000			03879cas|a2200421 i 4500
005			20260817162954.0
008			230399s1993 th uzm rtt 00| a1eng d
035			_a.b10089238
099		9	_aAIT Thesis no.EV-93-26
100	1		_aWerellagama, D. R. Induka B.
245	1	0	_aApplication of the floto filter unit for contact flocculation filtration of surface waters
260			_aBangkok : _bAsian Institute of Technology, _c1993
300			_a141 leaves + _e1 online resource
490	1		_aThesis ; _vno. EV-93-26
500			_aA thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering
502			_aThesis (M.Eng.) - Asian Institute of Technology, 1993
520			_aLaboratory scale experiments were carried out in contact flocculation filtration using a dual media filter. The objective of the research was to find an optimum synthetic media combination which would give acceptable quality water under varying conditions while maintaining a low headloss. The media was lighter than water hence the bed was floating. Since coarse media remained at the bottom the flow direction was upflow which had the added advantage that the flow was in the direction of grain compression. Polypropylene and Polystyrene were selected as the optimum combination of media which due to their large . density difference did not intermix even under severe agitation. Spherical fine media performed better than angular fine media giving lower headloss and better effluent quality. The dual media combination and the higher rates of filtration are in line with the current trends in the water industry. The influent concentrations were kept constant and the flow velocity and filter media size were varied. The headloss variation along the filter, the influent quality to the two filter layers and the effluent quality were studied. The filter performed for over 40 hours producing acceptable quality water at conventional rapid sand filtration rates, also having low headloss development. Another major advantage was the ease and economy in backwashing. The filter media did not mix even during or after backwashing, thereby eliminating the most common problem encountered in conventional multi media filters. The Floto Filter operation was compared with upflow sand filtration. The headloss development curves for Floto filter showed a characteristic shape easily identifiable from that for sand. The existing mathematical model was able to predict the headloss profile but the concentration profile was not predicted. The necessity of particle size data for mathematical modelling of filtration of heterodisperse suspensions is emphasized.
650		0	_aWater _xPurification _xFiltration
700	1		_aVisvanathan, C., _eChairperson
700	1		_aFujii, Shigeo, _eExamination committee
700	0		_aSamorn Muttamara, _eExamination Committee
710	2		_aSwedish International Development Agency (SIDA), _eScholarship donor
810	2		_aAsian Institute of Technology. _tThesis ; _vno. EV-93-26
856			_3Full-Text _uhttp://203.159.5.9/ait-thesis/detail.php?q=B16676
907			_a.b10089238 _bmnait _cx
902			_a240411
998			_b2 _c951012 _dm _ea _fx _g0
945			_lmnait
945			_lmnait
945			_lmnarc
942			_c20
942			_c22
942			_c40
909			_aBarcode : 30050120806087 _bCREATED : 1994-05-16 _cRECORD # : i10095366 _dLPATRON : 0 _eLCHKIN : - _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 0 _iTOT CHKOUT : 0 _jTOT RENEW : 0
909			_aBarcode : a _bCREATED : 1995-10-13 _cRECORD # : i10095378 _dLPATRON : 0 _eLCHKIN : - _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 0 _iTOT CHKOUT : 0 _jTOT RENEW : 0
909			_aBarcode : 30050160055728 _bCREATED : 2016-11-05 _cRECORD # : i12975187 _dLPATRON : 0 _eLCHKIN : - _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 0 _iTOT CHKOUT : 0 _jTOT RENEW : 0
999			_c6880 _d6880