scholarly journals EXTRACTION OF CHLORIDE AND THIOCYATE ACIDOCOMPLEXES OF METALS IN SALTING-OUT AGENT – MONOALKYLPOLYETHYLENE GLYCOL – WATER SYSTEMS

Author(s):  
V. A. Izmesteva ◽  
◽  
A. M. Elokhov ◽  

Distribution of iron (III), thallium (III, gallium, titanium (IV) chloride complexes in sodium chloride – synthanol DS-10 – water and ammonium sulfate – synthanol DS-10 – water systems, as well as iron (III), cobalt , nickel, cadmium and copper (II) thiocyanate complexes in the ammonium sulfate – synthanol DS-10 – water system investigated. It was found that the main influence on extraction is exerted by solution acidity and nature of the salting-out agent. The conditions for quantitative extraction of thallium (III) and gallium in the form of chloride complexes, as well as the conditions for maximum extraction of iron (III), zinc and cobalt thiocyanate complexes are established.

1993 ◽  
Vol 27 (5-6) ◽  
pp. 61-67 ◽  
Author(s):  
E. Jacobs ◽  
J. W. van Sluis

The surface water system of Amsterdam is very complicated. Of two characteristic types of water systems the influences on water and sediment quality are investigated. The importance of the sewer output to the total loads is different for both water systems. In a polder the load from the sewers is much more important than in the canal basin. Measures to reduce the emission from the sewers are much more effective in a polder. The effect of these measures on sediment quality is more than the effect on water quality. Some differences between a combined sewer system and a separate sewer system can be found in sediment quality.


1999 ◽  
Vol 39 (4) ◽  
pp. 221-231
Author(s):  
A. H. Lobbrecht

The properties of main water ways and infrastructure of rural water systems are often determined by very general design methods. These methods are based on standards that use only little information of the actual water system. Most design methods applied in the Netherlands are based on land use and soil texture. Standards have been developed on the basis of generalized properties of water systems. Details of the actual layout of the water system and the way in which that system is controlled, are usually not incorporated. Present-day dynamic simulation programs and the computer power currently available enable more detailed modeling and incorporation of location-specific data into models. Such models can be used to design the water system and can include real data. A model-based design method is introduced, in which the actual situation of the water system is taken into consideration as well as the way in which the water system is controlled. Stochastics concerning the operation and availability of controlling infrastructure are included in the method. Models can be evaluated by including real data. In this way the actual safety of the water system, for example during floods, can be determined. Water-quantity design criteria can be incorporated as well as water-quality criteria. Application of the method makes it possible to design safe water systems in which excess capacities are avoided and in which all requirements of interest are met. The method, called the ‘dynamic design procedure’, can result in considerable savings for water authorities when new systems have to be designed or existing designs have to be reconsidered.


2011 ◽  
Vol 85 (4) ◽  
pp. 568-572 ◽  
Author(s):  
E. V. Churilina ◽  
P. T. Sukhanov ◽  
Ya. I. Korenman ◽  
A. N. Il’in ◽  
G. V. Shatalov ◽  
...  

2010 ◽  
Vol 5 (1) ◽  
pp. 29-50 ◽  
Author(s):  
Terje Tvedt

AbstractGlobal history has centred for a long time on the comparative economic successes and failures of different parts of the world, most often European versus Asian regions. There is general agreement that the balance changed definitively in the latter part of the eighteenth century, when in continental Europe and England a transformation began that revolutionized the power relations of the world and brought an end to the dominance of agrarian civilization. However, there is still widespread debate over why Europe and England industrialized first, rather than Asia. This article will propose an explanation that will shed new light on Europe’s and England’s triumph, by showing that the ‘water system’ factor is a crucial piece missing in existing historical accounts of the Industrial Revolution. It is argued that this great transformation was not only about modernizing elites, investment capital, technological innovation, and unequal trade relations, but that a balanced, inclusive explanation also needs to consider similarities and differences in how countries and regions related to their particular water systems, and in how they could exploit them for transport and the production of power for machines.


2006 ◽  
Vol 4 (S2) ◽  
pp. 201-240 ◽  
Author(s):  
Michael Messner ◽  
Susan Shaw ◽  
Stig Regli ◽  
Ken Rotert ◽  
Valerie Blank ◽  
...  

In this paper, the US Environmental Protection Agency (EPA) presents an approach and a national estimate of drinking water related endemic acute gastrointestinal illness (AGI) that uses information from epidemiologic studies. There have been a limited number of epidemiologic studies that have measured waterborne disease occurrence in the United States. For this analysis, we assume that certain unknown incidence of AGI in each public drinking water system is due to drinking water and that a statistical distribution of the different incidence rates for the population served by each system can be estimated to inform a mean national estimate of AGI illness due to drinking water. Data from public water systems suggest that the incidence rate of AGI due to drinking water may vary by several orders of magnitude. In addition, data from epidemiologic studies show AGI incidence due to drinking water ranging from essentially none (or less than the study detection level) to a rate of 0.26 cases per person-year. Considering these two perspectives collectively, and associated uncertainties, EPA has developed an analytical approach and model for generating a national estimate of annual AGI illness due to drinking water. EPA developed a national estimate of waterborne disease to address, in part, the 1996 Safe Drinking Water Act Amendments. The national estimate uses best available science, but also recognizes gaps in the data to support some of the model assumptions and uncertainties in the estimate. Based on the model presented, EPA estimates a mean incidence of AGI attributable to drinking water of 0.06 cases per year (with a 95% credible interval of 0.02–0.12). The mean estimate represents approximately 8.5% of cases of AGI illness due to all causes among the population served by community water systems. The estimated incidence translates to 16.4 million cases/year among the same population. The estimate illustrates the potential usefulness and challenges of the approach, and provides a focus for discussions of data needs and future study designs. Areas of major uncertainty that currently limit the usefulness of the approach are discussed in the context of the estimate analysis.


