دانلود رایگان مقاله لاتین آبخوان بر غلظت فسفر زیرزمینی از سایت الزویر
عنوان فارسی مقاله:
تاثیر تغییرات شیمیایی انسانی و زمین شناسی آبخوان بر غلظت فسفر زیرزمینی
عنوان انگلیسی مقاله:
Impact of anthropogenic geochemical change and aquifer geology on groundwater phosphorus concentrations
سال انتشار : 2016
برای دانلود رایگان مقاله آبخوان بر غلظت فسفر زیرزمینی اینجا کلیک نمایید.
مقدمه انگلیسی مقاله:
1. Introduction
Groundwater phosphorus from leaching of soil or bedrock phosphorus could be an important control over the biological productivity of groundwater-fed lakes and streams. Higher phosphorus concentrations lead to increased aquatic biological productivity as measured by a variety of metrics (Dodds, 2006; Robertson et al., 2006). Most efforts to control the transfer of phosphorus from land to water focus on phosphorus from surficial soil that is transported in surface runoff. This is an important butepisodic source of phosphorus that may respond over the shortterm to land management strategies (for example, tillage changes or riparian buffer strips). In contrast, discharge of groundwater phosphorus to surface water systems is a baseline phosphorus transfer reflecting effects at a decadal time scale and cannot be managed over the short-term. The link between land management and increased groundwater phosphorus transfer is more equivocal than the association between land management and surficial phosphorus transfer (Sims et al., 1998; Holman et al., 2008; Browne et al., 2008). The potential importance of groundwater contributions to the trophic condition of surface waters necessitates a better understanding of the relationship between groundwater phosphorus, land management strategies, and geologic conditions. Previous research suggests two explanations for higher groundwater phosphorus concentrations: 1) movement of surficial phosphorus through the soil profile; and, 2) weathering of phosphorus-rich minerals within the soil and underlying geologicstrata. The movement of surficial phosphorus through the soil profile is often strongly controlled by reactions with secondary minerals of iron and aluminum. The high affinity of these minerals for phosphorus leads to low phosphorus concentrations in soil percolate and low export from the soil profile (Walker and Syers, 1976; Smeck, 1985). Phosphorus retained in the profile is subject to biological uptake and cycling to the surface in vegetation (Syers et al., 2008; Crews and Brookes, 2014). Elevated groundwater phosphorus has been observed where secondary mineral retention of phosphorus is weak. For example, higher phosphorus leaching rates or higher phosphorus concentrations in groundwater are found in very young soils where secondary minerals are less abundant (Boyle et al., 2013) or where secondary minerals are reductively dissolved (Domagalski and Johnson, 2011). Similar conditions are reported where high phosphorus application rates have saturated the capacity of the secondary minerals (McDowell et al., 2002), or where tile drainage shortens phosphorus migration paths through secondary mineral zones (Sims et al., 1998). Most of these studies have shown higher groundwater phosphorus concentrations over relatively short travel distances, and the extent to which this leads to watershed-scale increases in phosphorus transfer is not known. Groundwater phosphorus concentrations may also reflect the the abundance and weathering rate of phosphorus-rich minerals in the soil and bedrock (Meybeck, 1982; Mulholland, 1992). Porder et al. (2007) suggest that phosphorus in the soil profile transitions from phosphorus retained by secondary minerals in the upper profile to phosphorus that occurs in primary minerals at depth. That is similar to the transition from primary mineral phosphorus to secondary mineral phosphorus that occurs in the profile over time (Walker and Syers, 1976; Smeck, 1985). The rate and location of phosphorus mineral weathering in the soil profile and its proximity to the zone of retention and biotic cycling could control the rate of phosphorus leaching and groundwater phosphorus concentrations. Rock weathering reactions can extend more than several meters into the soil profile (Jin et al., 2008; White, 2014) and beyond where biological uptake most effectively cycles phosphorus back to the surface. This suggests that spatial variations in weathering rates, retention mechanisms, the timing and rate of water movement, and differences in rock phosphorus can combine and affect groundwater phosphorus concentrations. Anthropogenic acidity that increases rock weathering could increase the weathering rates of primary phosphorus minerals and ultimately increase groundwater phosphorus concentrations. A role for anthropogenic acidification on phosphorus concentrations in groundwater was suggested by Browne et al. (2008) who found increased groundwater phosphorus concentrations accompanied higher nitrate concentrations from agricultural fertilizers and increased calcium concentrations from rock weathering. Anthropogenic changes to groundwater geochemistry can arise from nitrification of land-applied ammonia in fertilizers, manures and wastewater which increases nitrate concentration and acidity (Eckhardt and Stackelberg, 1995; Hamilton and Helsel, 1995). The nitrification of ammonia can be written as:
برای دانلود رایگان مقاله آبخوان بر غلظت فسفر زیرزمینی اینجا کلیک نمایید.
کلمات کلیدی:
Impact of anthropogenic geochemical change and aquifer geology on ... https://www.researchgate.net/.../303690090_Impact_of_anthropogenic_geochemical_ch... Surficial geology in the study area ranged from Cambrian sandstones to Ordovician dolomites. Groundwater phosphorus concentrations were higher in aquifers ... U.S. Geological Survey Water-supply Paper https://books.google.com/books?id=jsDtrSEh4YsC 1982 - Water-supply The data also indicate that immediately after the introduction of uncontaminated ground water, dissolved phosphorus concentrations in the aquifer may sharply ... Impact of anthropogenic geochemical change and aquifer geology on ... https://www.deepdyve.com/.../impact-of-anthropogenic-geochemical-change-and-aqu... Read "Impact of anthropogenic geochemical change and aquifer geology on groundwater phosphorus concentrations, Applied Geochemistry" on DeepDyve, the ... US Geological Survey Circular - Page 8 - Google Books Result https://books.google.com/books?isbn=0607954159 Stephen J. Kalkhoff - Geology 2000) — an area of similar climate, topography, regional geology and soils, and ... Dissolved phosphorus concentration in the alluvial aquifers in agricultural ... Phosphorus in a Ground-Water Contaminant... https://books.google.com/books?isbn=1428990119 Elevated manganese concentrations (as high as about 10 mg/L) were ... used to calculate the annual phosphorus flux across a vertical section of aquifer near ... U.S. Geological Survey Toxic Substances Hydrology Program—Proceedings of ... [PDF]DISSOLVED PHOSPHORUS IN CANTERBURY GROUNDWATER flrc.massey.ac.nz/workshops/16/Manuscripts/Paper_Scott_2016.pdf by L Scott - Related articles geological sources of phosphorus contribute dissolved reactive phosphorus ... groundwater redox state is a better predictor of phosphorus mobility in aquifers than the ... Summary statistics for DRP concentrations in Canterbury groundwater ... Searches related to aquifer geology on groundwater phosphorus concentrations phosphorus levels in groundwater phosphorus groundwater contamination water methods of transport significant study of phosphate concentration in water samples phosphate in water health effects phosphate in drinking water where do phosphates come from phosphates in water
