Chemical‐Physical Leachate Treatment

The results of full‐scale chemical‐physical treatment of sanitary landfill leachate are analyzed. The plant receives approximately 75,000 L/day from a lined 50 acre landfill. The treatment sequence consists of equalization, lime precipitation, sedimentation, and air stripping of ammonia. Overall percent removal efficiencies are ${\mathrm{BOD}}_5\text{,}$ 69; kjeldahl‐N, 53; cadmium, 59; copper, 38; iron, 98; lead, 66; mercury, 52; nickel, 54; zinc, 95, and, suspended solids, 95. Equalization markedly reduces operating costs. The effects of temperature and pH on heavy metals removal are also reviewed.