(55i) Efficient Degradation of Naphthalene Using Hydrazine Assisted Nano-Iron Peracetic Acid Process

To improve the oxidation capability, a well-known reducing agent, hydrazine (HZ) was introduced in the nano-iron/peracetic acid process (NI-PAA). Significant oxidation performance was observed in the HZ-NI-PAA process for the degradation of naphthalene (NAP) in a wider range of pH values (3-9) even with the low dosage of NI i.e., 0.5 μ M. The reactive oxygen species (ROSs) were determined to quantify the presence of hydroxyl radicals (OH) by using electron spin resonance (ESR) technique. Benzoic acid (BA) was used as probe indicator confirming the higher intensity of hydroxyl radicals in the NI-PAA system for the naphthalene degradation. The conversion of Fe (III) to Fe (II) was significantly improved by the facile addition of hydrazine. The decomposition products of hydrazine include nitrogen gas, nitrogen dioxide and nitrous oxide whereas, nitrogen gas was the major environmentally friendly decomposition product among all. Intermediatory products were also determined that proposed three possible different pathways for the degradation of naphthalene. Higher dosages of NI and PAA significantly increased the naphthalene degradation. The humic acid showed inhibitory effect on the degradation of naphthalene whereas, anions (HCO₃^−, Cl^−, SO₄^2− ) have minor effect. Natural water was used to evaluate the oxidative capacity of Hz-NI-PAA process and further investigations were also performed for the degradation of different micropollutants to find its application. This study significantly improved the NI-PAA process and its possible application in water treatment.