Test: Disposal of Solid Wastes - Civil Engineering (CE) MCQ

Incineration is the process of disposing of dewatered sludge by burning them in a furnace. Pulverisation is a technique of refuse disposal by grinding refuse to a lesser volume thereby changing its character.

The leachate from sanitary landfill tend to pollute ground water. Incineration and pyrolysis release air pollutants. Composting does not have any harmful effect.

When sewage is applied continuously on a piece of land, the soil pores or voids may get filled up and clogged with sewage matter retained in them. Thus free circulation of air will be prevented and anaerobic conditions will develop within the pores. Sewage sickness is the condition when soil pores get filled up and clogged with sewage matter due to continuous application of waste water effluents. This develops anaerobic conditions and foui gases like methane, carbon-dioxide and hydrogen sulphide are evolved.
In order to prevent sewage sickness:
(i) Sewage should be given primary treatment
(ii) The soil chosen for effluent irrigation/sewage farming should be sandy or loamy.
(iii) A proper under drainage system (open jointed drains) should be designed.
(iv) Land should be given rest for some time and ploughed thoroughly.
(v) Rotation of crops to be followed.
(vi) Shallow depths of water should be applied.

Sealants are used of control for gas and leachate movement


The sealant material should be more impermeable than the soil. So sand will not be a suitable material. Flyash and lime themselves produce pollutants which dissolve in water. Therefore these materials cannot be used as sealants.

Upon heating in a oxygen free atmosphere during pyrolysis, most organic substances can be split through a combination of thermal cracking and condensation reactions in gaseous liquid and solid fractions.

Design loading rates for land application of biosolids can be limited by heavy metals or nitrogen. The annual loading rate is usually limited by nitrogen loading rate. The long-term loading rate is limited by heavy metals.

Gases found in landfills include air, ammonia, carbon dioxide, carbon monoxide, hydrogen, hydrogen sulphide, methane, nitrogen and oxygen. Carbon dioxide and methane are the principal gases produced from the anaerobic decomposition of the organic solid waste components.