Khz-cp was extracted by solvent extraction.
The solvent extraction method is based on the polarity property of phenol, which will be the developing direction of extraction phenol from coal tar, and it has many advantages, such as low price, nontoxic extraction agent, corrosion-free, moderate operation conditions, no waste water and no exhaust gas in the course of production (Tiwari and Sen 1991; Wu et al. 2001; Liu and Xie 2014).
The most common methods used for removal of phenol from industrial effluents include stripping, solvent extraction, oxidation, ion exchange, biodegradation and adsorption methods (Subramanyam and Das 2009).
Numerous methods have been used for elimination of phenol and cyanide from wastewater comprising biosorption, solvent extraction, electrochemical oxidation, membrane separation, chemical coagulation, and photocatalytic degradation, etc. (Akcil 2003; Dash et al. 2009; Kujawski et al. 2004).
Various processes were developed to treat the phenol-containing effluents including catalytic oxidation [8], biodegradation [9], solvent extraction [10] and adsorption [11].
Phenols can be removed from the aqueous solution through oxidation, precipitation, ion exchange, biodegradation, ultrasonic degradation, solvent extraction, ozonization and decomposition by fenton reagent (Aksu and Yener 2001; Rengaraj et al. 2002).
