Influence of Monolayers on the Natural Rate of Evaporation of Water

Mansfield, W. W.

doi:10.1038/175247a0

Cited by 69 publications

(27 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…2 The first field experiment was conducted in Australia in the beginning of the 50's, and the obtained evaporation reductions of 30% called attention of many research groups and governments around the world. 6,7 In the following decades, several experimental and theoretical works were published, and the main conclusions were collected in a review published in 1986. 8 Although the spreading of a monomolecular film on the surface of a reservoir has been considered as an alternative technology for fresh water conservation by the United Nations Environment Programme, only a few investigations on this subject have been reported in the last years.…”

Section: Introductionmentioning

confidence: 99%

Reduction of evaporation of natural water samples by monomolecular films

Gugliotti¹,

Baptista²,

Politi³

2005

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

A capacidade de filmes monomoleculares de álcoois graxos em reduzir a evaporação de amostras naturais de água, coletadas em dois reservatórios de São Paulo (Guarapiranga e Billings), foi estudada em laboratório. As reduções da evaporação foram determinadas diretamente, medindo-se o volume de água evaporado dos recipientes de teste após certo tempo. Filmes mistos de hexadecanol e octadecanol apresentaram alto potencial de redução da evaporação (até 57%) e persistência na superfície da água, por cerca de 48 horas. Uma breve discussão sobre a melhor eficiência desses filmes mistos na redução da evaporação de água é também apresentada.The ability of monomolecular films of fatty alcohols in reducing evaporation of natural water samples collected from two reservoirs in São Paulo (Guarapiranga and Billings) was studied in the laboratory. Evaporation reductions were determined directly by measuring the volume of water evaporated from the test recipients after a certain period of time. Mixed films of hexadecanol and octadecanol showed high potential of evaporation reduction (up to 57%) and persistence on the water surface of ca. 48 hours. A brief discussion on the better efficiency of these mixed films in reducing water evaporation is also presented. Keywords: water, evaporation, fatty alcohols, monomolecular films, surface tension IntroductionWater is the most precious natural resource available to mankind. Most of our usable fresh water is retained in lakes and reservoirs, but this type of storage allows for the greatest loss of water by evaporation. The increasing demand for municipal and industrial fresh water, and the current increase in the global temperature indicate that it is necessary to employ techniques for reducing evaporation aiming at the conservation of water supplies.It has been known for a long time that monomolecular films of certain surfactants can retard water evaporation. 1 This seems to be the only viable technology for reducing the evaporative losses of water from reservoirs. 2 For many years, important studies in laboratory scale were carried out in order to identify the optimal substances and conditions for reducing water evaporation. [3][4][5] Among the surfactants tested, biodegradable fatty alcohols of low toxicity presented the highest resistance to water evaporation, especially 1-hexadecanol and 1-octadecanol. 2 The first field experiment was conducted in Australia in the beginning of the 50's, and the obtained evaporation reductions of 30% called attention of many research groups and governments around the world. 6,7 In the following decades, several experimental and theoretical works were published, and the main conclusions were collected in a review published in 1986. 8 Although the spreading of a monomolecular film on the surface of a reservoir has been considered as an alternative technology for fresh water conservation by the United Nations Environment Programme, only a few investigations on this subject have been reported in the last years. 9 Among the most recent works on this subje...

show abstract

Section: Introductionmentioning

confidence: 99%

Reduction of evaporation of natural water samples by monomolecular films

Gugliotti¹,

Baptista²,

Politi³

2005

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…Mansfield (192) in 1953 experimented with flakes of cetyl alcohol on reservoirs but found them to be unwritable. The East African Industrial Research Organization (107) describes a method for pelletizing cetyl alcohol.…”

Section: -5®--3mentioning

confidence: 99%

“…Mansfield (191,192) used a sunken pan to assess the effectiveness of evaporation suppressants. This evaporimeter was calibrated to measure evaporation from small ponds that were used in a field test of hexadecanol.…”

Section: Evaporation Suppressionmentioning

confidence: 99%

Review of literature on evaporation suppression

Magin¹,

Randall²

1960

Professional Paper

View full text Add to dashboard Cite

“…The first attempts to apply monolayers under natural conditions to open water surfaces to reduce evaporation were some 53 years ago (Mansfield 1955). Since then a plethora of methods for applying a monolayer have followed, from Vines (1958) through to Lahav and Alto (1984).…”

Section: Introductionmentioning

confidence: 99%

Development of a Smart Monolayer Application System for Reducing Evaporation from Farm Dams: Introductory Paper

Brink

Symes

Hancock

2011

Australian Journal of Multi-Disciplinary Engineering

View full text Add to dashboard Cite

Chemical monolayer films are potentially an economical low-impact means of reducing evaporative loss from farm water storages. However, their performance can be highly variable as they are affected by climatic and environmental factors: principally wind, wave action and biodegradation. These limitations must be accommodated for in the management of the applied monolayer by means of appropriate and timely autonomous application and re-application.Although a number of autonomous application systems for monolayer already exist, none has proved overly successful. It is argued that whilst this is in part due to sub-optimal performance of monolayer materials, it is also due in large measure to inaccuracies and/or inappropriate design in both application systems and particularly application strategies which are not adaptive to the prevailing environmental conditions. Therefore, a control system is being developed to adaptively and spatially vary monolayer application rates according to changing conditions monitored on-site. This will form part of an autonomous electromechanical system for the optimal application and spreading of chemical monolayer.This paper reports progress towards this objective; firstly by evaluation of the design requirements for automated systems at a range of spatial scales; and secondly via the construction of a first "preprototype" to act as an evaluation platform and concept demonstrator.

show abstract

Influence of Monolayers on the Natural Rate of Evaporation of Water

Cited by 69 publications

References 5 publications

Reduction of evaporation of natural water samples by monomolecular films

Reduction of evaporation of natural water samples by monomolecular films

Review of literature on evaporation suppression

Development of a Smart Monolayer Application System for Reducing Evaporation from Farm Dams: Introductory Paper

Contact Info

Product

Resources

About