Effect of industrial pollution on the distribution of 137Cs in soil and the soil-to-plant transfer in a pine forest in SW Finland

The objective of this study was to evaluate the effect of industrial pollution on the distribution of radiocaesium in soil and on its transfer from soil to plants. The study was started in September 2000 in four Scots pine stands located at distances of 0.5, 2, 4 and 8 km along a transect running SE from the Cu-Ni smelter at Harjavalta in SW Finland. Annual emissions from the smelter in 1990 were 80 t of Cu, 31 t of Ni and 9000 t of SO(2), and in 1999 these were 5.9, 0.8 and 3400 t, respectively. At each site, soil profiles were sampled with a corer, and samples were separated into litter (L), organic soil layer (O) and mineral soil layers (B, E). Mushrooms, lichens (Cladina spp. and Cetraria islandica), lingonberry (Vaccinium vitis-idaea) and crowberry (Empetrum nigrum) plants were collected at each site, except at a distance of 0.5 km, where only mushrooms were available. In the organic soil layer, 137Cs activity decreased from 8000 Bq/m(2) at a distance of 8 km from the smelter to 1500 Bq/m(2) at a distance of 0.5 km; in litter, 137Cs concentration increased from 6300 Bq/m(2) at 8 km to 14000 Bq/m(2) at 0.5 km. 137Cs activity concentration decreased significantly in plants, mushrooms and lichens as the pollution load increased. In lichens, 137Cs activity decreased from 910 Bq/kg at 8 km to 170 Bq/kg at 2 km, while in lingonberry it decreased from 1470 to 20 Bq/kg and in crowberry from 310 to 20 Bq/kg. Aggregated transfer factors for 137Cs decreased in a similar way in lingonberry from 7.6x10(-2) m(2)/kg at 8 km to 7.7x10(-4) m(2)/kg at 2 km and in crowberry from 1.6x10(-2) to 7.9x10(-4) m(2)/kg.     

Gas-phase mercury in the atmosphere over the southern Baltic Sea coast

Results of atmospheric total gaseous mercury (TGM) measurements performed at two Baltic Sea coastal stations, Peninsula Hel (Poland) and Preila (Lithuania), from June 16 to August 11, 1997, are presented. High time-resolution data were obtained by using automated atomic absorption mercury vapor analyzers (Model Gardis-1A). Analysis of TGM concentration data (directional distribution, correlation with meteorological parameters, diurnal variability) detected the Baltic sea, in particular its southern part and Gulf of Gdansk, as the main gaseous mercury source for the region during the summer months. The source seemed to be activated by solar radiation, air temperature, and, probably, wind.     

Quality of dredged material in the river Seine basin (France). II. Micropollutants

Dredging rivers is needed to ensure safe navigable waters, rivers and waterways. To anticipate the management of dredged materials in the case of the river Seine basin, the quality of the sediments in the river is checked every 3 years before dredging operations. The river Seine Basin is heavily submitted to pollution pressure from nearby industrial activities and urban expansion of Paris and its region. Here, the micropollutant content of the sediment sampled in 1996, 1999 and 2000 before dredging is discussed compared to regulatory standards. The results indicate that most of the sediment samples from the river Seine basin are lightly to moderately contaminated with organic and inorganic micropollutants (heavy metals, PAH, PCB), which makes the management after dredging easier. This pollution is strongly correlated with the organic matter content and to the fine fraction (<50 microm) of the sediment. These results can lead to other management options than the ones already used in the river Seine basin: (1) dumping of lightly to moderately polluted sediments in quarries; and (2) physical treatment (sieving, hydrocycloning) of contaminated sediments issued from 'hot spots'.     

