Removal of Arsenic and Chromium Oxyanions by Hydrous Tin Dioxide and Tin(IV)-Loaded Exchangers

Tan, Wee Chang (2005) Removal of Arsenic and Chromium Oxyanions by Hydrous Tin Dioxide and Tin(IV)-Loaded Exchangers. Masters thesis, Universiti Putra Malaysia.

[img] PDF
94Kb

Abstract

The potential of tin-loaded poly(hydroxamic acid) ion exchange resin (SnPHA), hydrous tin dioxide (SnO2.xH2O) and hydrous tin dioxide-loaded poly(hydroxamic acid) resin (SnOPHA) to remove heavy metals As(V), As(III) and Cr(VI) from aqueous solution was investigated. Poly(hydroxamic acid) resin was prepared from poly methyl acrylate-divinyl benzene copolymer (PMA). The ester group of the PMA was converted to the hydroxamic acid using the hydroxylamine in an alkaline solution. The SnPHA was prepared by shaking the PHA resin with SnCl4 solution. SnO2.xH2O was prepared by neutralizing a Sn(IV) chloride solution with ammonia solution. The XRD result proved that the SnO2.xH2O prepared is pure. The SnOPHA was produced by direct treating SnPHA with ammonia solution. The XRD result also contributed clear information about the oxidation stated of Sn(IV) in the PHA resin. In order to understand the sorption characteristics of As(V), As(III) and Cr(VI) by the sorbents, batch and column studied were performed under various experimental conditions. The parameters studied were pH, temperature, contact time, isotherm study, sorbent dosage, presence of competitive anions, flow rate and sorption-desorption cycles. The sorbents were also tested to remove arsenic and chromium from industrial waste water samples. The results of batch study indicated that the sorption process by the sorbents was pH dependent and endothermic. It was found that the SnO2.xH2O sorbent has the highest sorption capacity for As(V), As(III) and Cr(VI), followed by SnPHA and SnOPHA. Kinetic study showed that uptake of As(V) ion by the sorbents reached equilibrium after about 13 hours and about 10 hours for Cr(VI) sorption. The maximum sorption capacity of the SnPHA for As(V) and Cr(VI) at room temperature determined from the Langmuir isotherm were 38.50 mg-As/g-resin and 22.12 mg-Cr/g-resin, respectively. Meanwhile, the maximum sorption capacity of the SnOPHA were 8.30 mg-As/g-resin and 14.93 mg-Cr/g-resin and the maximum sorption capacity of the SnO2.xH2O were 64.10 mg-As/g-sorbent and 28.57 mg-Cr/g-sorbent. The uptake increased with increasing sorbent dosage. In the presence of phosphate, sulphate and chromium anions, As(V) uptake decreased. In desorption study, As(V) and Cr(VI) could be removed almost quantitatively from SnPHA and SnOPHA by eluting with a 0.2M NaOH solution. However, a rather low flow rates have to be applied for sorption using the column method. The SnPHA column could be used at least for 3 cycles and 2 cycles for SnOPHA for removal of As(V) ions. More than 86 % of arsenic and chromium were successfully removed from industrial waste water samples by SnPHA.

Item Type:Thesis (Masters)
Subject:Water - Purification - Arsenic removal - Case studies
Chairman Supervisor:Associate Professor Md. Jelas Haron, PhD
Call Number:FS 2005 3
Faculty or Institute:Faculty of Science
ID Code:580
Deposited By:INVALID USER
Deposited On:15 Oct 2008 19:04
Last Modified:27 May 2013 06:49

Repository Staff Only: Edit item detail

Document Download Statistics

This item has been downloaded for since 15 Oct 2008 19:04.

View statistics for "Removal of Arsenic and Chromium Oxyanions by Hydrous Tin Dioxide and Tin(IV)-Loaded Exchangers"


Universiti Putra Malaysia Institutional Repository

Universiti Putra Malaysia Institutional Repository is an on-line digital archive that serves as a central collection and storage of scientific information and research at the Universiti Putra Malaysia.

Currently, the collections deposited in the IR consists of Master and PhD theses, Master and PhD Project Report, Journal Articles, Journal Bulletins, Conference Papers, UPM News, Newspaper Cuttings, Patents and Inaugural Lectures.

As the policy of the university does not permit users to view thesis in full text, access is only given to the first 24 pages only.