Phosphate, eutrophication

The efforts of the detergent industry toward solution of its part of the eutrophication problem are, at this point, less complete than its response to the biodegradabihty problem. Soda ash, Na2C02, sodium siUcate, and, to a lesser extent, sodium citrate formed the basis of the early formulations marketed in the areas where phosphates were harmed. Technically, these substances are considerably less effective than sodium tripolyphosphate. As a precipitant builder, soda ash can lead to undesirable deposits of calcium carbonate on textiles and on washing machines. 

Because phosphates cause eutrophication of water (algae grow because of the fertilizing power of phosphates), it is seldom used as a detergent additive except in toothpastes. 

Phosphate legislation. Environmental concern over the eutrophication of lakes prompted the advent of phosphate restrictions for laundry products. These restrictions were initially legislated in areas of high population density. They have since expanded to cover 40% of the U.S. population [2]. As more states and cities enacted phosphate restrictions, laundry formu-... 

Cyanides can be fatal to fish at <1 ppm. Because of concern over the possible in vivo conversion of nitrate into carcinogenic nitrosamines, the nitrate content of drinking water must be strictly controlled. Nitrate and phosphate pollution can also cause eutrophication in still or slow-moving warm waters by stimulation of algae growth in the presence of... 

An unusual example of a process that produces a lot of waste is the intensive rearing of pigs. They need additional phosphorus in their feed for healthy growth, and this is usually added as inorganic phosphorus in the form of monocalcium phosphate (calcium dihydroxy-oxido-oxo-phosphorane). Unabsorbed phosphorus passes through into the manure, and if spread onto fields as a fertiliser can lead to excess phosphorus run-off into rivers and lakes leading to eutrophication. 

The only element that was discovered in body fluids (urine). This is plausible, as P plays a main role in all life processes. It is one of the five elements that make up DNA (besides C, H, N, and 0 evolution did not require anything else to code all life). The P-O-P bond, phosphoric acid anhydride, is the universal energy currency in cells. The skeletons of mammals consists of Ca phosphate (hydroxylapatite). The element is encountered in several allotropic modifications white phosphorus (soft, pyrophoric P4, very toxic), red phosphorus (nontoxic, used to make the striking surface of matchboxes), black phosphorus (formed under high pressures). Phosphates are indispensable as fertilizer, but less desirable in washing agents as the waste water is too concentrated with this substance (eutrophication). It has a rich chemistry, is the basis for powerful insecticides, but also for warfare agents. A versatile element. 

Phosphate removal processes from wastewater have been studied by many workers, in order to protect stagnant water area, such as lakes and coastal region from eutrophication. Among conventional phosphate removal processes, the representative one was flocculation and sedimentation process, which was based on precipitation of insoluble metal phosphate or hydroxide. However, the main problem with this process, is to produce large amounts of sludge, which is difficult to dehydrate. 

As population and industrialization continue to expand, eutrophication has become a problem due to the accelerated aging of bodies of water by the excessive growth of plants and algae attributed to discharges of nitrates and phosphates. These pollutants have imposed demands on engineers to develop cost-effective systems that can eliminate them from water. 

Phosphates are a nutrient for many plants and microorganisms. In the past, the phosphates from used laundry detergents often made their way into rivers, lakes, and ponds, where they caused the growth of plants and microorganisms, which grew so rampant as to choke off the natural supply of dissolved oxygen—a process known as eutrophication. 

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