Method of treating a plant wastewater and treatment system therefor

摘要

A method of treating wastewater containing an organic compound includes feeding wastewater to an anoxic tank, adding compounds containing nitrogen and phosphorus components to wastewater, performing anaerobic treatment on wastewater, and discharging treated wastewater as pre-treated water; introducing pre-treated water into an anaerobic treatment tank, performing anaerobic treatment on pre-treated water, thereby decomposing the organic compound into organic compounds of smaller molecular size and a mixture gas containing methane and carbon dioxide, and discharging treated water as primary water; introducing primary water into an aerobic treatment tank, performing aerobic treatment on primary water, and discharging treated water through a solid-liquid separator as secondary water; and introducing at least a part of secondary water into a reverse osmosis membrane separation unit, and separating part of secondary water into RO permeated water and RO concentrated brine, wherein at least a part of RO concentrated brine is recycled to the anoxic tank.

主权项

1. A method of treating plant wastewater discharged from any one of a chemical, petroleum, and petrochemical plant and containing an organic compound comprising:
a pre-treatment step of
feeding the plant wastewater to an anoxic tank,adding compounds containing a nitrogen component and a phosphorus component to the plant wastewater,performing an anaerobic biological treatment on the plant wastewater, anddischarging the thus treated plant wastewater as pre-treated water; a primary treatment step of
introducing the pre-treated water into an anaerobic biological treatment tank,performing an anaerobic biological treatment on the pre-treated water, thereby decomposing the organic compound into organic compounds of smaller molecular size and a mixture gas containing methane and carbon dioxide, anddischarging the thus treated water as primary treated water; a secondary treatment step of
introducing the primary treated water into an aerobic biological treatment tank,performing an aerobic biological treatment on the primary treated water, anddischarging the thus treated water through solid-liquid separation means as secondary treated water; and a tertiary treatment step of
introducing at least a part of the secondary treated water into a reverse osmosis membrane separation unit, andseparating the part of the secondary treated water into RO permeated water and RO concentrated brine, wherein at least a part of the RO concentrated brine is recycled to the anoxic tank.