Natural attenuation mimics nature's own cleansing mechanism and offers an effective solution for contaminant treatment under prevalent environmental conditions without generating secondary toxins. Despite obvious advantages, these processes are restricted by a narrow range of reduction potential available within natural water systems. Complexation reaction offers to modulate the redox potential range of transition metals allowing detoxification of persistent contaminants. Consequently, present work describes complexation modulated redox potential of iron systems with environmentally available ligands for degradation of contaminants (textile dyes, antibiotics and toxic metal ions) for a possible application in water treatment under natural attenuation concept. The observed spectrophotometric results are indicative of a significant ligand effect on degradation kinetics of studied contaminants by iron(II) complexes. The kinetic efficacies of iron(II) complexes for contaminant degradation were in the order: aqua

Coordination compounds as dopants to conducting polymers combine desirable properties of individual components for a synergistic effect. Prussian red (PR) a low spin iron (III) coordination compound was doped in polythiophene (PTP) matrix to explore propensity of this inorganic-organic hybrid composite material towards wastewater treatment. PR doping was observed to improve mechano, thermal, electrical, and photocatalytic attributes of pure PTP. PTP/PR composite characterization was attempted using the powder X-ray diffraction, TEM, TGA, FTIR, BET analysis and UV-Visible spectroscopy. Optimization of adsorption conditions, adsorbent regeneration, adsorption thermodynamics studies of PTP/PR were carried out using malachite green (MG) dye as a model system. Under optimized conditions 92% MG dye adsorption was observed over 20 mg PTP/PR nanocomposite in 20 minutes at pH 7. PTP/PR nanocomposite also demonstrated a complimentary performance with real wastewater samples. Thermodynamic studies indicate spontaneous process with electrostatic attraction as the predominant noncovalent interaction. This study highlights designing catalysts capable of synergistic adsorption and photocatalytic activities for effective wastewater treatment.

No abstract