Optimization of Photocatalytic Degradation of Phenol Using Simple Photocatalytic Reactor

Abstract

The phenol photocatalytic degradation was investigated using heterogeneous catalyst Ag-doped ZnO nanowires under UV irradiation. Ag-ZnO nanowires were immobilized on borosilicate glass via a simple hydrothermal technique. Preliminary photodegradation studies were performed with Ag-ZnO nanowires at various concentrations of phenol (10 -60 mg/L) at undiluted pH. After determination of the optimal initial concentration (30 mg/L), additional parameters including pH and light intensity were investigated to optimize photodegradation of phenol for large-scale application. The experimental results illustrate that the kinetics of degradation of phenol are pseudo-first order. Based on the relationship, experimental model and empirical correlation were generated and compared for validity. The experimental data were found to fit a cubic model (linear in UV irradiation intensity, I, and cubic in pH), over ranges of 10 -60 W (UV lamp power) and 2.7 -11.0 (pH) with a coefficient of determination (R 2 ) of 0.9934. This model, of the form K(I, pH) = c 00 + c 10 I + c 01 pH + c 11 IpH + c 02 pH 2 + c 12 IpH 2 + c 03 pH 3 was found to yield a better fit than simpler (quadratic) or more complex (quartic) polynomial-based models considered. The model parameters c ij and corresponding 95% confidence intervals were obtained.

Optical Photocatalytic Degradation of Methylene Blue Using Lignocellulose Modified TiO<sub>2</sub>

“…Organic pollutant removal from waste water using electroconducting nanomaterial's photocatalysts has an attracted attention towards issue on environmental protections [1,2]. The photocatalytic activity of these nanoparticles under ultraviolet and visible lights has been found a considerable technique and academic interest throughout its property [3].…”

The role of pH in the decomposition of organic micropollutants during the heterogeneous photocatalysis process

“…The reaction of compounds with OH • radicals, which are generated in accordance with reactions from (4) to (6), resulted in the decrease of the micropollutant removal.…”

“…Advanced oxidations process, which include also the process of heterogeneous photocatalysis gives an opportunity to obtain satisfactory effects of micropollutant decomposition [5]. The oxidation and reduction of compounds by means of highly reactive free hydroxyl radicals OH • formed during the process depends on different operating parameters of the process, which include the wavelength emitted by the applied UV irradiation source [6], oxygen concentration in the irradiated water solution [7], catalyst dose and type [8] and also the physicochemical composition of the treated water [9,10].…”

EFFECT OF CALCINATION TEMPERATURE ON ZnO/TIO2 COMPOSITE IN PHOTOCATALYTIC TREATMENT OF PHENOL UNDER VISIBLE LIGHT

“…At present, a number of synthetic methods have been used to synthesize the nanostructures of catalyst. Sol gel technique is common and convenient approach to obtain products of controlled shape and size at high purity and low cost [6]. Others advantages are low processing temperature, which resulting uniform nanostructures for easier control of the kinetics of the chemical reaction.…”

“…A plot of − ln(C/Co) versus reaction time t yields a straight line, and the slope is the apparent rate constant (k). The crystallite size of the samples were then calculate using Scherrer's equation (6).…”