Since the second part of 20th century, there has been growing concern over the diverse effects of heavy metals on humans and aquatic ecosystems. A significant part of the anthropogenic emissions of heavy metals ends up in wastewater. Major industrial sources include surface treatment processes with elements such as Cadmium, Lead, Manganese, Copper, Zinc, Chromium Mercury, Arsenic, Iron and Nickel are discharged in wastes. Heavy metals can be hazardous even at very low concentrations, when they get in to water supplies and aqueous environments the health of plants, animals as well as humans will be impaired. As such they are stable elements and they cannot be metabolized by the body and bioaccumilative by nature. Toxic metals are commonly found in waste water and removing them efficiently poses a unique challenge. The author has developed an organic reagent“4- HydroxyBenzaldehydethiosemicarbazone”and studied the complexation reaction between various metal ions and 4- HBTS spectrophotometrically. The data pertaining to these studies reveals that heavy metals like Nickel Ni (II), copper Cu (II), and Bismuth Bi (III) shows favorable conditions for complex formation under weak acidic condition (PH- 5-6).The author calculated the range of determination of metal in each system. The results showed that these metal ions can be determined quantitatively in μg quantities using the standard procedures. The suitability of this method for the determination of nickel is in the range 0.2348-2.348 μg/mL, for copper the range is 0.127-1.27 μg/mL and Bismuth can be estimated in the range of 0.835-8.35μg/ml in metallic sample solutions. Thus the above mentioned method has been extended for the determination of heavy metals present in wastewater sample.
