Halogenated dicarboxylic acids, such as bromomalonic (Br-C-3), chlorosuccinic (Cl-C-4) and bromosuccinic (Br-C-4) acids, have been measured, for the first time, in the arctic aerosols during the polar sunrise experiment ALERT2000 ( February to May). They were detected in the light spring, but not in the dark winter. Concentration ranges of halogenated diacids in the spring were 0.11-0.68 ng m(-3) for Br-C-3 diacid, 0.04-0.10 ng m(-3) for Cl-C-4 diacid and 0.12-0.20 ng m(-3) for Br-C-4 diacid. Those of Br-C-3 diacid increased from late April to early May, whereas Cl-C-4 diacid decreased. In contrast, Br-C-4 diacid showed maximum concentrations in the middle of the experiment. A strong negative correlation (R = - 0.98) was obtained between Br-C-3 and Cl-C-4 diacids. Concentrations of methanesulfonic acid (MSA) also increased from late April to early May whereas those of Cl- ion decreased. A strong positive correlation was found between Cl-C-4 diacid and Cl- ion (R = 0.99) and between Br-C-3 diacid and MSA (R = 0.96). These results suggest that Br-C-3 diacid is primarily derived from marine biogenic source, whereas Cl-C-4 diacid is secondarily formed by heterogeneous reaction involving halogen chemistry on sea salt. Satellite images of sea ice concentrations and backward air mass trajectories suggest that the aerosols containing halogenated diacids were transported over the sampling sites from the Arctic Ocean covered with sea ice.
Objective To investigate the characteristics of microbial degradation of aniline by a stable bacterial consortium. Methods The bacterial consortium was isolated from activated sludge treating chemical wastewater using aniline as the sole source of carbon and nitrogen by enrichment and isolation technique. The biomass was measured as optical density (OD) at 510 mm using a spectrophotometer. Aniline concentrations were determined by spectrophotometer. The intermediates of aniline degradation were identified by GC/MS method. Results The bacterial consortium could grow at a range of aniline concentrations between 50 and 500 mg/L. The optimal pH and temperature for aniline degradation were determined to be 7.0 and 30, respectively. The presence of NH4NO3 as an additional nitrogen source (100-500 mg/L) had no adverse effect on bacterial growth and aniline degradation. The presence of heavy metal ions, such as Co2+, Zn2+, Ni2+, Mn2+ and Cu2+ had an inhibitory effect on aniline degradation. Conclusions The isolated bacterial consortium can degrade aniline up to 500 mg/L effectively and tolerate some heavy metal ions that commonly exist in chemical wastewater. It has a potential to be applied in the practical treatment of aniline-containing wastewater.
This study examines capital accumulation, military spending, arms accumulation, and output growth in a stochastic endogenous growth model. The analysis shows that higher (lower) growth in foreign military spending leads to faster (slower) economic growth in the home country if the home country¡¯s intertemporal substitution elasticity in consumption is smaller (larger); but more volatility in foreign military spending can lead to higher economic growth in the home country when its intertemporal substitution elasticity is large. In addition, shocks to output production may stimulate economic growth.