Absorbance Based Model for Determination of Biochemical Oxygen Demand

Development of Microcontroller Based Portable Optical Instrumentation System for Measurement of BOD

“…A part of this light is absorbed by the solution under test. A study of absorbance at various wavelengths has been carried out by the researchers and wavelength value of 440 nm has been selected after analyzing the response to wavelength ranging from 350 nm to 500 nm in this the spectrum based study [7]. As shown in Fig.…”

“…The calibration of BODMAS was carried out by using potassium dichromate solution and its testing was done by using the standard GGA solution as described in the following sections [7].…”

“…The ten different dilutions of GGA were prepared and tested. DO reading from the Winkler's titrimetric method and absorbance by BODMAS were recorded for Day1 and Day5 following the method reported from our laboratory [7]. The Winkler's DO (B 1 and B 5 ) and the absorbance readings (AB 1 and AB 5 ) for blank solutions i.e.…”

“…0% concentration, served as reference for both the days. A mathematical model [7] based on Pearson's correlation coefficient was derived by using the MATLAB ® Software 2012a in order to convert the absorbance values to DO values. The readings and intermediate calculations are depicted in Table 1.…”

“…This has resulted in the development of procedures based on UV absorbance [2][3][4][5] and fluorescence [5,6] properties of waste water. An optical method for BOD determination has been developed by measuring the absorbance of 440 nm monochromatic light by the sample after adding Winkler's reagents and mathematical modelling for correlating absorbance and DO has been reported [7]. This paper communicates the design and fabrication of a portable optical transducer with microcontroller based system to read DO at predetermined wavelength and calculates the BOD based on the difference of DO values of 1 st and 5 th day.…”