1. a) Biological methods:

   1. 1) Treatment via modified conventional wastewater treatment techniques;
   2. 2) Anaerobic, aerated and facultative lagoons;
   3. 3) Supported growth biological reactors.

2. b) Chemical methods:

   1. 1) Chlorination;
   2. 2) Precipitation, flocculation, sedimentation;
   3. 3) Neutralization;
   4. 4) Equalization;
   5. 5) Chemical oxidation.

3. c) Physical methods:

   1. 1) Air stripping;
   2. 2) Carbon adsorption;
   3. 3) Ion exchange;
   4. 4) Reverse osmosis;
   5. 5) Permeable bed treatment;
   6. 6) Wet air oxidation;
   7. 7) Incineration.

In most cases, these techniques can be considered long-term permanent solutions. Many of these direct treatment methods are not fully developed and the applications and process reliability are not well demonstrated. Use of these techniques for waste treatment may require considerable pilot plant work. Technologies applicable to the direct treatment of wastes are: