| The topic derives from the project of high concentration dyestuff drainagetreatment from chemical industry of Hubei Province. The COD content of the effluentis very high, if not treated and discharged directly, the water environment will beempoisoned seriously.The effect and influencing factors of the upflow anaerobicsludge blanket(UASB) reactor to treat the dye wastewater under laboratory conditionswere investigated in this article, which mainly focused on anaerobic assimilationcharacteristics, ability, stability and the influencing factors of the wastewatertreatment with UASB reactor, to explore the optimum conditions.The first stage of the trial is the debugging for the reactor, which is the key to thesuccessful operation of the UASB installation. Because most of the anaerobic bacteriaare very sensitive to the environment, small change will directly affect the microbialactivity in the reactor. In general, it will consume a long time to start the reactor, twoor three months as short, even can be up to six months, which has seriously affectedthe application in sewage disposal. Mature anaerobic grain mud was added to thereactor as seed sludge to shorten the start-up time of anaerobic reactor. In the startingprocess of the reactor, with dextrose as carbon source，sludge was domesticated withlow organic loading and neutral water sample, which took the effluent with glucosefor the ratio of1:1, and the initial concentration was controlled at2000mg/L. Increasethe organic loading after organic removal rate reaching more than60%, ascending20%~30%each time, to develop advantage microbial strain required for dyewastewater treatment eventually. During the commissioning phase, the CODdegradation rate rised with the increase of COD chroma. Influent concentrationapproached to raw water after17d, and the degradation rate of COD was62.57%. Thesample water was kept6000mg/L, until COD removal rate reached72.47%. After21d,to domesticate the microbial adapting to this water quality, the proportion of theglucose was reduced gradually, until the31th d, the dye wastewater was the watersample. In the later phase，the degradation rate of COD was still more than70%, which showed the reaction device started smoothly, and this phase sustained for33days.The second one of the experiment is the stable operation, to explore the CODelimination efficiency at the stable conditions. During the transversion, the pH, watertemperature and residence time were stabilized at7,35℃,48h, respectively. Theexperimental results reveal that the UASB implementor has a better effect on treatingdye wastewater, the removal rate of COD can remain at between72%~73%.The third stage is the test on technological factors, to study the influence of HRT,T and pH on the COD disposal.The single factor trial indicates that, the degradationeffect of COD rises with the reaction time prolonging, after a certain time, the trend isclose to flat, at this time, the degradation ability of microbes reaches saturation.Withthe raise of temperature, the degradation of COD presents such a trend, namely, raisesfirst and decline later, and the microbial activity will be suppressed in high or lowtemperature conditions. The change of pH also can produce an effect on microbialactivity, possessing a higher activity at neutral condition. The suitable conditions forthe treatment of dye wastewater by up flow anaerobic sludge bed reactor are asfollows: residence time is24h~48h, the water temperature is33℃~37℃, the inletpH is7.0~7.5.Finally, based on the normal trial and range theory, the relevant diathesis on theCOD degradation proportion in order of priority is HRT, T, pH. The optimal operationcondition for the best seawater treatment efficiency is as follows: HRT is48h,temperature is37℃, the inlet pH is7.2, and the degradation extent of COD can attain76.46%. The anaerobic effluent can meet the requirement of subsequent treatmentprocess, solving the practical problems of anaerobic effluent high COD concentrationin sewage station for enterprises. |
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