Study On Removal Of COD From Coking Wastewater By Suspended And Flocculent Manganese And Powder Activated Carbon

In this paper,treatment of coking wastewater by catalytic oxidation with flocculating manganese suspension as catalyst together with the absorption of active carbon, in which the catalytic oxidation of flocculating manganese suspension was the pretreatment process and the absorption of active carbon was the advanced oxidation process, the degradation of organic pollutants or the further removal of refractory organics in wastewater was carried out in order to reuse treated wastewater at last.Through a series of experiment, the volume ratio of the suspended and flocculent manganese (0.1mol/L) to the wastewater was 1:4, the aeration rate was 150L/h, pH and temperature were unadjusted, after 30min's treatment the eliminating percentage of COD in wastewater reached 80%. Under the same condition, prepared flocculating manganese suspension from coking wastewater directly and after 30min's treatment the eliminating percentage of COD in wastewater reached 70%, but the real handling capacity of wastewater increased 25% and the water consumption decreased 25% compared with the former, and the economic benefits were obvious.Studied morphological structure of solid residue from the pretreated wastewater by SEM and granular analysis of the liquid phase, carried out the comparative tests for the degradability of regenerated catalyst. The feasibility of the recycle of the manganese catalyst was proved by the experiment, the problem of circulation and regeneration of the flocculating manganese suspension was solved, second pollution of manganese was eliminated, and the flocculating manganese catalyst still kept its catalytic activity as usual.Static adsorption experiment of the powder activated carbon was developed, the adsorption characteristics of the powder activated carbon and the optimum parameters were acquired as follows: pH was 10; the aeration rate was 150L/h; the amounts of added active carbon was 15g/L and the removal rate can reach 80% after 30min.Orthogonal experiments of jonint adsorption was adopted, economic factor was considerded, the time of the pretreatment of flocculating manganese suspension was considered the main factor of influencing the removal rate of the coking wastewater COD and the optimum parametes were acquired as follows:the pretreatment time was 30min; the wastewater load was 600mL/h; the amount of active carbon for the suspended system was 30g and 40g for fixed bed.. The value of the effluent COD was relatively stable and operation modes was better than that of the suspended system.