Toxicity of chlorpyrifos and TCP alone and in combination to Daphnia carinata: the influence of microbial degradation in natural water

The acute toxicity of chlorpyrifos and its principal metabolite 3,5,6-trichloropyridinol (TCP) alone and in combination to a cladoceran, Daphnia carinata, was studied in both cladoceran culture medium and natural water collected from a local suburban stream. TCP was found to be more toxic than its parent chemical chlorpyrifos to Daphnia survival in cladoceran culture medium. However, TCP in natural water was not toxic to D. carinata up to 2 microgL(-1). The LC(50) values for chlorpyrifos, TCP and chlorpyrifos+TCP were 0.24, 0.20 and 0.08 microgL(-1), respectively, in cladoceran culture medium. Although the parent chemicals and their degradation products co-exist in natural waters, the existing guidelines for water quality are based on individual chemicals. The results of this investigation suggest that chlorpyrifos and TCP can interact synergistically, additively or antagonistically, resulting in an increase or decrease in the overall toxicity of the mixture compared to individual compounds. The indigenous microorganisms in natural water could play a significant role in degradation of these compounds thereby influencing their toxicity in receiving waters. This study clearly suggests that the joint action of pesticides and their degradation products should be considered in the development of water quality guidelines. To our knowledge, this is the first study on the interactive effect of chlorpyrifos and TCP to a cladoceran and suggests that these two compounds are non-toxic when present together at concentrations up to 0.12 microgL(-1). However, these compounds together act additively at and above 0.5 microgL(-1) to fresh water invertebrates and therefore pollution with these compounds may adversely affect natural ecosystems.     

Lead, cadmium, mercury and selenium in Greenland marine biota and sediments during AMAP phase 1

Lead, cadmium, mercury and selenium levels in the Greenland marine environment from the first phase of the AMAP are presented. Samples were collected in 1994-1995 covering four widely separated regions in Greenland. Samples included sediments, soft tissue of blue mussel; and liver of polar cod, shorthorn sculpin, glaucous gull, Iceland gull and ringed seal. Concentrations of lead were found to increase with the size of blue mussel, but not with the age of gulls or ringed seal. Both cadmium and mercury concentrations were found to increase with the size/age of all species. Selenium concentrations decreased with increasing size of blue mussel, but increased with the age of gulls and ringed seal. Element levels found are within the range of those found in previous studies in Greenland. Relative to global background levels, lead levels must be considered low, whereas levels of cadmium, mercury and selenium in Greenland marine biota are high. Significant differences in element levels in sediments and biota among regions in Greenland were seen in several cases. There was a tendency for the highest lead and mercury concentrations to be found in east Greenland, whereas the highest cadmium concentrations were found in central west Greenland. However, the geographical differences among the media did not show a consistent pattern.     

明尼苏达大学土木采矿工程系建筑物的岩土工程设计

在美国明尼阿波斯市明尼苏达大学校内,新近竣工的土木采矿工程(CME)系建筑物是由上面四层明挖建筑和距地表约100英尺的两层暗挖建筑组成。一层30英尺厚产状平缓的石灰岩岩层将这一建筑物分成两个部分,暗挖部分是在灰岩顶板下的软质砂岩岩层里。这项革新节能建筑被美国土木工程学会评为1983年度的最佳工程。该大学所作出的设计和建造此项建筑是依据当地经验的类似建筑和研究工作。其中部分     

Temporal variability of dissolved P speciation in a eutrophic reservoir--implications for predicating algal growth

Weak-anion exchange chromatography was used to explore the temporal variability in the speciation of dissolved P in the surface layer of a eutrophic reservoir. Authentic free ortho-P ion was the most common form of P on three of the five sampling occasions-including during a bloom of the green algae Botryococcus braunii indicating that the bloom was not P limited. Conversely, the absence of authentic ortho-P during a bloom of the dinoflagellate Ceratium hirundinella suggested the bloom was either P limited or co-limited. These observations were confirmed by algal-growth bioassay experiments.     

