| The limit-exceeding problems of total nitrogen and phosphorus in effluent are very common in current cornstarch wastewater treatment. The typical corn deep processing industries were used as object of the present research. The enhanced pretreatment technologies were used to reduce phosphorus emission. Supplying the carbon source for denitrification process by using hydrolysis-acidogenosis wastewater and the effluent of primary sedimentation tank was studied to enhance nitrogen removal ability. The preferable results were obtained in the experiment.(1) The pretreatment process should be based on natural precipitation and supplemented by coagulation sedimentation. Under the condition of natural sedimentation, the average removal rates of CODCr, total nitrogen, total phosphorus and suspended matter reached 35.1%～60.3%,31.5%～40.0%,21.7%～46.5% and 91.3%～96.9%, respectively. After adding FeCl3 to wastewater as the flocculent, the removal rate of total phosphorus reached 93.5%.(2) It was proved to be feasible that supply two types of wastewater as carbon sources. Under certain conditions (T=40℃, pH=7.0, C/N=7, t=4h), the removal rate of nitrate was over 96% by using hydrolysis-acidogenosis wastewater. Under certain conditions (T=40℃, pH=7.0, C/N=9, t=2h20min), the removal rate of nitrate was over 96% by using the effluent of primary sedimentation tank.(3)The results showed that the experimental data accorded with Monod differential equation and piecewise zero-order kinetic model, while a higer denitrification rate could obtained by using hydrolysis-acidogenosis wastewater as carbon source. Using the method of fluorescence excitation-emission matrix (EEM) spectroscopy combined with parallel factor (PARAFAC), the types of organic matters and the fluorescence intensities were studied to analyze the denitrification process. And the change of fluorescence intensities demonstrated that microorganism could make full use of the protein-like matter in the waste water as the electron donor. |
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