Transformation of phosphorus species in settling seston and during early sediment diagenesis   总被引：9，自引：0，他引：9  

M. Hupfer  R. Gächter  R. Giovanoli 《Aquatic Sciences - Research Across Boundaries》1995,57(4):305-324

Sequential P extraction was combined with electron microscop and X-ray spectroscopy to characterise various P species and to study their transformation in settling seston and in recent sediment. During early diagenesis most of the particulate P formed in the water was redissolved. No net transformation into species that would resist dissolution was observed.It was shown that

•	the phosphorus (P) content and the P flux of settling particles varied seasonally over one order of magnitude
•	particles became enriched with reductant soluble P (BD-P) while settling through the hypolimnion
•	changes in BD-P were highly significantly correlated with changes in reductant soluble iron (BD-Fe)
•	bacteria oxidising Fe and Mn seemed to be mainly responsible for this increase in P concentration
•	other fractions including organic P did not change during sedimentation
•	most of the organic P and of the Fe bound P and 70% of TP was released from the sediment during early diagenesis
•	the sediment surface did not act as a trap for P migrating upwards from deeper sediment layers
•	CaCO3 sedimentation contributed little to P sedimentation but significantly to the permanent burial of P.

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Nährstoff- und Sauerstoffbilanz eines hochbelasteten Klärwerksableiters unter besonderer Berücksichtigung der submersen Makrophyten     

S. Krner 《洁净——土壤、空气、水》1997,25(1):34-40

Nutrient and Oxygen Balance of a Highly Polluted Treated Sewage Channel with Special Regard to the Submerged Macrophytes The changes of the concentrations of inorganic nitrogen compounds, orthophosphate, and oxygen were measured in the flowing wave along the flowing stretch of the Berlin treated sewage channel Wuhle monthly over a period of two years (1993/94) to estimate the nutrient and oxygen balances. This treated sewage channel is rich in nutrients and densely covered with submerged macrophytes. During the period of investigation in 1993 (1994), the effluent of the sewage treatment plant Falkenberg, which is lacking in adjustable nitrification and denitrification. contained in average 16.1 (12.7) mg/L of NH-N, 13.7 (9.4) mg/L of NO₃^?-N. 0.94 (0.69) mg/L of NO-N. and 0.36 (0.26) mg/L of PO-P. Due to the neglectable influence of other processes like nutrient uptake by submerged macrophytes and algae, desorption of ammonia or dilution, the changes of the concentrations of the inorganic nitrogen compounds are mainly influenced by nitrification and denitrification. The nitrification is mainly done by sessile nitrifiers in the treated sewage channel Wuhle. The nitrification rates. calculated from the decrease of the ammonium concentrations, were between 0.5 and 20 g/(m²d) related to the flowing stretch area. The ammonium concentrations decreased along the flowing stretch in average by 20 to 44%. The highest nitrification rates could be found at the stretches with a dense colonization with submerged macrophytes and a good oxygen supply due to low water depth and high flowing velocities. The denitrification rates, calculated from the decrease of the total of the concentrations of the inorganic nitrogen compounds, were between 0.5 and 23 g/(m²d) related to the flowing stretch area. The total loss of nitrogen due to denitrification was between 10 and 20% along the flowing stretch of the treated sewage channel Wuhle. This corresponds to a total amount of up to 530 kg nitrogen per day. The main part of the phosphorus occured as orthophosphate in concentrations between 0.04 and 0.87 mg/L of PO-P in the effluent of the treatment sewage plant Falkenberg. The orthophosphate concentration changed along the flowing stretch mostly in such a manner that it were at the same level at the end of the flowing stretch at the mouth into the river Spree. The self-purification capacity of the channel does not lead to a relevant reduction of the very high nutrient load under the present conditions. The rates of the photosynthetic production (P) and the community respiration (R) were calculated from the rates of the total changes of oxygen with regard to the physical aeration. The rates of the photosynthetic production were between 0 and 33 g/(m²d), the rates of the community respiration between 15 and 75 g/(m²d). Therewith, the Wuhle treatment sewage channel belongs to the very productive waters. A positive balance (P > R) could only be measured on two segments in May. The rates of oxygen production depend on the ratio width to depth of the water. It is possible that the positive influence of the submerged macrophytes on the oxygen balance also at higher biomasses than 250 g/m² (as dry weight) predominates at the segments with a favourable ratio. The portion of the oxygen input through diffusion along the flowing stretch and at the weirs was 30%, respectively, that of the photosynthic production 40% in summer. The rates of community respiration decreased along the flowing stretch by 50 to 90%. The nitrification had the main portion of the oxygen depletion in the Wuhle treated sewage channel with 60…80%. Despite the high biomass, the respiration of the submerged macrophytes had only a small portion of the total oxygen depletion. Nevertheless, the submerged macrophytes contributed to the nearly total oxygen depletion at the most densely covered segment 2 at night. The decrease of the content of particular organic material and the ammonia concentrations at the effluent of the sewage treatment plant, a diminishing of the biomass of submerged macrophytes by shading, and the widening of a few flowing stretches are demanded for the improvement of the oxygen balance of the Wuhle treated sewage channel.  相似文献   

