the present invention discloses a method for advanced treatment of bio - treated coking wastewater . it employs polymeric ferric sulfate and polyacrylamide as the flocculant for the pre - treatment of bio - treated effluent . after the process of precipitation and filtration , the effluent is guided through an adsorption column filled with environmentally - friendly nano - composites whereby the advanced treatment of the bio - treated coking wastewater is achieved . when the absorption process reaches the breakthrough point , the adsorption operation will be stopped and sodium hydroxide solution is used as the desorption reagent for regenerating the nano - composites . the high - concentrated component of the desorption liquid is sent out for incineration or production of coal water slurry , meanwhile the low - concentrated component of the desorption liquid is used to prepare sodium hydroxide solution for the adsorption process of the next batch .