for the examination of regional climate processes in complex, heterogeneous terrain. In a first application of the new modelling system, simulations of progressively higher horizontal resolution are performed over the Mackenzie Basin for the spring of 1995 in order to determine if turbulent fluxes associated with a heterogeneous land surface can generate mesoscale atmospheric circulations of relevance to the surface energy budget during the critical snow melt period.
We have found that shallow, diurnally forced mesoscale circulations associated with surface flux heterogeneity developed regularly throughout the snow melt period in the higher resolution experiments. In one case, a localized downdraft associated with a low level isothermal layer was found to enhance turbulent heat exchange with the underlying snow. The net importance of this process to the overall energy balance of the snowpack did increase with resolution, but remained relatively small for the resolutions considered here.
Water resources management of the Yellow River and sustainable water development in China
Authors: Shucheng Wang 
Published: May 2018

China is a country frequently hit by floods and droughts. Managing water resources and minimizing the losses caused by water disasters has always been among the most important issues faced by the Chinese government in governing the state. In recent years, to tackle the water problems in China and to meet the requirement of sustainable economic and social development, we have actively pursued sustainable water development. Thinking about water management has thus been greatly modified and remarkable achievements have been made accordingly.
The Yellow River, known as the Mother River of China, is the cradle of Chinese civilization, whose problems can represent that of most Chinese rivers. Citing the Yellow River management in recent years as an example, this paper elaborates the strategy of sustainable water development in China.
Water, poverty and gender: review of evidences from Nepal, India and South Africa
Authors: Upadhyay Bhawana 
Published: May 2018

Access to water in equitable manner and the improved management of water are imperative to sustainable development, poverty alleviation and biodiversity preservation. Despite much research on gender and natural resources management, there have been only a handful of studies on gender and water, especially those trying to link the two with poverty issues. This paper seeks to fill this gap specifically by looking at the linkages among gender, water and poverty in terms of gender participation in irrigated agriculture and irrigation institutions. The main objective of the study is to examine gender participation in irrigated agriculture and irrigation institutions and to analyze the impact of irrigation projects on men and women. The study approach has been a qualitative and quantitative analysis of primary and secondary data.
Key findings reveal a considerable degree of gender inequalities, especially in terms of participation in irrigation institutions. Despite a high level of female involvement in irrigated agriculture, their participation in irrigation institutions is much lower. Furthermore, water projects with gender equality interventions have enhanced women's status in particular by raising their abilities to participate. The results suggest that the incorporation of gendersensitive policies and programs in irrigation schemes could have significant positive impacts both on gender equality and poverty.
Copper corrosion control in the Netherlands
Authors: Slaats P.G.G. , Brink H. , van der Hoven T.J.J. 
Published: May 2018

Copper is the most commonly used material for pipes in domestic installations in the Netherlands. Depending on the composition of the water the copper pipes can add a significant amount of copper to drinking water. In the new European Drinking Water Directive (98/83/EC) the parametric value for copper in drinking water is decreased from 3 to 2 mg/l. The new directive also stipulates that copper levels should be determined on the basis of a sample ‘taken at the consumers' tap’ representative of the weekly average intake by humans. Harmonisation of monitoring protocols for copper in the European member states is necessary.
In the Netherlands about 45% of the drinking water is already softened or de-acidified in order to decrease copper concentrations in drinking water. In the Netherlands two new treatment techniques have been studied for their impact on copper release; these are Reverse Osmosis (RO) and the addition of inhibitors.
Copper pipe rig tests have shown that RO treatment decreases copper release. Split treatment of water with RO reduces copper solubility of drinking water through a decrease in both total inorganic carbon (TIC) and sulphate level. Remarkable was the relatively small decrease in copper release after split treatment with RO, compared to previous experiences in the Netherlands, suggesting an effect of natural organic matter. A new promising technique in the Netherlands is the addition of the inhibitor carbonate-activated silicate. At the test sites, the reduction in copper solubility due to the use of carbonate-activated silicate was 15 to 35%.
Membrane filtration of surface water in the presence of ozone
Authors: Sawada S. , Sumida I. , Matsumoto K. 
Published: May 2018

The preliminary study investigated the effect of pre-ozonation of synthetic raw water (bentonite and humic acid) on membrane fouling. The results showed that humic acid, not bentonite, was the dominant factor in membrane fouling. When the synthetic raw water was pre-treated using ozone and activated carbon, stable operation was possible at twice the flux of membrane filtration without pre-treatment. Thus, ozone and activated carbon reduced the concentration of organic matter (humic acid), leading to an increase in flux.
Secondly, an MF membrane filtration device with ozone tolerance was attached downstream of the ozone reactor so that residual ozone could reach the membrane surface. When water was treated with MF membrane filtration in the presence of ozone, the flux was stable at 4 m/d. The membrane filtration resistance increased when ozone was not injected, and decreased when it was injected. This phenomenon was repeatable. In the presence of ozone, organic matter that could accelerate fouling as decomposed and converted to less fouled materials, resulting in a suppression of fouling as well as facilitating removal of the fouling layer during back washing.
The new concept of flux enhancement during cell separation with MF/UF processes
Authors: Kołtuniewicz A. 
Published: May 2018

