Question 5 a. Estimate the life expectancy of a 55 ha site chosen by a city...
Question 5 a. Estimate the life expectancy of a 55 ha site chosen by a city council to serve for sanitary landfilling of solid wastes generated by a design population of 300000. The solid waste generation rate is 2.0 kg/cap.d. The site can accommodate a compacted fill of final depth 6m. A density of 500 kg/m' is expected to be achieved in the compacted landfill. Estimate also the quantity of cover soil required to meet the needs of daily cover, intermediate cover, and final cover. b. It is proposed to blend fresh manure with rice hulls. Laboratory tests gave the following data: Manure: moisture content = 80% Nitrogen content = 1.5% Carbon content = 11% Rice hulls: moisture content = 31% Nitrogen content = 0.5% Carbon content = 21.5% What mixing ratio is needed to produce a compost with a moisture content of 53%. What is the C/N ratio of the mix. What mixing ratio is needed to produce a compost with a C/N ratio of 25:1. What is the moisture content of the mix. c. The clay liner of a landfill is 75 cm thick with a hydraulic conductivity of 6 x 10 cm/s. The average depth of leachate above the liner is 60 cm. The leachate has among other contaminants) a concentration 1.5 mg/L of a chemical compound C. Compute the steady-state contaminant transport rate, in kg/year, through the leachate from the landfill which has a plan area of 20 ha. How much drinking water per year could be contaminated if the drinking water standard restricts the chemical C to 0.006 mg/L? Marks: 7+6+7