Showing papers on "Tris(2-chloroethyl) phosphate published in 2021"

Effect of pH, temperature, and use of synergistic oxidative agents on the ultrasonic degradation of tris-2-chloroethyl phosphate, gemfibrozil, and 17β estradiol in water

Abstract: The degradation of three contaminants: tris-2-chloroethyl phosphate (TCEP), gemfibrozil (GEM), and 17β estradiol (E2) by ultrasonication (US) was investigated in a 0.6 L batch reactor. The effect of power intensity and temperature on degradation kinetics was quantified. The impact of oxygen (O2), hydrogen peroxide (H2O2), and sodium persulfate (Na2S2O8) on US effectiveness was assessed to determine potential synergism with US. The results illustrated that degradation of contaminants by US followed a first order rate expression and achieved their highest rate of degradation at pH 3, the lowest pH evaluated, except for TCEP which had a relatively constant rate of degradation with respect to solution pH. The maximum rate constants were achieved using US combined with Na2S2O8 and were found to be: 0.0070, 0.039, and 0.033 min–1 for degradation of TCEP, GEM, and E2, respectively. Combining US with H2O2 did not show synergism, while a small degree of synergism was observed when amending with O2. A 20% (average) decrease in the kinetic constant values was observed as the reaction temperature increased from 25 °C to 55 °C at pH 3. This study has provided a better understanding of the US process applied to the removal of organic contaminants from water.

Degradation of Tris (2-Chloroethyl) Phosphate via UV/Fe(III) Photocatalysis: Kinetics, Products, and Toxicity Assessment

Abstract: In this research, the feasibility of UV/Fe(III) photocatalytic technology for the degradation of tris (2-chloroethyl) phosphate (TCEP) was investigated. Experimental results showed that TCEP had a significant removal efficiency in UV/Fe(III) ([TCEP]0 = 10 ppm, [Fe2(SO4)3]0 = 0.5 mM, near-100% degradation rate after 90 min). A free radical scavenging experiment and EPR detection indicated that the formation of ·OH by the Fe(III) under ultraviolet light played a major role. Experiments on influencing factors revealed that oxygen accelerated the degradation of TCEP by accelerating the Fe(II)/Fe(III) cycle, but Cl− and PO43− inhibited TCEP degradation. Three intermediate products were generated, including C4H9Cl2O4P (product A, m/z 222.9690), C6H13Cl2O5P (product B, m/z 266.9954), and C2H6ClO4P (product C, m/z 160.9762). Moreover, the degradation pathways primarily involved the C–Cl bond and phosphoric center being attacked. Escherichia coli toxicity test revealed that UV/Fe(III) treatment reduced environmental risk of TCEP. Therefore, UV/Fe(III) photocatalysis is a promising technique for TCEP control in wastewater treatment.

Changes in Human Erythrocyte Exposed to Organophosphate Flame Retardants: Tris(2-chloroethyl) Phosphate and Tris(1-chloro-2-propyl) Phosphate.

Abstract: Tris(2-chloroethyl) phosphate (TCEP) and tris(1-chloro-2-propyl) phosphate (TCPP) are the main representatives of organophosphate flame retardants (OPFRs). The exposure of humans to OPFRs present in air, water, and food leads to their occurrence in the circulation. Thus far, no report has been published about the influence of these retardants on non-nucleated cells like mature erythrocytes. Therefore, the impact of TCEP and TCPP (in concentrations determined in human blood as well as potentially present in the human body after intoxication) on human erythrocytes was evaluated. In this study, the effect of TCEP and TCPP on the levels of methemoglobin, reduced glutathione (GHS), and reactive oxygen species (ROS), as well as the activity of antioxidative enzymes, was assessed. Moreover, morphological, hemolytic, and apoptotic alterations in red blood cells were examined. Erythrocytes were incubated for 24 h with retardants in concentrations ranging from 0.001 to 1000 μg/mL. This study has revealed that the tested flame retardants only in very high concentrations disturbed redox balance; increased ROS and methemoglobin levels; and induced morphological changes, hemolysis, and eryptosis in the studied cells. The tested compounds have not changed the activity of the antioxidative system in erythrocytes. TCPP exhibited a stronger oxidative, eryptotic, and hemolytic potential than TCEP in human red blood cells. Comparison of these findings with hitherto published data confirms a much lower toxicity of OPFRs in comparison with brominated flame retardants.