The microfiltration and ultrafiltration processes are considered as matured membrane processes that are well established in industrial practice. Nevertheless, the main obstacles of their further development in the new competitive implementations are the economical problems. The key economic factors are permeate flux and energy consumption. However, although the cross-flow systems enable us to attain higher flux, it is usually very expensive. The high energy is consumed to maintain circulation velocity of the retentate that is sufficient for sweeping out the retained component from the membrane surface. Moreover in the case of cells separation the high intensity of the fouling and low cake permeability makes it necessary to apply additional efforts, such as backflushing, backpulsing, promoters of turbulence, vibrations, ultrasounds and many other. Therefore, dead-end systems are still quite competitive with cross-flow, especially for diluted (less than 0.5% of dry mass) suspensions or solutions.
Cell separation with membranes is one of the most vivid problems for modern biotechnology, wastewater and water treatment. Membranes offer mild process conditions and high selectivity of separation. This enables us to solve a variety of problems such as cell culturing, fractionation, concentration, purification and sterilisation. The selected cells may be precisely separated from other components of broth and subsequently directed into the reaction space again in good conditions to ensure a quasi-continuous mode of operation. Moreover, membranes enable us to attain high efficiency of the bioconversion by removal of all product and inhibitors directly from the bioreactor. This is the reason for the huge interest in cell separation with membranes.
The idea of the paper was to present the new concept of flux enhancement for cell separation on membranes. This concept lies in taking advantage of the specific rheological nature of biopolymers, which are the main foulants. The biopolymers retained on the membrane surface (i.e. on the top layer) can be applied as a lubricant for the cells that can settle on such a ‘movable layer’. As is shown, further in the paper, the thickness of the moving layer is lower and the flux is greater. The common movement of the cells and gel layer is very convenient from the cells integrity point of view. However the hydrodynamic conditions always play an important role in cross-flow systems; the resistance of ultrafiltration membranes may be reduced much more when compared with more open microfiltration membranes.
Aerated biological filtration for the removal of ammonia and manganese in a major new water treatment works under construction in Hong Kong
Authors: Heard T.R. , Hoyle B.G. , Hieatt M.J. 
Published: May 2018

Construction is currently under way in Hong Kong of a US$ 575 million water treatment and transfer scheme including the first 250 Ml/d stage of a new water treatment works at Tai Po, with an ultimate capacity of 1,200 Ml/d. The design incorporates primary aerated biological filters for ammonia and manganese removal as a key element of the treatment strategy.
Pilot filter work was carried out for a period of over twelve months covering seasonal variations. The work included investigations into “start up” times; ammonia removal efficiency at different filtration rates; effects of flow changes; ammonia peaks and temperatures; aeration and chemical dosing requirements; recovery after a “kill” and operation in both downflow and upflow modes. The pilot filters demonstrated the process to be effective and robust and provided design parameters for the sizing of the process units and for the provision of chemical dosing and aeration equipment.
The paper sets the context to the scheme, describes the pilot filter work and the results, discusses the reaction kinetics and shows how the design parameters obtained from the pilot filter work were used in the development of the engineering design of the treatment works.
How do consumers perceive water quality? Example of an anthropological study carried out in Paris
Authors: Euzen A. 
Published: May 2018

Observation of quality standards is the prime concern of water producers, but are the quality criteria used by professionals the same as those of consumers? How do consumers perceive the quality of the water distributed to their homes? The main concern of SAGEP, water producer for the City of Paris, is to respond at all times to users' expectations. To answer that requirement, SAGEP launched a consumer study on the reaction to tap water.
Analysis of the perceptions of water quality is presented in this paper. It reveals multiple and singular responses, which themselves depend on personal history and development of the individual concerned. An anthropological approach enables one to gain a grasp of the degree to which the diversity of perception comes into play in the day-to-day practice in the domestic environment of tap water. The example of consumer practice in regard to the type of water drunk demonstrates how custom changes with the context and how each person builds up confidence in tap water.
The complexity of what are a priori trivial uses confirms the need for water producers and distributors to make this reality an integral part of their overall management. They should now take in to account, perhaps in a different way, the consumers' expectations.
The “go with what you know” approach to forecasting future asset replacement expenditure
Authors: D’Agata S. 
Published: May 2018

