Enhanced Removal of Micropollutants from Groundwater,Using pH Modification Coupled with Photolysis

Direct ultraviolet (UV) photolysis coupled with modification of solution pH was explored as a method for the removal of organic micropollutants from groundwater. Photodegradation rates of most of the investigated compounds were pH dependent, however, its correlation with photodegradation rate varied among compounds. The potential of the pH modification during photolysis was determined for removal of a mixture of two pharmaceuticals sulfamethoxazole (SMX) and triclosan (TCS) in groundwater. The treatment included initial photolysis of the mixture at the optimal pH for TCS (i.e., 7.5–7.9), followed by pH modification to the optimal pH for SMX (i.e., 5), prior to a second irradiation period. The described procedure dramatically increased the removal efficiency (up to threefold) of the treated mixture compared to UV treatment at constant pH.     

Fly ash concentrations in philadelphia aerosol determined by electron microscopy

In a study to differentiate between coal-fly ash and minerals in the atmosphere, samples were collected on Nuclepore filters in dichotomous samplers and analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry. The samples included ambient aerosol from two sites, resuspended soil, and emissions from coal- and oil-fired power plants in the Philadelphia area. Fly ash and minerals were identified by observing high abundances of Al, Si, K, Ca, Ti, and Fe in individual particles, and their mass concentrations were estimated from measured dimensions and an assumed density. Fly ash was distinguished from minerals by morphology. Sulfate was the major component of the fine fraction (<2.5 μm aerodynamic dia.). Crustal matter concentrations in the fine fraction estimated by SEM ranged from 40 to 300 ng m^?3, and fly ash accounted for 7 to 62% of the crustal matter. In the coarse fraction (2.5 to 10 μm), minerals were the predominant component and ranged in concentration from 500 to 6000 ng m^?3. Fly ash accounted for 0 to 16% of the crustal matter; the typical amount was 6%. Other less abundant coarse particles included botanical matter and industrial source emissions. Coarse fraction crustal matter estimated from x-ray fluorescence elemental data agreed well with that based on electron microscopy.     

The potential of liposomes as a nutrient supplement in first-feeding marine fish larvae

The ingestion rate (ng liposome larva^–1 h^–1) of extruded [1–¹⁴C] palmitic acid-labelled liposomes containing physiological saline (PHS) or cod fish extract (CFE), was tested in 5-day-old gilthead seabream Sparus aurata and white grouper Epinephelus aeneus larvae. A follow-up study compared the assimilation of radioactive free fatty acid (FFA) label of these two liposome treatments into six phospholipid and neutral lipid fractions as well as the nonlipid fraction in 5-day-old seabream. In seabream larvae, there was a 50-fold ( P  < 0.05) increase in the net consumption rate when fed CFE liposomes (2305.8 ng liposome larva^–1 h^–1) compared with liposomes containing physiological saline (42.7 ng liposome larva^–1 h^–1). A similarly significant ( P  < 0.05) but less marked pattern was also observed in the grouper larvae where the CFE treatment larvae ingested 238.5 ng liposome larva^–1 h^–1 compared with 54.3 ng liposome larva^–1 h^–1 in larvae fed the PHS liposomes. In seabream larvae ingesting CFE and PHS liposomes, radioactivity was found in all larval fractions analysed. However, marked treatment differences ( P  > 0.05) in assimilation were found only in the triacylglycerol fraction (3.4 and 0.6 dpm larva^–1 h^–1, respectively) and nonlipid fraction (11.2 and 15 dpm larva^–1 h^–1, respectively).