In the present study, the waste water of Durgapur steel industry were taken which consist a lot of phenol and its compound, NH3, cyanide, grease oil etc. These are the very much poisonous to the living system. If it is released without sufficient treatment the fauna flora of the receiving water bodies are severely affected. Thus for safe discharge of this wastewater and saving our natural aquatic system proper treatment is urgently required. The treatment initially has been performed with aerobic microbes of P.Putida. It has been observed that this genus of microbes is capable to degrade waste 80% within 4 days .The bacterial growth was increased with increasing treatment time. This indicates that microbes are taking the waste material as food. The treatment of waste was very much dependent on process parameters like temperature, pH, inoculums volume and nutrient composition. It was also observed that the microbial growth rate was influenced with changing process parameters. This indicates that optimum process parameter has to design and stringent control is needed for treatment of such type of wastewater with minimum time.
From the present study it again reveals that biochemical treatment is a low cost, energy saving and environmentally safe process but the process is time consuming although acclimatized seeds were used. Thus an advanced oxidation process was incorporated prior to the biochemical treatment to reduce the treatment time and remove all sorts of pollutants present in the waste water. As advanced oxidation process Fenton’s reagents were chosen due to its wide applicability and first waste oxidation capability. It also improves the biodegradability of the treated wastewater. In the present study it has been observed that with increasing the Fenton’s reagent concentration the waste removal in terms of COD is enhanced and 95% COD were removed at a Fenton’s dose of FeSO4 – 4.8 g/L and H2O2 - 88.80 g/L. Thus Fenton’s treatment is an effective treatment system to treat this waste water. But the treatment cost increases with increasing Fenton’s dose. Therefore a combination treatment was considered a suitable treatment system. In the present study it is observed that Fenton’s reagent enhance the biodegradability and reduce overall treatment time. In brief, at first waste water has been treated with a lower dose of Fenton’s reagent and after pH adjustment biochemical treatment were performed. All together 30 hrs were required to remove more than 95% COD from the waste water and eventually it turns that this process is a cost effective, energy saving and environmentally safe.
