Comparative Efficiencies for Phenol Degradation on Solar Heterogeneous Photocatalytic Reactors: Flat Plate and Compound Parabolic Collector

Abstract

Phenol is a recalcitrant anthropogenic compound whose presence has been reported in both wastewater and drinking water; human exposure to phenolic substances can lead to health problems. The degradation of phenol (measured as COD decrease) through solar heterogeneous photocatalysis with immobilized TiO2 was performed in two different reactors: a flat-plate reactor (FPR) and a compound parabolic collector (CPC). A 23 full factorial experimental design was followed. The variables were the presence of TiO2, H2O2 addition, and the type of reactor. Data were fitted to the pseudo-first-order reaction-rate-kinetics model. The rate constant for photocatalytic phenol degradation with 1 mM of H2O2 was 6.6 × 10−3 min−1 for the FPR and 5.9 × 10−3 min−1 in the CPC. The calculated figures of merit were analyzed with a MANCOVA, with UV fluence as a covariate. An ANCOVA showed that the type of reactor, H2O2 addition, or fluence had no statistically significant effect on the results, but there was for the presence of TiO2. According to the MANCOVA, fluence and TiO2 presence were significant (p < 0.05). The CPC was on average 17.4% more efficient than the FPR when it came to collector area per order (ACO) by heterogeneous photocatalysis and 1 mM H2O2 addition.

Arsenite to Arsenate Oxidation and Water Disinfection via Solar Heterogeneous Photocatalysis: A Kinetic and Statistical Approach

“…[93]). This finding supports the fact that the outcome of an HP operation might depend on a plethora of variables and the interactions between them, such as the photocatalyst properties, the source of light, the intensity of the light, the pH, the concentration of the pollutant, and the temperature of the geometry of the reactor [44]. Finally, the effect of the covariable, Q UV , was not statistically significant, possibly because of uniformity in the timeframe of the operation, which translated into minimal Q UV variations (solar noon operation and only on sunny days) [41,44] (p < 0.05 in all three cases).…”

“…Table 8 shows the A CO value for each one of the treatments. A smaller Aco is generally associated with a more efficient process [44]. On average, CPC needed 30% less photocatalyst covered area than the FPR, which is in accordance with the improved optical efficiency provided by the reflector [52], accounting for an improved use of the photocatalyst-covered area.…”

“…The PMMA compartment was placed onto an inclinable metal assembly; reactor's drainage led to the water reservoir, which, with the help of a submergible water pump (Model H-331 BioPro, Jiangsu, China), was fed to the reactor (Figure 2). Table 1 shows additional reactor operational parameters, as reported in previous work [44].…”

“…While in the FPR, a 33 cm wide and 30 cm long frosted glass plate was used as photocatalyst support. The immobilization methodology has been reported elsewhere [44].…”

Synthesis, Characterization, and Photocatalytic Performance of ZnFe2O4-g-C3N4 Composites for Tetracycline Removal from Contaminated Water

“…Considering the surging energy cost, utilizing solar energy to drive heterogenous photocatalytic systems has become a priority for researchers. Te parabolic trough reactor (PTR) is a promising confguration for wastewater remediation adopted from thermal power concentrators [31]. It has a parabolic shape that refects solar rays along a focal line where a collector tube holding wastewater is positioned [32].…”