All plants need phosphates to grow, but phosphorous is normally present in surface water at a rate of only 0. Introducing additional phosphates in water results in a massive growth of algae, which are aquatic plants including many single-celled, free-floating plants.
Excessive amounts of algae cloud the water in an effect called an algal bloom, which reduces the sunlight available to other plants and sometimes kills them. When the algae die, the bacteria that break them down use up dissolved oxygen in the water, depriving and sometimes suffocating other aquatic life.
Fertilizers containing phosphates pollute surface water. Phosphates enter water systems naturally by dissolving out of rock, but phosphates are also mined and made into chemical fertilizers to grow crops. Crops feed farm animals, which excrete phosphate-rich manure. Applying chemical fertilizers to soil already saturated with phosphates and spreading excessive amounts of manure on land causes phosphates to run off during heavy rainfall and pollute nearby water sources.
When the amount of total phosphorous exceeds parts per billion ppb in streams or 50 ppb in lakes, eutrophication -- the effect of algal blooms -- is a danger. Excessive phosphate levels also affect the processes in drinking water treatment plants. Phosphates in water come from a range of sources. Runoff from fertilizer on lawns and gardens is one contributor, and others include human and pet sewage, chemical manufacturing, vegetable and fruit processing and the pulp and paper industry.
A sign of this is excess algae in the lake. State laws to reduce phosphorus coming from wastewater-treatment facilities and to restrict the use of phosphorus detergents has caused large reductions in the amounts of phosphorus in the Chattahoochee River south of Atlanta, Georgia and in West Point Lake. The first chart below shows the amount of phosphorus, in tons per year, upstream and downstream of the Chattahoochee River at Atlanta, which is a major source of the local water supply.
As the bottom line shows, though, the total phosphorus load in the more agricultural area north of town continues to increase.
The chart below shows both the wastewater discharge and the amount of phosphorus discharged from Atlanta's wastewater-treatment plants. It makes sense that the total amount of wastewater would be going up as population increases, but the tonnage of phosphorus has been greatly reduced both by improvements in the treatment process and by restrictions on phosphate detergents.
Want to know more about phosphorus and water? Follow me to the Nutrients and Eutrophication website! USGS scientists have gained a better understanding of the nutrient supply and how nutrients affect habitat quality, algal productivity, and food-web dynamics in the Bay-Delta. Nutrients, such as nitrogen and phosphorus, are essential for plant and animal growth and nourishment, but the overabundance of certain nutrients in water can cause several adverse health and ecological effects.
This collaborative project between the U. S Department of Agriculture at several research sites throughout the United States. Goals included:. Obtain detailed data concerning the survival of pathogenic microorganisms from manure applied to soil Historical data on nutrients nitrogen and phosphorus from about 12, ground-water and more than 22, stream samples have been compiled and related to possible sources.
This existing information was collected by many agencies for a variety of purposes. Therefore, though it can be used to determine where concentrations differ, the exact This report presents the results of a cooperative study by the U. The primary objectives of the study were to quantify temporal This report is the first in a series of nontechnical publications, 'The quality of our nation's waters,' designed to describe major findings of the National Water-Quality Assessment Program regarding water-quality issues of regional and national concern.
Sources, seasonal and geographic patterns of occurrence, and long-term trends are evaluated The GLRI Edge-of-Field Monitoring project focuses on identifying and reducing agricultural sources of excess nutrients which can threaten the health of the Great Lakes.
Modeling results can be exported as an Excel spreadsheet or a geospatial dataset. Rankings can be shown by major watershed, state, HUC8, tributary, and catchment.
Nutrient data can be explored using maps and interactive graphs and tables. A Wisconsin Department of Natural Resources scientist collects water quality data to better understand nutrients' role in the overabundance of duckweed and algae. Too much nitrogen and phosphorus in water could lead to an overgrowth of free-floating plants such as duckweed and filamentous algae. These overgrowths can result in dense layers of scum on the surface of.
