Phosphorus Flux from the Pelham Bay Wetlands, Bronx, New York

Phosphorus (P) released and transported from wetlands affects wetland ecosystems and surrounding water systems. Sediment samples from the Pelham Bay wetlands in the Bronx, NY, have been collected and analyzed. Analysis of the sorption characteristics, P compound identification and P mineralization, showed significant correlations between the sorption maximum (Smax) and Ox-Fe (r = 0.894), ash-TP and HCl-Ca (r = 0.94), ash-TP and TOC (r = 0.96), as well as TOC vs HCl-Ca (r = 0.93). These results indicate that mineral content affects the OP content and the sorption process. P sorption maxima Smax ranged from 70.4 to 1667 mg/Kg, and the equilibrium P concentration EPC0 ranged from 0.09 to 0.2 mg/L. The high Smax in most of the sites, fairly high EPC0 and high percentages of Pr (>96%), indicate substantial amounts of P could be bioavailable for plant uptake in the water column under changing hydro-climatic conditions. Dominant P compounds are dihydroxyacetone phosphate (DHAP), phosphoenolpyruvates (PEP), inosine monophosphate (IMP), glucose-6-phosphate (G6P), nucleoside monophosphates (NMP), glycerophosphate (GlyP), polynucleotides (PolyN), and pyrophosphates (Pyrop). The active P pool could maintain substantial P bioavailability and potentially cause eutrophication. The mineralization of 7, 15 and 30 days in laboratory experiments indicates a decrease of NaHCO3 and HCl, and an increase of NaOH.

STUDY ON FLOTATION OF RARE EARTH MINERALS WITH P538 AND ITS MECHANISM

The properties and collecting ability of a new collector,monoalkyl ester phosphoric acid(P538),for the flotation of rare earth minerals are described in the paper.The mechanism of P538 adsorption on the surfaces of monazite or bastnaesite is explored by modern measuring techniques,such as IR and ESCA,etc.

Biodiversity,current developments and potential biotechnological applications of phosphorus-solubilizing and-mobilizing microbes:A review

As one of the most important and essential macronutrients next to nitrogen,phosphorus(P)is important for plant development,but it is the least mobile nutrient element in plant and soil.Globally,P is mined from geological sediments and added to agricultural soils so as to meet the critical requirements of crop plants for agronomic productivity.Phosphorus exists in soil in both organic and inorganic forms.The various inorganic forms of the element in soil are salts with calcium,iron,and aluminum,whereas the organic forms come from decaying vegetation and microbial residue.There is a huge diversity of plant microbiomes(epiphytic,endophytic,and rhizospheric)and soil microbiomes that have the capability to solubilize the insoluble P and make it available to plant.The main mechanism for the solubilization of inorganic P is by the production of organic acids,which lowers soil pH,or by the production of acid and alkaline phosphatases,which causes the mineralization of organic P.The P-solubilizing and-mobilizing microorganisms belong to all three domains,comprising archaea,bacteria,and eukarya.The strains belonging to the genera Arthrobacter,Bacillus,Burkholderia,Natrinema,Pseudomonas,Rhizobium,and Serratia have been reported as efficient and potential P solubilizers.The use of P solubilizers,alone or in combination with other plant growth-promoting microbes as an eco-friendly microbial consortium,could increase the P uptake of crops,increasing their yields for agricultural and environmental sustainability.