A 50 mL sample of water was placed in a 300 mL BOD bottle, dilution water was added to fill the bottle, and the sample was incubated for 5 days. The initial DO concentration was 7.25mg/L, and at the end of the incubation period the concentration was 2.28 mg/L.  Determine BOD5 for the sample. Assuming a typical value for the reaction constant, k, of 0.20 d-1, determine the ultimate BOD of the sample

For an electrostatic precipitator of given geometry and operating conditions, the collection efficiency for 2 micrometer particles is 99.90 percent. On the basis of a Deutsch-type equation for efficiencies, estimate the collection efficiency for (a) 1 micrometer and (b) 0.5 micrometer particles

11   Aerobic digestion takes place during pyrolysis. Select one: True False

The waste water of a certain large colony contains 10-5.6 ions mmol/l of OH at 25 °C. The pH of this sample is

In determination of Acidity experiment, If the volume of 0.02N NaOH when use Methyl Orange (M.O) is 0.8 mL and 7.8 mL when use Phenolphthalein (Ph.Ph), the volume of sample is 25mL and the EW for CaCO3 is 50. The Mineral Acidity as mg (CaCO3)/L is

Which type of sample of the same weight will reach EMC fastest in the same RH? Place in the order from fastest to slowest. Fastest = ◆ -> ◆ -> wood powder wood chips wood block ◆ = Slowest

The following test results (Table Ql-2) were obtained from a raw water sample. All of the tests were performed using a sample volume of 50 mL. Table Q1-2 Weight (g) Mass of residue after drying at 105 ỏC Mass of residue after ignition at 550 ¿C Mass of residue on Whatman GF/C filter paper after drying at 0.7148 0.3818 0.3571 105 'C Mass of residue on Whatman GF/C filter paper after ignition at 550 'C 0.1418 Calculate the concentration (mg/L) of : (i) total solids. (ii) total volatile solids. (iii) total suspended solids. (iv) total dissolved solids.

Q4 (25%): A certain culture of bacteria grows at rate proportional to its size. If the size doubles in 4 days, find the time required for the culture to increase to 10 times to its original size.