Mobility and Methylation of Mercury in Forest Soils Development of an In-Situ Stable Isotope Tracer Technique and Initial Results

A method for investigating in-situmethylation and mobility of mercury has beendeveloped and applied to forest soil. The methodis based on additions of stable ¹⁹⁹Hgisotopes to forest soil plots followed bysampling and analysis of isotope ratios of totalmercury and MeHg using ICP-MS. Initial resultsindicate that a fraction (30%) of the mercuryadded to the forest soils is immobilised over atime scale of 16 months. A small but significantfraction of the mercury is methylated during thesame time scale. Higher methylation rates werefound in wetland soil than in dry forest podzolsoil.     

Cu2＋胁迫下湿地微生物热代谢活性及Cu2＋的固定/转化率

应用微量热法结合常规分析方法,研究了桂林会仙湿地沼泽底泥和水稻田微生物在800 - 4 000 μg·g-1 Cu2＋胁迫下的热代谢活性及Cu2＋的固定/转化率。结果表明,在w（Cu2＋）为800 μg·g-1条件下,水稻田和沼泽底泥土壤微生物对Cu2＋的固定/转化率分别为44.93%和34.59%,但在w（Cu2＋）为4 000 μg·g-1 时则分别是93.16%和85.13%;Cu2＋对水稻田和沼泽底泥土壤微生物代谢活性的半抑制浓度分别为2 043和2 325 μg·g-1;水稻田土壤微生物代谢活性低于沼泽底泥,在土壤及其微生物共同作用下Cu2＋的固定/转化率随Cu2＋浓度递增而升高;在相同条件下,水稻田和沼泽底泥土壤微生物的代谢速率在α = 0.05或α = 0.01水平上显著相关。湿地土壤用途发生改变后,土壤微生物在固定/转化Cu2＋的作用上发生了明显变化。     

生物技术在微污染景观水处理中的应用

利用生物砂和多孔活性材料作为载体与滤料,投入硝化细菌和相容的复合菌群,构成小试规模的循环式过滤装置,模拟自然水体的生态净化系统,观察微污染的景观水中NH3-N,NO-2 -N,有机物,色度等等的去除效果。经长期运行测试表明,系统对 NH3-N去除率达99%, NO-2 -N 的去除率达 87%,对COD,浊度,都能较好地保持在较低水平。并使 DO、pH稳定在适合水生生物生长的范围。