Search results for "fosfaatit"
showing 10 items of 16 documents
Synthesis and Structures of Aluminum and Magnesium Complexes of Tetraimidophosphates and Trisamidothiophosphates: EPR and DFT Investigations of the P…
2005
Reactions of (RNH)3PNSiMe3 (3a, R = tBu; 3b, R = Cy) with trimethylaluminum result in the formation of {Me2Al(μ-NtBu)(μ-NSiMe3)P(NHtBu)2]} (4) and the dimeric trisimidometaphosphate {Me2Al[(μ-NCy)(μ-NSiMe3)P(μ-NCy)2P(μ-NCy)(μ-NSiMe3)]AlMe2} (5a), respectively. The reaction of SP(NHtBu)3 (2a) with 1 or 2 equiv of AlMe3 yields {Me2Al[(μ-S)(μ-NtBu)P(NHtBu)2]} (7) and {Me2Al[(μ-S)(μ-NtBu)P(μ-NHtBu)(μ-NtBu)]AlMe2} (8), respectively. Metalation of 4 with nBuLi produces the heterobimetallic species {Me2Al[(μ-NtBu)(μ-NSiMe3)P(μ-NHtBu)(μ-NtBu)]Li(THF)2} (9a) and {[Me2Al][Li]2[P(NtBu)3(NSiMe3)]} (10) sequentially; in THF solutions, solvation of 10 yields an ion pair containing a spirocyclic tetraimid…
Screening of microalgae and LED grow light spectra for effective removal of dissolved nutrients from cold-water recirculating aquaculture system (RAS…
2019
Popularity of recirculating aquaculture systems (RAS) is increasing. Because of the high water recirculation rate, dissolved nutrients originating from fish feed are concentrated enough in RAS wastewater (WW) to enable growth of primary producers, e.g. microalgae. This study evaluated nitrate-nitrogen (NO3-N) and phosphate-phosphorus (PO4-P) removal efficiency of ten temperate zone freshwater microalgae species during their exponential growth phase in unfiltered RAS WW at 17 ± 0.5 °C. Growth and nutrient uptake efficiency of six green and four non-green microalgae strains were compared between WW and reference growth medium in batch monocultures. The effect of three different LED grow light…
Use of Calcined Dolomite as Chemical Precipitant in the Simultaneous Removal of Ammonium and Phosphate from Synthetic Wastewater and from Agricultura…
2019
Phosphorus as phosphate and nitrogen as ammonium or nitrate are the main nutrients in wastewaters and agricultural sludges. They runoff easily to waterways and cause eutrophication in water bodies. However, ammonium and phosphate could be precipitated simultaneously and used as recycled nutrients. In this research, dolomite calcined at 650 °
The use of calcined paper mill sludge as a chemical precipitant in the simultaneous removal of ammonium and phosphate : paper mill waste recycling an…
2020
Currently, recycling and re-use of materials is extremely important due to the diminishing of natural resources. The objective of the European Union’s circular economy strategy is to increase recycling and the use of industrial waste materials and side streams as secondary raw materials. In this study, a chemical precipitation method to simultaneously remove ammonium nitrogen and phosphate from the liquid phase of anaerobic digestate using calcined paper mill sludge was studied. Papermill sludge is a waste material that forms in the paper-making process. In addition, commercial calcium oxide (CaO) was used as a reference precipitant. The suitability of the formed precipitate’s composition f…
Sharing the salt bowl: counterion identity drives N-alkyl resorcinarene affinity for pyrophosphate in water
2021
N-Alkyl ammonium resorcinarene chloride receptors, NARX4, have been shown to act as high-sensitivity detectors of pyrophosphate (PPi), a biomarker of disease, in aqueous media through the chloride-to-PPi exchange [NAR(Cl)4 to NARPPi]. The nature of the anion of the macrocyclic NARX4 (X = Cl−, Br−, triflate OTf−) receptor greatly influences the PPi-affinity in aqueous media. The binding affinity for [NAR (Cl)4] is 3.61 × 105 M−1, while the NAR (Br)4 and NAR (OTf)4 show stronger binding of 5.30 × 105 M−1, and 6.10 × 105 M−1, respectively. The effects of upper rim ammonium cation, –N+H2R substituents (R = 3-hydroxypropyl, cyclohexyl, benzyl, or napththalen-1-ylmethyl), of the macrocyclic resor…
Optimizing the H3PO4 leaching conditions of post-precipitated sewage sludge using response surface methodology
