Phosphate amendment

Hodson, M. E., Valsami-Jones, E., Cotter-Howells, J. D., Dubbin, W. E., Kemp, A. J., Thornton, I. Warren, A. 2001. Effect of bone meal (calcium phosphate) amendments on metal release from contaminated soils - a leaching column study. Environmental Pollution, 112, 233-243. 

Reynolds, J.G., Naylor, D.V. and Fendorf, S.E. (1999) Arsenic sorption in phosphate-amended soils during flooding and subsequent aeration. Soil Science Society of America Journal, 63(5), 1149-156. 

Over the last decade, extensive research has been conducted on conversion of hazardous metals from different waste streams using phosphate stabilizers. Eighmy and Eusden [10] searched the literature on phosphate amendment of various industrial waste streams. They found 39 patents in this area since 1994. An updated summary of the various waste streams, either treated or tested by phosphate amendment or solidification, is given in Table 16.3. 

Peat and phosphate amendments are known to inhibit Cd uptake by plants. The mobility of Cd in phosphorus-amended soil is reduced significantly with a decrease in exchangeable fraction and a corresponding increase in carbonate and oxide fractions (Hettiarichchi et al., 1997). 

Cao, X., Ma, L. Q., Singh, S. P., Chen, M., Harris, W. G., and Kizza, P. (2003). Field Demonstration of Metal Immobilization in Contaminated Soils Using Phosphate Amendments, final report to Florida Institute of Phosphate Research, Bartow, FL. Publ. 01-148-194. 

Mauric A, Lottermoser BQ (2011) Phosphate amendment of metalliferous waste rocks. Century Pb-Zn mine, Australia laboratory and field trials. Appl Geochem 26 45-56 McCloskey AL (2005) Prevention of acid mine drainage generation from open-pit highwalls— final report. Mine waste technology program activity III, project 26, EPA/600/R-05/060 Miller G, Van Zyl D (2008) Personal communication... 

Several authors [11-16,18,19,41,42] have suggested that the precipitation of the lead-bearing apatites pyromorphite and hydroxypyromorphite results from prior dissolution of hydroxyapatite, which is much more soluble than the lead phases. Continuous dissolution of hydroxyapatite was observed as the result of the formation of less soluble species [12, 15, 29, 53]. Some workers have studied the effect of different phosphate amendments (synthetic... 

Calcium. Calcium is the fifth most abundant element in the earth s cmst. There is no foreseeable lack of this resource as it is virtually unlimited. Primary sources of calcium are lime materials and gypsum, generally classified as soil amendments (see Calcium compounds). Among the more important calcium amendments are blast furnace slag, calcitic limestone, gypsum, hydrated lime, and precipitated lime. Fertilizers that carry calcium are calcium cyanamide, calcium nitrate, phosphate rock, and superphosphates. In addition, there are several organic carriers of calcium. Calcium is widely distributed in nature as calcium carbonate, chalk, marble, gypsum, fluorspar, phosphate rock, and other rocks and minerals. 

Hirsh and Banin (1990) reported that an increase in Cl concentration decreased Cd sorption due to formation of the CdCl+ ion pair. Enhanced sorption in the presence of HC03 was observed due to the formation of the CdHC03+ ion pair. Mahler et al. (1980) found that in calcareous soils treated with sewage sludge spiked with CdS04, Cd complexes were mainly Cd sulfate and carbonate complexes, and the formation of Cd-Cl complexes increased in both soils as total Cd increased. In sludge-amended California soils with pH 7-8, both Cd and Zn organic complexes and Cd phosphate complexes increase with P levels, but free Cd2+ and Zn2+ decrease with P levels (Fig. 3.4) (Villarroel et al., 1993). 

All chemicals were used as received. PDADMAC and PAMPS were obtained from Aldrich Chemical Co. (Milwaukee, WI). Diclofenac sodium, sodium sulfathiazole, labetalol HCl, propranolol HCl, verapamil HCl, and diltiazem HCl were purchased from Sigma Chemical (St. Louis, MO). Dextrose USP was obtained from Amend Co. (Irvinton, NJ). Water was distilled and deionized using a Nanopure purihcation system (Fischer Scientihc, Fair Lawn, NJ). Simulated intestinal fluid was prepared using a O.OIM phosphate buffer (sodium phosphate monobasic and potassium phosphate dibasic) at pH 7 and 5.5 with different amounts of NaCl to vary the ionic strength. Simulated gastric fluid (pH 1.5) was prepared with concentrated HCl with different amounts of NaCl to vary the ionic strength. 

Rhoton, F.E. and Bigham, J.M. (2005) Phosphate adsorption by ferrihydrite-amended soils. Journal of Environmental Quality, 34(3), 890-96. 

Lima, J.A., E. Nahas, and A.C. Gomes (1996). Microbial populations and activities in sewage sludge and phosphate fertilizer-amended soil. Appl. Soil Ecol., 4 75-82. 

The effects of five phenolic compounds, catechol, protocatechuic, p-coumaric, p-hydroxybenzoic, ferulic acids and their mixture were studied on pH, organic matter, organic-nitrogen, total phenolic content and certain inorganic ions of forest mineral soils (Ae and B horizons). The A- and B-horizon soils, were amended with 104 M concentration of each phenolic compound and their mixture. In general, soil properties were affected by phenolics amendement. However, soils amended with catechol did not influence any of the soil characteristics. Contents of organic matter, nitrogen and phosphate were lower in soils amended with different phenolic compounds compared to the unamended control soil (Inderjit and Mallik, 1997). 

Breman, H. (1997) Building soil fertility in Africa Constraints and perspectives.-Paper presented at International workshop on development of national strategies for soil fertility recapitalization in Sub-Saharan Africa, including the use of phosphate rock and other amendments, Lome, Togo, 22-25 April 1997. 

Figure 11.6 Results from seasonal in situ bioassays in the southwest basin of Pamlico Sound. Bars are means of 5 replicates and error bars are on standard deviation.The top panel shows the response of primary productivity of the natural phytoplankton community to the addition of nitrate (+N, 20 pM-N), phosphate (+P, 5 pM-P), nitrate and phosphate (+NP), and the un-amended control.The bottom panel shows the response of chlorophyll a to the same treatments. Relative to controls, strong N limitation was observed in Pamlico Sound despite high load of N to the upstream Neuse River Estuary.

Laboratory incubations of wetland soils with nitrogen and phosphorus amendments have shown either no elfect or an inhibitory effect on methanogenesis (Bodelier et al., 2000a,b Bridgham and Richardson, 1992 Wang and Lewis, 1992). A low rate of phosphate supply to rice roots stimulated CH4 emission (Lu et al., 1999), while phosphate concentrations 20mM specifically inhibited acetotrophic methanogenesis (Conrad et al., 2000). 

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