Optimizing lanthanum (III) hydroxide by varying drying methods to maximize surface area to adsorb ar...

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" Optimizing lanthanum (III) hydroxide by varying drying methods to maximize surface area to adsorb arsenic in water "
Allan J. Stockinger G. C. Miller

Document Type	:	Latin Dissertation
Language of Document	:	English
Record Number	:	54939
Doc. No	:	TL24893
Call number	:	‭1447803‬
Main Entry	:	Allan J. Stockinger
Title & Author	:	Optimizing lanthanum (III) hydroxide by varying drying methods to maximize surface area to adsorb arsenic in water\ Allan J. Stockinger
College	:	University of Nevada, Reno
Date	:	2007
Degree	:	M.S.
student score	:	2007
Page No	:	75
Abstract	:	Removal of arsenic for drinking water is a problem in locations such as Nepal, Bangladesh, South America, western United States, and in Nevada. Previous work has been done at the University of Nevada, Reno to design packed columns containing lanthanum-based compounds to treat & remove arsenic from water. The purpose of this research was to find an optimum set of heating parameters to achieve the highest surface area in the lanthanum hydroxide crystals for arsenic removal. It is hypothesized that the surface area of La(OH)3 can be optimized by the drying protocol used during preparation. Specifically, the baking temperature and duration have a quantifiable impact on such characteristics. Previous work suggests baking temperatures of under 400°C tend to have the highest surface area of lanthanum hydroxide. In addition, higher baking temperatures of 600°C or more have shown a large decrease in surface area of the crystals (Misra, 2006). Using the B.E.T. method to determine surface area, the most favorable conditions for drying lanthanum hydroxide are 150°C for 4 hours. Using the intrinsic properties of surface area, batch adsorption tests were conducted to verify that surface area is directly proportional to arsenic removal in water. Waters containing 77 ppb and 210 ppb of arsenate, respectively, were treated with 500mg of La(OH)3 and after 15 minutes, the arsenic levels were <3 ppb. All samples were effective as arsenic removal under the experimental conditions utilized.
Subject	:	Health and environmental sciences; Applied sciences; Sanitation; Environmental science; Environmental engineering; 0768:Environmental science; 0554:Sanitation; 0775:Environmental engineering
Added Entry	:	G. C. Miller
Added Entry	:	University of Nevada, Reno