For phenol and formaldehyde wastewater (PFW) treatment, combined processes, such as extraction-oxidation-adsorption (EOA) and dilution-biological-disinfection (DBD), rather than a single technique (e.g., biological technique) are more efficient and effective. In this article, the EOA technique was introduced and experimental studies on PFW treatment were conducted. Two parallel experiments, adopting EOA and DBD processes, respectively, were carried out in a factory with a discharge capacity of 24 m(3) PFW/d, containing 6000 mg/L phenol. Experimental results indicates that the DBD process is featured by long hydraulic retention time (HRT) (72.5 h) and high treatment cost and investment, whereas EOA is characterized by short HRT (0.73 h), low treatment cost, and low investment. Only when the concentration of phenol is lower than 2700 mg/L was the operational cost of DBD lower than that of EOA.