Activated soil filters for removal of biocides from contaminated run-off and waste-waters

Building facades can be equipped with biocides to prevent formation of algal, fungal and bacterial films. Thus run-off waters may contain these highly active compounds. In this study, the removal of several groups of biocides from contaminated waters by means of an activated soil filter was studied.A technical scale activated vertical soil filter (biofilter) with different layers (peat, sand and gravel), was planted with reed (Phragmites australis) and used to study the removal rates and fate of hydrophilic to moderate hydrophobic (log K_ow 1.8-4.4) biocides and biocide metabolites such as: Terbutryn, Cybutryn (Irgarol® 1051), Descyclopropyl-Cybutryn (Cybutryn and Terbutryn metabolite), Isoproturon, Diuron, and its metabolite Diuron-desmonomethyl, Benzo-isothiazolinone, n-Octyl-isothiazolinone, Dichloro-n-octylisothiazolinone and Iodocarbamate (Iodocarb). Three experiments were performed: the first one (36 d) under low flow conditions (61 L m⁻² d⁻¹) reached removal rates between 82% and 100%. The second one was performed to study high flow conditions: During this experiment, water was added as a pulse to the filter system with a hydraulic load of 255 L m⁻² within 5 min (retention time <1 h). During this experiment the removal rates of the compounds decreased drastically. For five compounds (Cybutryn, Descyclopropyl-Cybutryn, Diuron, Isoproturon, and Iodocarb) the removal dropped temporarily below 60%, while it was always above 70% for the others (Terbutryn, Benzo-isothiazolinone, n-Octyl-isothiazolinone, Dichloro-n-octylisothiazolinone). However, this removal is a considerable improvement compared to direct discharge into surface waters or infiltration into soil without appropriate removal. In the last experiment the removal efficiencies of the different layers were studied. Though the peat layer was responsible for most of the removal, the sand and gravel layers also contributed significantly for some compounds. All compounds are rather removed by degradation than by sorption.     

Potential nitrogen enrichment of soil and surface water by atmospheric ammonia sorption in intensive livestock production areas

Elevated atmospheric NH₃ levels near intensive livestock operations can add significant N to local agroecosystems. In this study, the potential atmospheric NH₃ sorbed by soil and water was assessed over a 2-year period starting October 2000 in an intensive livestock production area in southern Alberta, Canada. Fifty-two uneven grid sampling sites were selected in the 53,905 ha study area. The sorption rate of atmospheric NH₃ was estimated weekly by exposing distilled water and air-dried soil samples to the atmosphere at the sampling sites. The increases in NH₄–N content in the samples after 1-week exposure was regarded as an index of the atmospheric NH₃ sorbed for that week. The NH₃ sorption rates were highly variable across the 52 sites, with water ranging from 4 to 125 kg ha⁻¹ year⁻¹ with a mean of 22 kg N ha⁻¹ year⁻¹ and soil from 5 to 84 kg N ha⁻¹ year⁻¹ with a mean of 20 kg N ha⁻¹ year⁻¹. Considerable variation in NH₃–N sorption across the study area reflects the effects of size, direction (upwind or downwind) and proximity of nearby livestock operations or other NH₃ sources and operators’ activities around the sampling sites. The NH₃ sorption rate at each site also varied considerably in response to weather conditions. The high rate of NH₃ input poses a direct risk of surface water eutrophication in intensive livestock operation areas. If fertilizer recommendations are not reduced to account for NH₃ sorption by soil, excess N may also contribute to eutrophication through runoff and leaching.     

