ABSTRACT
Scientific concepts are needed in order to understand how waste management and treatment processes work and the nature of impacts resulting from waste disposal and dispersal in the environment. Since society's waste streams contain material and energy resources, waste management decision-making must be tied inextricably to resource conservation and utilization issues. Changes in the nature of wastes, concern for environmental protection, and the desire to recover resources from the waste stream have stimulated the development of new waste management technologies and processes. Many states in the United States have also responded to the guidelines contained in the integrated waste management approach by providing financial incentives for recycling. The most obvious risks to human health and the environment are associated with the air emissions and ash from incinerators; the leachate and gaseous emissions of landfills; the sludges from wastewater processing; the air emissions, effluents, and residues from composting; and the residues from recycling.