电解脱氮除磷技术在海产养殖废水治理中的研究     

容川  尚姣博  张媛媛  宋艳群  王英辉  余克服 《矿产与地质》2016,(3):485-489

海产养殖迅速发展造成水域富营养化、赤潮频发,海产养殖废水污染的治理迫在眉睫。为解决此问题将电解脱氮除磷技术应用在海产养殖废水处理中,并探讨电压、pH、极板间距和电解时间对脱氮除磷去除率的影响。结果表明:脱氮除磷的去除率与电压成正相关,与极板间距成负相关。在电压为30V,极板间距10cm,pH为7时,NH_4~+-N、NO_3~--N和TP的去除率达到最大分别为72%、90%、85%。  相似文献   

生物炭作为海绵城市雨水滞留池填料的效果初探   总被引：1，自引：0，他引：1  

汤逸帆  陈圆  范弟武  韩建刚 《湿地科学与管理》2016,(2):33-36

生物炭吸附性强、抗氧化,在海绵城市建设中具有广阔的应用前景。通过模拟渗水实验,对土壤、生物炭和土壤生物炭混合物等对雨水吸持和净化效果进行研究。结果表明:以生物炭作为滞留池填料,具有较好的储水能力,储水量达0.45 mL/mL;能够缓冲酸性地表径流雨水的pH值,模拟雨水pH值从6.34提升至7.82;对雨水中总氮、总磷和铵氮的截留率分别为34.4%、48.0%和35.0%。因此,生物炭可作为海绵城市建设中雨水滞留池的新型填料。  相似文献   

饮马河流域典型湿地植物净化河流水环境效果研究   总被引：1，自引：0，他引：1  

李廷超  王咏  张刚  王肇钧 《湿地科学与管理》2016,(2):41-45

采取单种及混种方式,通过小型湿地模拟实验,研究松花江支流饮马河流域河流湿地中常见的芦苇、香蒲、槽秆荸荠、藨草、慈姑、花蔺、菱角、紫背浮萍和金鱼藻9种湿地植物及其组合对河流水体中化学需氧量(COD_(cr))、氮、磷等的净化效果。结果表明:所选湿地植物,在模拟环境条件下均能有效提升取自河流水体的水质;不同的湿地植物对污水中各污染物净化具有明显的差异,花蔺对总磷(TP)、COD_(cr)和氨氮(NH_3-N)净化效果最好,去除率依次为99.65%、68.22%和99.54%;香蒲、菱角、金鱼藻混合组对总氮(TN)的净化效果最好,去除率是66.19%;槽杆荸荠、芦苇和金鱼藻对亚硝酸盐氮(NO_2-N)的净化效果最好,去除率是83.64%。两种植物混种后对某一种污染物指标的处理效果弱于分别独种时的处理效果,但对多种污染物指标的综合处理效果一般要好于独种时的处理效果。  相似文献   

Plowing paradise: snow clearing and urban solar radiation absorption     

Susan W. S. Millar 《自然地理学》2017,38(2):197-209

Abstract

Urban heat islands result from human modification of land surfaces. Snow cover reduces heating due to its reflectivity; however, urban snow is quickly plowed, thus altering surface radiative properties. The goal of this study was to evaluate the extent to which municipal snow removal affects the magnitude of solar input associated with changes in the radiation balance. Incoming and reflected shortwave radiation, surface radiating temperature, air temperature, and snow depth were measured with portable devices at eight sites in Syracuse, New York. Sites were classified as cleared, undisturbed, or snow piles. Measurements were taken following fresh snowfall, and continuing until snow had melted. A HOBO weather station provided hourly baseline conditions. Longevity of snow varied across snow site types, with greater persistence when in piles and on open areas. Albedo was reduced and surface temperatures were higher over cleared areas. The difference between absorbed energy due to clearing was quantified using an albedo regression model for undisturbed sites and comparing these to average reflectivity of cleared surfaces. The magnitude difference over the study period ranged from 841 million to 1670 million MJ. Snow plowing is therefore a significant source of additional energy that enhances the winter urban heat island.  相似文献   

