Kinetics and Process Characteristics of Hydrolysis-acidogenosis Wastewater as Denitrification Carbon Source

In the treatment of starch wastewater, the hydrolysis-acidogenosis wastewater can be used as a potential carbon source in the process of denitrification. Not only the problem of carbon source shortage in denitrification process can be solved, but also the resource utilization of wastewater can be achieved. The optimal conditions were determined through orthogonal experiments as follows: the temperature was 40 ℃, pH was 7, C/N ratio was 7. The denitrification rates of the carbon sources were 4.66～14.22 mg/(g•h) (calculated by NO₃^--N) under the optimal conditions. The methods of fluorescence excitation-emission matrix (EEM) spectroscopy combined with PARAFAC were utilized to analyze the denitrification process. Three kinds of fluorescence components could be identified in the system. Component 1 (225, 275nm/350nm) and component 3 (220, 275 nm/335 nm) were tryptophan-like substance. Component 2 (230, 275nm/305nm) was tyrosine-like substance. The fluorescence intensity of component 1 and component 2 increased at first and then decreased, and both of their fluorescence peaks disappeared finally. The fluorescence intensity of component 3 was negatively correlated with that of component 1. A trend of total fluorescence intensity first increasing and then decreasing was showed with the time.