Final Purification of Waste Phenol Liquors by Ozonization

摘要

The ozone concentrations that provide the decrease of the phenol concentration after biochemical purification from 4 to 1-2 mg/dm~3 were determined: 90-120 mg/dm~3. The capacity of the ozonization installation being designed will make it possible to carry out the final purification of 200 m~3/hr of wastewater instead of the planned 300 m~3/hr.It is not expedient to subject the wastewater to a thorough purification after the biochemical installation since the microorganisms continue to decompose phenol in the storm sewer before they enter the municipal sewage works.The operating regime of the ozonizer was determined, with which the preozonization process occurs: the voltage on the electrodes 12-13 kV, the air flow rate 350-400 m~3/hr, the ozone concentration 60-90 mg/dm~3. The capacity of the ozonizer is 3-3.5 of ozone per hour.The operation of the ozonizer without the air-drying block leads to a decrease of its capacity by 25 percent and to the failure of the electrodes and control instrumentation.