“
“BACKGROUND: Comparison experiments were carried out with three kinds of micro-bubbles on the coagulation flotation process treatment of coke waste-water under optimum coagulation conditions obtained from zeta potential measurement.
RESULTS: Micro-bubble flotation with ozone showed the best performance. The ozone micro-bubbles exhibited high absolute zeta potential values, creating repulsion forces thus avoiding the
coalescence of bubbles as well as creating attractive interaction between bubbles and particles in the waste-water. Moreover, the fluorescence intensity of three micro-bubble samples showed that the ozone micro-bubble system produced the most hydroxyl radicals, which contributed to the degradation of organic material in the coke waste-water. Compared with either air micro-bubble flotation and oxygen micro-bubble flotation processes, NSC23766 in vivo pyridine removal efficiency of the ozone micro-bubble flotation process was, respectively, 4.5 and 1.7 times higher, and benzene removal efficiency 3.6 and 1.5 times higher. Finally, drainage models Fludarabine concentration and oxygen diffusion models of the three kinds of micro-bubble water samples verified the long persistence of the three kinds of micro-bubbles in the water.
CONCLUSION: The application of ozone micro-bubble
technology in coagulation processes may provide an efficient and cost-effective approach to the treatment of waste-water containing
refractory organic compounds. (C) 2011 Society of Chemical Industry”
“BACKGROUND: Polybrominated diphenyl ethers (PBDEs) are emerging persistent LY411575 ic50 organic pollutants. Degradation of PBDEs is a significant challenge owing to their extreme persistence and recalcitrance nature. The objective of this study was to evaluate the effect of a sequential nano-bio treatment using nanoscale zero-valent iron (nZVI) and diphenyl ether degrading bacteria Sphingomonas sp. PH-07 for degradation of PBDEs.
RESULTS: In the bacterial tolerance test for determining the maximum endurable concentration of nZVI, the PH-07 strain was able to grow in the presence of nZVI up to 5 g L(-1) in minimal salt medium by using non-brominated diphenyl ether as growth substrate. Reductive debromination of decabrominated diphenyl ether (deca-BDE; 1 mg) with nZVI (100 mg per vial) resulted in a 67% reduction of deca-BDE and produced various intermediates ranging from nona-BDEs totri-BDEs during a 20 day period. Additional experiments with 2,4,4′-tri-BDE and 2,4,6-tri-BDE as initial substrates revealed that both tri-BDEs were further debrominated to mono-BDEs. Following the reductive debromination process, reaction mixtures were aerobically treated with DE-grown Sphingomonas sp. PH-07 strain to mineralize the low brominated-DEs (tri-BDEs -mono-BDEs) for additional 4 days.