ABSTRACT
Melamine-Formaldehyde- diethylenetriaminepentaacetic acid (MF-DTPA) resin was
prepared as a new adsorbent for removing heavy metals from wastewater effluents.
In the synthesis process, the chelating agent diethylenetriaminepentaacetic acid
(DTPA) anchored to melamine via amide covalent bond during melamineformaldehyde
condensation reaction in aqueous acidic medium. Resin
characterisation using FT-IR, elemental analysis and N2 gas adsorption (BET) were
carried out to determine DTPA functionality and porosity. Water regain factor was
also determined to find out hydrophilic character of the resin. Removal of Cu(II), as a
representative of heavy metals, from synthetic wastewater using fixed-bed column
packed with MF-DTPA grains was studied considering bed height, influent
concentration and influent flow rate as controlling factors. The Thomas model was
used to fit the adsorption data and its constants were evaluated. The Bed Depth
Service Time (BDST) model was conducted to predict the service time of columns
operated at different influent concentration and influent flow rates. It was found that
DTPA successfully anchored to MF during resin matrix formation. The produced resin
is hydrophilic (water regain 72%) and its surface area is 162 m2 g-1 with neglected
micro-porosity. DTPA is suggested to be present as 0.93 mmole per gram solid resin.
The removal of Cu(II) ion using fixed-bed mode column packed with MF-DTPA grains
kinetically follows Thomas model. BDST model was found to fit the results and
applicable for scaling up the system with dynamic capacity, N○=7232 mg ml-1 and
active zone, Z○=2.2 cm.
The MF-DTPA resin has a potential for removal of heavy metals from wastewater
effluents.