Study On Degradation Of Organic Pollutant With Combination Of Micro-Nano Bubble And Cu@CAC

Industrial wastewater is a kind of organic wastewater with complex water quality,poor biodegradability and high concentration of organic pollutants and salt.The objective of this subject is to develope a kind of physical and chemical treatment method with high efficiency and no secondary pollution.In this study,the effects of two kinds of decompression and release devices on micro and nano bubble physicochemical properties were compared;and activated molecular oxygen catalyst with high activity and high stability were developed;At last,the high concentration organic compounds were mineralized and degraded with micro nano bubbles and activated molecular oxygen catalysts.The degradation pathway of organic pollutants is further explored.The research results could be included as the follows:1)The two systems can produce different numbers and distributions of micro-nano bubbles and nanoscale bubbles.The concentration of nano bubbles in the jet system is high,and the particle size is distributed at 100-400 nm.However,in the swirling nozzle system,the concentration of micro-nano bubbles and the gas-liquid mass transfer rate is high.Bubble size and gas-liquid turbulence are important factors affecting the gas-liquid mass transfer in the two systems respectively.The optimal operation condition for the jet system is Q pump/L=1:14.7 and Qjet =32mL/min,and Qpump/L=1:13.2 for the swirling nozzle system,respectively.2)Defoamer should be added to the two systems to slow down the foaming phenomenon during the degradation of organic pollutants.The foaming effect of the swirling nozzle system is obviously higher than that of the jet system,and the defoamer can extremely improve the removal rate of the swirling nozzle system.pH value,temperature and salt concentration are important factors affecting the degradation of methylene blue in the two systems,and pH value of the jet system increased faster in the degradation process.After 100min,the highest removal rate of 6mg/L methylene blue in the swirling nozzle system can reach more than 89%.The mechanism of methylene blue degradation is hydroxylation with a final product of 1,2,4-butanol.3)The columnar activated carbon loaded copper presented higher hydrophobicity,which can promote the diffusion of cupric oxide into the body phase in N2 atmosphere by calcination,it results in the acid dissolution of Cu2+reduced by about 3 times.In addition,the addition of Ce and Zr can obviously improve the dispersion of cupric oxide,promote the transformation of Cu2+ to reducing state,which can increase the chemisorbed oxygen of the catalyst surface and improve the degradation effect of methylene blue,and the dissolution of Cu2+ can reach the national first level emission standard.4)The removal rate of 20mg/L methylene blue was 70%,the removal rate of TOC reached 53%.The columnar copper carbon could fully utilize the dissolved oxygen and free radicals in the miro-nano bubblesto treate(?)wastewater with high concentration.Methylene blue degradation mechanism includes hydroxylation and demethylation with a final product of 1,2,4-butanol.