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) Some famous heavy metals present in different wastewaters: Chromium, Lead, Copper, Zinc, Cadmium, Nickel, Iron, Cobalt, Mercury, Silver, Aluminium, ….. Department of Chemical & Process Engineering

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) ion exchange (EIX) ► Reverse osmosis (Membrane separation) ► ADSORPTION (liquid / solid extraction) ADSORPTION - Active carbon, fly ash, etc.. - biomaterials (e.g. wastes of agricultural origin) - inorganic resins - organic resins Department of Chemical & Process Engineering

Adsorption Adsorption Adsorption is an attractive technology for treatment of wastewater for retaining heavy metals from dilute solutions. Adsorption (liquid/solid extraction): Adsorption (liquid/solid extraction): - physical adsorption (weak forces) - physical adsorption (weak forces) - chemical adsorption (chemical bond) - chemical adsorption (chemical bond) - surface micro-precipitation adsorption - surface micro-precipitation adsorption - coordination adsorption (ligands or chelates and depend on O,N,S,P donor atoms) - 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. Examine the new adsorbent under continuous mode (column study) considering Cu(II) ion Department of Chemical & Process Engineering

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…) polyaminepolycarboxilic acids (e.g. DTPA, NTA, CDTA, etc…) Department of Chemical & Process Engineering DTPA

Chemistry of preparation (MF-DTPA) resin Department of Chemical & Process Engineering MF matrix formation DTPA anchoring (amide bond)

Chelating site Resin matrix Proposed structure MF-DTPA resin Department of Chemical & Process Engineering

IR spectra of MF and MF-DTPA MF MF-DTPA C=O O-H Department of Chemical & Process Engineering

C 13 -NMR of MF and MF-DTPA MF-DTPA MF

N 15 -NMR of MF and MF-DTPA MF-DTPA MF

Resin C : H : N : O MF-DTPA 35.7 : 5.2 : 37.7 : 21.6 MF 31.7 : 5.5 : 40.4 : 22.3 From elemental analysis results, 36.7% of the resin mass is DTPA (around 0.93 mmole per gram of solid resin). Elemental analysis About 93.3 mmole DTPA per gram MF-DTPA resin Department of Chemical & Process Engineering

Desorption Adsorption BET Surface Area, m 2 /g Micropore Area, m 2 /g BJH Adsorption cumulative pore volume., cm 3 /g Average pore diameter, Å N 2 gas adsorption-desorption (BET) Department of Chemical & Process Engineering

SEM Image of MF-DTPA resin MF-DTPA aggregates Department of Chemical & Process Engineering

Cu(II) adsorption (continuous mode) Cu(II) adsorption (continuous mode) Department of Chemical & Process Engineering

Peristaltic Pump Influent tank Effluent tank Packed column Sampling valve Experimental removal set ( fixed-bed up-flow column) ( fixed-bed up-flow column) flow Department of Chemical & Process Engineering

Suggested removal mechanism (chelation) Cu(II) Cu(II) coordination with DTPA part Resin body resin active part Department of Chemical & Process Engineering

Effect of bed height579 cm Effect of influent concentration ppm Effect of influent flow rate ml/min Parameters to discuss Department of Chemical & Process Engineering

Effect of bed height 10% Flow rate=5.5 ml/min C (initial)= 30 ppm Department of Chemical & Process Engineering

Effect of influent concentration Flow rate=5.5 ml/min Bed height = 7 cm 10% Department of Chemical & Process Engineering

Effect of influent flow rate 10% Flow rate=5.5 ml/min C (initial)= 30 ppm Department of Chemical & Process Engineering

Experimental results of up-flow column adsorption considering bed height, influent concentration and influent flow rate [Z(cm),C ○ (mg l -1 ), υ (ml min -1 )] V eff (ml) T b (min) q m (mg g -1 ) [5, 30, 5.5] [7, 30, 5.5] [9, 30, 5.5] [7, 20, 5.5] [7, 40, 5.5] [7, 30, 3.2] [7, 30, 8.1] Department of Chemical & Process Engineering

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; Thomas model (Kinetics) Department of Chemical & Process Engineering

Parameters predicted from Thomas model considering bed height, influent concentration and influent flow rate [Z(cm),C ○ (mg l -1 ), υ (ml min -1 )] k Th (l mg -1 min -1 ) Q (mg g -1 ) R2R2R2R2 [5, 30, 5.5] 1.17 × [7, 30, 5.5] 1.21 × [9, 30, 5.5] 1.25 × [7, 20, 5.5] 1.50 × [7, 40, 5.5] 1.32 × [7, 30, 3.2] 9.13 × [7, 30, 8.1] 1.42 × height concentration Flow rate Department of Chemical & Process Engineering

BDST model (Bed Depth Service Time) Minutes cm BDST constants: N ○ = 7232 mg/ml (25.8 mg per gram of solid resin) k ad = 4.91×10 -4 l mg -1 min -1 Z ○ = 2.2 cm. Department of Chemical & Process Engineering

BDST model analysis The BDST equations of these lines are as follows: T s = 62.5 Z – for C t /C ○ = 0.033(R 2 =0.9995) T s = 67.5 Z – for C t /C ○ = 0.1(R 2 =0.9995) T s = 66.3 Z – for C t /C ○ = 0.5(R 2 =0.9999) T s = 63.8 Z – 1.25for C t /C ○ = 0.9(R 2 =0.9988) BDST plots at Ct/C ○ = 0.033, 0.1, 0.5 and 0.9. Department of Chemical & Process Engineering

2.2 cm Department of Chemical & Process Engineering

BDST model fitting with influent concentration condition and influent flow rate condition [Z(cm),C ○ (mg l -1 ), υ (ml min -1 )] Experimental service time (min) BDST model time, T S (min) [7, 20, 5.5] [7, 30, 5.5] [7, 40, 5.5] [7, 30, 3.2] [7, 30, 8.1] Department of Chemical & Process Engineering

Regeneration and re-adsorption EDTA (0.01 M) 9 bed volumes Department of Chemical & Process Engineering Regeneration efficiency 84% (C t /C o =1) 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

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