The Study on Ozonation of Naphthalene and Surfactants Containing Solutions with High-Gravity Rotating Packed Bed
Date Issued
2004
Date
2004
Author(s)
Huang, Yi-Hua
DOI
zh-TW
Abstract
The objective of this study is to examine the ozonation of naphthalene (NAP) and surfactants with high-gravity rotating packed bed (HGRPB). Furthermore, the influences of surfactants on mass transfer and the ozonation performance were investigated in this study.
The HGRPB for semi-batch operation with recycle liquid is employed to the ozonation of surfactants in this part of experiment. The results showed that sodium dodecylsulfate (SDS) reacted with ozone insignificantly but polyoxyethylene (4) lauryl ether (Brij 30), which reacted with ozone via the electrophilic addition reaction. However, it is difficult to mineralize both SDS and Brij 30 into carbon dioxide (CO2) and water (H2O) by means of ozonation. Regarding the mass transfer experiments, the results showed that dissolved liquid ozone increased from 2.32 to 0.49 mg/L with the decrease of the SDS concentration from 0.00164 to 0.1M. The self-decomposition rate constant of ozone depended on the concentration of SDS in aqueous phase is .
The results of HGRPB of continuous flow operation to strip naphthalene from aqueous solution showed that the efficiency of the stripping is better in deionized water than in surfactants-containing solution (above CMC). When the concentration of surfactants is above CMC, the concentrations of the surfactant and NAP affect the removal efficiency of stripping. The stripping efficiency may be related to the gas flow rate. The efficiency of ozonation of NAP dissolving in the SDS solution is better than that in the Brij 30 solution with same concentration of NAP. The removal efficiencies of NAP decreased from 98.3 to 82.36 % as the concentration of Brij 30 was from 100 to 1000 mg/L. The concentration of NAP increased from 10 to 100mg/L, while the efficiency of ozonation decrease from 82.26 to 35.67%. The contacting volume of HGRPB is 185 mL, in which the contact time is too short for ozone to completely react with NAP. Due to the comsumption of ozone by Brij 30, the higher concentrations of Brij 30 and NAP decreased the removal efficiency of NAP.
The surfactant-containing solution after ozonation and can further re-dissolve NAP of 35 (SDS of 100 mg/L) and 120 mg/L (Brij 30 of 1000 mg/L), respectively. Therefore, it is feasible to reuse the surfactant-containing solutions after ozonation.
Subjects
萘
超重力旋轉填充床
臭氧
多環芳香族
碳氫化合物
high-gravity rotating packed bed
napthalene
ozo
Type
thesis