The invention discloses a process for treating high-concentration oil refining
wastewater, which mainly comprises the following steps: the oil refining
wastewater is subjected to physicochemical pretreatment such as oil removal, air flotation and the like; the pretreated
wastewater is delivered to a three-section biochemical
treatment system; according to the
water quality condition of the wastewater, the biochemical
treatment unit of the first section can be switched into a
facultative reaction tank or an
aerobic reaction tank to correspondingly complete front
denitrification reaction or
aerobic reaction to remove sulfides; a
phosphate is quantitatively added into the biochemical
treatment unit of the second section, and organic pollutants such as volatile
phenol and the like are mainly removed; the biochemical
treatment unit of the third section mainly completes
nitration reaction, a
mixed solution of
sodium hydroxide and
sodium carbonate is accurately added, and the
alkalinity and the pH value are regulated to create an optimal
nitration environment; the biochemical tank of each section is operated in a plug flow manner, and the interior of each tank is of internal-circulation
complete mixing manner; and the biochemically treated wastewater is delivered to an oblique tube
sedimentation tank, and the bottom
sludge of the
sedimentation tank is lifted by an air lift device. The
system adopting the process discharges clear water and runs stably, and the process is flexible and can adapt to the oil refining wastewater of various concentration.