Atmospheric Nitrogen and Phosphorus Deposition at Three Sites in Nanjing,China, and Possible Links to Nitrogen Deposition Sources   总被引：1，自引：0，他引：1       下载免费PDF全文

Liying Sun  Yinglie Liu  Jinyang Wang  Mohammad Aslam K. Khalil  Jianwen Zou  Zhengqin Xiong 《洁净——土壤、空气、水》2014,42(11):1650-1659

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Fluctuation of Cadmium Load on a Tide‐Influenced Waterfront Lake in the Middle‐Lower Reaches of the Yangtze River          下载免费PDF全文

Hua Wang  Yiyi Zhou  Yong Pang  Xianmin Wang 《洁净——土壤、空气、水》2014,42(10):1402-1408

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Immobilisation of Pb and Zn in Soils Using Stabilised Zero‐valent Iron Nanoparticles: Effects on Soil Properties          下载免费PDF全文

María Mar Gil‐Díaz  Araceli Pérez‐Sanz  María Ángeles Vicente  María Carmen Lobo 《洁净——土壤、空气、水》2014,42(12):1776-1784

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Surveillance of Invasive Bacterial Pathogens and Human Enteric Viruses in Wastewater Final Effluents and Receiving Water Bodies – a Case Study from Durban,South Africa     

Ademola O. Olaniran  Shalinee Naidoo  Balakrishna Pillay 《洁净——土壤、空气、水》2012,40(7):681-691

The physico‐chemical characteristics and microbial composition of the final effluents of two municipal wastewater treatment plants in South Africa were assessed between July and September 2009. The impact of the treated final effluents on the receiving water bodies was also evaluated. The temperature across all sampling points ranged between 14 and 22°C, while pH varied from 6.9 to 7.6. High levels of turbidity, chemical oxygen demand (COD), ammonia, nitrate, nitrite and orthophosphate (PO₄) were observed in many cases. Turbidity of the samples was in the range of 2.2–288.6 NTU. The concentrations (mg/L) of other physico‐chemical parameters are as follows: COD (9.33–289); ammonia (0.000340–45.4); nitrate (0.062–539); nitrite (0.021–22.6); PO₄ (5.3–33.2). The microbial quality of the effluents discharged from the plants did not comply with the limits set by the South African guidelines with respect to pathogens such as Salmonella, Shigella, Escherichia coli, total coliform, faecal coliform, enterococci, faecal streptococci, and viral particles for effluents intended for discharge into receiving watersheds. This study revealed an undesirable impact on the physico‐chemical and microbial qualities of the receiving water bodies as a result of the discharge of inadequately treated effluents from the wastewater treatment facilities. This poses a health risk to several rural communities which rely on the receiving water bodies primarily as their sources of domestic water and recreational purposes. There is therefore a need for the intervention of appropriate regulatory agencies in South Africa to ensure compliance of treatment facilities with wastewater effluent quality standards.  相似文献   

The geomorphic function and characteristics of large woody debris in low gradient rivers, coastal Maine, USA   总被引：1，自引：0，他引：1  

F.J. Magilligan  K.H. Nislow  G.B. Fisher  J. Wright  G. Mackey  M. Laser 《Geomorphology》2008,97(3-4):467-482

The role, function, and importance of large woody debris (LWD) in rivers depend strongly on environmental context and land use history. The coastal watersheds of central and northern Maine, northeastern U.S., are characterized by low gradients, moderate topography, and minimal influence of mass wasting processes, along with a history of intensive commercial timber harvest. In spite of the ecological importance of these rivers, which contain the last wild populations of Atlantic salmon (Salmo salar) in the U.S., we know little about LWD distribution, dynamics, and function in these systems. We conducted a cross-basin analysis in seven coastal Maine watersheds, documenting the size, frequency, volume, position, and orientation of LWD, as well as the association between LWD, pool formation, and sediment storage. In conjunction with these LWD surveys, we conducted extensive riparian vegetation surveys. We observed very low LWD frequencies and volumes across the 60 km of rivers surveyed. Frequency of LWD ≥ 20 cm diameter ranged from 15–50 pieces km^− 1 and wood volumes were commonly < 10–20 m³ km^− 1. Moreover, most of this wood was located in the immediate low-flow channel zone, was oriented parallel to flow, and failed to span the stream channel. As a result, pool formation associated with LWD is generally lacking and < 20% of the wood was associated with sediment storage. Low LWD volumes are consistent with the relatively young riparian stands we observed, with the large majority of trees < 20 cm DBH. These results strongly reflect the legacy of intensive timber harvest and land clearing and suggest that the frequency and distribution of LWD may be considerably less than presettlement and/or future desired conditions.  相似文献