The Effect of Solvent, Hydrogen Peroxide and Dioxide Titanium on Degradation of PCBs, Using Microwave Radiation in Order to Reduce Occupational Exposure

Abstract

Polychlorinated biphenyls (PCBs) are one group of persistent organic pollutants (POPs) that are of international concern because of global distribution, persistence, and toxicity. Removal of these compounds from the environment remains a very diffi cult challenge because the compounds are highly hydrophobic and have very low solubility in water. A 900 W domestic microwave oven, pyrex vessel reactor, pyrex tube connector and condensing system were used in this experiment. Radiation was discontinuous and ray powers were 540, 720 and 900 W. The PCB S were analyzed by GC-ECD. The application of microwave radiation and H 2 O 2 /TiO 2 agents for the degradation of polychlorinated biphenyl contaminated oil was explored in this study. PCB -contaminated oil was treated in a pyrex reactor by microwave irradiation at 2450 MHz with the addition of H 2 O 2 /TiO 2 . A novel grain TiO 2 (GT01) was used. The determination of PCB residues in oil by gas chromatography (GC) revealed that rates of PCB decomposition were highly dependent on microwave power, exposure time, ratio to solvent with transformer oil in 3:1, the optimal amount of GT01 (0.2 g) and 0.116 mol of H 2 O 2 were used in the study. It was suggested that microwave irradiation with the assistance of H 2 O 2 /TiO 2 might be a potential technology for the degradation of PCB -contaminated oil. The experiments show that MW irradiation, H 2 O 2 oxidant and TiO 2 catalyst lead to a degradation effi ciency of PCBs only in the presence of ethanol. The results showed that the addition of ethanol signifi cantly enhanced degradation effi ciency of PCBs.

Application of microwave irradiation for the removal of polychlorinated biphenyls from siloxane transformer and hydrocarbon engine oils

“…Only few blank experiments on real contaminated oils and soils without the addition of any reagents in the only presence of MW are reported in the literature as reference runs (Kamarehie et al, 2014;Tajik et al, 2014;Liu et al, 2008) and evidenced little efficiencies towards PCB removal. The effects of the reaction time, runs T6 performed for 15 min and T6L for 30 min, and of the simultaneous cooling, run T6R carried out for 15 min with cooling, were investigated at 100 C and 300 W and the results are shown in Fig.…”

“…Cravotto combined solid Fenton-like reagents (sodium percarbonate and the urea/hydrogen peroxide complex) and MW irradiation for the decomposition of organic pollutants of the soil, highlighting that 4-chloronaphthol, 2,4-dichlorophenoxyacetic acid and p-nonylphenol were completely degraded (Cravotto et al, 2007). On the other hand, the use of MW irradiation for the removal of PCBs from oil matrices has been less investigated (Kamarehie et al, 2014;Kastanek et al, 2011;Lin et al, 2013;Liu et al, 2008Liu et al, , 2011Tajik et al, 2014). Liu studied the applicability of MW irradiation for the removal of PCBs from the soil heavily contaminated by capacitor oil in the presence of sodium hypophosphite, iron powder and granular activated carbon as MW-adsorbing materials.…”

“…More recently, other approaches have been developed for remediation of PCBs, such as thermal, oxidative, reductive photocatalytic and microbial technologies (Beless et al, 2014;Borja et al, 2005;De Filippis et al, 1997;Field and Sierra-Alverez, 2008;Habekost and Aristov, 2012;Jelic et al, 2015;Kanbe and Shibuya, 2001;Kume et al, 2008;O'Brien et al, 2005;Ohbayashi et al, 2002;Ohmura et al, 2007;Peng et al, 2014;Rastogi et al, 2009;Seok et al, 2005;Shaban et al, 2016;Van Aken and Bhalla, 2001;Villalobos-Maldonado et al, 2008;Wang et al, 2016;Wu et al, 2005Wu et al, , 2012Yao et al, 2014;Zhao et al, 2015). In addition to these techniques, also microwave irradiation (MW) has been investigated due to its advantages ascertained in many different applications (Abramovitch et al, 1999a(Abramovitch et al, , 1999b(Abramovitch et al, , 1998Cravotto et al, 2007;Huang et al, 2011;Kamarehie et al, 2014;Lin et al, 2013;Liu and Yu, 2006;Liu et al, 2008;Tajik et al, 2014). In fact, in the past few years the interest in the employment of MW irradiation has considerably increased because it represents a sustainable and green tool for many applications, improving selectivity together with a significant reduction of the reaction time (often by orders of magnitude) and of energy consumption (Antonetti et al, 2015(Antonetti et al, , 2012Appleton et al, 2005;Raspolli Gall...…”

Archives of Environmental Protection

“…Specifi cally, polychlorinated biphenyl (PCB), one kind of typical persistent organic pollutants (POPs), is a commercial admixture based on biphenyl ring and is a mixture system of chlorine biphenyl homologenchloridized by metallic catalysis in high temperature. Due to its stable physical and chemical characteristics, PCB is widely used in industrial production, in transformer oil, anti-friction material, plastic, and resin fi elds (Billingsley et al 2002, Burke et al 1978, Tajik et al 2014, Zheng et al 2004. On the other hand, the large quantity plant use and unconscious release of POPs led to their wide distribution around the world, which brought pollution to our environment.…”