The green scum shown in this image is the worst algae bloom Lake Erie has experienced in decades. Phosphorus from farms, sewage, and industry fertilized the. On September, 24, The USGS briefed Congress, the media and the public on a new USGS study documenting nutrient concentrations in the Nation's water resources, key sources of nutrients, potential effects on humans and aquatic life, and changes in concentrations since the early 's. The picture shows Brookmill Park Lake again, 11 months later in September I'm not sure if odor was a problem at this time, but I'm sure even if no smells.
This picture show Brookmill Park Lake, a pleasant country lake in a public park amid the urban settings near Greenwich in Great Britain. Water in the lake comes from streamflow from a nearby river. Certainly a pleasant pastoral setting for any person or duck. The picture, taken in October , shows Brookmill Park Lake during normal conditions. Orthophosphate forms are produced by natural processes, but major man-influenced sources include: partially treated and untreated sewage, runoff from agricultural sites, and application of some lawn fertilizers.
Orthophosphate is readily available to the biological community and typically found in very low concentrations in unpolluted waters. Poly forms are used for treating boiler waters and in detergents. In water, they are transformed into orthophosphate and available for plant uptake.
Organic phosphates are typically estimated by testing for total phosphate. The organic phosphate is the phosphate that is bound or tied up in plant tissue, waste solids, or other organic material. After decomposition, this phosphate can be converted to orthophosphate.
Apatite is a mineral family of phosphates containing calcium, iron, chlorine, and several other elements in varying quantities. The most common variety contains fluorine, and fluorapatite is the main constituent in bones and teeth! Huge quantities of sulfuric acid are used in the conversion of the phosphate rock into a fertilizer product called "super phosphate" the phosphate in apatite is not readily available to plants; treating the apatite with sulfuric acid converts it into a form, orthophosphate, that is readily available.
Small amounts of certain condensed phosphates are added to some water supplies during treatment to prevent corrosion and this chemical is used extensively in the treatment of boiler waters. Larger quantities of these compounds can be found in laundering and commercial cleaning fluids. Orthophosphates applied to agricultural or residential lands as fertilizers are carried into the surface water during storm events or snow melt.
In addition, storm events can cause the vertical migration of the phosphates into the groundwater system, but because of the affinity of soils for phosphate it adsorbs onto the soil particles , the soil mantle acts as a storage medium for phosphate. Phosphorus is one of the key elements necessary for the growth of plants and animals and in lake ecosystems it tends to be the growth-limiting nutrient; it is a backbone of the Krebs Cycle and for the manufacture of ATP adenosine triphosphate and DNA.
The presence of phosphorus is often scarce in well-oxygenated lake waters and, importantly, the low levels of phosphorus limit the production of freshwater systems Ricklefs, Unlike nitrogen, phosphate is retained in the soil by a complex system of biological uptake, absorption, and mineralization.
Phosphates are not toxic to people or animals unless they are present at very high levels. Digestive problems could occur from extremely high levels of phosphate.
The soluble or bio-available orthophosphate is then used by plants and animals. ATP, adenosine triphosphate, is important in the storage and use of energy and a key stage in the Krebs Cycle. Therefore, the availability of phosphorus is a key factor controlling photosynthesis. Photosynthesis is a complex series of reactions carried out by algae, phytoplankton, and the leaves in plants, which utilize the energy from the sun. The simplified version of this chemical reaction is to utilize carbon dioxide molecules from the air and water molecules and the energy from the sun to produce a simple sugar such as glucose and oxygen molecules as a by-product.
All of the organic compounds of a plant or animal are ultimately produced as a result of this photosynthesis reaction. The net equation describing photosynthesis is:. Phosphate will stimulate the growth of plankton and aquatic plants which provide food for larger organisms, including zooplankton, fish, humans, and other mammals.
Plankton represents the base of the food chain.
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