ENVE 101 : Introduction to Environmental Engineering
Assignment I
Deadline for submission :
Make logical assumption for any missing data or information. Handwritten solutions are
solicited. Brief answers are expected, however, a clarity of the statements is desirable. Full
marks will be given to original answers. Plagiarism is considered as a crime and submissions of
the offenders can be considered null and void.
1. Find the equivalent of 1 mg/L in (a) kg / m3 (b) kg / L
2. A resident in Kathmandu produces 0.3 kg of solid waste. If the volume of this waste is 1
L. Determine the density of the solid wastes in (i) kg/L and (ii) ton / m3. Based on this
information, determine the volume (in m3) and weight (in tons) of the solid wastes
generated in Kathmandu Valley assuming the population to be 7 million.
3. Colloids are particles of size 10-7 cm to 10-8 cm in size. Give these sizes in nm. Compare
the sizes with the size of a bacteria (1 m).
4. Convert the following concentration in to g/m3 (a) 100 ppm (b) 0.05 ppm. Assume that
the density of the solution is 1 kg/L.
5. Per capita water consumption in Kathmandu Valley is 120 L per day. Estimate the
quantity of wastewater being discharged to Bagmati river in (a) MLD and (b) m3 /sec (c)
करोड िलटर, assuming 30 % of the wastewater is lost by evaporation and population of
Kathmandu to be 1.5 million.
6. Estimate the volume of snow in the Mountains of Nepal. Assume that 17% of the surface
area of Nepal is covered by snow and average depth of snow is 1m. Report the figure in
appropriate unit.
7. Estimate the rural and urban water demand in your home district. Assume that the rural
and urban water demands are: 45 lpcd and 120 lpcd.
8. Dhulikhel campus of Kathmandu University has about 1800 undergraduate students and
450 students graduate every year. Supposing that everyone enrolled at the university
graduates eventually. What is the approximate retention time (the time the students spend)
of the students at Dhulikhel campus?
9. A power plant emits 60 kg of flyash per hour up the stack. The flow rate of the hot gases
in the stack is 700 l/s. What is the concentration of the flyash in g/m3 ?
10. (a) How much milk is consumed in Nepal everyday? (Make reasonable assumptions).
(b) One gram of table salt is put into a glass of 400 mL. What is the concentration of salt
in mg/L ?