Study On The Degradation Of Dissolved Organic Matter In The Source Of Algae And Macrophytes

The rapid development of industry and agriculture accompanied by a large number of exogenous input of dissolved organic matter (DOM) into the natural lake water. The accumulation of nitrogen and phosphorus nutrients in water leads to abnormal proliferation of phytoplankton and plankton, and death degradation further increases the endogenous input of DOM. There are two main pathways for the degradation of dissolved organic matter, one way is the photochemical degradation of direct absorption energy of light degradation changes or intermediates in water absorption of photons through the electron transfer process of energy will pass organic matter degradation ; the other way is biodegradation, the type of microorganism uses the energy needed to degrade organic matter for its activity. Internal and external sources DOM can be degraded by photochemical degradation and biodegradation, which can reduce its concentration, molecular weight and spatial structure complexity. We studied photochemical degradation and biodegradation of dissolved organic matter from macrophytes and algae in this paper. The EEM-PARAFAC model was established by means of UV-Vis spectroscopy (UV-Vis Spectra),excitation-emission matrix fluorescence spectroscopy (EEM) combined with parallel factor analysis (PARAFAC).The degradation of DOM and its components in different sources was investigated under different influencing factors (temperature, pH, dissolved oxygen, wavelength,concentration,etc.).The experimental results show that photochemical degradation is beneficial to photochemical degradation of DOM and its components under the condition of increasing light intensity, increasing dissolved oxygen concentration, neutral pH and lower initial concentration. The degradation of DOM was mainly in the ultraviolet region.Biodegradation is beneficial to the degradation rate, degradation rate and degradation degree of DOM and its components under the conditions of oxygen, temperature rise and organic matter concentration. The organic matter of different sources has a very different composition and structure, and the same source of photochemical degradation and biodegradation process is not the same product...