250 likes | 600 Views
Hacettepe University , Department of Chemistry ANKARA-TURKEY. Prof. Dr. Bekir SALİH. SPECIFICALLY LEAD REMOVAL FROM DRINKING, LAKE AND SEA-WATER BY LEAD IONOPHORE MODIFIED POLYMERS. http//:www.sareg.hacettepe.edu.tr bekir@hacettepe.edu.tr. OUTLINE. THEORETICAL INFORMATIONS
E N D
Hacettepe University,Department of Chemistry ANKARA-TURKEY Prof. Dr. Bekir SALİH SPECIFICALLY LEAD REMOVAL FROM DRINKING, LAKE AND SEA-WATER BY LEAD IONOPHORE MODIFIED POLYMERS http//:www.sareg.hacettepe.edu.tr bekir@hacettepe.edu.tr
OUTLINE • THEORETICAL INFORMATIONS • SOURCE OF TOXIC METALS • DETECTION OF METAL IONS • SEPERATIONS • PRE-CONCENTRATION, MATRIX ELIMINATION AND RECOVERY • REMOVAL • EXPERIMENTAL • RESULTS AND DISCUSSION
TOXIC HEAVY METALS • Coal Combustion • Sewage Waste Water • Automobile Exhaust • Battery Industry • Mining Activities • Fossil Fuels
In human body Trace metals toxic non toxic but non essential essential for life processes Biological molecules such as proteins, enzymes and DNA have specific structures and certain components that are essential for their roles.
If a metal ion binds to the amino acids of a protein, the resulting metal-protein complex may lack the protein's original biological activity • One metal may also substitute for another similar metal. This can lead to alterations in that protein that can have toxic consequences. • Metal ions can also remove an electron from the amino acids of a protein in a redox reaction that disrupts its ability to carry out its biological function.
Binding form Long term effects Accumulation of metals in biological media more important than the total concentrations of these metals Because of the different toxicity of metal ions and their complexes and species, Separation and spectrometric detection (GF-AAS, ICP, ICP-MS) at low levels are required.
SEPARATION & PRE-CONCENTRATION TECHNIQUES • Adsorption • Co-precipitation • Cation/anion exchange • Complexation or Chelatation • Oxidation/reduction • Liquid-liquid extraction
Separation of metals and their complexes and also different oxidation species Combination of chromatographic techniques Liquid Chromatography (LC; HPLC and GPC) Gas Chromatography (GC) Electrophoretic Separation Techniques Two Dimensional Polyacrylamide (2-D PAGE) Capillary Zone Electrophoresis (CZE or CE)
DETECTION OF METAL IONS AT LOW CONCENTRATION Graphite Furnace-Atomic Absorption Spectrometry (GF-AAS) Atomic Emission Spectrometry (AES) Inductively-Coupled Plasma-Mass Spectrometry (ICP-MS) Neutron Activation Analysis (NAA) Matrix-assisted Laser Desorption/Ionization-Mass Spectrometry (MALDI-MS) Electro Spray Ionization-Mass Spectrometry (ESI-MS)
HYDROGELS • Hydrogels are cross-linked and swellable polymers, and they are very convenient polymeric sorbents for removal, separation and pre-concentration of metal ions. • They have three-dimensional network structure, containing hydrophilic functional groups and are not dissolved in water but swell more than 95% • They have lots ofanalytical and clinical applications, such as, controlled release, contact lenses, drug delivery systems and selectively binding to some species(i.e., metal ions, proteins, enzymes and some organic pollutants).
RADIATION POLYMERIZATION TECHNIQUE Easy process control, Possibility of joining hydrogel formation and sterilization in one technological step, No necessity to add any initiators and cross linkers, possibly harmful or difficult to remove, No waste, Relatively low running cost for the using irradiation technique.
EXPERIMENTAL Synthesis of Poly(NHMMA-Pb-IONOPHORE) Hydrogels Adsorption Desorption Reuse Pre-concentration Recovery of Pb(II) Ions Different aqueous samples Selectivity of the hydrogels for Lead ion in the presence of the other ions
Desorption Ratio 96.6% 95.7% From single Pb(II) solution From certified Sea-water solution Matrix effect for Pb(II) adsorption onto the hydrogels
Direct measurement by GF-AAS Drinking water Measured by GF-AAS after pre-concentrated 100-fold
Direct measurement by GF-AAS Lake water Measured by GF-AAS after pre-concentrated 100-fold
Direct measurement by GF-AAS Tap water Measured by GF-AAS after pre-concentrated 100-fold
Measured by GF-AAS after adsorption-desorption cycle (no matrix) Direct measurement by GF-AAS Measured by GF-AAS after pre-concentrated 100-fold Sea water
ACKNOWLEDGEMENTS ✜Ömür Çelikbıçak (PhD) (University of Akron) ✜Basri Gülbakan (PhD) (University of Florida) ✜Aslı Öztürk (PhD) ✜Burak Tiftik (PhD) ✜Savaş Malcı (PhD) ✜Cansel Taşağır (MSc) ✜Özlem Demirel (MSc) ✜Mehmet Atakay (MSc) ✜Erdem Akıncı (MSc) ✜Ülkü Güler (BS) ✜Selim Gerişlioğlu (BS)