太湖现代沉积物中磷的沉积通量及空间差异性   总被引：5，自引：0，他引：5  

朱广伟  秦伯强  高光 《海洋与湖沼》2007,38(4):329-335

在水文状况、水质状况、生态类型均显著不同的三个太湖典型湖区, 利用^210Pb定年测定了近百年来沉积物及磷的沉积通量.结果发现, 三个湖区磷的沉积通量及其变化规律相差很大.发生蓝藻水华暴发的梅梁湾近百年来沉积物和磷的沉积通量都比较小, 只是在近十几年来才有明显增加的趋势; 太湖上游的夹浦沉积物沉积速率近百年来持续增加, 只有表层有所下降, 但表层12cm沉积物中磷的沉积通量却显著下降; 处于太湖下游草型化的胥口湾湖区, 在20世纪60年代以前沉积物沉积通量呈增加趋势, 之后呈下降趋势, 磷的沉积通量则呈振荡下降趋势.研究表明, 太湖沉积物中磷的累积通量具有明显的空间异质性.  相似文献   

Utilizing in vivo nuclear magnetic resonance spectroscopy to study sublethal stress in aquatic organisms     

Viant MR  Pincetich CA  Walton JH  Tjeerdema RS  Hinton DE 《Marine environmental research》2002,54(3-5):553-557

In vivo nuclear magnetic resonance spectroscopy (NMR) is a powerful technique for characterizing the sublethal actions of physical and chemical stressors in live, intact organisms. In particular, 31P NMR is ideal for observing perturbations to cellular energetics since critical metabolite concentrations, including phosphagens, ATP and inorganic phosphate (Pi), can be measured non-invasively and in real time. This technique's versatility is demonstrated not only in the diversity of organisms that can be studied, but also in its broad-ranging applicability to environmental research. Illustrative studies include the actions of copper in adult red abalone (Haliotis rufescens) and changes in energetically important metabolites in developing medaka embryos (Oryzias latipes). Advantages and disadvantages of in vivo NMR will be discussed.  相似文献   

Atmospheric input of anthropogenic phosphorus to the northwest mediterranean under oligotrophic conditions     

C. Migon  V. Sandroni  J. -P. Bthoux 《Marine environmental research》2001,52(5):413-426

Phosphorus (P) concentration in the atmospheric aerosol was measured at a northwestern Mediterranean coastal site. Airborne P ranged between 25 and 85 ng m(-3) (geometric mean: 51 ng m(-3)). Due to a significant contribution (about 90%) of anthropogenic land-based source emissions, dry deposition velocities of 0.1-0.5 cm s(-1) were used to estimate a dry flux of 0.15-0.7 micromol P m(-2) day(-1). The theoretical impact of the dry flux on primary production (0.1-0.4 mg C m(-2) day(-1)) is 50-200-fold lower than that of a single significant wet event. The incineration plant of the Nice district is identified as a possible major source of airborne anthropogenic P. As the implementation of waste plants is currently expanding along the western European shores, the importance of the P atmospheric source to the western Mediterranean is likely to increase with time.  相似文献   

A high sensitivity, low volume HPLC method to determine soluble reactive phosphate in freshwater and saltwater   总被引：1，自引：0，他引：1  

Jaime L. Haberer  Jay A. Brandes   《Marine Chemistry》2003,82(3-4):185-196

A reverse phase High Performance Liquid Chromatography (HPLC) method was developed to detect soluble reactive phosphate (SRP) in marine and freshwater samples. This technique is scalable over a range of sample volumes from 10 μl to 10 ml, requires minimal sample preparation, and responds linearly from 1 nM to 100 μM (R²>0.964). Standard Murphy–Riley molybdenum blue reagents were used to react with phosphate in samples for analysis. Solid phase extraction tubes were used to clean the mixed complexing reagent prior to combining the reagent with samples. The method was applied to freshwater samples collected in July 2001 along an Andean mountain stream located in the Eastern Cordillera (2400 m) of Peru and marine samples collected in January 2002 within the low marsh of the estuarine Nueces Delta System, Texas Coastal Bend. For method comparison, field samples were analyzed using a standard manual spectrophotometric method. Field sample phosphate concentrations produced from each method were nearly identical. This method offers the advantages of low sample volume (1 ml or less) with high sensitivity, precision, and potential automation.  相似文献