scholarly journals Characteristics and Distribution of Organic Phosphorus Fractions in the Surface Sediments of the Inflow Rivers around Hongze Lake, China

Author(s):  
Jie Wan ◽  
Xuyin Yuan ◽  
Lei Han ◽  
Hongmeng Ye ◽  
Xiaofan Yang

In this study, the characteristics and distribution of the organic phosphorus (Po) fractions in the surface sediments of seven inflow rivers around Hongze Lake in China were analyzed with a soil Po fraction method, as used by Ivanoff. The relationships between the Po fractions and physiochemical features of sediments were also discussed. The results showed that, the sediments of the rivers had been moderately pollution with certain ecological risk effects except the Waste Yellow River. The relative contribution order of the Po fractions in the sediments was residual Po > HCl-Po > fulvic acid-Po > humic acid-Po > labile organic phosphorus (LOP). Moderately labile organic phosphorus (MLOP) was the main part of the Po forms in the whole sediments. The risk of phosphorus released from river sediments was the highest in the western region, followed by the southwestern region, and finally the northwestern region. There were significant correlations between Po forms and total phosphorus (TP), inorganic phosphorus (Pi), and Po. Non labile organic phosphorus (NLOP) had the strongest correlation with TP. The distribution of Po forms in each region was different due to the impact of human activities, industrial and agricultural production and the land types; the heaver polluted sediments with higher Po fractions. It is suggested that most of the sediments of the inflow rivers in the regions have certain ecological risk effects and P of them have an important contributions on the eutrophication of Hongze Lake. Po forms can provide a reliable theoretical basis for dealing with the change of water quality and should be paid more attention in the lake eutrophication investigation. There was reciprocal transformation between different Po forms, especially non-bioavailable fraction can change into bio-available ones. The results can provide a basis for the earth cycle of phosphorus and a new perspective of eutrophication control of shallow lakes.

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1858 ◽  
Author(s):  
Xiaolong Cheng ◽  
Yanan Huang ◽  
Xunchi Pu ◽  
Ruidong An ◽  
Wendian Huang ◽  
...  

The Yarlung Zangbo River basin ecosystem is fragile. The distribution and transportation of phosphorus is of great significance for aquatic environmental protection and ecological security. The sequential extraction method and molybdenum antimony anti-spectrophotometry were used to measure the concentrations of different forms of phosphorus in the surface sediments from 15 sampling sites along the middle reaches of the Yarlung Zangbo River and its tributaries. The results show that the total phosphorus concentration in the surface sediments is 194.0~540.7 mg/kg, which is mainly composed of inorganic phosphorus. The concentrations of various phosphorus forms ranked as calcium-bound phosphorus (355.6 ± 86.0 mg/kg) > soluble phosphorus (15.9 ± 10.0 mg/kg) > iron-bound phosphorus (12.4 ± 12.3 mg/kg) > organic phosphorus (9.6 ± 6.1 mg/kg) > occluded phosphorus (9.2 ± 3.8 mg/kg) > aluminum-bound phosphorus (5.4 ± 2.3 mg/kg). On the whole, phosphorus concentration is greater in wet season than dry season. Regarding the spatial distribution characteristics, there are great disparities in the different forms of phosphorus in the middle reaches of the Yarlung Zangbo River. Comprehensive analysis shows that phosphorus of this area is mainly self-generated, and concentration of bioavailable phosphorus is small, demonstrating there will not be a large release. We also drew a “specific triangle” of the different forms of phosphorus concentrations in the research area and defined the “α” angle to determine the nutrient status of the overlying water quickly and effectively. Finally, phosphorus flux of the mainstream was estimated. This research may provide information on the phosphorus of Plateau Rivers.


2020 ◽  
Author(s):  
Sebastiaan J. van de Velde ◽  
Rebecca K. James ◽  
Ine Callebaut ◽  
Silvia Hidalgo-Martinez ◽  
Filip J. R. Meysman

Abstract. It has been hypothesised that the evolution of animals during the Ediacaran-Cambrian transition had a major impact on atmospheric O2 and CO2 concentrations. The models upon which this hypothesis rests, critically assume that bioturbation by the newly evolved fauna increased the burial of organic phosphorus (Porg) within the seafloor, relative to organic carbon (Corg) and that inorganic phosphorus (Pinorg) burial was not affected by bioturbation. This assumption is centrally based on data compilations from marine sediments deposited under oxic and anoxic bottom waters. Since anoxia excludes the presence of infauna and sediment reworking, the observed differences in P burial are assumed to be solely driven by the presence of bioturbators. This reasoning however ignores the potentially confounding impact of bottom water oxygenation on phosphorus burial. Here, our goal is to provide a field verification for the idea that bioturbation increases the relative burial of organic phosphorus, while accounting for bottom water oxygenation. We present solid-phase phosphorus speciation data from salt marsh ponds with and without bioturbation (Blakeney salt marsh, Norfolk, UK). In both cases, the pond sediments are exposed to oxygenated bottom waters and so the only difference is the presence/absence of bioturbating macrofauna. Our data reveal that both the Corg : Porg ratio of buried organic matter and the rate of Pinorg burial are indistinguishable between bioturbated and non-bioturbated sediments. The absence of a clear effect of bioturbation on total P burial implies that previous studies may have overestimated the impact of the rise of bioturbation on atmospheric O2 and CO2 concentrations in the early Cambrian.


