Treatment Of Phenolic Wastewater By Adsorption Or Oxidation As Well As Combination Processing Of Oxidation And Adsorption

Abstract:With the rapid development of petroleum, plastics, composites and coking industries, the phenolic wastewater has been significantly increased recently. The phenols have been attracted attentions by the majority of researchers due to their toxicity, carcinogen and potential genetic mutagen. The removal and/or degradation of phenolic pollutants from wastewater have a great impact on aquatic life and terrestrial plant growth and reproduction, as well as human society including food and drinking water safety. Therefore, technology development for phenolic removal with high efficiency is a great practical significance to the environmental protection.At present, there are mainly three types of common methods used for treatment of phenolic wastewater including physical adsorption, chemical oxidation and biochemical degradation. It has been found that no single method can accomplish the phenol removal from wastewater with a great satisfactory in industries. The development of technology combining two or more removal methods hence becomes focus in the field.This paper is based on laboratory simulated phenol-containing wastewater. In the separate treatment by resin adsorption process and Fenton oxidation method, an innovation of phenol removal from wastewater has been developed using Fenton oxidation process and the adsorption through macroporous resin beads. At the same time, the study was tested on the strengthening action of reactor for the simulated phenolic wastewater and actual industrial wastewater treatment taking advantages of three phase fluidized bed reactor. The treatment effect and its influencing factors have been analysised and discussed. It provides the theory basis for the industrial application of this new technology.The major results of this research are briefly described below.After comparative study of three kinds of adsorption resins for phenol adsorption properties, H-103macroporous adsorption resin is of optimal performance. The removal of phenol from aqueous phenol solution was investigated using H-103macroporous resins. The effects of solution initial concentration, pH, reaction time and temperature on phenol removal were studied. The experimental results indicated that the adsorption reached equilibrium within30min and adsorption kinetics could be well described by the pseudo-second-order kinetic model, and Langmuir isotherm model was better to describe the isothermal adsorption of phenol onto the macroporous resin, At this point the concentration of phenol was1000mg/L. The equilibrium adsorption capacity (Qm) and Langmuir constant (KL) were86.00mg/g and0.2719L/mg, respectively,when the tempreture is25℃. Using70%(ω) ethanol as desorption agent, the desorption ratio was94.5%.Comparative study on the oxidation resistance of MnO2, KMnO4and Fenton reagent on phenol solution, the experimental results showed that Fenton reagent oxidation is of the best performance. The efficiency of Fenton agent was examined using phenol as a model compound in simulated wastewater. Batch studies were conducted to optimize the parameters such as the Fe2+initial concentration, the molar ratio of n(H2O2)/n(Fe2+), pH, temperature and reaction time governing the Fenton process. It was found that optimal operating conditions existed as:Fe2+initial concentration of3mmol/L, H2O2initial concentration of80mmol/L, pH=6, T=25℃and reaction time of60min. Under these conditions, the phenol removal ratio was95%.The efficiency of Fenton agent combined with macroporous resin H-103was examined using phenol as a model compound in simulated wastewater. A batch study was conducted to optimize parameters like the pH, reaction temperature, reaction time and solid holdup governing the process. The experimental results indicated that the phenol removal rate was98.6%using the oxidation-adsorption combination process at25℃, pH=4, Fe2+initial concentration of3mmol/L, H2O2initial concentration of80mmol/L, resin mass percent of1%, after a reaction time of5min. At this point the concentration of phenol was1000mg/L. It is obvious that the efficiency of phenol removal by using the oxidation-adsorption process is better than any of the single methods. Fitting the experimental data, kinetic model was established for the adsorption-oxidation combined process of synergetic degradation of phenol. The efficiency of Fenton agent combined with macroporous resin H-103was examined using phenol as a model compound in simulated wastewater in a gas-liquid-solid three-phase fluidized bed. A batch study was conducted to optimize parameters like the pH, reaction time, the resin solid holdup rate, H2O2initial concentration, Fe2+initial concentration and ventilation volume governing the process. The experimental results indicated that resin particle fluidization can strengthen the combination process of phenol removal effect, the phenol removal ratio was99.6%using the oxidation combined with adsorption process at25℃, pH=4, Fe2+initial concentration of3mmol/L, n(H2O2)/n(Fe2+)=20:1, resin mass percent of1%, ventilation volume of0.12m3/h, after reaction time of5min, At this point the concentration of phenol was1000mg/L. Other conditions are the same, no detection of phenol in solution, at this point the concentration of industrial phenol-containing wastewater was878mg/L.