Experimental Study Of Cavitation Technology And Device For Treating P-nitrophenol

Development of a new water treatment technology is extremelyurgent when the troubles of water pollution are fearful increasingly.Choking cavitation is a new type of hydrodynamic cavitation technique.Researching the choking cavitation used in water treatment industry isaimed at developing a new technology to deal with the industrialeffluents.Hydroxyls produced by cavity collapses have high chemical activity,which can oxidize organism. The micro jet, shock wave and shearturbulence occurred when cavities collapse have homogeneous effect ongas-liquid two-phase flow and can intensify the chemical reaction. Theyield of hydroxyl produced by choking cavitation was studied usingmythylene blue dosimetry, and analyzed the effects of the equivalentdiameter of backpressure holes, initial concentration of MB and treatingtime on the yields of hydroxyl. Using P-Nitrophenol as the model water,the choking cavitation technology and choking cavitation/H2O2synergetictechnology, which treat the poisonous, refractory and less volatileeffluents, were studied, and the effects of structure parameter of chokingcavitator and the physicochemical parameter of effluent on thedegradation rate of P-NitropHenol were analyzed.Structure parameters of choking cavitator, the physicochemicalparameter of liquid and treating time have an effect on the chokingcavitation technology. The experimental results showed that the highestyield of hydroxyl radical was acquired when the equivalent diameter ofback-pressure holes was5.4mm,the initial concentration of MB was12mgï¹'l-1and the treating time was15min. When the initial concentration ofP-Nitrophenol was1mgï¹'l-1, PH was3and the treating time was100min, the degradation of P-Nitrophenol reached the optimal value of16.9%.The synergetic effect of choking cavitation/H2O2is obvious. Theeffects of the equivalent diameter of back-pressure holes, the dosage ofH2O2, and the treating time on the degradation ratio were analyzed with a visible spectrophotometer. The experimental results showed that when theequivalent diameter of back-pressure holes was5.4mm, the dosage ofH2O2was1ml, the pH of the liquid was3, and the treating time is9min,the degradation ratio can reach to74.7%, which is26%higher than H2O2processing alone.