Distribution Of Phosphorus Species Research Articles

Soil nutrients, phosphatase activities and phosphorus species distribution in soils amended sheep manure biochar

Soil nutrients, phosphatase activities and phosphorus species distribution in soils amended sheep manure biochar

Improving the Hydrothermal Stability of ZSM-5 Zeolites in 1-Octene Aromatization by Sequential Alkali Treatment and Phosphorus Modification

For the aromatization of olefins (in Fischer–Tropsch synthetic oil), especially for the fluidized bed reaction with steam as the fluidized medium, improving the catalytic and hydrothermal stabilities of ZSM-5 catalysts is a research focus because of both fundamental research interests and potential commercial applications. In this work, sequential alkali treatment and phosphorus modification were carried out for ZSM-5 samples. The results obtained from characterization and reaction evaluation show that the introduction of mesopores facilitates the dispersion of phosphorus species into the pores and improves the reaction stability for 1-octene aromatization. After the hydrothermal treatment, the P-0.5A-Z5-ST sample treated with an appropriate concentration of alkali retains the most acid sites and shows the highest aromatic selectivity (22.5%) at TOS = 660 min. Therefore, a moderate distribution of mesopores in a zeolite plays an important role in the diffusions of reactants and products, as well as in the distribution of phosphorus species.

Effect of biogas slurry application on soil nutrients, phosphomonoesterase activities, and phosphorus species distribution

Biogas slurry (BS) is used for soil productivity amendment, but its effect on soil phosphorus (P) form distribution has not been thoroughly examined. The objective of this study was to determine the effect of BS on soil nutrients, phosphomonoesterase activities, and P species distribution. A 91-day incubation study was carried out for a silt soil which was amended with BS at a rate equivalent to 120 kg N ha−1 and 38 kg P ha−1 and 240 kg N ha−1 and 76 kg P ha−1. The soil with no BS addition was used as control. Solution P-31 nuclear magnetic resonance (31P-NMR) spectroscopy was used to characterize soil P species. Acid phosphomonoesterase (ACP) and alkaline phosphomonoesterase (ALP) activities, pH, cation exchange capacity (CEC), NH4+–N, NO3−–N, and Olsen P were also evaluated. The results indicated that the application of BS increased pH, CEC, NH4+–N, NO3−–N, and Olsen P contents. Moreover, the addition of BS inhibited ACP activity, but it increased ALP activity. A significant positive correlation was found between ALP and orthophosphates, suggesting ALP activity may play important roles in the release of orthophosphates. The P composition was dominated by inorganic orthophosphate (59.9–76.2% extracted P) and orthophosphate monoesters (23.8–38% extracted P), with smaller concentration of pyrophosphates (1.2–3.6% extracted P), and orthophosphate diesters (less than 1.5% of the extracted P). The P was mainly in the form of inorganic orthophosphates and organic monoesters. The present study shows that BS can be a substitute solution for the supply of essentials nutrients for plants. However, care would be entirely taken with long-term application of BS, since extreme nutrients addition may cause eutrophication of water bodies.

Distribution of phosphorus species and their release risks in the surface sediments from different reaches along Yellow River.

In order to further explore the relationship between water body eutrophication of some reaches of Yellow River and phosphorus species in sediments, and evaluate phosphorus release potential from sediments to overlying water, we investigated the distribution of P species and their release risk in the surface sediments from different reaches along Yellow River, as well as the influence of artificial dam on phosphorus cycle in Yellow River. The results show that the content of calcium phosphorus (PCa) is higher than the content of bioavailable phosphorus (BP) (BP = Pex + PFe; in the formula, Pex means exchangeable phosphorus and PFe means iron phosphorus) in the surface sediments from Yellow River. Among all the surface sediment samples from 21 stations, only Dayudu section (H15) has a ratio of W (BP)/W (PCa) higher than 0.5; the results show that the intensity of phosphorus release from H15 is high, and there is a potential risk of eutrophication in water, while the phosphorus release level of water sediment in other reaches of Yellow River is low. The content of BP and total phosphorus (∑P) in surface sediments along the Yellow River is in descending order: middle reaches of Yellow River > upper reaches of Yellow River > Yellow River downstream, while the content order of total phosphorus (TP) in the overlying water is as follows: Yellow river downstream > middle reaches of Yellow River > upper reaches of Yellow River (except the H7 station), indicating that extensive artificial corresponding damming in Yellow River basin makes the concentration of TP increasing significantly in overlying from upstream to downstream. The establishment of Haibowan water conservancy project in Yellow River makes the total particulate matter (TPM) concentration in the water to reduce to very low lever in Wuhai H7 section, and the phosphorus concentration in the overlying water reaches 0.136 mg L-1.

Temporal Variation of Nitrogen and Phosphorus Species Distribution on Total Phytoplankton Biomass in Eutrophic Lakes

To aid in the eutrophication management, the relationships between total algal biomass in response to varying nitrogen and phosphorus species concentrations, Volatile (VSS), and Total Suspended (TSS) solids in the water column were investigated. Sampling was conducted at the deepest portion of the reservoir for analysis of phosphorus, nitrogen, chlorophyll a, VSS, and TSS.

A sequential extraction to determine the distribution of phosphorus in the seawater and marine surface sediment

The distribution of phosphorus species among environmental compartments (e.g., between water and sediment), significantly affects the bioavailability of these species to organisms. The eastern Mediterranean Sea is one of the most extreme oligotrophic oceanic regions on earth in terms of nutrient concentrations and primary productivity. The paper presents the results of inorganic and organic forms in surface sediment and seawater from NE Mediterranean Sea (Burclar Bay, Erdemli, South Anatolia of Turkey) in May 2007. Speciation of phosphorus in seawater and surface sediment using inductively coupled plasma-atomic emission spectrometer (ICP-AES) has been reported here. The method is based on sequential extractions of the seawater and sediment each releasing four forms of inorganic phosphorus: loosely sorbed phosphorus, phosphorus bound to aluminium (P–Al), phosphorus bound to iron (P–Fe) and phosphorus bound to calcium (P–Ca). The most abundant form of inorganic phosphorus in the seawater and surface sediment is calcium-bound phosphorus. Relative abundances of the remaining phosphorus forms in sediment follow the order: P–Al > P–Fe > loosely bound-P and in seawater follow the order P–Fe > P–Al > loosely bound-P.

Spatial Variation in the Distribution of Phosphorus Species in the Surficial Sediments of Canadohta Lake, Pennsylvania; Implications for Internal Phosphorus Loading Estimates

The concentrations of total, loosely sorbed, metal-bound, calcium-bound, and organic phosphorus, iron, and organic matter (loss on ignition) were determined for 71 surface sediment samples from Canadohta Lake, Pennsylvania. The results indicate that lake sediments can be highly variable with respect to these parameters. Most of these parameters were highly intercorrelated, and some general patterns appear to exist based on these and previously published data. Given the highly variable nature of sediment quality, particularly among these parameters which have been shown to be good predictors of sediment phosphorus release rates, estimates of internal phosphorus loading based on a few incubated cores taken from the deepest area of a lake may contain serious errors. We recommend that sediment heterogeneity be assessed in order to determine an appropriate number and distribution of cores to be incubated for internal loading estimates.