Nitrification and denitrification as a source for NO and NO2 production in high-strength wastewater

Laboratory and half-technical scale experiments were performed to evaluate nitric oxide (NO) and nitrogen dioxide (NO2) production during biological N-elimination from wastewater with high ammonium concentration (about 700 mg N L-1). In a laboratory scale bioreactor with biomass retention, the ammonia oxidizer Nitrosomonas europaea and the denitrifier Paracoccus denitrificans were grown as reference organisms in co-culture in order to simulate the nitrifying and denitrifying community of wastewater treatment plants. Synthetic wastewater and sludge liquor from the municipal wastewater treatment plant in Lueneburg (Germany) were used. In the laboratory scale reactor, during the treatment of synthetic wastewater, 0.28% of the oxidized ammonium-N was released as NO-N by a pure culture of Nitrosomonas. A simultaneously nitrifying and denitrifying co-culture only released 0.04 to 0.2%. NO2 formation was not observed. NO production was much higher in sludge liquor. A pure culture of Nitrosomonas produced 0.52% NO + NO2-N (= NOx-N), a co-culture of Nitrosomonas and Paracoccus even 1.64% NOx-N. The production rate strongly depended on the media and the organisms used. In a co-culture of N. europaea and P denitrificans, Nitrosomonas was shown to be the most efficient NO producer. NO production increased with ammonium oxidation rate and with nitrite concentration of the medium. In synthetic wastewater, NO production was not influenced by reduced oxygen content. However, in sludge liquor NO production rate increased with decreasing O2 concentration. Here, for the first time, the formation of significant amounts of NO2 during simultaneous nitrification/denitrification could be demonstrated. In half-technical scale experiments, only 0.07% of the oxidized ammonium-N was released as NO-N from the nitrification stage. NO2 was not detectable. Release of nitric oxide from the denitrification stage was mainly diffusion limited and the amount produced did not exceed 0.0001%. A calculation on the basis of the results presented, revealed that biological treatment of nitrogen-rich wastewater is not a significant source for pollution of the atmosphere with NOx in industrial areas.     

Magnetic water treatment for scale prevention

A home-made magnetic device was built with permanent magnets for treating scaling waters. Its efficiency was evaluated by measuring the remaining ionic calcium at the output of the device by means of an ion selective electrode. The scaling power of the treated water was estimated through an electrochemical scaling test. Chroamperometric curves and chronoelectrogravimetric curves were plotted to obtain the scaling time and the nucleation time of the scale deposition. The variation of the efficiency of the magnetic treatment was studied when the length of treatment, the flow velocity of the scaling water in the device, the material of the pipe where the scaling water flowed were changed. An empirical relationship, which gives the value of the efficiency in function of the length of treatment and the flow velocity, was proposed. Possible mechanisms of action of the magnetic treatment were discussed.     

Land inputs of trace metals, major elements, particulate organic carbon and suspended solids to an industrial coastal bay of the NE Atlantic

Rivers, streams and municipal and industrial effluents flowing into the Ferrol Ria (NW Spain) were analyzed for dissolved and particulate trace elements (Cd, Cu, Pb, Zn), particulate major elements (Al, Fe, Si), particulate organic carbon and nitrogen (POC and PON), and total suspended solids. Trace metal clean techniques were applied. Mean annual fluxes of these components were calculated. Dissolved trace metal concentrations in the major freshwater inputs were found to be within typical values for uncontaminated rivers: Cd: 0.020-0.035 nM; Cu: 11.7-19.2 nM; Pb: 0.40-0.71 nM and Zn: 18-54 nM. Two sources of suspended particulate matter (SPM) were observed: (i) a detrital SPM, which becomes more important at high river discharges, with metal concentrations tending to lithogenic values; (ii) an organic- and metal-rich SPM, which becomes dominant at low discharges. Municipal and industrial effluents in the northern shore, despite of constitute a minor freshwater contribution to the bay, were responsible for more than 50% of total inputs of Cu, Cd, Pb, Zn, POC and PON. The fluxes of trace metals obtained for the Ferrol Ria are in the range of other inhabited world semi-enclosed embayments.