Atmospheric mercury in Norway: contributions from different sources

The environmental loadings of national Norwegian mercury emissions compared to the loadings of atmospheric long range transported mercury have been estimated using national emission data and EMEP model data. The results indicate that atmospheric long-range transport to Norway is somewhat larger than the national Norwegian emissions of mercury. Atmospheric deposition of mercury has been studied using data from Norwegian monitoring programs on mercury in precipitation, mosses, natural surface soils, and lake sediments. Precipitation data show no significant time trend during 1990-2002, whereas moss samples show similar concentrations from 1985 to 1995, but a 30% decrease from 1995 to 2000. Concentrations of mercury in peat cores and reference sediments indicate that the current mercury levels measured in surface sediments, surface soils and mosses at background sites in Norway are substantially affected by long-range atmospheric transport.     

泥煤和镍离子间作用研究初步

泥煤如何吸附金属目前尚未定论,不同学者给出不同答案,笔者通过试验不同量泥煤在不同pH溶液中溶液pH前后变化,不同pH下泥煤吸附镍阳离子后溶液pH前后变化以及不同pH下溶液紫外吸收变化对比,结果表明泥煤具有一定缓冲性,不能仅以溶液酸度变化来证明泥煤吸附镍离子的机理。     

Filter pore size selection for characterizing dissolved organic carbon and trihalomethane precursors from soils

Filters with a pore size of 0.45 microm have been arbitrarily used for isolating dissolved organic carbon (DOC) in natural waters. This operationally defined DOC fraction often contains heterogeneous organic carbon compounds that may lead to inconsistent results when evaluating trihalomethane formation potential (THMFP). A finer pore size filter provides more homogeneous DOC properties and enables a better characterization of organic matter. In this study, we examined the effects of filter pore size (1.2, 0.45, 0.1 and 0.025 microm) on characterizing total organic carbon, ultra-violet absorbance at 254 nm (UV(254)) and THMFP of water extracts from a mineral and organic soil in the Sacramento-San Joaquin Delta, California. Results showed that the majority of water extractable organic carbon (WEOC) from these soils was smaller than 0.025 microm, 85% and 57% in organic and mineral soils, respectively. A high proportion of colloidal organic carbon (COC) in mineral soil extracts caused water turbidity and resulted in an abnormally high UV(254) in 1.2 and 0.45 microm filtrates. The reactivity of organic carbon fractions in forming THM was similar for the two soils, except that COC from the mineral soil was about half that of others. To obtain a more homogeneous solution for characterizing THM precursors, we recommend a 0.1 microm or smaller pore-size filter, especially for samples with high colloid concentrations.     

烟田施用有机肥对土壤理化性状和烟叶香气成分含量的影响

本试验研究了烟田施用不同数量草炭对土壤的有机质含量、理化性状、土壤微生物数量及烟叶中香气成分含量的影响。结果表明,烟田施用有机肥草炭8250~16500 kg/hm2,随着施肥量的增加,土壤有机质、腐殖质含量,土壤真菌、细菌和放线菌数量均增加;烟叶香气成分中总醇量增加,总醛量减少,总酮量稍有增加。