菲的挥发特性及挥发模型研究

Research of Volatilization Characteristics and Models of Phenanthrene

研究了菲在水环境、污泥中的挥发特性,根据双膜理论推导出菲的挥发模型,结合实验对其进行了验证,并对其挥发的影响因素做了讨论。在无污泥和添加污泥的不同条件下进行试验,同时改变转速、温度以及投加的污泥量,按相同时间间隔取样,用液相色谱仪对菲浓度进行测定,结果表明,与不加污泥时相比,污泥的加入明显抑制了菲的挥发;无污泥时,150 r/min时,去除率达到76.4%,35℃时,去除率达到92.2%;添加污泥时,150 r/min时,去除率47.5%,35℃时,去除率55.7%,;水的流动速度、温度的增加都将显著增大菲的挥发速率;菲在水环境和污泥中的挥发过程符合一级动力学方程。25℃时,实验得出的挥发速率常数k a=0.060 7 h-1,总传质系数k=1.079×10-6m/s,而理论估算出的总传质系数k=2.240×10-6m/s。

The characteristics of the volatilization of phenanthrene in water and domesticated sludge are studied, the phenanthrene volatilization model based on double film theory is logical relative to experimental data. In the absence of sludge and adding sludge conditions, changing therotational speed and temperature meanwhile, the concentration of phenanthrene is de-termined by liquid chromatograph according to the same sampling time interval. The results show that the addition of sludge significantly inhibites the volatilization of the phenanthrene, in the absence of sludge condition, when the rotational speed is150 r/min, the removal efficiency reaches 76.4%, and the removal rate reaches 92.2% when the temperature is 35 ℃, however,the removal efficiency merely reaches 47.5% when the rotational speed is 150r/min with the addition of sludge, and the removal rate reaches 55.7% when the temperature is 35 ℃. The increase of water flow velocity and temperature promote the volatilization rate. The volatilization of phenanthrene in domesticated sludge could be fit with the first-order kinetics model.The volatilization rate constant ka=0.060 7 h-1and the total mass transfer coefficient k=1.079×10-6m/s obtain from the experiment data and the calculated total mass transfer coefficient using the empirical formula is 2.240×10-6m/s.