Chemical Coagulation-sbr Treatment Of Oily Wastewater

Oily wastewater has extensive sources,wide damaging range and complex constituent. Among multitudinous wastewater treatment, as a result of technical and economic, it is very difficultly purified and does not completely attain to integrated wastewater discharge standard. Chemical coagulation-SBR processes was seleced to treat oily wastewater, the optimal coagulation operational parameter was researched through the experiment in the physico-chemical process. Influence of removal efficiencies was studied the bio-chemical system degrade the organic pollutant at different aeration time, different MLSS, different temperature and different pH in the bio-chemical process. And dynamic model of SBR process was investigated.The experiment results showed that, in the phase of coagulation experiment, by adding FeCl₃ with concentration 90mg/L into oily wastewater with concentrations of COD and oil 600mg/L and 80mg/L respectively, then stirring the mixture for 60s with frequency 200r/min and then depositing for 30 min, the removal efficiencies of COD and oil were more than 40% and 52% if the pH value was controlled between 6.5～8.5. The cost of medicaments used in the process of coagulation is 0.4yuan/m³. In the phase of biological processes, when average concentrations of COD and oil of influent were 500mg/L and 60mg/L respectively, keeping SBR operating three times a day( aeration time 6h/cycle), MLSS 3～4g/L, pH value between 7～8, temperature about 25℃, the concentrations of COD and oil of the effluent were less than 100mg/L and 10mg/L, and met the national wastewater discharge standard Ⅱ. If the concentration of salt was between 1～5g/L in the biological processes, the effect of the biological treatment system was not obvious. If the concentration of salt was up to 5g/L, the effect was obvious, for example, removal efficiencies of organic pollutant reduced, morphology of microorganisms changed.When oily wastewater was treated by SBR processes, the dynamic model of SBR is: during the influent, the maximum substance degradation rate is worked out byS_F/S₀ = 0.145 v_max + 0.4788, correlation coefficient R = 0.935, during the reaction,...