Decomposition Of P-nitrophenol In Water By Adsorption-ozonation Process

Adsorption-ozonation process is one of the advanced oxidation processes for wastewater treatment, which consists of adsorption and ozonation processes. The toxic and bio-refractory pollutant p-nitrophenol (PNP) widely exists in wastewaters, such as chemicals, pesticides and dyes wastewaters. In the present study, Activated Carbon Fiber (ACF) is chosen as an adsorbent during the treatment of PNP wastewater using the adsorption-ozonation process. The effects of some operational parameters on PNP degradation, the reaction mechanisms, and reaction kinetic models are investigated. Lastly, SEM, XRD, N2 adsorption isotherm, pHpzc, Zeta-potential, Boehm titration and FT-IR are used to characteristics the changes of the function groups existed on the surface of ACF, microcrystalline configuration, aperture and hole's configuration before and after adsorption-ozonation treatment. The experiment was divided into three parts:(1) The adsorption characteristics of PNP by ACF in waste water were investigated. Based on the static state adsorption technique, the adsorption thermodynamics and adsorption kinetics characteristics of PNP on ACF were also studied. The result showed that isotherm adsorption of PNP was best described by Freundlich and Dubinin-Radushkevich equations. The wastewater, with the initial PNP concentration of 100mg/L, can meet the national discharge standard for wastewater after ACF adsorption treatment.(2) By investigating the effects of operational parameters on PNP degradation efficiency, the decomposition of PNP on ACF by ozonation was studied. This part included the study of operational parameters on its decomposition, kinetics and mechanisms through adsorption-ozonation.(3) ACF Characteristics:The surface morphology and microlitic structure were characterized with the help of SEM photos and XRD. The N2 adsorption-desorption analysis was used to investigate the changes of the specific surface area and the pore size distribution of ACF before and after treatment. The BET equation and BJH/DFT methods were also used to estimate the surface area and pore size distribution. The pHpzc, Zeta-potential, Boehm titration and FT-IR were employed to investigate the surface chemical properties.