5L aqueous solution is kept in the presence of oxygen and suitable microorganism for five days at 20°C. If the O2 consumed is 0.2g, the BOD value of the sample is (EAMCET 2008)

Water pollution is measured by BOD. weight of oxygen in mg BOD volume ofwater sample in L Given, weight of oxygen = 0.2g = 200 mg Volume of solution = 5L 200 BOD mg/L 40 mg/L = 40 ppm 5