| With rapid industrial and social development, chemical products cause severeenvironmental pollution along with huge economical proifts, and much of the pollutioninvolves hazardous, even toxic and nondegradable pollutants with complex structures.Chemical wastewater treatment is a dififcult task. So how to improve the removal effectof organic pollutants in chemical wastewater in some chemical industry park has beenone of the daunting tasks in current environmental protection and pollution control.The paper mainly researched on using integrated technology of coagulation&activated carbon adsorpiton for the treatment of chemical wastewater in a chemicalindustry park Chongqing. Petrochemical industry, natural gas, chlor-alkali industry,biomass industry, ifne chemicals and advanced materials have formed the foundationof the industry park, and also caused wastewater from the park diiffcult to processsince quality of the influent is quite complex containing a wide variety of toxicorganic compounds situation of the wastewater is not stable. The paper managed toprocess mixed nondegradable chemical wastewater with high concentration and it’s anovel and practical technology worthy of spreading. Results and conclusions of theresearch are as follows:? Current status of chemical industry wastewater in chemical industry parkswas analyzed from four aspects including characteristics of the wastewater,development of its processing technology, pollution sources and harm caused by thepollution.②Mechanismand development of coagulation&activated carbon adsorpiton forthe treatment of chemical wastewater was analyzed and the importance of usingcoagulation in pretreatment and advantages of using activated carbon adsorpiton inadvanced treatment were also summed.③Experiments were carried out to research removal effect of coagulationtechnology when it’s used for the treatment of chemical wastewater. Removal effectsof several commonly-used coagulants were compared and conclusions were reached asfollows: both effects and costs of coagulation technology with different coagulantswere analyzed and PAC was elected as the ifnal coagulant. Coagulation conditions are:pH value is7.0，PAC dosage is20mg/L and no PAM is added in. during the initialcoagulation, wastewater to be treated was stirred at a speed of300r/min for lmin; in the middle of coagulation, wastewater was stirred at a speed of lOOr/min for7min;during the ifnal precipitation, wastewater was stirred at a speed of50r/min for15min.after coagulation, COD and turbidity were decreased by49.4%and73.89%respectively, and thus relive some burden for follow-up aerobic biological treatment.④Experiments were carried out to research removal effect of activated carbonadsorpiton when it’s used for the treatment of chemical wastewater. Activated carbonused in the experiment was3mm coal carbon particles and its typical value is900.Conclusions were reached as follows: both eflfuent from the ifnal settling basin withoutfluctuation and eflfuent from the airlift basin after lfuctuation were processed withactivated carbon. By comparison, there was a big difference of treatment effectsbetween of these two kinds of effluents. So fluctuation was added after ifnal settlingbasin to improve absorption ability of activated carbon and also extend its regenerationc’ycle. Its better to control the contacting time of activated carbon to be lh so that CODof the ifnal eflfuent will stay below50mg/L and turbidity stay at around10NUT. CODof the ifnal effluent was below60mg/L, achieving B，I，standard of “Discharge standardof pollutants for municipal wastewater treatment plant"(GB18918-2002). Otherpollutants emission achieved I standard of "Integrated wastewater discharge standard"(GB8978-1996).Conclusions of the paper can offer technical support for wastewater treatment plantin treatment of similar nondegradable wastewater from chemical industry park. |
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