Researching the technology of tar removal from coke-chemical plants’ wastewater by reagent flotation method

Sedimentation of pollutant­containing aggregates during purification of wastewater from coking plants

“…Comparing the efficiency of removal of resinous substances by the use of different methods, we should take into account that the maximum permissible concentration of such substances in purified water should be less than 25 mg/dm 3 [1,2]. Data from Table 3 shows that we can achieve a required degree of purification using coagulants Al 2 (OH) 5 Cl and FeCl 3 , as well as in processing with bentonite clay with the addition of Extrafloc P70.…”

“…Typical and most common method of purification of phenolic waters from resinous substances is flotation with an addition of special reagents (coagulants or flocculants) [1][2][3].…”

“…Numerous scientific papers [1][2][3][4][5][6][7][8][9][10][11][12] describe it. There are many coke enterprises in Dnipropetrovsk and especially Donetsk regions.…”

“…The main reason is the lack of efficiency of removal of resins at the stage of mechanical purification. Experiments proved the effectiveness of the reagent flotation method with a use of coagulants: Al 2 (OH) 5 Cl, Al 2 (SO 4 ) 3 , AlCl 3 , FeSO 4 , Fe 2 (SO 4 ) 3 and FeCl 3 [2]. Treatment with alkaline bentonite clay with the addition of cationic flocculant reduced a content of resins to modern requirements for disposal of sludges in construction of road pavements [3].…”