2018
The leaching procedure of post-precipitated aluminium phosphate sludge with dilute phosphoric acid was developed. The leaching offers a route to recover both critical phosphorous from sewage sludge and the metal used in precipitation. Using phosphoric acid as leaching solution makes it possible to continue the recovery process without the need to remove chloride or sulfate anions. The optimization of the leaching was based on experimental three-level-four-variable central composite face-centered design. The four variables included were acid concentration, volume of acid, temperature and time of leaching. The leaching was conducted for dewatered and water-containing sludge (total solid conte…
Efficient stabilisation of a dihydrogenphosphate tetramer and a dihydrogenpyrophosphate dimer by a cyclic pseudopeptide containing 1,4-disubstituted …
2017
A cyclic pseudooctapeptide 2 is described containing 1,4-disubstituted 1,2,3-triazole moieties. This compound features eight converging hydrogen bond donors along the ring, namely four amide NH and four triazole CH groups, which enable 2 to engage in interactions with anions. While fully deprotonated sulfate anions exhibit only moderate affinity for 2, protonated anions such as dihydrogenpyrophosphate and dihydrogenphosphate anions are strongly bound. Complexation of the phosphate-derived anions involves sandwiching of a dihydrogenpyrophosphate dimer or a dihydrogenphosphate tetramer between two pseudopeptide rings. X-ray crystallography provided structural information, while 1H NMR spectro…
Cubic and Spirocyclic Radicals Containing a Tetraimidophosphate Dianion [P(NR)3(NR‘)]•2-
2005
The reaction of Cl3PNSiMe3 with 3 equiv of LiHNR (R = iPr, Cy, tBu, Ad) in diethyl ether produces the corresponding tris(amino)(imino)phosphoranes (RNH)3PNSiMe3 (1a, R = iPr; 1b, R = Cy; 1c, R = tBu; 1d, R = Ad); subsequent reactions of 1b−d with nBuLi yield the trilithiated tetraimidophosphates {Li3[P(NR)3(NSiMe3)]} (2a, R = Cy; 2b, R = tBu; 2c, R = Ad). The reaction of [(tBuNH)4P]Cl with 1 equiv of nBuLi results in the isolation of (tBuNH)3PNtBu (1e); treatment of 1e with additional nBuLi generates the symmetrical tetraimidophosphate {Li3[P(NtBu)4]} (2d). Compounds 1 and 2 have been characterized by multinuclear (1H, 13C, and 31P) NMR spectroscopy; X-ray structures of 1b,c were also obtai…
Precipitation of potassium as hazenite from washing water of spent alkaline batteries
2022
Hazenite (KNaMg2(PO4)2 × 14 H2O), a new type of struvite mineral, was precipitated from the potassium-rich washing water of spent alkaline battery black mass. Hazenite can be used as a fertilizer, which would be an additional benefit derived from the sustainable recovery of battery materials. Precipitation experiments were performed using different pH values (9.5–12), Mg:K:PO4 ratios ((1.0–1.5):1:(1.0–1.5)) and temperatures (10–40 °C). Based on the results, hazenite precipitated in a wide pH range under alkaline conditions. The precipitation kinetics were fast, and the purity of the hazenite was high. Overall, hazenite can be precipitated at room temperature without the addition of excess c…
Effects of a glyphosate-based herbicide on survival and oxidative status of a non-target herbivore, the Colorado potato beetle (Leptinotarsa decemlin…
2018
Abstract Glyphosate is the globally most used herbicide against a wide range of weeds. Glyphosate has been considered safe to animals as it mainly targets physiological pathways in plants. However, recent toxicological studies have revealed that glyphosate can cause various toxic effects also on animals. In this study, we investigated the direct toxic effects of a glyphosate-based herbicide (GBH, Roundup® Bio) on 1) survival and 2) oxidative status of a non-target herbivore by using Colorado potato beetles (Leptinotarsa decemlineata), originating from Poland and USA, as model species. Larvae were randomly divided into three groups: 1) high concentration (100% Roundup Bio, 360 g/l), 2) low c…