METHOD OF TREATING A PLANT WASTEWATER AND TREATMENT SYSTEM THEREFOR

[OBJECT) PROVIDED IS A METHOD OF TREATING A PLANT WASTEWATER WHICH REDUCES THE TREATMENT COSTS OF ANAEROBIC AND AEROBIC BIOLOGICAL TREATMENTS ON A PLANT WASTEWATER. CONTAINING A NITROGEN COMPONENT AND A PHOSPHORUS COMPONENT EITHER IN AMOUNTS INSUFFICIENT FOR THE BIOLOGICAL TREATMENTS OR NOT AT ALL. [SOLVING MEANS) THE METHOD IS CHARACTERIZED BY INCLUDING: A PRE-TREATMENT STEP OF FEEDING PLANT WASTEWATER 11, WHICH CONTAINS AN ORGANIC COMPOUND AND IS DISCHARGED FROM A CHEMICAL PLANT, A PETROLEUM PLANT, OR A PETROCHEMICAL PLANT, TO AN ANOXIC TANK 1, AND ADDING COMPOUNDS 12 CONTAINING A NITROGEN COMPONENT AND A PHOSPHORUS COMPONENT TO THE PLANT WASTEWATER 11, THEREBY PERFORMING AN ANAEROBIC BIOLOGICAL TREATMENT THEREON; A PRIMARY TREATMENT STEP OF INTRODUCING THE THUS TREATED WASTEWATER INTO AN ANAEROBIC BIOLOGICAL TREATMENT TANK 2, AND PERFORMING AN ANAEROBIC BIOLOGICAL TREATMENT THEREON; A SECONDARY TREATMENT STEP OF INTRODUCING THE THUS TREATED WASTEWATER INTO AN AEROBIC BIOLOGICAL TREATMENT TANK 3 PERFORMING AN AEROBIC BIOLOGICAL TREATMENT THEREON, AND DISCHARGING THE THUS TREATED WASTEWATER THROUGH SOLID-LIQUID SEPARATION MEANS AS SECONDARY TREATED WATER; AND A TERTIARY TREATMENT STEP OF INTRODUCING THE SECONDARY TREATED WATER INTO THE REVERSE OSMOSIS MEMBRANE SEPARATION UNIT 4 FOR SEPARATING THE SECONDARY TREATED WATER INTO RO PERMEATED WATER 16 RO CONCENTRATED BRINE 17. HERE, AT LEAST A PART OF THE RO CONCENTRATED BRINE 17 IS RECYCLED TO THE ANOXIC TANK 1.