Nonpoint Pollution of Surface Waters With Phosphorus and Nitrogen

Abstract

Agriculture and urban activities are major sources of phosphorus and nitrogen to aquatic ecosystems. Atmospheric deposition further contributes as a source of N. These nonpoint inputs of nutrients are difficult to measure and regulate because they derive from activities dispersed over wide areas of land and are variable in time due to effects of weather. In aquatic ecosystems, these nutrients cause diverse problems such as toxic algal blooms, loss of oxygen, fish kills, loss of biodiversity (including species important for commerce and recreation), loss of aquatic plant beds and coral reefs, and other problems. Nutrient enrichment seriously degrades aquatic ecosystems and impairs the use of water for drinking, industry, agriculture, recreation, and other purposes. Based on our review of the scientific literature, we are certain that (1) eutrophication is a widespread problem in rivers, lakes, estuaries, and coastal oceans, caused by overenrichment with P and N; (2) nonpoint pollution, a major source of P and N to surface waters of the United States, results primarily from agriculture and urban activity, including industry; (3) inputs of P and N to agriculture in the form of fertilizers exceed outputs in produce in the United States and many other nations; (4) nutrient flows to aquatic ecosystems are directly related to animal stocking densities, and under high livestock densities, manure production exceeds the needs of crops to which the manure is applied; (5) excess fertilization and manure production cause a P surplus to accumulate in soil, some of which is transported to aquatic ecosystems; and (6) excess fertilization and manure production on agricultural lands create surplus N, which is mobile in many soils and often leaches to downstream aquatic ecosystems, and which can also volatilize to the atmosphere, redepositing elsewhere and eventually reaching aquatic ecosystems. If current practices continue, nonpoint pollution of surface waters is virtually certain to increase in the future. Such an outcome is not inevitable, however, because a number of technologies, land use practices, and conservation measures are capable of decreasing the flow of nonpoint P and N into surface waters. From our review of the available scientific information, we are confident that: (1) nonpoint pollution of surface waters with P and N could be reduced by reducing surplus nutrient flows in agricultural systems and processes, reducing agricultural and urban runoff by diverse methods, and reducing N emissions from fossil fuel burning; and (2) eutrophication can be reversed by decreasing input rates of P and N to aquatic ecosystems, but rates of recovery are highly variable among water bodies. Often, the eutrophic state is persistent, and recovery is slow.

Influence of Physical and Chemical Parameters on the Treatment of Heavy Metals in Polluted Stormwater Using Zeolite—A Review

“…In recent years, intensive efforts have been focused on utilising largely unused stormwater as an alternative water source as it is generally available in large volumes and easily accessible [3][4][5]. However, stormwater can contain harmful pollutants such as heavy metals, hydrocarbons and pathogens when collected from various land surfaces [6,7]. Thus, a significant level of treatment is required before reuse.…”

Penilaian Kerentanan Air Permukaan terhadap Pencemaran di Sub DAS Garang Hilir Berbasis Multi-Indeks

“…Hal tersebut mengakibatkan sungai lebih mudah dalam mengakumulasi berbagai jenis buangan dari daerah sekitarnya, sehingga menjadikan air sungai sangat rentan terhadap pencemaran yang banyak dipengaruhi oleh aktivitas manusia seperti pembuangan limbah industri (Azrina, Yap, Ismail, Ismail, & Tan, 2006;Mokaya, Mathooko, & Leichtfried, 2004), perkebunan, pertanian dan limbah perkotaan (Carpenter et al, 1998;Palmer, 1965), maupun proses alam seperti perubahan iklim, curah hujan dan transportasi sedimen (Ravichandran, 2003). Sungai yang tercemar mengakibatkan terjadinya degradasi pada kualitas air (Bordalo, Nilsumranchit, & Chalermwat, 2001;Carvalho, Cortes, & Bordalo, 2011), habitat fisik serta integritas biologi sistem lotik (sungai) (Carpenter et al, 1998;Varol & Şen, 2009) dan keanekaragaman hayati perairan (Maddock, 1999).…”

Concentraciones de nitrógeno en la precipitación y escorrentíade parcelas con manejo orgánico y convencional

“…However, global use of synthetic nitrogen fertilizers is causing regional and global problems by overloading this element and its compounds. In the last decade there has been great concern about the loss of nutrients from agricultural systems and the consequences for the health and sustainability of aquatic ecosystems (Carpenter et al, 1998;Sharpley et al, 1994Sharpley et al, ). 2005.…”

“…No obstante, el consumo mundial de fertilizantes sintéticos con nitrógeno está causando problemas regionales y mundiales por sobrecarga del elemento y sus compuestos. En la última década ha existido gran preocupación por la pérdida de nutrientes de los sistemas agrícolas y las consecuencias sobre la salud y la sostenibilidad de los ecosistemas acuáticos (Carpenter et al, 1998;Sharpley et al, 1994).…”