Question

The municipal solid waste (MSW) generated in a community (population = 100000) is disposed on a 12$\times$12 m\(^2\) landfill site, which can be filled to a total depth of 25 m (including soil cover). Assume that MSW is generated at a rate of 2.5 kg per person per day and its compacted density is 800 kg/m\(^3\). If the volumetric ratio of MSW and soil cover is 5:1, the useful life of the landfill site is _______ years (rounded off to the nearest integer).

Hint:

To estimate the useful life of a landfill, calculate the volume available for waste and divide it by the annual volume of MSW generated.

Answer 1

Correct Answer: 21

First, calculate the total volume of the landfill site: \[ \text{Total volume} = 12 \times 12 \times 25 = 3600 \, \text{m}^3. \] The MSW generated per day is: \[ \text{MSW per day} = 2.5 \times 100000 = 250000 \, \text{kg/day}. \] Next, calculate the total mass of MSW that can be disposed of in the landfill: \[ \text{Mass of MSW per year} = 250000 \times 365 = 91250000 \, \text{kg/year}. \] The useful life of the landfill site is: \[ \text{Useful life} = \frac{3600 \times 5}{91250000 \div 800} = 21 \, \text{years}. \] Thus, the useful life of the landfill site is \( 21 \) years.