排序方式: 共有17条查询结果,搜索用时 15 毫秒
1.
2.
基于RuO2-IrO2/Ti形稳电极和Fe0牺牲电极实现电氧化-电絮凝(EO-EC)一体化处理含Tl (I)废水,并与单一的电絮凝(EC)进行比较,探讨了EO-EC处理含Tl废水的机理.结果表明,相较于单一EC,EO-EC (1:1)组合技术适应于宽pH (4-10)以及电流密度范围(5-20mA/cm2)下含Tl废水高效处理,且不易发生钝化;活性氯以及氧化还原电位在Tl (I)间接氧化Tl (III)过程中扮演重要角色,沉淀分析表明生成的Tl (OH)3(s)与絮体Fe (OH)3(am)共沉淀,纤铁矿位点可吸附残留Tl (I).EO-EC一体化技术可满足实际含Tl废水达标处理(<2µg/L)且具有经济可行性. 相似文献
3.
Ken M. Fritz Elisabeth Hagenbuch Ellen D'Amico Molly Reif Parker J. Wigington Jr. Scott G. Leibowitz Randy L. Comeleo Joseph L. Ebersole Tracie‐Lynn Nadeau 《Journal of the American Water Resources Association》2013,49(4):867-882
Supreme Court cases have questioned if jurisdiction under the Clean Water Act extends to water bodies such as streams without year‐round flow. Headwater streams are central to this issue because many periodically dry, and because little is known about their influence on navigable waters. An accurate account of the extent and flow permanence of headwater streams is critical to estimating downstream contributions. We compared the extent and permanence of headwater streams from two field surveys with values from databases and maps. The first used data from 29 headwater streams in nine U.S. forests, whereas the second had data from 178 headwater streams in Oregon. Synthetic networks developed from the nine‐forest survey indicated that 33 to 93% of the channel lacked year‐round flow. Seven of the nine forests were predicted to have >200% more channel length than portrayed in the high‐resolution National Hydrography Dataset (NHD). The NHD and topographic map classifications of permanence agreed with ~50% of the field determinations across ~300 headwater sites. Classification agreement with the field determinations generally increased with increasing resolution. However, the flow classification on soil maps only agreed with ~30% of the field determination despite depicting greater channel extent than other maps. Maps that include streams regardless of permanence and size will aid regulatory decisions and are fundamental to improving water quality monitoring and models. 相似文献
4.
5.
Néstor Gutiérrez B. Stefanie Gärtner Juan Y. López H. Carlos E. Pacheco Albert Reif 《Regional Environmental Change》2013,13(5):1069-1085
High deforestation rates in tropical countries continue to reduce forest cover and thereby habitat quantity and quality. However, in some places the forest is recovering and expanding thus offsetting the biodiversity and ecosystem service losses. In order to characterize the forest recovery, land use and land cover (LUC) changes were analyzed using aerial photographs, taken between 1952 and 2009, of a peri-urban watershed in the Andes region of Venezuela. The qualities of the changes were assessed using landscape indices and hemeroby indicators. In that period, the forest cover increased about 18 %, mainly due to abandoned pastures on steep slopes. At the same time, the urban area expanded about 4 % on valley bottoms, while pastures and crop fields were reduced about 20 %. The results also showed that forest patches were aggregating, whereas pastures were fragmenting. A reduction in direct human impacts on forests growing on abandoned pastures resulted in a slight recovery of the lower montane cloud forest structure and plant composition. But non-native species were found in all LUC categories. During the study period, we documented not only forest recovery, but also urban area growth, intensified land use and invasions by non-native species all of which could partially counterbalance the positives of forest recovery. 相似文献
6.
7.
