Page 17 - Materials Chemistry, Second Edition

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7.4.3.9 Rotary Shear.............................................................................................194
7.4.3.10 Hammer Wear...........................................................................................194
7.4.3.11 Safety Issues Related to Size Reduction..................................................194
7.4.4 Magnetic Separation..................................................................................................196
7.4.5 Eddy Current Device.................................................................................................199
7.4.6 Air Classifier .............................................................................................................200
7.4.7 Efficiency of Separation in an Air Classifier ............................................................204
7.4.8 Miscellaneous Processing..........................................................................................205
7.4.8.1 Dryers.........................................................................................................205
7.5 Materials Flow in the MRF...................................................................................................206
7.6 The Contamination Issue ......................................................................................................207
7.7 Environmental Control..........................................................................................................208
7.7.1 Dust Collection..........................................................................................................208
7.7.2 Odors and their Control.............................................................................................209
7.7.3 Noise Suppression ....................................................................................................209
7.7.4 Aesthetics ..................................................................................................................209
References ......................................................................................................................................210
Suggested Readings .......................................................................................................................211
Questions........................................................................................................................................211

Chapter 8
Composting MSW..........................................................................................................................213
8.1 Introduction ...........................................................................................................................213
8.2 Benefits of Composting.........................................................................................................213
8.3 Overview of the Composting Process...................................................................................214
8.4 The Role of Microorganisms in Composting........................................................................214
8.5 Factors Affecting the Composting Process ...........................................................................216
8.5.1 Preprocessing of the Feedstock.................................................................................217
8.5.2 Environmental Factors...............................................................................................217
8.5.3 Nutrients ....................................................................................................................218
8.5.4 C:N Ratio...................................................................................................................218
8.5.5 Aeration ....................................................................................................................219
8.5.6 Moisture Content.......................................................................................................221
8.5.7 Temperature...............................................................................................................222
8.5.8 pH ..............................................................................................................................223
8.6 The Composting Stage..........................................................................................................223
8.6.1 Turned Piles...............................................................................................................223
8.6.2 Turned Windrows ......................................................................................................224
8.6.3 Aerated Static Piles ...................................................................................................225
8.6.4 In-Vessel Systems......................................................................................................226
8.7 The Curing Stage ..................................................................................................................226
8.8 Environmental Concerns During Composting......................................................................227
8.8.1 Air Quality.................................................................................................................227
8.8.2 Odor...........................................................................................................................227
8.8.3 Noise..........................................................................................................................228
8.8.4 Toxins Within the Pile...............................................................................................229
8.8.5 Leachate.....................................................................................................................231
8.8.6 Runoff........................................................................................................................232
8.8.7 Vectors .......................................................................................................................233
8.8.8 Fires ...........................................................................................................................233
8.8.9 Litter ..........................................................................................................................234