chapter7_固体废弃物处置

Reducing waste volume
Handling (nontoxic) organic matter Recycling Other options
Liquid – waste disposal
Secure landfills Deep-wellห้องสมุดไป่ตู้disposal
Liquid – waste disposal
(2)How small a dose is harmless ?
Radioactive wastes Radioactive decay Effects of radiation Nature of radioactive wastes Historical suggestions :space ,ice ,and
Septic systems
Municipal sewage treatment
Radioactive wastes
Radioactive decay
Effects of radiation
(1)How much damage is done by a given dose of radiation ?
Outline of the Talk
Solid wastes – general Municipal waste disposal Reducing waste volume Liquid-waste disposal Sewage treatment Septic systems The ghost of toxins past :superfund Radioactive wastes Overview
Municipal waste disposal
Open dumps Sanitary landfills Incineration
Reducing waste volume
Handling (nontoxic) organic matter
（1） Swine were once extensively used for garbage disposal ,since they will consume a variety of food waste . In 1941 ,more than 2 million tons of municipal garbage were so used.
（2）Organic matter can be turned to good use through composting ,a practice long familiar to gardeners and farmers .
There are additional general obstacles to recycling ,some of which were mentioned earlier . Where recovery of materials from municipal refuse is desired ,source separation is generally necessary . This means that individual homeowners ,businesses ,and other trash generators must sort that trash into categories － paper ,plastic ,glass ,metal ,and so on － prior to collection .
plate tectonics Seabed disposal Bedrock caverns for liquid waste Bedrock disposal of solid high-level waste Waste isolation pilot plant (WIPP)
Secure landfills Deep-well disposal Other strategies
Sewage treatment
Problems arising from organic matter in water in include oxygen depletion and “algal bloom ” .these problem ,and concern about the spread of disease through biological contamination of drinking-water supplies by disease-causing organisms ,provide the motivation for effective sewage disposal .appropriate treatment strategy varies with population density and local geology .