The Comparative Photodegradation Activities of Pentachlorophenol (PCP) and Polychlorinated Biphenyls (PCBs) Using UV Alone and TiO2-Derived Photocatalysts in Methanol Soil Washing Solution

Abstract

Photochemical treatment is increasingly being applied to remedy environmental problems. TiO2-derived catalysts are efficiently and widely used in photodegradation applications. The efficiency of various photochemical treatments, namely, the use of UV irradiation without catalyst or with TiO2/graphene-TiO2 photodegradation methods was determined by comparing the photodegadation of two main types of hydrophobic chlorinated aromatic pollutants, namely, pentachlorophenol (PCP) and polychlorinated biphenyls (PCBs). Results show that photodegradation in methanol solution under pure UV irradiation was more efficient than that with either one of the catalysts tested, contrary to previous results in which photodegradation rates were enhanced using TiO2-derived catalysts. The effects of various factors, such as UV light illumination, addition of methanol to the solution, catalyst dosage, and the pH of the reaction mixture, were examined. The degradation pathway was deduced. The photochemical treatment in methanol soil washing solution did not benefit from the use of the catalysts tested. Pure UV irradiation was sufficient for the dechlorination and degradation of the PCP and PCBs.

Coupling of Anodic Oxidation and Soil Remediation Processes: A Review

“…In this frame, selective removal of the contaminants from the effluents could be achieved by combining processes in order to ensure the reusability and recyclability of the extracting solution. Therefore, some studies have employed different remediation processes such as selective electrochemical adsorption [ 113 ], photocatalysis [ 2 , 3 , 114 , 115 ], Fenton’s reaction based oxidation [ 2 , 3 , 116 , 117 ], and electrochemical AOPs [ 2 , 12 , 54 ] for treatment of effluents of SW/SF and EKSR processes and the possible recycling step of the extracting agents. Among the studied treatment techniques, AO using “non-active” anodes, especially boron-diamond electrode, is an efficient and effective method for both remediation of the contaminant loaded SW/SF and EKSR effluents, as well as recycling of the extracting agents for possible reuse.…”

Effect of Plastics on the Photodegradation Behavior of Chlorophenols

“…e degradation products TriCP, DCP, and CPs were detected (Figure 4). Because these products can be produced by reductive dechlorination (Yamada et al, 2008;Zhou et al, 2014), it is possible that PE acted as a hydrogen donor.…”

“…For persistent halogenated organic pollutants, photodegradation could be a major cause of transformation on the sea surface. e shortest cuto wavelength of sunlight hitting the earth's surface (∼290 nm) can cause dechlorination and degradation of PCP and PCBs (Zhou et al, 2014).…”

“…Many studies have investigated the photodegradability of organohalogen pollutants in various media, such as water (Czaplicka, 2006) and organic solvents (Minghui et al, 1996;Yamada et al, 2008;Zhou et al, 2014), using ultraviolet (UV) lamps as the light source. Interestingly, photodegradation experiments of hexachlorobenzene in n-hexane, isopropanol, and methanol showed the photodegradation rate in n-hexane was the highest (Yamada et al, 2008), while photosensitized dechlorination of hexachlorobenzene was observed with coexistence of a polymeric carbazole chromophore (Nowakowska and Szczubiałka, 1999).…”

Remediation of Nitrobenzene Contaminated Soil by Combining Surfactant Enhanced Soil Washing and Effluent Oxidation with Persulfate

“…Among physical and chemical remediation techniques, surfactant enhanced remediation is a suitable approach for removal of hydrophobic organic pollutant [ 9 , 10 ]. The use of surfactant results in enhanced solubilization capabilities of micelles and decreased interfacial tension between the washing liquid and the soil particles, which facilitate the desorption of organic contaminants from soil pores [ 11 , 12 ].…”