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Removal of Cu(II) ions from aqueous solution effluent using Melamine-Formaldehyde-DTPA resin in a fixed-bed up-flow column. By Ahmad Baraka Supervisors Prof. Peter Hall Dr. Mark Heslop. Department of Chemical & Process Engineering. The problem.
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Removal of Cu(II) ions from aqueous solution effluent using Melamine-Formaldehyde-DTPA resin in a fixed-bed up-flow column By Ahmad Baraka Supervisors Prof. Peter Hall Dr. Mark Heslop Department of Chemical & Process Engineering
The problem Sources of pollution (Mining-industrial activities- agricultural runoff, etc...) Discharging heavy metals into water bodies Non-degradable Accumulation of toxic heavy metals (World wide problem) Department of Chemical & Process Engineering Some famous heavy metals present in different wastewaters: Chromium, Lead, Copper, Zinc, Cadmium, Nickel, Iron, Cobalt, Mercury, Silver, Aluminium, …..
How to solve the problem? The main methods for heavy metals removal • Chemical precipitation (hydroxides and carbonates) • Solvent extraction (liquid / liquid extraction) • Ion Exchange • Electrochemical method (Electrodialysis – Electrochemical ion exchange (EIX) • Reverse osmosis (Membrane separation) • ADSORPTION(liquid / solid extraction) - Active carbon, fly ash, etc.. - biomaterials (e.g. wastes of agricultural origin) - inorganic resins - organic resins Department of Chemical & Process Engineering
AdsorptionAdsorption is an attractive technology for treatment of wastewater for retaining heavy metals from dilute solutions. Adsorption (liquid/solid extraction): - physical adsorption (weak forces) - chemical adsorption (chemical bond) - surface micro-precipitation adsorption - coordination adsorption (ligands or chelates and depend on O,N,S,P donor atoms) Department of Chemical & Process Engineering
Aim of the project • Synthesis and characterization of a new organic resin (MF-DTPA) . • Studying adsorption performance of MF-DTPA towards some heavy metals (Cu, Co, Cd, and Zn) through thermodynamics, kinetics, and isotherm. (batch study) • Estimate the adsorption mechanisms. Department of Chemical & Process Engineering Examine the new adsorbent under continuous mode (column study) considering Cu(II) ion
Why MF resin?(Advantages) • Availability of main precursors (Melamine and Formaldehyde) with low price. • Production of Monolithic, granules, fine powder products. • Controllable porosity (pH, Temp., solvent type, solvent content). • Good mechanical hardness. • Chemical and thermal stability. • Ability to functionalize with different polyaminepolycarboxilic acids (e.g. DTPA, NTA, CDTA, etc…) Department of Chemical & Process Engineering DTPA
Chemistry of preparation (MF-DTPA) resin MF matrix formation Department of Chemical & Process Engineering DTPA anchoring (amide bond)
Proposed structure MF-DTPA resin Chelating site Resin matrix Department of Chemical & Process Engineering
IR spectra of MF and MF-DTPA MF MF-DTPA Department of Chemical & Process Engineering O-H C=O
C13-NMR of MF and MF-DTPA MF-DTPA MF
N15-NMR of MF and MF-DTPA MF-DTPA MF
Elemental analysis From elemental analysis results, 36.7% of the resin mass is DTPA (around 0.93 mmole per gram of solid resin). Department of Chemical & Process Engineering About 93.3 mmole DTPA per gram MF-DTPA resin
N2 gas adsorption-desorption (BET) Desorption Adsorption Department of Chemical & Process Engineering
SEM Image of MF-DTPA resin Department of Chemical & Process Engineering MF-DTPA aggregates
Cu(II) adsorption (continuous mode) Department of Chemical & Process Engineering
Experimental removal set ( fixed-bed up-flow column) Sampling valve Packed column Influent tank flow Effluent tank Department of Chemical & Process Engineering Peristaltic Pump
Suggested removal mechanism(chelation) resin active part Resin body Department of Chemical & Process Engineering Cu(II) Cu(II) coordination with DTPA part
Parameters to discuss Effect of bed height 5 7 9 cm Effect of influent concentration 20 30 40 ppm Department of Chemical & Process Engineering Effect of influent flow rate 3.2 5.5 8.1 ml/min
Effect of bed height Flow rate=5.5 ml/min C (initial)= 30 ppm Department of Chemical & Process Engineering 10%
Effect of influent concentration Flow rate=5.5 ml/min Bed height = 7 cm Department of Chemical & Process Engineering 10%
Effect of influent flow rate Department of Chemical & Process Engineering 10% Flow rate=5.5 ml/min C (initial)= 30 ppm
Experimental results of up-flow column adsorption considering bed height, influent concentration and influent flow rate Department of Chemical & Process Engineering
Thomas model (Kinetics) The data collected in continuous mode studies was used to determine the kinetic parameters using the Thomas model which is widely used for column studies. The Thomas model has the following expression; Department of Chemical & Process Engineering
Parameters predicted from Thomas model considering bed height, influent concentration and influent flow rate height concentration Department of Chemical & Process Engineering Flow rate
BDST model(Bed Depth Service Time) cm Department of Chemical & Process Engineering Minutes BDST constants: N○ = 7232 mg/ml (25.8 mg per gram of solid resin) kad = 4.91×10-4 l mg-1 min-1 Z○ = 2.2 cm.
BDST model analysis Department of Chemical & Process Engineering BDST plots at Ct/C○ = 0.033, 0.1, 0.5 and 0.9. The BDST equations of these lines are as follows: Ts = 62.5 Z – 144.17 for Ct/C○ = 0.033 (R2=0.9995) Ts = 67.5 Z – 149.17 for Ct/C○ = 0.1 (R2=0.9995) Ts = 66.3 Z – 65.417 for Ct/C○ = 0.5 (R2=0.9999) Ts = 63.8 Z – 1.25 for Ct/C○ = 0.9 (R2=0.9988)
BDST model fitting with influent concentration condition and influent flow rate condition Department of Chemical & Process Engineering
Regeneration and re-adsorption EDTA (0.01 M) Regeneration efficiency 84% (Ct/Co=1) 9 bed volumes Department of Chemical & Process Engineering Capacity decreased by 20% (Ct/Co=1) due to Hydrolysis
Conclusions • Instrumental analysis (IR, NMR, Elemental analysis, BET, SEM) gave proof for synthesis success of the new chelating resin, MF-DTPA and showed its high porosity . • The metal removal was due to strong chelating agent (DTPA) which can coordinate several types of heavy metals. • Thomas model fitted data and can be used to determine capacity and rate constant. • High rate constant of removal. • The dynamic capacity is around 30 mg Cu(II) / g. • BDST model fitted data and can be used for scaling up the system for practical application. • Regeneration by EDTA solution. Department of Chemical & Process Engineering
THANK YOU Department of Chemical & Process Engineering