Suppression of Bacterial Oxidation of Arsenopyrite by Coating

Name: Nitinai Khummalai

Organization : มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี

keyword: Arsenopyrite

; Thin films

; Adsorption

Abstract: Arsenic releasing is a severe environmental problem that results from the oxidationof arsenopyrite (FeAsS). Arsenic is often associated with abandoned mines, in whicharsenopyrite exists. Moreover, the oxidation rate is accelerated when the bacterial, such asTl~iohucillu~~sf errooosid~znsc,e lls are present. Coating with sol-gel thin films on thearsenopyrite surfaces is considered to be a promising approach for abatement. Theobjectives of this study are the characterization of the formation of thin-films by sol-gel onarsenopyrite and the investigation of the effect of the thin films on the bacterial adsorptionand oxidation. We found that in the area contaminated with arsenic, arsenopyrite usually co-existswith T. ,jerrooxiduns in the contaminated area. This implied that the biooxidation ofarsenopyrite is the major cause of the arsenic releasing. The adsorption of T. Jir.r.ooxidanswas investigated and formed follow Lailgmuir isotherm with the maximum adsorptioncapacity of T.f,e rrooxiduns on arsenopyrite 1 . 5 21~0 ' ' cell/m%nd kA 1.161~0 ~ ' b ~ l c e A coating of thin films on the arsenopyrite surface is proposed to prevent the cellsfrom attaching to arsenopyrite surfaces. We selected Methyltrimethoxysilane (MTMOS),Tetraethoxysilane (TEOS), Tetramethoxysilane (TMOS) and N-(2-aminoethy1)-3-amiilopropyl trimethoxysilane (AAPS) as a sol-gel precursor. SEM micrographsdemonstrated the hon~ogeneous topology of MTMOS film without fractures. TMOS,TEOS and AAPS resulted in cracking due to the shrinkage of films exposed to the hightemperature and shortage of hydrolysis time. However, MTMOS, TEOS, TMOS andAAPS coatings suppressed both chemical and biological oxidation of arsenopyrite atdifferent level. MTMOS suppressed both biooxidation of T. jerrooxidan.~ and hydroxideoxidation, while TMOS, TEOS and AAPS yield lower efficiency.

มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี

Address: Bangkok

Email: info.lib@mail.kmutt.ac.th

Name: Virote Boonamnuayyitaya

Role: Supervisor

Created: 2545

Issued: 2007-02-12

Modified: 2014-05-25

วิทยานิพนธ์/Thesis

ISBN: 9744561769

CallNumber: JGSEE35

eng

DegreeName: Doctor of Philosophy

Level: Doctoral Degree

Descipline: Environmental Technology

Grantor: King Mongkut's University of Technology Thonburi

©copyrights King Mongkut's University of Technology Thonburi

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3	JGSEE35.txt	2.2 KB	9	2018-05-10 17:35:13

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