Reif R Santos A Judd SJ Lema JM Omil F 《Journal of environmental monitoring : JEM》2011,13(1):137-144
The occurrence and fate of eight pharmaceutical and personal care products (PPCPs) during sewage treatment has been studied in a pilot-scale treatment plant, comprising a primary settler (2.85 m(3)), an aeration tank (1.845 m(3)) and a secondary clarifier (0.5 m(3)), placed on site at a wastewater treatment works in the north west of the UK. It was fed both with raw sewage and the return liquor produced after sludge centrifugation, thus representing the most common configuration for a municipal sewage treatment plant based on the activated sludge process. Samples were taken at six different locations, including the return liquor stream, and analysed for musk fragrances and pharmaceutically active compounds belonging to various therapeutic groups such as anti-inflammatory drugs, tranquillisers and antiepileptics. Mass balances were conducted for those PPCPs that were quantifiable. The fate of the PPCPs was found to differ according to their physical-chemical characteristics. Anti-inflammatories underwent a degradation process and were almost completely removed from sewage during the biological treatment step. Musk fragrances were only partially removed, through adsorption onto the primary suspended solids and the biomass in the aerobic process, due to their strong lipophilic characteristics. The results of this study provide increasing evidence that the partial removal of these substances through the sewage treatment process contribute to the environmental occurrence of PPCPs. Consequently, existing STPs should be upgraded in order to attenuate the release of these substances into the aquatic environment. 相似文献
8.
9.
V. Pellissier R. Schmucki G. Pe'er A. Aunins T. M. Brereton L. Brotons J. Carnicer T. Chodkiewicz P. Chylarecki J. C. del Moral V. Escandell D. Evans R. Foppen A. Harpke J. Heliölä S. Herrando M. Kuussaari E. Kühn A. Lehikoinen Å. Lindström C. M. Moshøj M. Musche D. Noble T. H. Oliver J. Reif D. Richard D. B. Roy O. Schweiger J. Settele C. Stefanescu N. Teufelbauer J. Touroult S. Trautmann A. J. van Strien C. A. M. van Swaay C. van Turnhout Z. Vermouzek P. Voříšek F. Jiguet R. Julliard 《Conservation biology》2020,34(3):666-676
The European Union's Natura 2000 (N2000) is among the largest international networks of protected areas. One of its aims is to secure the status of a predetermined set of (targeted) bird and butterfly species. However, nontarget species may also benefit from N2000. We evaluated how the terrestrial component of this network affects the abundance of nontargeted, more common bird and butterfly species based on data from long-term volunteer-based monitoring programs in 9602 sites for birds and 2001 sites for butterflies. In almost half of the 155 bird species assessed, and particularly among woodland specialists, abundance increased (slope estimates ranged from 0.101 [SD 0.042] to 3.51 [SD 1.30]) as the proportion of landscape covered by N2000 sites increased. This positive relationship existed for 27 of the 104 butterfly species (estimates ranged from 0.382 [SD 0.163] to 4.28 [SD 0.768]), although most butterflies were generalists. For most species, when land-cover covariates were accounted for these positive relationships were not evident, meaning land cover may be a determinant of positive effects of the N2000 network. The increase in abundance as N2000 coverage increased correlated with the specialization index for birds, but not for butterflies. Although the N2000 network supports high abundance of a large spectrum of species, the low number of specialist butterflies with a positive association with the N2000 network shows the need to improve the habitat quality of N2000 sites that could harbor open-land butterfly specialists. For a better understanding of the processes involved, we advocate for standardized collection of data at N2000 sites. 相似文献
10.
Mass balance of pharmaceutical and personal care products in a pilot-scale single-sludge system: influence of T, SRT and recirculation ratio 总被引:1,自引:0,他引:1
The influence of operation condition on the fate of 16 pharmaceutical and personal care products (PPCPs) in a single-sludge nitrifying/denitrifying pilot plant was assessed. Volatilisation, sorption and degradation were included in the mass balances to determine the most relevant removal mechanisms during PPCP treatment.Sludge retention time (SRT) was an important factor for the removal of compounds that significantly sorb onto sludge, as ethinylestradiol, whose removal increased 11% when working at SRT above 20 d. The internal recirculation ratio was significant for the removal of moderately biodegradable compounds, as citalopram. The positive effect of operating at warmer temperatures was particularly significant for two antibiotics, implying a 30% increase in their transformations. In the case of naproxen, an influence of sludge acclimation and concentration was observed, leading to removal efficiencies from 27% to 99%.Concerning removal mechanisms, most compounds were removed due to biotransformation, although for fragrances sorption and volatilisation played a role. 相似文献