IJIRST (International Journal for Innovative Research in Science & Technology)ISSN (online) : 2349-6010

 International Journal for Innovative Research in Science & Technology

Comparative Study of Oxidants in Removal of Chemical Oxygen Demand from the Wastewater


Print Email Cite
International Journal for Innovative Research in Science & Technology
Volume 4 Issue - 1
Year of Publication : 2017
Authors : Prof. Dr. K N Sheth ; Kavita V Italia

BibTeX:

@article{IJIRSTV4I1018,
     title={Comparative Study of Oxidants in Removal of Chemical Oxygen Demand from the Wastewater},
     author={Prof. Dr. K N Sheth and Kavita V Italia},
     journal={International Journal for Innovative Research in Science & Technology},
     volume={4},
     number={1},
     pages={56--59},
     year={},
     url={http://www.ijirst.org/articles/IJIRSTV4I1018.pdf},
     publisher={IJIRST (International Journal for Innovative Research in Science & Technology)},
}



Abstract:

Chemical Oxygen Demand (COD) test involves chemical oxidation using chromic acid as a strong oxidizer. COD of a wastewater sample is the amount of oxidant- potassium dichromate that reacts with the sample when it is heated for 2 hours under controlled environmental conditions and result is expressed as mg of oxidant consumed per liter of a given sample of wastewater. COD can be helpful in determining the quantity required for dilution needed for conducting Biochemical Oxygen Demand (BOD) five day test. In the present investigation attempts have been made to use other oxidants like hydrogen peroxide H2O2, sodium hypo-chlorite, calcium hypo-chlorite and potassium permanganate for measurement of COD by standard method and compare the results obtained using potassium dichromate as strong oxidant. Experiments were carried out for each oxidizing agent for COD removal at temperatures like 1000C, 750C and 500C. The duration of exposure time in each experimental set up was taken as temperature wise, for 1000C, it was 1-5 minutes , for 750C it was 20-40 minutes and for 500C it was 45-75 minutes. It was found that temperature plays very important role in in deciding the exposure time to be allocated for reduction of COD. The various oxidants have different oxidizing capacity at the given exposure time and temperature. When the temperature is lower and exposure time is higher the percentage reduction of COD for any given oxidant is found to be higher. Out of the five oxidants the hierarchy of each of the oxidant based on oxidizing power can be generalized as K2Cr2O7, H2 02, Kmn04, NaOCl and then Ca (OCl) 2.


Keywords:

COD, oxidants, exposure time, exposure temperature


Download Article