000			03966nas|a2200385 i 4500
005			20260818173856.0
008			020799s1999 th uzm rtt 00| a1eng d
035			_a.b11753961
099		9	_aAIT Thesis no.EV-99-3
100	1		_aZhu, Ling
245	1	2	_aA preliminary study on heavy metal removal from contaminated soils using supercritical fluid extraction
260			_aBangkok : _bAsian Institute of Technology, _c1999
300			_a68 leaves
490	1		_aThesis ; _vno. EV-99-3
500			_aA thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development
502			_aThesis (M.Sc.) - Asian Institute of Technology, 1999
520			_aThe goal of the study was to investigate the feasibility of removing heavy metals from the tlu·ee types of tropical soil which is different in character, by chelation in supercritical carbon dioxide. The selected topsoil were Karat sandy soil, Pakchong kolinitic soil, and Rangsit acid sulfate soil. Copper was used as the model contaminant while Hexafluoracetylacetone (HF A) as a chelating agent. This study was consisted of two parts include ( 1) The investigation of the effect of density, temperature, methanol modifier, extraction time, HF A/Cu molar ratio, soil pH, moisture content and contaminant level on the extraction efficiency and (2) The comparison of the recovery yield, cost, and waste disposal problem between Supercritical fluid extraction and solvent extraction which is widely used in real site remediation. For the first part, The result indicated that, under optimum condition of SFE, 82%, 74%, 56% removal of copper can be achieved for Korat, Pakchong and Rangsit soils, respectively. Increased the density from 0.25 to 0.75 g/ml, it was found to have negligible effect on the copper recovery. At constant density (0.55 g/ml) increased the temperature from 40 °c to 80 °C were found to have negative effect on Rangsit soil and negligible effect on Korat and Pakchong soil. Adding methanol at 5% had the highest yield for all tlu·ee kinds of studied soils. The dynamic extraction time was conducted varying from 5 to 35 min. The pH appears to be an important factor determine the extraction efficiencies. The effective pH range has lied between 3 to 10. Addition of a small amount of water to the soil samples can significantly increase the extraction efficiency. Extraction of higher contaminated soil get higher recovery. The possible reasons were discussed. For the second pru1, by comparison between the two methods, it is discovered that both SFE and solvent extraction can yield quite similar removal efficiency. However, SFE is an environmental-friendly method for removing heavy metal in contaminated soil while conventional method created the waste disposal problem. It is important to conduct further study in order to reduce the treatment cost of the new SFE technique and enable it to be commercially accepted.
650		0	_aSoil remediation
700	0		_aPreeda Pakpian, _eChairperson
700	1		_aOzaki, Hiroaki, _eExamination committee
700	0		_aApisit Eiumnoh, _eExamination Committee
710	2		_aAIT employee Student, _eScholarship donor
810	2		_aAsian Institute of Technology. _tThesis ; _vno. EV-99-3
856			_3Full-Text _uhttp://203.159.5.9/ait-thesis/detail.php?q=B12038
907			_a.b11753961 _bmnait _cy
902			_a240411
998			_b0 _c990702 _dm _ea _fy _g2
945			_lmnait
945			_lmnarc
942			_c22
942			_c40
909			_aBarcode : 30050120654867 _bCREATED : 2014-03-19 _cRECORD # : i12772835 _dLPATRON : 0 _eLCHKIN : - _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 0 _iTOT CHKOUT : 0 _jTOT RENEW : 0
909			_aBarcode : 30050160077714 _bCREATED : 2016-05-23 _cRECORD # : i12988042 _dLPATRON : 0 _eLCHKIN : - _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 0 _iTOT CHKOUT : 0 _jTOT RENEW : 0
999			_c91107 _d91107