Heavy metals in flue gas cleaning residue

During combustion, most of the inorganic nutrients and trace elements in the fuel are retained and enriched in the ash. However, here we show that, due to the low total heavy metal concentrations, the flue gas cleaning residue (i.e. the fly ash) originating from the wet scrubber device at a medium-sized (32 MW) municipal district heating plant, is a potential forest fertilizer. Furthermore, the easily soluble calcium (1,980 mg kg⁻¹; d.w.) and phosphorus (50 mg kg⁻¹; d.w.) concentrations indicate that the flue gas cleaning residue is a potential agent for soil remediation and for improving soil fertility.     

Concentrations of PCDD/Fs,PCBs and PBDEs in breast milk of women from Catalonia,Spain: A follow-up study

The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined in breast milk from women living in the vicinity of a new hazardous waste incinerator (HWI) in Catalonia, Spain. The results were compared with the levels obtained in two previous surveys carried out in 1998 (baseline study) and 2002. The current concentrations of PCDD/Fs in breast milk ranged from 45 to 143 pg/g fat (2.8 to 11.2 pg WHO-TEQ/g fat), while total PCBs ranged from 114 to 617 pg/g fat (2.8 to 17.6 pg WHO-TEQ/g fat). PBDE concentrations (sum 15 congeners) ranged from 0.57 ng/g fat to 5.9 ng/g fat, with a mean value of 2.5 ng/g fat. A general decrease of the concentrations for PCDD/Fs and both planar and total PCBs was observed. Regarding to PBDE concentrations in breast milk, similar levels between the 2002 and the present study were noted. The levels of PCDD/Fs and PCBs in milk of women living in urban areas were higher than those corresponding to the industrial zones (38% and 40%, respectively). However, the current PBDE levels were slightly lower (13%) in the urban than in the industrial zone. For PCDD/Fs and PCBs, the current decreases are in accordance with the reduction in the dietary intake of these pollutants found in recent studies carried out in the same area of study.     

Effects of changing climate on water and nitrogen availability with implications on the productivity of Norway spruce stands in Southern Finland

An integrated process-based model was used to study how the changing climate affects the availability of water and nitrogen, and consequently the dynamics of productivity of Norway spruce (Picea abies) on sites with different initial soil water conditions in southern Finland over a 100-year period. The sensitivity of the total stem volume growth in relation to short-term availability of water and nitrogen was also analyzed. We found that a high proportion (about 88–92%) of the total precipitation was lost in total evapotranspiration (incl. canopy evaporation (E_c), transpiration (E_t) and ground surface evaporation (E_g)), under both current and changing climate. Furthermore, under the changing climate the cumulative amount of E_c and E_g were significantly higher, while E_t was largely lower than under the current climate. Additionally, the elevated temperature and increased expansion of needle area index (L) enhanced E_c. Under the changing climate, the increasing soil water deficit (W_d) reduced the canopy stomatal conductance (g_cs), the E_t, humus yield (H, available nitrogen source) and nitrogen uptake (N_up) of the trees. During the latter phases of the simulation period, the canopy net photosynthesis (P_nc) was lower due to the reduced N_up and soil water availability. This also reduced the total stem volume production (V_s) on the site with the lower initial soil moisture content. The growth was slightly more sensitive to the change in precipitation than to the change in nitrogen content of the needles, when the elevated temperature was assumed. According to our findings, drought stress episodes may become more frequent under the changing climate. Thus, adaptive management strategies should be developed to sustain the productivity of Norway spruce in these conditions, and thus, to mitigate the adverse impacts of climate change.     

Levels of PCDD/Fs,PCBs and PBDEs in breast milk of women living in the vicinity of a hazardous waste incinerator: Assessment of the temporal trend

The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were determined in breast milk from women living in the vicinity of a hazardous waste incinerator (HWI) in Catalonia, Spain. The results were compared with the levels obtained in previous surveys carried out in the same area in 1998 (baseline study), 2002 and 2007. The current total concentrations of 2,3,7,8-chlorinated PCDD/Fs in breast milk ranged from 18 to 126 pg g⁻¹ fat (1.1–12.3 pg WHO₂₀₀₅-TEQ_PCDD/F), while the total levels of PCBs ranged from 27 to 405 pg g⁻¹ fat (0.7–5.3 pg WHO₂₀₀₅-TEQ_PCB). In turn, PBDE concentrations (sum of 15 congeners) ranged 0.3–5.1 g g⁻¹ fat, with a mean value of 1.3 ng g⁻¹ fat. A general decrease in the concentrations for PCDD/Fs, both planar and total PCBs, and PBDEs in breast milk was observed. The levels of PCDD/Fs, PCBs, and PBDEs in milk of women living in urban zones were higher than those corresponding to industrial zones (41%, 26%, and 8%, respectively). For PCDD/Fs and PCBs, the current decreases are in accordance with the reduction in the dietary intake of these pollutants that we have also observed in recent studies carried out in the same area of study.     

