Distribution characteristics of nonylphenolic chemicals in Masan Bay environments, Korea

To understand the distribution characteristics of nonylphenolics and sterols, samples such as in creek water, sea surface water, waste water treatment plant (WWTP) effluent water, sediment and mussel were collected and analyzed. The principal analytes are nonylphenol (NP), nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO), coprostanol (5beta) and cholestanol (5alpha). All these target pollutants showed 100% detection frequency in all of the samples analyzed. Total concentration of nonylphenolic compounds ranged from 334 to 3628ngl(-1) (average: 1331ngl(-1)) in creek water, from 15 to 36400ngl(-1) (average: 1013ngl(-1)) in sea surface water, from 131 to 2811ngg(-1) dry weight (average: 581ngg(-1) dry weight) in sediment and from 50.5 to 289ngg(-1) dry weight (average: 139ngg(-1) dry weight) in mussel. For water samples, levels of nonylphenolics determined in summer season were higher than those in spring season. Among them, nonylphenol and NP1EO was dominant in creek water and seawater, respectively. The highest concentration was recorded in sediment near a WWTP effluent outlet. And high levels of nonylphenolics and sterols were found in about 3km area surrounding WWTP effluent outlet. Coefficient of linear regression (R(2)) for NP in mussel and in sediment was 0.90. Similarly good correlation (R(2)=0.98) was obtained between concentration in water and in mussel indicating that a steady state has been reached in this bay. The calculated bio concentration factor (BCF=2990) for NP in Masan Bay agrees well with reported values in the literature.     

Oxidation of elemental mercury using atmospheric pressure non-thermal plasma

The oxidation of gas phase elemental mercury (Hg0) by atmospheric pressure non-thermal plasma has been investigated at room temperature, employing both dielectric barrier discharge (DBD) of the gas mixture of Hg0 and injection of ozone (O3) into the gas mixture of Hg0. Results have shown that the oxidative efficiencies of Hg0 by DBD and the injection of O3 are 59% and 93%, respectively, with energy consumption of 23.7 J L(-1). This combined approach has indicated that O3 plays a decisive role in the oxidation of gas phase Hg0. Also the oxidation of Hg0 by injecting O3 into the gas mixture of Hg0 proceeds with better efficiency than DBD of the gas mixture of Hg0. These results have been explained by the incorporation of the competitive reaction pathways between the formation of HgO by O3 and the decomposition of HgO back to Hg0 in the plasma environment.     

Assessing soil and groundwater contamination in a metropolitan redevelopment project

The purpose of this study was to assess contaminated soil and groundwater for the urban redevelopment of a rapid transit railway and a new mega-shopping area. Contaminated soil and groundwater may interfere with the progress of this project, and residents and shoppers may be exposed to human health risks. The study area has been remediated after application of first remediation technologies. Of the entire area, several sites were still contaminated by waste materials and petroleum. For zinc (Zn) contamination, high Zn concentrations were detected because waste materials were disposed in the entire area. For petroleum contamination, high total petroleum hydrocarbon (TPH) and hydrocarbon degrading microbe concentrations were observed at the depth of 7 m because the underground petroleum storage tank had previously been located at this site. Correlation results suggest that TPH (soil) concentration is still related with TPH (groundwater) concentration. The relationship is taken into account in the Spearman coefficient (α).     

Characterization of the monthly variation in (1 → 3)-β-d-glucan concentrations in university laboratories

We characterize the monthly variation in (1 → 3)-β-d-glucan concentration measured over the course of 1 year, and we evaluate the characteristics of size selection using a two-stage cyclone sampler. The (1 → 3)-β-d-glucan concentrations were measured in four bio-related laboratories. A total of 156 samples were collected using a new two-stage cyclone sampler. Analysis of (1 → 3)-β-d-glucan was performed using the kinetic Limulus amebocyte lysate assay. The study showed that airborne (1 → 3)-β-d-glucan concentrations were significantly higher in laboratory D (mean ± SD 1,105?±?1,893 pg/m³) and in the spring (5,458 pg/m³). The highest concentration of (1 → 3)-β-d-glucan occurred in the spring, particularly in May.     

Accumulation of butyl- and phenyltin compounds in starfish and bivalves from the coastal environment of Korea

Triphenyltin (TPT) and tributyltin (TBT) concentrations were determined in two starfish species (Asteria pectinifera and Asterias amurensis), bivalves (Crassostrea gigas or Mytilus edulis), and seawater samples from sites around the coasts of Korea. Both TPT and TBT concentrations in starfish ranged from 8 to 1560 ng/g and from <2 to 797 ng/g as Sn on a dry weight basis, respectively. TPT concentration accounted for 75.4% and 86.4% of total phenyltin concentration in A. pectinifera and A. amurensis, respectively, while monobutyltin, a degradation product of TBT, accounted for 86.3% and 57.2% of total butyltin, respectively. Triphenyltin concentrations in A. pectinifera were significantly correlated to water and bivalve TPT concentrations, which implies that dietary uptake of TPT from contaminated prey as well as direct uptake from surrounding water contribute to TPT body residues in the starfish. Starfish could be target organisms for monitoring TPT compound in the marine environment, due to their high accumulation and low degradation capacity towards TPT.     

Evaluation of the relationship between two different methods for enumeration fecal indicator bacteria： Colony-forming unit and most probable number

Most probable number (MPN) and colony-forming unit (CFU) estimates of fecal indicator bacteria (FIB) concentration are common measures of water quality in aquatic environments. Thus, FIB intensively monitored in Yeongsan Watershed in an attempt to compare two di erent methods and to develop a statistical model to convert from CFU to MPN estimates or vice versa. As a result, the significant di erence was found in the MPN and CFU estimates. The enumerated Escherichia coli concentrations in MPN are greater than those in CFU, except for the measurement in winter. Especially in fall, E. coli concentrations in MPN are one order of magnitude greater than that in CFU. Contrarily, enterococci bacteria in MPN are lower than those in CFU. However, in general, a strongly positive relationship are found between MPN and CFU estimates. Therefore, the statistical models were developed, and showed the reasonable converting FIB concentrations from CFU estimates to MPN estimates. We expect this study will provide preliminary information towards future research on whether di erent analysis methods may result in di erent water quality standard violation frequencies for the same water sample.