Environment and Environmental Hygiene (Water) Questionbank 2
FILL IN THE BLANKS

 The candle of Pasteur Chamberland filter is made of _______________ and that of Berkefeld filter is made of _______________
ANS: porcelain , kieselgurh (infusrial earth)
The bactericidal action of Ktadyn filter is due to the _______________ ation of silver ions
ANS: oligodynamic
The UV rays disinfection of water involves the exposure of a fim of water about _______________ mm thick.
ANS: 120
The most effective and cheapest way of disinfecting wells is by _______________ and should not use _______________
ANS: bleaching powder, potassium permanganate
Chlorine demand of well water can be estimated by using _______________
ANS: Horrock’s apparatus
The double pot method of chlorination is a method devised by _______________
ANS: National Environmental Engineering Research Institute, Nagpur
Water with turbidity of more than _______________ nephlometric turbidity units (NTU) is usually noticeable to the naked eyes
ANS: 4
The WHO (2011) guideline value for colour of drinking water is _______________
ANS: 15 true colour units ( TCU)
The standard prescribed level for chloride in drinking water is …………….. mg/L and maximum permissible level is _______________ mg/L
ANS: 200, 600
Levels of ammonia in ground and surface water is _______________ mg/L and that in anaerobic ground water is _______________ mg/L
ANS: 0.2 , 3
Acceptable pH of drinking water is between _______________
ANS: 6.5 and 8.5
The taste and odour threshold of hydrogen sulphide in water are estimated to be between _______________
ANS: 0.05-0.1 mg/L
Water with a total dissolved solids (TDS) below _______________ mg/L is usually acceptable and that with a TDS level below _______________ mg/L is considered to be good
ANS: 1000, 600
The prsence of faecal _______________ indicate recent faecal pollution of water
ANS: Streptococci
Disinfection with 0.5mg/L of free chlorine residual after contact period of _______________ minutes at a pH of _______________ is sufficient to inactivate virus
ANS: 30, 8
Cadmium accumulates primarily in the _______________
ANS: kidney
_______________ is the main target organ for inorganic mercury and that for methyl mercury is ______________
ANS: kidney, central nervous system
The upper limit of cocentration of carbon tetrachloride in water is _______________
ANS: 2 microgram/L
The upper limit of concentration of DDT in water is _______________
ANS: 2 microgram/L
High levels of fluoride causes _______________ of dental enamel
ANS: mottling
High nitrate content of water is associated with _______________
ANS: methaemoglobinemia
_______________ is an estimate of the amount of a substance in food or drinking water that can be ingested daily over a lifetime without appreciable health risk
ANS: tolerable daily intake (TDI)
_______________ is the highest dose or concentration of a chemical in a single study, found by experiment that causes no detectable adverse health effect
ANS: NOAEL ( no-observed-adverse-effect level)
_______________ is the lowest observed dose or concentration of a substance at which there is detectable adverse health effect
ANS: LOAEL (lowest-observed-adverse-effect level)
The effects of radiation exposure are called_______________ if the become manifest in the exposed individual, and _______________ if they affect the descendants.
ANS: somatic, hereditary
_______________is the most important delayed somatic effect of radiation
ANS: Malignant disease
The proposded guide line value for gross alpha activity is _______________
ANS: 0.5 Bq/L
The proposed guide line value for gross beta activity is _______________
ANS: 1 Bq/L
_______________test is based on estimating the most probable number (MPN) of coliform organisms in 100ml of water
ANS: Mutiple tube method
Multiple tube method is carried out using _______________broth with _______________as indicator
ANS: McConkey’s Lactose Bile Salt Broth, Bromocresol purpleMut
Multiple tube method will give the result as _______________
ANS: Presumptive coliform count
For confirmation of the coliform _______________broth is used
ANS: Brilliant green bile broth
For confirmation of the presence of coliform organisms the broths are incubated at _______________degree and for E coli at _______________degree
ANS: 37, 44
In membrane filtration technique for testing the presence of coliform organisms _______________membranes are used
ANS: cellulose ester
Colony counts on nutrient agar at _______________degree and _______________degree are used in bacteriological examination of water
ANS: 37, 22
The recommended plate count for estimating the bacterial purity of disinfected water is _______________after 2 days at 37 degee and _______________after 3 days at 22 degree.
ANS: 0, 20
_______________organisms are an index of pollution.
ANS: Plankton
_______________is dedfined as the soap destroying power of water.
ANS: Hardness
The hardness in water is caused mainly by the bicarbonates and sulphates of _______________and _______________
ANS: Calcium, Magnesium
_______________hardness is due to the presence of calcium and magnesium bicarbonates
ANS: Temporary
_______________hardness is due to the prsence of calcioum and magnesium sulphates, chlorides and nitrates
ANS: Permanent
One milli-equivalents per ltre of hardness producing ion is equal to _______________mg/L of CaCO3
ANS: 50
Level of hardness in soft water is _______________mg/L
ANS: < 50
Level of hardness of moderately hard water is _______________mg/L
ANS: 50-150
Level of hardness in hard water is _______________mg/L
ANS: 150-300
Level of hardness in very hard water is _______________mg/L
ANS: > 300
Boiling, addition of lime , addition of sodium carbonate and permutit process are methods to remove _______________hardness
ANS: temporary
The methods to remove permanent hardness are _______________and _______________
ANS: addition of sodium carbonate, base exchange process
In Clark’s method of softening water _______________is used
ANS: quick lime
_______________is a complex compound of sodium, aluminium and silica used in permutit process
ANS: Sodium permutit
_______________and _______________methods removes both temporary and permanent hardness.
ANS: Addition of sodium carbonate, Permutit process
_______________has the property of exchanging sodium cation for the calcium and magnesium ions in the water
ANS: Sodium permutit
Epidermophyton and Trichophyton species produce _______________
ANS: Athlete,s foot
_______________virus is the inciting agent of plantar warts
ANS: Papilloma
Water of zero hardness has _______________action
ANS: corrosive
The recommended maximum limit of concentration of Arsenic in drinking water is _______________mg/L
ANS: 0.01
The recommended maximum limit of concentration of Antimony in drinking water is _______________mg/L
ANS: 0.02
The recommended maximum limit of concentration of Cadmium in drinking water is _______________mg/L
ANS: 0.003
The recommended maximum limit of concentration of Fluoride in drinking water is _______________mg/L
ANS: 1.5
The recommended maximum limit of concentration of Lead in drinking water is _______________mg/L
ANS: 0.01
The recommended maximum limit of concentration of Mangenese in drinking water is _______________mg/L
ANS: 0.4
The recommended maximum limit of concentration of Mercury (total) in drinking water is _______________mg/L
ANS: 0.006
The recommended maximum limit of concentration of Nitrate in drinking water is _______________mg/L
ANS: 50
The recommended maximum limit of concentration of Nitrite in drinking water is _______________mg/L
ANS: 3
The recommended maximum limit of concentration of Selenium in drinking water is _______________mg/L
ANS: 0.04