Warming autumns at high latitudes of Europe: an opportunity to lose or gain in cereal production?

Regional Environmental Change - Climate change is projected to prolong Finland’s short growing season at both ends though warming autumns are not expected to benefit arable crops such as...     

Market basket study on dietary intake of PCDD/Fs, PCBs, and PBDEs in Finland

We have measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDD/F), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDE) in 10 market baskets consisting of almost 4000 individual food samples representing 228 different food items, and also in the total diet basket. Lower bound concentrations of PCDD/Fs ranged between 0.0057 and 5.6 pg/g fresh weight in the market baskets and the corresponding values for PCBs from 39 to 25,000 pg/g. The fish basket contributed most to the concentrations of dioxins and PCBs, and also to concentrations of PBDEs in which the lower bound range was from 0.82 to 850 pg/g. We also assessed the average daily intakes of these substances by the Finnish adult population. The average daily intake of sum of PCDD/Fs and PCBs as WHO toxic equivalents was assessed to be 115 pg, which was 1.5 pg WHO-TEq/kg body weight using an average mean weight of 76 kg for the general population in Finland. The contribution of fish to the intake of PCDD/Fs was between 94% and 72%, depending on whether lower or upper bound concentrations were used. With respect to PCBs, the contribution of fish was 80%. The calculated intake of PBDEs of 44 ng/day was comparable to intake assessments from other countries. Fish also contributed most to the PBDE intake, but there was some other source of PBDEs that distinguishes the exposure to PBDEs from exposure to PCDD/Fs and PCBs. This additional source seemed to be found in the market basket that included beverages, spices, and sweets.     

Oxidation of gas mixtures containing dimethyl sulfide, hydrogen sulfide, and methanethiol using a two-stage biotrickling filter

A biofiltration technique was developed for removing a mixture of hydrogen sulfide (H2S), methanethiol (MeSH), and dimethyl sulfide (Me2S) from waste gases. Since H2S, especially at high concentrations, disturbs the removal of Me2S, two biotrickling filters with different microbes and operating pH levels were connected in series to create a two-stage system. Different loads of these gases were studied in order to determine their impact on the removal capacity of the system. The microbial consortia for these filters were enriched from the sludge of a Finnish refinery with bubbling H2S or Me2S. Acclimation for Me2S took 2 weeks, though no acclimation time was needed for the other gases. The first filter, at a pH of 2, removed most of the H2S and some of the MeSH and Me2S. The second filter, at a pH of approximately 6.5, removed the rest of the MeSH and most of the Me2S. The total maximum loads of the whole two-stage biotrickling filter were 1150 g/m3/day for H2S-S (suffix S indicates the results are counted as sulfur amounts), 879 g/m3/day for Me2S-S, and 66 g/m3/day for MeSH-S treated in a gas mixture. The average removal efficiencies for all gases tested were 99% or higher.     

Organohalogen pollutants in herring from the northern Baltic Sea: concentrations, congener profiles and explanatory factors

Organohalogen contaminants were investigated in Baltic herring caught from three catchment areas in the Baltic Sea, off the coasts of Finland. Pools of both small and large herring were analysed for polychlorinated biphenyls (PCB), dibenzo-p-dioxins, dibenzofurans, naphthalenes, camphenes (toxaphene), polybrominated diphenyl ethers and the pesticide DDT and its metabolites. PCB concentrations per fresh weight in small herring were at the same level in all catchment areas, i.e. the Bothnian Bay, the Bothnian Sea and the Gulf of Finland, revealing no hot spots and reflecting most likely long term emissions and atmospheric deposition. Differences in the levels and/or congener profiles of other contaminants between catchment areas may be explained by point sources. Similar concentrations in small and large herring in the Gulf of Finland were possibly due to their common nutrition. In the other areas, differences between small and large herring most likely reflected their different food sources.     

A simple formula for calculating the ionization potential of two-electron ions

The ionization potential of one-electron ions can be calculated from a well-known simple equation, but no such equation has been available for calculating the ionization potential of multi-electron ions. I report here an equation that accurately gives the ionization potential of helium-like (i.e., two-electron) ions as a function of the atomic number, the relative difference from experimental values being below 1% for all ions for which reliable experimental data were found (Z = 3–29). The equation also predicts the stability of the negative hydrogen ion (the hydride ion), H⁻, although with twice too large a value for the ionization potential.     

An estimate on the rainout of atmospheric CO2

IntroductionCarboncirculatesbetweentheatmosphere ,biosphere ,oceansandthelithosphere(Warneck ,1988) .Thecarbonfluxesbetweenthesereservoirs,suchasburningoffuels ,photosynthesisandrespirationofecosystems,andtheuptakeoftheocean ,havebeenestimatedquantitative…