2017 ◽  
pp. 3-14
Author(s):  
Alexander Prosekov ◽  
Alexander Prosekov ◽  
Olga Babich ◽  
Olga Babich ◽  
Irina Milenteva ◽  
...  

Bacteriocins are antibacterial, mainly complex, substances of protein nature. The promising strains producing bacteriocins used in the food industry are lactic acid microorganisms. This study examines the development of a technology for the production of a recombinant peptide with broad-spectrum antimicrobial properties. An important step is the isolation and purification of the recombinant peptide. It has been proved that the highest antimicrobial activity is manifested by a recombinant peptide isolated by a method based on salting out with ammonium sulfate. During the purification of the recombinant bacteriocin preparation, three kinds of columns were used. In the purification process, the volume of bacteriocin produced decreases 3-fold, while the RU/mL increases 3-fold, and RU/mg increases 6-fold. Purification allows the use of a smaller amount of recombinant bacteriocin in technologies with greater efficacy. Based on the results of determining the molecular weight and purity of the recombinant bacteriocin, it was found that the molecular weight of the recombinant bacteriocin having the amino acid sequence: KYYGNGVTCCKHSCSVDXGKASSCIINNGAMAXATGGH GGNHCCGMSRYIQGIPDFLRGYLHGISSANKHKKGRL, is 13 kDa. A technology for the preparation of a broad-action antimicrobial spectrum peptide has been developed. The process of production of antimicrobial peptide includes such stages as: cultivation of the recombinant strain of Escherichia coli BL21DE3; separation of biomass from the nutrient medium; precipitation of bacteriocins by ammonium sulfate; centrifugation; washing the precipitate; centrifugation at 4200 rpm and separation of the preparation; purification of bacteriocins by HPLC method; packing in bags of polymeric and combined materials; storage at a temperature of 18±2°C for 12 months.


2021 ◽  
Author(s):  
Pedro Medeiros ◽  
Xi Chen ◽  
Thushara Gunda ◽  
Pieter van Oel ◽  
Giulia Vico ◽  
...  

<p>Dynamic interactions between humans and water have produced unanticipated feedbacks, leading to unsustainability. Current water management practices are unable to capture the relevant spatial and temporal detail of the processes that drive the coupled human-water system. Whereas natural and socioeconomic processes occur slowly, local communities and individuals rapidly respond to ensure supply-demand balance. In this context, agricultural human-water systems stand out, as roughly 70% of global water demand is for agricultural uses. Additionally, interactions between humans and agricultural water systems involve many actors and occur at multiple spatial and temporal scales. For example, farmers are influenced by risk perceptions, and decisions made at the farm level influence regional hydrologic and socioeconomic systems, such as degradation and depletion of water sources as well as prices of crops. Regional behaviors, in turn, affect national and international dynamics associated with crop production and trade of associated investments. On the other hand, global and national priorities can also percolate down to the regional and local levels, influencing farmer decision-making through policies and programs supporting production of certain crops and local investments. Over the last decade, relevant phenomena in the coupled agricultural human-water systems have been described, as the irrigation efficiency paradox, reservoir effect, and river basin closure. Along with the globalization in the food market, attempts have been taken to developing and applying benchmarks for water-efficient food production, focusing on water productivities, water footprints and yield gaps for agricultural products. Furthermore, significant advancements have been achieved by incorporating social dimensions of agricultural human-water systems behavior. Fusion of quantitative datasets via observations, remote sensing retrieval, and physically-based models has been explored. Advancements have also been made to capture qualitative or relatively intangible concepts of community values, norms, and behaviors, by interacting with stakeholders, identifying the most important elements of their environments, and incorporating these insights into socio-hydrological models. Based on what has been done during the IAHS Panta Rhei decade and what we have learned, and despite recent efforts towards a more comprehensive understanding of the effects of human interventions in agricultural systems, several challenges persist, of which we highlight: 1) Identification of the cross-scale causal effect on agricultural water uses; 2) Quantification of human behavior uncertainties shaped by social norms and cultural values; 3) Development of a high spatial and temporal resolution global dataset.</p>


Water Policy ◽  
2020 ◽  
Vol 22 (5) ◽  
pp. 908-924
Author(s):  
Kaycie Lane ◽  
Graham Gagnon

Abstract Drinking water advisories (DWAs) are used as a tool for identifying water safety concerns in many jurisdictions. Evidence from previous research demonstrates a lack of improvement in water system operations over time, with an increase in the total number of DWAs in place. DWAs are predominantly issued due to operational concerns within a water system, implying a lack of proactive management measures for preventable issues. Therefore, DWAs represent a chronic issue for many water systems, particularly those lacking resources to implement operational improvements. This study explores DWA characteristics in Atlantic Canada, including frequency and duration, focusing on municipal and private water systems. Seasonality was identified as a trend in DWA issuance in Nova Scotia, and reasons for DWA issuance are largely unchanged over time. Neither of these identified concerns has led to a change in DWA reporting or issuance procedures. Additionally, this study identifies a lack of a common reporting format, leading to the proposal of a template of minimum characteristics for future DWA reporting. Overall, this study highlights deficiencies in the DWA issuance process as a water safety measure and suggests alternative methods for risk management in water systems to alleviate the persistence and prevalence of DWAs in Canada.


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