Abstract

Research has shown that many compounds can enter the environment, disperse and persist for far longer years than anticipated. The presence of these compounds results in risks which include reproductive impairment, increased incidences of cancer, the development of antibiotic-resistant bacteria, and potential increased toxicity of chemical mixtures. The increasing awareness of the potential harmful effects of these compounds has prompted development of treatment technologies which are cost effective. Hence there is a demand for advanced, industrial wastewater treatment systems in view of the stimulated increasing stringent legislation relating to the disposal of wastewater. The rising demand for water is forcing industry to adopt water re-use systems. The commonly used physico-chemical treatment processes are filtration, air stripping, ion-exchange, chemical precipitation, chemical oxidation, carbon adsorption, ultra filtration, reverse osmosis, electro dialysis, volatilization and gas stripping. One more process has been developed to the commercial stage and is being used in city wastewater treatment plants all over Europe and a few US cities. This process is known as the Harness Targeted Electric Water Fusion Technology or Electrocoagulation. Electrocoagulation provides chemical free water treatment of aqueous waste streams and is suitable for a wide range of wastewater of single or combined element contamination. This paper describes treatment of wastewater by an electrochemical method using electrocoagulation with aluminum, and iron electrodes. In the first step, the influence of parameters such as contact time, pH, various types of electrodes and current variation were investigated and optimized. The efficiency of the process in the removal of heavy metals, fluoride and treatment of pharmaceutical effluents is discussed.