000			03983cas|a2200421 i 4500
005			20260818144318.0
008			150399s1990 th uzm rtt 00| a1eng d
035			_a.b10379502
099		9	_aAIT Thesis no. EV-90-13
100	1		_aMayige, Christopher Ngelya
245	1	0	_aInvestigation of ClO2 disinfection at Bangkhen Water Works
260			_aBangkok : _bAsian Institute of Technology, _c1990
300			_a57 p.
490	1		_aThesis ; _vno. EV-90-13
500			_aA Thesis submitted in partial requirements for the degree of fulfillment Master of of the Science, School of Environment, Resources and Development
502			_aThesis (M.Sc.) - Asian Institute of Technology, 1990
520			_aThis stud y investigated the occurrence of reaction products with public health significance when chlorine dioxide disinfection is adopted in place of the current chlorination at Bangkhen Water Treatment Plant . An earlier study at the plant (GHAZALI,1989) h ad revealed a threat to public health in the future from continued chlorination due to the formation of excessive amounts of trihalomethanes (THMs ) in drinking water. The THMs, arise from t h e reaction of chlorine with a variety of organic compounds present in the water a nd, have toxic effects. The present study involved monitoring the resulting levels o f THMs, chlorates , chlorites a nd residual chlorine dioxide in the untreated water and after adding the disinfectant. Chlorine dioxide doses of 1 to 10mg/L were applied to filtered unchlorinated water from Bangkhen Water Treatment Plant. The organic content of t h e water was on average about 2.4mg/L , as the total organic carbon (TOC ) . The trihalomethanes (THMs ) were measured by the head space - gas chromatographic method. Chlorine dioxide residuals were monitored with the simple iodometric method . Chlorates and chlorites were quantified u sing iodometric titrations while varying the pH in a de-aerated medium. Neither bromine nor THMs were found in t he filtered water from the treatment plant . After application of chlorine dioxide dioxide, no THMs were detected in t h e treated water . Very l ow levels of chlorites and chlorates ( 0.1mg/L) were observed in t he finished water even after 48 hours of contact after the dosing of chlorine dioxide in excess of 10mg/L. The stability of the chlorine dioxide was evident from the observed ( - 0 .lmg/L) residuals at the end of 48 h ours contact time. From t h is study it can b e seen that chlorine dioxide at doses of 1mg/L to 1 .2mg/L constitutes a viable alternative for Bangkhen Water Treatment Plant to the present chlorination for curbing THMs and adequate disinfection of t h e water.
650		0	_aWater _xPurification
650		0	_aDisinfection and disinfectants
700	0		_aSamorn Muttamara, _eChairperson
700	1		_aVigneswaran, Saravanamuthu, _eExamination Committee
700	1		_aHarada, Hideki, _eExamination Committee
710	2		_aDanish International Development Agency, Denmark., _eScholarship Donor
810	2		_aAsian Institute of Technology. _tThesis ; _vno. EV-90-13
856			_3Full-Text _uhttp://203.159.5.9/ait-thesis/detail.php?q=B18366
907			_a.b10379502 _bmnait _cx
902			_a240402
998			_b2 _c951012 _dm _ea _fx _g0
945			_lmnait
945			_lmnait
945			_lmnarc
942			_c20
942			_c40
909			_aBarcode : 30050003045522 _bCREATED : 1994-05-17 _cRECORD # : i1047402x _dLPATRON : 0 _eLCHKIN : - _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 0 _iTOT CHKOUT : 0 _jTOT RENEW : 0
909			_aBarcode : 30050120806657 _bCREATED : 1994-05-17 _cRECORD # : i10474031 _dLPATRON : 1018548 _eLCHKIN : 2005-05-10 _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 0 _iTOT CHKOUT : 3 _jTOT RENEW : 0
909			_aBarcode : 30050120222939 _bCREATED : 2016-11-05 _cRECORD # : i12974109 _dLPATRON : 0 _eLCHKIN : - _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 0 _iTOT CHKOUT : 0 _jTOT RENEW : 0
999			_c64666 _d64666