2020 ◽  
Vol 82 (4) ◽  
pp. 787-798
Author(s):  
Zhipeng Lin ◽  
Lei Song ◽  
Baohong Han ◽  
Hao Li ◽  
Qian Wang

Abstract Ulansuhai nur is located in the cold and dry area of China, and the management of heavy metals in the sediments is related to water safety in the lower places of the Yellow River. Graphene oxide (GO) is modified to obtain magnetic graphene oxide (G-F) and chitosan grafted graphene oxide (G-N-C) materials, which are used to immobilize Cu in the sediments. The modified materials are characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffractometer (XRD). G-F respectively reduces the concentration of Cu in the overlying and interstitial water by 61.5–66.3% and 22.4–47.1%, which is more effective than GO and G-N-C. Experiments are designed to determine the effect of phosphates concentration on immobilizing Cu in the sediments by modified materials. The results show that a low concentration of phosphates solution is beneficial to the immobilization of Cu in the sediments, and the capability of G-F to immobilize Cu is higher than that of GO and G-N-C. G-F presents a lower increase in organic phosphorus in the sediments than GO and G-N-C. In summary, the modified materials can immobilize Cu in the sediments, potentially reduce the water body eutrophication, and improve the lake ecological environment.


Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1801
Author(s):  
Valentina Andreea Calmuc ◽  
Madalina Calmuc ◽  
Maxim Arseni ◽  
Catalina Maria Topa ◽  
Mihaela Timofti ◽  
...  

It is a well–known fact that heavy metal pollution in sediments causes serious problems not only in the Danube basin, but also in the large and small adjacent river streams. A suitable method for assessing the level of heavy metals and their toxicity in sediments is the calculation of pollution indices. The present research aims to assess heavy metal pollution in the Lower Danube surface sediments collected along the Danube course (between 180 and 60 km) up to the point where the Danube River flows into the Danube Delta Biosphere Reserve (a United Nations Educational, Scientific and Cultural Organization – UNESCO, protected area). In addition, this monitored area is one of the largest European hydrographic basins. Five heavy metals (Cd, Ni, Zn, Pb, Cu) were analyzed in two different seasons, i.e., the autumn of 2018 and the spring of 2019, using the Inductively Coupled Plasma Mass Spectrometry (ICP– MS) technique. Our assessment of heavy metal pollution revealed two correlated aspects: 1. a determination of the potential risks of heavy metals in sediments by calculating the Potential Ecological Risk Index (RI), and 2. an evaluation of the influence of anthropogenic activities on the level of heavy metal contamination in the surface sediments, using three specific pollution indices, namely, the Geo–Accumulation Index (Igeo), the Contamination Factor (CF), and the Pollution Load Index (PLI). The results of this pioneering research activity in the region highlighted the presence of moderate metal (Ni and Cd) pollution and a low potential ecological risk for the aquatic environment.


1963 ◽  
Vol 43 (1) ◽  
pp. 97-106 ◽  
Author(s):  
R. L. Halstead ◽  
J. M. Lapensee ◽  
K. C. Ivarson

In a laboratory experiment, liming resulted in an average decline of 3.6 per cent in the total organic phosphorus content of incubated surface samples of seven acid soils from eastern Canada. Increases of 2.6 and 5.1 per cent in 1N H2SO4- and 4N HCl-soluble inorganic phosphorus, respectively, and a decrease of 46.4 per cent in NaHCO3-soluble organic phosphorus (pH 8.5) provided further evidence of mineralization of organic phosphorus following liming. There was some evidence, however, that the differences in NaHCO3-soluble organic phosphorus following liming were due only in part to mineralization, since Ca(OH)2 added to a soil just prior to extraction with NaHCO3 had a repressive effect on the solubility of the organic phosphorus compounds.Some mineralization of organic phosphorus occurred when unlimed samples were incubated in the laboratory for 9 months.Marked increases in microbiological activity, as indicated by increased numbers of microorganisms, and increased CO2 and NO3-nitrogen production, were associated with lower values for extractable organic phosphorus following liming. Partial sterilization of samples with toluene lowered biological activity in the unlimed and limed samples. Toluene was found, however, to have a positive effect on release of phosphorus from organic form.


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