Characteristic Of Organic Matter Degradation By Solar Thermal Activation Persulfate

Aiming at the problems of high efficiency,low consumption and green activated persulfate（PS）,a set of solar collector was constructed in which light-to-thermal was achived to heat activated PS.The effects of PS concentration,substrate concentration and initial p H on the degradation rate of organic pollutants were systematically measured to study the degradation characteristics of Rhodamine B（Rh B）and traditional Chinese medicine wastewater.And the mechanism of oxidative degradation of organic pollutants by solar thermal activated PS was analyzed.A new idea was provided for the practical application of solar thermal activated PS technology in water treatment.In order to explore the degradation efficiency and mechanism of Rhodamine B by solar thermal activated PS,the degradation efficiency of Rhodamine B under different solar irradiation intensity,PS concentration,substrate concentration and initial p H of solution was investigated.It was showed that organic pollutants was degraded abundantly in the solar thermal activated PS system.The removal rate and mineralization rate of Rhodamine B were 94%and 60%after 120 min reaction,respectively.On condition of different weather,it was found that the solar radiation intensity was positively correlated with the degradation rate.And controlling the reaction environment of the system,it was found that the concentration of PS was increased and the initial concentration of the substrate was decreased by optimizing the degradation efficiency of the system while the initial p H of the solution was adjusted to be neutral.In order to explore the effect of inorganic anions and humus like substances in the process of solar thermal activated PS degradation of specific pollutants,the degradation efficiency of pollutants in different reaction environments was compared.It was showed that the competition was existed in inorganic anions,humus like substances and the target pollutants to consume the active oxidizing substances in the system which resulted in reduction of the treatment efficiency of the system.Through EPR and free radical probe,the active oxides in the reaction process were analyzed.It was found that SO₄^-·and·OH were produced in the solar thermal activated PS system,and the contribution rate of·OH was more than 60%,which played a major role in degradation.At the same time,the treatment efficiency of the reaction system was verified by the actual wastewater of traditional Chinese medicine,The results showed that the organic matter in the wastewater was degraded and mineralized effectively by the solar thermal activated PS system.The removal rate of UV₂₅₄,UV₂₈₀ and chroma in the wastewater was more than 98%,and the removal rate of COD was more than 86%.The degradation efficiency of organic matter in TCM wastewater was improved significantly by increasing the concentration of PS appropriately and adjusting the system to neutral or alkaline.Combined with the results of three-dimensional fluorescence spectrum analysis,the fluorescence intensity of soluble microbial metabolites and humic acids in EEM spectra was obviously eliminated after the PS system was activated by solar energy for 240 min which indicated that organic matters in actual wastewater was degraded effectively in the PS system based on solar energy.