Blending of wastes to achieve an optimum C/N ratio. Leaves, with a C/N ratio of 30, are to be blended with waste-activated sludge from a wastewater treatment plant, with a C/N ratio of 4.5. Determine the proportions of each component to achieve a blended C/N ratio of 20. Assume that the following conditions apply: moisture content of sludge = 70%; moisture content of leaves = 60%; nitrogen content of sludge = 3.6%; and nitrogen content of leaves = 0.7%.