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Refinery spent caustic wastewater is more difficult to deal with waste water, with odor, color and high chemical oxygen demand (COD) is high, low biodegradability, toxic and other characteristics, such as untreated or inadequately treated directly discharged, it may cause water pollution and ecological damage to the environment and harm to human health, and further restricted the sustainable development of society. Alkali treatment currently used in the refining process are still not completely processed, the processing costs are high, complex process and other issues. Therefore, for this type of waste, research and development with good effect, low-cost technology become a hot field of water treatment. Initially identified a new refinery spent caustic wastewater treatment process, after the refinery spent caustic wastewater treatment process can achieve the national appropriate wastewater discharge standards, while the process for other high concentration organic wastewater treatment, with better application value. The topic for the Dushanzi refinery refinery spent caustic wastewater generated, select coagulation - micro-electrolysis / Fenton-macroporous resin as a pretreatment process, improve the biodegradability of wastewater, and further through the conventional activated sludge process, effluent able to reach the design requirements. Through laboratory experiments demonstrated that the refinery spent caustic wastewater treatment process feasibility, through study of the various factors on the treatment effect, get the best conditions for the process operation. Through analysis of the experimental results the following conclusions: (1) coagulation experiments to determine the optimum conditions are: PAC PAC coagulant dosage 900 mg / L, coagulant cationic polyacrylamide CPAM vote plus the amount of 30 mg / L, pH 8, stirring time of 15 min, on CODcr, chroma removal rate was 46.5%, 51.4%. (2) Micro-Alkali Electrolysis refinery wastewater, the operating parameters are: the temperature, the aeration conditions, water pH value 3, the reaction time of 2 h, water and the volume ratio of the filler 2, in this condition, Micro-electrolysis treatment of wastewater CODcr average removal rate was 42.5%; effluent CODcr in 16000 ~ 17000 mg / L between. Fenton's reagent processing refinery spent caustic wastewater optimal operating conditions are: pH value between 2 and 3, reaction time 2.5 h, Fe2 concentration of 800 mg / L or so, H 2 O 2 concentration of 0.25 mol / L, micro-electrolysis reaction to the Fenton reagent oxidation process provides sufficient Fe 2 , in this condition, Fenton reagent micro-electrolysis treatment Alkali refining wastewater CODcr removal rate was 63.8% above the water CODcr at 6000 mg / L or so. Microelectrolysis / Fenton process on CODcr removal rate of 79.2% in total around. (3) by means of static adsorption experiments and found that the LS-100 resin wastewater treatment is better. LS-100 macroporous resin at room temperature, the adsorption rate was 2 BV · h -1 , wastewater treatment volume at 70 ~ 80 BV (BV of times resin volume) between. Through stability test, when the influent CODcr average concentration of 6000 mg / L or so, the effluent CODcr average concentration of 1356 mg / L, run to the adsorption resin penetration point, resin adsorption capacity of the average working 346 mg / mL, treatment wastewater volume of 75 BV. (4) Activated sludge acclimation at room temperature conditions, the influent CODcr concentration of 1278 ~ 1516 mg / L, hydraulic retention time of 24 hours, the water CODcr concentrations averaged 334 mg / L, the average removal rate of 76% CODcr . Water quality and stability. (5) The results show that coagulation - micro-electrolysis / Fenton-macroporous resin - the activated sludge treatment process combined refinery spent caustic wastewater can effectively remove pollutants in the effluent treatment process to meet the design standards, there is a strong impact load capacity, it is worth learning pilot project.
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