Search results for " Phosphorus"

RAVITA Technology : new innovation for combined phosphorus and nitrogen recovery

2018

Abstract Present phosphorus (P) recovery technologies mainly contain P recovery from sludge liquor or ash. These types of technologies are suitable for large wastewater treatment plants (WWTPs) with enhanced biological phosphorus removal (EBPR), digestion and/or incineration. In Finland and other Nordic countries, strict P discharge limits require chemical precipitation, thus EBPR alone is not sufficient. Ammonium recovery from wastewater, on the other hand, is not so often discussed. However, recovery from WWTP reject waters would decrease the energy demand of ammonium synthesis by Haber-Bosh technology and the energy demand of the WWTP's biological process. Helsinki Region Environmental S…

Influence of sludge age on enhanced phosphorus removal in biological systems

1996

The phosphorus removal process was studied in a bench-scale plant for a period of 300 days. The process was observed to depend greatly on two parameters: the amount of volatile fatty acid (VFA) taken up in the anaerobic stage and sludge age. For a given sludge age, phosphorus release versus VFA uptake in the anaerobic stage could be fitted to a straight line, while phosphorus uptake in the non-anaerobic stages fitted a logarithmic curve. Thus, phosphorus removal occurred within a limited VFA uptake range. The range width and the phosphorus removal capacity varied with sludge age.

Pentakis(dimethylzinn)diphosphid, struktur und kernresonanzspektren eines zinnreichen bicyclus

1979

Abstract Dehydrogenation of dimethylstannane combined with the hydrostannolysis of white phosphorus yields pentakis(dimethyltin) diphosphide, a tin-rich heterocyclic compound, which has the highly symmetric, bicyclic molecular structure of norbornane. Using the X-ray structure data the magnetic resonance spectra are discussed.

Speciation of chitosan-phosphate and chitosan-nucleotide systems in an NaCl aqueous solution

2010

AbstractThe speciation of chitosan (310 kDa) with organic (adenosine 5’-monophosphate, AMP, and adenosine 5’-triphosphate, ATP), and inorganic phosphorus containing ligands (phosphate and pyrophosphate) was investigated in NaCl aqueous solutions at I = 0.1mol L−1 and T = 25°C. For all the systems, the investigated results obtained gave evidence for the formation of (chitosan)LHi complex species (L = nucleotides, phosphate and pyrophosphate; i = 1 to 4, but for AMP, i = 1 to 3). The stability data of complex species were used to calculate the sequestering ability of chitosan towards phosphorus compounds considered here, expressed as pL50 i.e., – log(total chitosan concentration) necessary to…

Design of nutrient removal activated sludge systems

2003

A mechanistic mathematical model for nutrient and organic matter removal was used to describe the behavior of a nitrification denitrification enhanced biological phosphorus removal (NDEBPR) system. This model was implemented in a user-friendly software DESASS (design and simulation of activated sludge systems). A 484-L pilot plant was operated to verify the model results. The pilot plant was operated for three years over three different sludge ages. The validity of the model was confirmed with data from the pilot plant. Also, the utility of DESASS as a valuable tool for designing NDEBPR systems was confirmed.

Calcium effect on enhanced biological phosphorus removal.

2006

The role of calcium (Ca) in enhanced biological phosphorus removal and its possible implications on the metabolic pathway have been studied. The experience has been carried out in an SBR under anaerobic–aerobic conditions for biological phosphorus removal during 8 months. The variations of influent Ca concentration showed a clear influence on the EBPR process, detecting significant changes in YPO4. These YPO4 variations were not due to influent P/COD ratio, pH, denitrification and calcium phosphate formation. The YPO4 has been found to be highly dependent on the Ca concentration, increasing as Ca concentration decreases. The results suggest that high Ca concentrations produce “inert” granul…

Organic Field Effect Transistors: Noncovalent Functionalization and Passivation of Black Phosphorus with Optimized Perylene Diimides for Hybrid Field…

2020

White Phosphorus Is Air-Stable Within a Self-Assembled Tetrahedral Capsule

2009

Molecular Fire Quencher Cage-shaped molecular assemblies can regulate the reactivity of smaller molecules trapped within them. Mal et al. (p. 1697 ) extend this approach to enable the protection of elemental white phosphorus (P 4 ), a substance that rapidly ignites on contact with oxygen. The tetrahedral cages self-assemble in aqueous solution through coordination of six ligands to four iron ions, and efficiently capture phosphorus from a suspension. The water-soluble host-guest constructs were stable in air for at least 4 months, but released intact P 4 rapidly on displacement by added benzene.

1,1′-(Diphosphene-1,2-diyl)bis(2,2,6,6-tetramethylpiperidine)

2017

The title compound, C18H36N2P2, crystallizes in the triclinic space groupP-1 with two independent molecules in the asymmetric unit. Both molecules adopt atransconfiguration of the tetramethylpiperidine units along the P=P axis. The crystal packing is stabilized only by van der Waals interactions.

Biological nutrient removal in membrane bioreactors: denitrification and phosphorus removal kinetics.

2007

The impact of including membranes for solid liquid separation on the kinetics of nitrogen and phosphorus removal was investigated. To achieve this, a membrane bioreactor (MBR) biological nutrient removal (BNR) activated sludge system was operated. From batch tests on mixed liquor drawn from the MBR BNR system, denitrification and phosphorus removal rates were delineated. Additionally the influence of the high total suspended solids concentrations present in the MBR BNR system and of the limitation of substrate concentrations on the kinetics was investigated. Moreover the ability of activated sludge in this kind of system to denitrify under anoxic conditions with simultaneous phosphate uptak…