Incineration of Water Pollutants with Activated Char from Coal, Wood, or Crop Residues in a System Designed to Produce Energy and Pyrolysis By-Product Chemicals

摘要

A wastewater treatment system, particularly useful for treating chemical leachates, was developed on a laboratory scale. Subbituminous coal, 20-60-mesh, was pyrolyzed. A synthetic wastewater containing 3520 ppm total organic carbon was contacted with nonactivated char, char activated in water-saturated nitrogen at 850 degrees C, and coal ash. During a contact time of 0.5 hour, organic removals from the wastewater were 13.3% by nonactivated char, 38.8% by activated char, and 46.5% by ash. For a contact time of 72 hours, organic removals were about 25% for nonactivated char, 58.8% for activated char, and 53.4% for ash. This treatment system is applicable where large amounts of waste carbonaceous material (coal, wood, crop residues) are available. The spent char can be incinerated. Heat from incineration can be used in the pyrolysis step, and the coal ash can be recycled to the water purification step.