黄河包头段不同粒径沉积物分形校正下重金属的吸附研究

推导了分粒级的表面分形维数计算公式,根据推导公式计算了分粒级沉积物的分维值.应用已有的表面分形分维计算公式分别计算了黄河包头段沉积物整体的表面分形分维(1.91)及＜63 μm粒级的分维值(1.36),揭示出黄河水环境的磨蚀和分选2个原因引起黄河包头段沉积物低的分维值.用分形校正吸附模型、Freundlich和Langmuir吸附模型对黄河包头段重金属分粒级沉积物吸附进行了拟合,表明分形校正吸附模型具有较好的适用性,同时揭示分形校正吸附模型与MEA理论结合能更好的对热力学吸附结果进行描述;由吸附结果分析得出4种重金属因粒径引起的吸附量变化程度序列为Cu＞Pb＞Zn≈Cd,初始浓度高的吸附量曲线变化较初始浓度低的曲线变化明显,同时指出Cu、Pb的吸附主要与矿物组成有关,而Zn、Cd的吸附则与吸附剂沉积物空间几何性质(或沉积物表面物理特征)有关.     

The presence of bacterial virus in groundwater and treated drinking water

Ten raw urban well water samples and twelve water samples collected from distribution lines after the well waters were treated were examined for bacteriological and coliphage/bacteriophage populations. The raw well waters were found to contain <1/100 ml total coliforms and fecal streptococci, but they all contained varying concentrations of coliphage and bacteriophage. The treated waters were all found to have <1 total coliforms and fecal streptococci per 100 ml with the exception of one treated water sample from Community C. However, even though the treated water samples contained free and total chlorine levels varying from 0.05 to 1.5 ppm, they were all found to contain usually greater amounts of coliphage and bacteriophage than the raw well waters.     

Contributions of paraecologists and parataxonomists to research,conservation, and social development

Citizen science has been gaining momentum in the United States and Europe, where citizens are literate and often interested in science. However, in developing countries, which have a dire need for environmental data, such programs are slow to emerge, despite the large and untapped human resources in close proximity to areas of high biodiversity and poorly known floras and faunas. Thus, we propose that the parataxonomist and paraecologist approach, which originates from citizen‐based science, is well suited to rural areas in developing countries. Being a paraecologist or a parataxonomist is a vocation and entails full‐time employment underpinned by extensive training, whereas citizen science involves the temporary engagement of volunteers. Both approaches have their merits depending on the context and objectives of the research. We examined 4 ongoing paraecologist or parataxonomist programs in Costa Rica, India, Papua New Guinea, and southern Africa and compared their origins, long‐term objectives, implementation strategies, activities, key challenges, achievements, and implications for resident communities. The programs supported ongoing research on biodiversity assessment, monitoring, and management, and participants engaged in non‐academic capacity development in these fields. The programs in Southern Africa related to specific projects, whereas the programs in Costa Rica, India, and Papua New Guinea were designed for the long term, provided sufficient funding was available. The main focus of the paraecologists’ and parataxonomists’ activities ranged from collection and processing of specimens (Costa Rica and Papua New Guinea) or of socioeconomic and natural science data (India and Southern Africa) to communication between scientists and residents (India and Southern Africa). As members of both the local land user and research communities, paraecologists and parataxonomists can greatly improve the flow of biodiversity information to all users, from local stakeholders to international academia.     

宁夏生态移民社区生活空间融合与重构的影响因素及机理——以宁夏闽宁镇为例

生态移民的空间位移引致了迁入区多因素的相互作用及长期演化,成为多学科深入探究的重要问题之一。以闽宁镇生态移民社区为例,采用主成分分析法和地理探测器分析法,对生态移民社区生活空间融合的影响因素和机理进行了研究,结果发现：（1）生态移民社区生活空间融合与重构受多种因素影响,生活基础设施、经济收入增长、移民社区环境、邻里关系、政府政策、民族生活六个主成分对生态移民社区生活空间融合的影响可以起到解释作用。（2）影响生态移民社区生活空间的因子解释力由强到弱依次排序为：X₁生活基础设施>X₂经济收入增长>X₃邻里关系>X₄政府政策>X₅民族生活>X₆移民社区环境;交互探测结果表明社区各要素因子交互后因子解释力呈双线性增强,即任意两个因子交互作用对于生态移民社区生活空间融合的影响强度都大于单个因子的独自作用强度。（3）各影响因素之间的互动影响,共同促进生态移民社区固有的生活方式、文化习惯、社会交往关系的演化,进而形成了生活空间的融合与重构。