A review of the role of bed deposits in the phosphate eutrophication of lakes and rivers

Abstract

The distribution of phosphates in fresh waters is briefly discussed and the different phosphorus cycles are mentioned. The chemistry of phosphorus in lakes is reviewed with special reference to the extraction methods used for the fractionation of phosphorus in soils and sediments. The models of the sedimentwater exchange are also discussed together with their environmental implications. The relevant publications on the adsorption by and desorption from sediments, especially clays, are reviewed with special reference to the adsorption mechanism on clays and the oxides of Fe and Al. The important topic of the desorption of phosphate from the relevant minerals and soils is presented with special reference to the effects of the sediment and water parameters affecting the release of phosphate from sediments.

Formation and Aggregation of Lead Phosphate Particles: Implications for Lead Immobilization in Water Supply Systems

“…Furthermore, overdosed phosphate can cause eutrophication problems if the phosphate is not adequately removed from the water before it is discharged back to the environment. 87 The presence of Ca 2+ and Mg 2+ at concentrations of 0.5 mM or higher promoted the aggregation of lead phosphate particles within 1 h, which are at levels that are below the 500 mg/L total dissolved solids concentration required for drinking water. 86 In the U.S.A., the divalent cation concentrations in drinking water range from very low concentrations to nearly 5 mM for calcium and 2 mM for magnesium.…”

“…Thus, it is vital to determine an optimal phosphate dosage for lead immobilization in lead pipes. Furthermore, overdosed phosphate can cause eutrophication problems if the phosphate is not adequately removed from the water before it is discharged back to the environment . The presence of Ca 2+ and Mg 2+ at concentrations of 0.5 mM or higher promoted the aggregation of lead phosphate particles within 1 h, which are at levels that are below the 500 mg/L total dissolved solids concentration required for drinking water .…”

Studies on manganese nodule leached residues

“…The main interest in the study of phosphate adsorption is to understand its fixation in the soil and to minimize phosphorus eutrophication of lakes, rivers, etc. [2][3][4][5][6][7][8]. Earlier workers have reported the adsorption of phosphorus using various metal oxides, goethite, γ -alumina, hematite, etc.…”

Adsorption of Phosphate from Aqueous Solution Using Activated Red Mud

“…Adsorption of phosphate from aqueous solution has been studied in the past few decades by several authors using different adsorbents, like activated alumina (2), half-burnt dolomite (3), activated carbon (4,5), coconut shell carbon (6), clays (7), bentonite (8), ferrihydrite (9), goethite (10), -alumina (11), and hematite (12). The studies aimed to understand its fixation in soil and to minimize eutrophication of lakes, rivers, and ponds (13,14). The present paper reports preparation of activated red mud and use of the same as an adsorbent for phosphate removal from aqueous solution.…”