Study On Treatment Of Di-n-butyl Phthalate Wastewater With Anaerobic Baffled Reactor

Environmental hormone is a class of chemical compounds in environment. It may affecthuman and animals on their normal endocrines, leading to reproductive, developmental andbehavioral disorder. Phthalic acid esters(PAEs) are an important group of environmentalhormones. Their main application is as plasticizers in the manufacture of plastics. In recent years,large amounts of plastics have caused a wide distribution of PAEs into environment. PAEs havebecome one of the most prevalent contaminants in the world.Based on the technique of bio-rotating contactor, anaerobic baffled reactor(ABR) has beendeveloped as a high effective anaerobic wastewater treatment recently, it has the ability toseparate acidogenesis and methanogenesis. Compared with other traditional anaerobic processes,ABR has its unique characters, which include less microbial losses and better sludge sediment,better resilience to hydraulic and organic shock loadings, longer biomass retention time, reducedclogging, simple construction and easy operation.In this paper, the treatment of Di-n-Butyl Phthalate (DBP) wastewater by an anaerobicbaffled reactor(ABR) was studied. We had been in progress ABR dealing with the highconcentration of fine chemical wastewater laboratory research, engineering design andengineering debugging works. Priority has studied ABR reactor starting, activated discussion ofthe degradation of COD and volume load, influent concentration, HRT, alkalinity, volatile acid,pH right degradation of pollutants; all of the sludge compartment different stages of the operationcharacteristics; meanwhile the chemical raw water for the anaerobic toxicity teats confirmed thepresence of toxic size and toxicity. The research results showed:(1) In the upper compartment added filler, which can effectively prevent the loss of sludge,played intercepting pollution and increasing efficiency.(2) Low influent load was used to culture sludge. The result showed that the process ofstart-up of ABR have used60days; at room temperature, gradually to not more than30%, whenthe concentration of influent increased from1000mg/L to3400mg/L, COD removal efficienciesfrom90%dropped to about85%, only drop5%, this showed that ABR is very stable to shockload; when hydraulic retention time was12h, organic loading was6.8kgCOD/m3d, the CODremoval efficiency was90.7%, the DBP removal efficiency was87.3%.(3) In fixed HRT for12h, temperature from25to30℃, DBP degradation rate stabilized ataround80%. Go a step research ABR classification compartment of the ability to removeorganics found that the different compartments of the removal of organic matter with differentabilities: the first compartment removed about30%,the second compartment about25%, the thirdcompartment of about25,and the last compartment of about5%. Changing HRT and changing in the influent COD concentration of volume load test showed that used ABR to treat DBPwastewater, HRT12h was to be better. Load control recommendations in2.0KgCOD/(m3·d)~10KgCOD/(m3·d).(4) Test results showed entered ABR reactor COD concentration should not exceed8000mg/L,4000mg/L~5000mg/L suitable control. At this time, the wastewater is a good activity ofanaerobic biological treatment, ABR reactor can from a good grade anaerobic bacterialcommunities: in the first compartment the bacillus occupies the superiority and the sludgeinterspersed with a filamentous fungus; in the second compartment the coccus occupies thesuperiority and also has large number if bacilli; in the third compartment of fungus and bacilli; inthe last compartment main contain fungus and bacilli. Study found that the first and secondcompartment of the hydrolysis acidification will lead to over-acidification, affecting systemoperation. To prevent over-acidification, adding the necessary alkalinity can effectively reducethe excessive accumulation of VFA.(5) Anaerobic degradation of DBP wastewater shows that the best pH of enter water byABR reactor treatment is7.0~7.5, too acidic or too alkaline will inhibition of biological, it iseffectively to use the ABR treated the DBP waste water, and it better to set up amicro-electrolysis pretreatment, to a certain degration of the toxicity and improvebiodegradability.