Beyond what concentration of H2S in air, acute danger to human life exists ?

Related Mcqs:

In water treatment plant, zeolite process is used to remove the _____________ of water?

A. Acidity B. Alkalinity C. Hardness D. Iron & zinc...

Fine grit present in sewage is removed in the _____________ during sewage treatment?

A. Grit chamber B. Detritus tank C. Trickling filter D. Skimming tank...

Exposure to chemicals having carcinogenic properties cause ____________________?

A. Dermatitis (skin disorder) B. Cancer C. Asphyxiation (suffocation) D. Asthma...

Infective bacteria in water is killed by the _____________ process?

A. Sterilisation B. Aeration C. Disinfection D. None of these...

Turbidity of water is an indication of the presence of__________________?

A. Suspended inorganic matter B. Dissolved solids C. Floating solids D. Dissolved gases...