The United States generates the largest amount of solid waste per person in the world. The old practice of direct landfilling and storage is receiving greater public resistance and is attributing to the search for alternative disposal methods. The evergrowing problem of solid wastes requires environmentally benign and good public acceptance for the safe and ultimate disposal of the various kinds of solid wastes. Incineration and various kinds of mass burn-type systems have been used to reduce the volume and mass of the wastes, which can be characterized by their operational temperature. In all types of incineration systems, different kinds of gas clean-up devices are used to meet the local, state, and federal regulations for the gases before being released into the environment. A major concern over these systems have been in the by-products produced from these systems during their normal design and off-design point of operation. Indeed, the by-products generated from some incineration systems, under certain operational conditions, can be a health hazard and the solid residue may be leachable. Recent trends in advanced thermal destruction systems are described which can destroy the solid waste to the molecular level. Advanced systems can be designed to meet almost any emission standards. The use of oxygen-enriched air in place of air for the combustion of gases released from the solid waste reduces the amount of effluent gas, and, hence, the reduced size and cost of the gas clean-up system. The use of an excess enthalpy system offers attractive benefits in which the energy released from the waste is recycled back into the system under controlled conditions with the final desired objectives of reduced emissions, higher efficiency, and lower costs. Thermal destruction of solid wastes using advanced techniques makes good technical, environmental, economical, and human health and safety. The issues concerning recyclability, life cycle integration, and health effects from incineration are only expected to grow in the future.
Supercritical carbon dioxide extraction of lycopene from tomato processing by-products: Mathematical modeling and optimization
