Studies on the Removal of ABS and Phenol by PAC Adsorption Associated with Membrane Separation
| Autor: | Wen-Cheng Lee, 李文成 |
|---|---|
| Rok vydání: | 2002 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 90 Removal of the toxic and refractory pollutants from contaminated water is the main purpose of wastewater treatment. Laundry wastewaters generally contain the hardly biodegradable alkyl benzene sulfonate (ABS). Wastewaters from manufacture processes of petroleum industry, resin, and dyeing often contain the toxic phenolic compounds. These two kinds of organic pollutants should be removed from the discharge water to avoid environmental pollution. Experiments were performed to investigate the feasibility for removal of ABS and phenol from aqueous solutions by powdered activated carbon (PAC) adsorption in conjunction with membrane filtration. Four kinds of activated carbons from different manufacturers were employed to do the batch isotherm tests. After comparing the removal efficiencies among each activated carbon, the best one was chosen to do the subsequent experiments including the following items: (1) investigation of the effects of particle size on the PAC adsorption and utilization of the homogeneous solid diffusion model (HSDM) associated with CSTR operation mode to predict the required dosage of PAC, (2) investigation of the removal efficiency of ABS and phenol with granular activated carbon (GAC) by column tests, (3) investigation of the removal of ABS and phenol by PAC adsorption associated with membrane separation. Results show that the adsorption rate significantly increase by using smaller-size PAC. The adsorption capacity of PAC is larger for ABS than for phenol. While the time attaining isotherm equilibrium is much shorter for phenol than for ABS. The calculated values of the effective diffusion coefficient, Ds, by fitting experimental data into the HSDM are 4.9210-7 cm2/min for ABS and 3.9810-7 cm2/min for phenol, respectively. The deviation between the predicted and experimental values of average adsorption concentration is within 10% for 38 m to 48 m PAC. It also reveales that the isoelectric point of the PAC approaches pH=2.3 and the solution pH slightly affects the adsorption of species. It is favorable for ABS adsorption in acidic solution, while phenol is well adsorbed in neutral solution. Finally, the conceptual design of two different kinds of operation mode including continuous and batch-wise PAC-UF processes has been proposed for removing organic pollutants from aqueous streams. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|