000			03478cas|a2200409 i 4500
005			20260817162845.0
008			050499s1994 th uzm rtt 00| a1eng d
035			_a.b10087564
099		9	_aAIT Thesis no. EV-94-31
100	1		_aThayalakumaran, Nagalingam
245	1	0	_aApplication of constructed wetlands to the treatment of a heavy metal wastewater
260			_aBangkok : _bAsian Institute of Technology, _c1994
300			_a99 leaves
490	1		_aThesis ; _vno. EV-94-31
500			_aA thesis submitted in · partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources & Development
502			_aThesis (M.Eng.) - Asian Institute of Technology, 1994
520			_aVarious industrial activities such as electroplating and metal finishing generate tons of metallic pollutants into the air and water bodies. There are a number of techniques available for the removal of heavy metals from wastewaters. Electroplating industries produce Cr and Ni wastewaters. Because constructed wetlands are cost-effective and energy-efficient, they were used to investigate efficiencies in treating an electroplating wastewater. One pilot-scale and three lab-scale constructed wetland units were constructed at the Environmental Research Station, AIT campus where cattail plants were grown. These constructed wetlands were fed with mixtures of the electroplating wastewater and a domestic wastewater and maintained at a hydraulic retention time of 7 days. Physico-chemical parameters such as pH, SCOD, TSS, DO and influent and effluent heavy metal concentrations were measured at three days interval. Heavy metal removal efficiencies of more than 99 3 were observed in pilot-scale unit even when the influent heavy metal concentrations were 25 mg/l. The heavy metals were removed mainly by precipitation and adsorption. The soil adsorbed more Cr and Ni than the plants. The Cr and Ni ions were strongly held by the root cells showing high concentrations in the roots. Cr was more strongly chelated in the root than Ni. Ni fed wetland plants showed some phytotoxic effects. In the pilot-scale unit, removal efficiencies of SCOD, TSS, TKN were more than 64, 89 and 85 3 respectively.
650		0	_aSewage _xPurification _xHeavy metals removal
700	0		_aChongrak Polprasert, _eChairperson
700	0		_aSamorn Muttamara, _eExamination Committee
700	1		_aUmita, Teruyuki, _eExamination Committee
710	2		_aGovernment of Finland, _eScholarship Donor
810	2		_aAsian Institute of Technology. _tThesis ; _vno. EV-94-31
856			_3Full-Text _uhttp://203.159.5.9/ait-thesis/detail.php?q=B15821
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909			_aBarcode : 30050003048039 _bCREATED : 1994-05-16 _cRECORD # : i10092961 _dLPATRON : 1013913 _eLCHKIN : 2006-03-31 _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 0 _iTOT CHKOUT : 8 _jTOT RENEW : 12
909			_aBarcode : 30050003604203 _bCREATED : 1994-05-16 _cRECORD # : i10092973 _dLPATRON : 1017232 _eLCHKIN : 2006-01-21 _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 0 _iTOT CHKOUT : 12 _jTOT RENEW : 5
909			_aBarcode : 30050160055306 _bCREATED : 2016-11-05 _cRECORD # : i12975618 _dLPATRON : 0 _eLCHKIN : - _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 0 _iTOT CHKOUT : 0 _jTOT RENEW : 0
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