Preliminary study on PAH degradation by bacteria from contaminated sediments in Xiamen Western Sea, Fujian, China

In order to estimate the biodegradation of three polycyclic aromatic hydrocarbons (PAHs) compounds, bacterial strains were isolated from marine sediments in three heavily contaminated sites (Yuandang Lake, Dongdu Port and Aquacultural zones in Maluan Bay) in Xiamen Western Sea. The results show three bacterial strains, which used pyrene as the sole carbon source, were identified as strains of Aureobacterium sp., Arthrobacter sp., Rhodococcus sp. The PAH-degrading bacteria isolated had a strong ability to degrade phenanhrene,fluoranthene and pyrene at different degradation rates. The highest degradation rate was observed when three PAH compounds were mixed with an individual strain in the medium. The three PAHs were degraded after one week with a degradation rate of 89.94% for phenanthrene and 93.4 % for both of fluoranthene and pyrene.In addition, after 25 days of incubation, the degradation rate was 99.98 % for phenanthrene and 99.97 % for both of fluoranthene and pyrene. Optical density was measured to estimate bacterial growth during the degradation of PAHs. Highest levels of bacterial growth were observed with a three PAH mixture in the culture, suggesting that the concentration of PAHs influenced bacterial growth and the highest levels of degradation for most series were detected after one week of incubation.Supported by the NSFC (No.30070157, 40206015), and the Scientific Fund of Quanzhou City (No. Z200234)

The distribution characteristics of bacterial β-glucosidase activity in Taiwan strait

Twenty stations were established in the near-shore regions of South Fujian Shoal (116°10’-119°00’E,21°20’-24°10’N) on summer and winter cruises during the period from August 1997 and February to March 1998. The distribution pattern of marine bacterial β-glucosidase activity (β-GlcA) has been investigated by using fluorogenic model substrate (FMS) technique in order to have better understanding of the β-GlcA, as well as its relation to marine bacterial biomass, productivity and environmental factors in Taiwan strait. The results showed that: (1) In summer, the average of β-GlcA at the Southern stations of Taiwan strait was 1.94 nmol/1 h. While in winter, the average of β-GlcA at the Northern stations was 0.86 nmol/1 h and the range of variation (0.34–1.89 nmol/1 h) was much more narrow than that in summer (0.31–8.1 nmol/1 h). (2) According to the carbon conversion factor, the β-GlcA was 0.14 and 0.062 ugc/1 h in summer and winter respectively. These β-GlcA values were higher than the bacterial production of the two seasons respectively. (3) The β-GlcA gradually rises from offshore water to near-shore water. (4) The correlation between the β-GlcA and the bacterial secondary production was not so obvious. (5) The correlation between the section distributions, daily varying of the β-GlcA and the bacterial production was not obvious. (6) In the surface water, the distribution character of free-state β-GlcA from bacteria was equal to that of the total β-GlcA in the whole sea area

Contamination of soil , leaves and vegetables by polychlorinated biphenyls in Xiamen region , China

The paper aimed to identify the primary of polychlorinated biphenyls( PCBs) in the Jiulong River Estuary , inve stigate the spatial distribution of PCBs contamination in the environment,localize the atmospheric source and evaluate ongoing PCBs emissions by analyzing soil sample s collected along the Jiulong River region. In addition , the accumulation of PCBs in the human food chain wa s quantified by analyzing leaf of orange tree s and vegetable samples collected along a gradient of soil/ atmospheric contamination moving away from the source. Consequently , the impact on the human health and the eco system wa s quantified, different management options were proposed to reduce this impact and to carry out re search on organic contaminants along the Jiulong River and Xiamen region.The National Natural Science Foundation of China (No. 40206015) ; the Fork Ying Tong Education Foundation(No. 94002) and the State Key Laborator

Assessment of the interactions between aquatic colloids and pharmaceuticals facilitated by cross-flow ultrafiltration

Interactions between pharmaceuticals and aquatic colloids are a key process regulating their environmental fate, but poorly understood. A validated cross-flow ultrafiltration (CFUF) system was used to isolate river colloids and to determine the partition of selected pharmaceuticals between colloidal (>1 kDa but <0.7 μm) and dissolved phases (<1 kDa) by liquid chromatography-tandem mass spectrometry (LC-MS-MS). The kinetics of pharmaceutical binding to colloids was rapid, reaching equilibrium within 5 min. The mass balance of chosen pharmaceuticals through CFLUF system was satisfactory for propranolol, sulfamethoxazole, meberverine, carbamazepine, indomethacine, diclofenac, and meclofenamic acid. The partition coefficient normalized to colloidal organic carbon content (Kcoc) varied from 5.45 × 104 to 7.54 × 105 mL/g for the chosen pharmaceuticals, which are greater than those for endocrine disrupting chemicals (EDCs), suggesting substantially stronger colloidal interactions with pharmaceuticals than with EDCs. Linear relationships were demonstrated between log-Kcoc and pharmaceutical properties such as log Kow (octanol-water partition coefficient), highlighting the importance of compound hydrophobicity in controlling their binding with colloids. Such a finding is in contrast to that for EDCs whose Kcoc values were independent of their Kow values. The CFUF-LC-MS technique has the potential to become a widely applicable tool for quantifying the distribution of emerging organic pollutants between nanoparticles and the dissolved phase. © 2007 American Chemical Society

Evaluation and fate of the organic chlorine pesticides at the waters in Jiulong River Estuary

18 Organochlorine Pesticides at the water(surface water and porewater) in Jiulong River Estuary were determined. The range of organochlorine pesticides at surface water was 51.3-2479 ng/L, and the concentration in porewater was 266-33,355 ng/L. The results showed that the organochlorine pesticides were removed in the estuary and the sediments were the reservior of the organochlorine pesticides. Compared with the results of other harbor and estuaries, it showed that the contamination for organic chlorine pollutants in Jiulong River Estuary was similar to those of others. At the same time, the risk of organochlorine pesticides in the estuary was evaluated

Distribution and composition of PAHs in surface waters, porewater and sediments from Xiamen Western Bay

This work determined the effect of niobium segregation on the surface and near-surface composition of Nb-doped TiO2, containing 0.18 atom % Nb and 0.018 atom % Nb, after annealing in the gas phase of controlled oxygen activity. The segregation-induced concentration profiles were determined using a range of analytical techniques of different depth resolution, including secondary ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS), Rutherford backscattering (RBS), and proton-induced x-ray emission (PIXE). The XPS analysis of the 0.18 atom % Nb specimen annealed at 1273 K in oxidizing conditions and showed segregation-induced niobium surface enrichment of 2.83 atom % and 2.35 atom % in p(O2) = 75 kPa and p(O2) = 10 Pa, respectively. However, annealing at 1273 K in strong reducing conditions, p(O2) = 10-10 Pa, leads to depletion of the surface layer in niobium to the level of 0.05 atom % (desegregation). The results of SIMS, RBS, and XPS are consistent. The derived theoretical model, explaining the effect of oxygen activity on niobium segregation, considers contribution from three driving forces of segregation, including (i) strain relaxation, (ii) the formation of a low-dimensional surface structure, and the (iii) electric field associated with the surface charge. The established effect of oxygen activity on niobium segregation/desegregation may be used as a technology for imposition of (i) controlled surface composition that is required to achieve enhanced performance of TiO2 in solar-to-chemical energy conversion and (ii) chemically induced electric field required for charge separation