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Petrochemical wastewater often contains high concentrations of phenol and sulfate that must be properly treated to meet discharge standards. This study acclimated anaerobic-activated sludge to treat saline phenolic wastewater with sulfate reduction and clarified the diversity and degradation mechanism of the microbial community. The active sludge in an upflow anaerobic sludge blanket (UASB) reactor could remove 90 % of phenol and maintain the effluent concentration of SO4 (2-) below 400 mg/L. Cloning and sequencing showed that Clostridium spp. and Desulfotomaculum spp. were major phenol-degrading bacteria. Phenol was probably degraded through the carboxylation pathway and sulfate reduction catalyzed by adenosine-5'-phosphosulfate (APS) reductase and dissimilatory sulfite reductase (DSR). A real-time polymerase chain reaction (RT-PCR) showed that as phenol concentration increased, the quantities of 16S rRNA gene, dsrB, and mcrA in the sludge all decreased. The relative abundance of dsrB dropped to 12.46 %, while that of mcrA increased to 56.18 %. The change in the electron flow ratio suggested that the chemical oxygen demand (COD) was removed mainly by sulfate-reducing bacteria under a phenol concentration of 420 mg/L, whereas it was removed mainly by methanogens above 630 mg/L.

With the advent of efficient and relatively inexpensive pulsed and CW laser systems for both civilian and military applications, the need for adequate eye and sensor protection is becoming increasingly important. While it is possible to filter out harmful wavelengths if the laser frequency is known, the proliferation of frequency agile laser sources underscores the need for “smart” passive materials that can sense the incident wavelength and provide protection. There has been considerable progress made in recent years in the design of optical power limiting (OPL) materials that can function by a variety of mechanisms, most of which derive their limiting behavior from some type of nonlinear absorption process. The most well-studied of these processes involve excited state absorption in which the absorption cross-sections of the photo-generated transient species are much greater than the original S0 to S1 transition. In this presentation we will discuss the efficacy of charge transfer species for optical limiting, and the need for more and better electron acceptor species.

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