東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

Onsite Defluoridation Systems for Dr...

Wong, Elaine Ying Ying.

Linked to FindBook

Google Book

Amazon

博客來

Onsite Defluoridation Systems for Drinking Water Production.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Onsite Defluoridation Systems for Drinking Water Production./
Author:	Wong, Elaine Ying Ying.
Published:	Ann Arbor : ProQuest Dissertations & Theses, : 2017,
Description:	133 p.
Notes:	Source: Dissertation Abstracts International, Volume: 79-02(E), Section: B.
Contained By:	Dissertation Abstracts International79-02B(E).
Subject:	Environmental engineering. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10635657
ISBN:	9780355361414

Onsite Defluoridation Systems for Drinking Water Production.
Wong, Elaine Ying Ying.

Onsite Defluoridation Systems for Drinking Water Production. - Ann Arbor : ProQuest Dissertations & Theses, 2017 - 133 p.

Source: Dissertation Abstracts International, Volume: 79-02(E), Section: B.

Thesis (Ph.D.)--University of California, Los Angeles, 2017.

Fluoride in drinking water has several effects on the teeth and bones. At concentrations of 1--1.5 mg/L, fluoride can strengthen enamel, improving dental health, but at concentrations above 1.5 to 4 mg/L can cause dental fluorosis. At concentrations of 4--10 mg/L, skeletal fluorosis can occur. There are many areas of the world that have excessive fluoride in drinking water, such as China, India, Sri Lanka, and the Rift Valley countries in Africa. Treatment solutions are needed, especially in poor areas where drinking water treatment plants are not available. On-site or individual treatment alternatives can be attractive if constructed from common materials and if simple enough to be constructed and maintained by users. This dissertation investigates using calcium carbonate as a cost effective sorbent for an onsite defluoridation drinking water system. Batch and column experiments were performed to characterize F-- removal properties. Fluoride sorption was described by Freundlich, Langmuir and Dubinin-Radushkevich isotherm models, and it was found that the equilibrium time was approximately 3 hours, with approximately 77% of equilibrium concentration reached within 1 hour. Granular calcium carbonate was found to have comparable F-- removal abilities to the commercial ion exchange resins and possessed higher removal effectiveness compared to calcium containing eggshells and seashells. It was also found that the anion Cl- did not compete with F-- at typical drinking water concentrations, having little impact on the effectiveness of the treatment system. A fluoride removal system is proposed that can be used at home and can be maintained by users. Different calcium phosphate systems were also analyzed to find ways to improve fluoride removal rates. Adding phosphoric acid and calcium carbonate were effective in increasing fluoride removal rates. However, there would need to be a significant amount of phosphoric acid and initial pH would need to be approximately 1.5 or less to have optimal removal rates. We found the best results by using Ca(OH) 2 and NaH2PO4,with fluoride concentrations decreasing to 0.003 mg/L F--. Through this work, we can be a step closer to bringing safe drinking water to those that do not have access to it.

ISBN: 9780355361414Subjects--Topical Terms:

548583
Environmental engineering.

Onsite Defluoridation Systems for Drinking Water Production.
LDR:03233nmm a2200313 4500 001 2164313
005 20181106104112.5
008 190424s2017 ||||||||||||||||| ||eng d
020 $a 9780355361414
035 $a (MiAaPQ)AAI10635657
035 $a (MiAaPQ)ucla:16196
035 $a AAI10635657
040 $a MiAaPQ $c MiAaPQ
100 1 $a Wong, Elaine Ying Ying. $3 3352359
245 1 0 $a Onsite Defluoridation Systems for Drinking Water Production.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2017
300 $a 133 p.
500 $a Source: Dissertation Abstracts International, Volume: 79-02(E), Section: B.
500 $a Adviser: Michael K. Stenstrom.
502 $a Thesis (Ph.D.)--University of California, Los Angeles, 2017.
520 $a Fluoride in drinking water has several effects on the teeth and bones. At concentrations of 1--1.5 mg/L, fluoride can strengthen enamel, improving dental health, but at concentrations above 1.5 to 4 mg/L can cause dental fluorosis. At concentrations of 4--10 mg/L, skeletal fluorosis can occur. There are many areas of the world that have excessive fluoride in drinking water, such as China, India, Sri Lanka, and the Rift Valley countries in Africa. Treatment solutions are needed, especially in poor areas where drinking water treatment plants are not available. On-site or individual treatment alternatives can be attractive if constructed from common materials and if simple enough to be constructed and maintained by users. This dissertation investigates using calcium carbonate as a cost effective sorbent for an onsite defluoridation drinking water system. Batch and column experiments were performed to characterize F-- removal properties. Fluoride sorption was described by Freundlich, Langmuir and Dubinin-Radushkevich isotherm models, and it was found that the equilibrium time was approximately 3 hours, with approximately 77% of equilibrium concentration reached within 1 hour. Granular calcium carbonate was found to have comparable F-- removal abilities to the commercial ion exchange resins and possessed higher removal effectiveness compared to calcium containing eggshells and seashells. It was also found that the anion Cl- did not compete with F-- at typical drinking water concentrations, having little impact on the effectiveness of the treatment system. A fluoride removal system is proposed that can be used at home and can be maintained by users. Different calcium phosphate systems were also analyzed to find ways to improve fluoride removal rates. Adding phosphoric acid and calcium carbonate were effective in increasing fluoride removal rates. However, there would need to be a significant amount of phosphoric acid and initial pH would need to be approximately 1.5 or less to have optimal removal rates. We found the best results by using Ca(OH) 2 and NaH2PO4,with fluoride concentrations decreasing to 0.003 mg/L F--. Through this work, we can be a step closer to bringing safe drinking water to those that do not have access to it.
590 $a School code: 0031.
650 4 $a Environmental engineering. $3 548583
650 4 $a Environmental health. $3 543032
650 4 $a Civil engineering. $3 860360
690 $a 0775
690 $a 0470
690 $a 0543
710 2 $a University of California, Los Angeles. $b Civil Engineering 0300. $3 2095388
773 0 $t Dissertation Abstracts International $g 79-02B(E).
790 $a 0031
791 $a Ph.D.
792 $a 2017
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10635657