41.

42.

43.

44.

45.

46.

47.

48.

49.

Coliforms which are the indicator organisms for microbiological pollution are
(A) Gram +ve bacilli (B) Gram —ve bacilli
(ಲ) Gram +ve cocci (D) Gram —ve cocci

Kjeldahl Nitrogen is a measure of
(A) Ammonia & Organic Nitrogen (B) Nitrate & Nitrite
(C) Ammonia & Nitrite D) Nitrate & Organic Nitrogen

30 ml of sample is pipetted directly to 300 ml incubation bottle. The initial DO of the
diluted sample is 8 mg/L and final DO is 1 mg/L. The initial DO of the dilution water is
9 mg/L and final DO is 8 mg/L. The temperature of incubation is 20°C for 5 days. What
is the 5 day BOD of the sample ?

(^) 180 mg/L (B) 600 mg/L
(C) 61 mg/L (D) 80 mg/L
For slow sand filters the effective size of the sand ranges from
(A) 0.45 71171 - 0.55 mm (B) 0.5 01/7 - 0.6 ൩൩
(0) 0.09 प - 1.0 mm (0) 0.25 71 - 0.35 mm

Colloids become destabilized when
(^) Repulsive force >Van der Waals force
(B) Van der Waals force > Repulsive force
(C) Gravitational force > Viscous force
(D) Viscous Force > Gravitational force

On analysis for coliform group using 3 samples of 10 mL, 50 mL and 500 mL by
membrane filter technique the results obtained are: 10 mL portion- 5, 6, 7, 8, 9; 50 mL
portion- 30, 35, 26, 36, 38; and 500 mL portion- 300, 380, 340, 360, 320. The number of
coliforms per 100 mL is

(A) 100 (B) 66
(C) 320 (D) 35
Oxidation of nitrites to nitrates is done by
(^) Nitrobacter (B) Nitrosomonas
(C) Pseudomonas (D) Azetobacter

Form of chlorine, which can prevent the formation of disinfection by products (DBP)

some of which are carcinogens, is
(^) Bleaching powder (B) Chlorine tablets
(C) Gaseous Chlorine ൯൩) Chloramines

Determination of chemical elements that compose the solid waste is known as
(^) Proximate analysis (B) Energy analysis
(C) Ultimate analysis (D) Inert value analysis

073/202 = ` 8 A