A reliable predictive model for the deterioration of water mains and sewers has been the quest of water industry asset managers for several decades. No doubt driven by finance managers, asset managers have been searching for that mythical formula that will tell them exactly when an asset will fail and allow them to accurately forecast replacement and renewal expenditure into the future.
Although it is imperative that water authorities act to avoid and prevent the catastrophic failure of major infrastructure assets where the consequence of failure is high, for most authorities these assets form a relatively small part of the asset base. Therefore, the detailed predictive modelling and analysis of pipe material properties employed to plan the replacement of these critical assets is not appropriate or practical to apply to reticulation assets that represent over 95% of the total infrastructure for most Authorities.
The application of predictive models based upon pipe material performance to develop replacement programs for extensive reticulation systems, does not adequately take into consideration the variations in construction methods, ground conditions, consumption patterns, topography and climatic conditions that exist in many networks. These variations are, however, implicit in historical performance data which also provides information of the rate of failure of assets which is the main driver for the replacement of reticulation assets. It is only when the rate of failure of an asset becomes unacceptable that replacement is necessary and this adopted level of service will have a greater influence on future asset replacement expenditure than the assessment of the deterioration of pipe materials. All the more reason to base asset replacement programs around historical data and go with what you know.
Colour removal by ion exchange and reuse of regenerant by means of nanofiltration
Authors: Schippers D. , Kooi M. , Sjoerdsma P. , de Bruijn F. 
Published: May 2018

In the past year Vitens, The Netherlands' largest water supply company, and Witteveen+Bos, have prepared the preliminary, basic and detailed design for a full-scale ion exchange plant reducing colour in drinking water to a value of less than 10 mg/l PtCo. Current pilot study shows that the results are even better than expected. The plant will be built in 2004 and start-up is scheduled for mid 2005. The introduction of ion exchange at WTP (Water Treatment Plant) Oldeholtpade is part of a larger project, also including softening in pellet reactors, preceded by counter-current aeration and renovation of the existing treatment plant.
The colour content present in groundwater is caused by peat layers. In contrast with conventional ion exchange processes, previous pilot studies showed that the exchange capacity of the resin for organics is much larger than expected. The excellent results can be explained by assuming the simultaneous occurrence of adsorption and ion exchange processes on the resin. It can be concluded that optimising operating conditions, such as higher exchange capacity (as KMnO4/liter resin), higher superficial velocity, shorter contact time and longer filter run cycle clearly affect resin volume as well as the required amount of regenerant.
Vitens has started additional experiments at WTP Spannenburg to confirm the innovative design parameters. Aim of the research is the relation between adsorption and ion exchange during filtration, in order to clarify the achieved results. Furthermore the relationship between the specific water type (characterisation of organic compounds) and the operational results of ion exchange will be studied.
In order to minimise the waste regenerant, treatment towards recycling is studied by dead end nanofiltration. With nanofiltration it is possible to concentrate the waste stream to a maximum of 10% of the original waste stream. The recovered regenerant can be recycled for regeneration of the resin.
Water-Pollution Research and Its Application in Developing Countries
Authors: Isaac P , Pescod W 
Published: May 2018

Much research into the control of water pollution is of little practical application in developing countries, being too concerned with abstract science. Research to be applied in the Third World must not only lead to inexpensive solutions, that can be developed as finances allow, but must take account of the social, political, religious and financial factors in the poorer rural areas of the world.
This paper draws the attention of research-workers in this field to the wider realities of developing countries, and emphasizes that success in the field, as opposed to success in the laboratory, will demand a multidisciplinary approach. Research must be prepared to take full account of non-technical and non-scientific factors.
Inhibition Modelling in Anaerobic Digestion
Authors: Duarte A C , Anderson G K 
Published: May 2018

The effects of volatile acids and pH on anaerobic digestion were studied in laboratory and pilot-scale digesters. The wall growth was shown to be an important parameter when operating digesters at low solid concentrations.
The role of propionic acid inhibition is emphasized.
Mathematical models to predict digester performance are discussed and are used to fit available inhibition data.
Process Integration in Sludge Management
Authors: Dick R I , Simmons D L , Hasit Y 
Published: May 2018

Complex interactions occur between individual sludge treatment processes and other sludge management processes. Sludge treatment processes also interact with wastewater treatment processes. Consideration of those interactions has been facilitated in this work by a computerized optimization scheme using models of process performance and cost based on fundamental design and operational variables.
Illustrations of the type of results obtained are described. It is indicated that the mean cell residence time of activated sludge processes and the retention time of anaerobic digesters should, with current energy costs, be as short as possible while assuring satisfactory operation. The additional cost of larger gravity thickeners is often offset by savings in anaerobic digestion and other process costs. The method by which sludge is transported to a point of ultimate disposal has an important effect on identification of the lowest cost technique for sludge management. Based on available cost information, ocean disposal, where feasible, is nearly always cost effective and sludge combustion is not. The cost of energy significantly affects optimal design of sludge treatment processes.