Search results for "Phosphorus"

Detection and discrimination of organophosphorus pesticides in water by using a colorimetric probe array

2014

[EN] Detection and discrimination of several organophosphorus pesticides in water using a colorimetric probe array containing twelve dyes has been achieved. A clear discrimination for malathion, leptophos, dichlorvos, dibrom and diazinon was observed. The array was used to determine the concentration of diazinon in orange leaves

Seasonal Variation in Nutrient Status of Foxglove Leaves

2006

The seasonal variation of mineral elements and the relationships among them were studied in natural populations of foxglove (Digitalis obscura). Young and mature leaves were collected in 10 different populations and on four sample dates (May, July, October, and February). Leaf mineral elements [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu)] were determined. The highest concentrations of N, P, and K in young leaf were recorded in May, followed by a decrease in the other months, while in contrast Ca and Fe showed the lowest concentration in May. Mature leaves showed differential seasonal behavior. Besides seaso…

Detection and prevention of enhanced biological phosphorus removal deterioration caused by Zoogloea overabundance.

2008

A sequencing batch reactor was operated in the conventional anaerobic-aerobic mode for enhanced biological phosphorus removal using acetate as the sole substrate. Despite the nutrients concentrations in the influent being high enough to satisfy the biological requirements, Zoogloea ramigera managed to grow in the system until it had negative effects on the process performance. The excess of exocellular polymeric material produced by this microorganism contributed to a viscous bulking phenomenon and caused important settling problems. The examination of the sludge under the microscope was a valuable tool to diagnose the cause of the imbalance in the process. The strategy adopted to avoid the…

Ekstrakcja fosforu z osadów ściekowych i popiołów ze spalania osadów - analiza problemu

2016

Fosfor jako pierwiastek niezbędny do produkcji rolniczej, w miarę wyczerpywania się zasobów fosforytów, staje się komponentem coraz bardziej deficytowym. Koniecznym wydaje się wdrożenie metod taniego i efektywnego odzysku tego pierwiastka z wszelkiego rodzaju odpadów. Szczególnie cennym źródłem fosforu są popioły z osadów ściekowych i same osady. Optymalizacja metod sekwencyjnej ekstrakcji fosforu zawartego w popiele z termicznego przekształcania osadów ściekowych i odwodnionych osadów pozwala na wybór efektywnej i nieskomplikowanej technologicznie możliwości odzysku fosforu, przy jednoczesnym zachowaniu niskiego obciążenia eluatu metalami ciężkimi, które są jedną z głównych przyczyn ograni…

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…

ChemInform Abstract: Benzothietes. Versatile Synthons for the Preparation of Heterocycles

2010

Abstract Thermal or photochemical ring opening transforms benzo[b]thiete to o-thiobenzoquinonemethide, a highly reactive 8π electron system. Cycloaddition reactions or linear additions with subsequent cyclizations lead to larger heterocyclic rings. A variety of compounds containing sulfur and possibly further heteroatoms like nitrogen, oxygen or phosphorus in normal, medium and large ring systems can be synthesized on this route.

AC3-Symmetric Palladium Catalyst with a Phosphorus-Based Tripodal Ligand

2006

Studies on the synthesis of heterocyclic compounds. III. Preparation of some pyrazolo[3,4-C] [1,5]benzodiazocin-10(11H)one derivatives

1979

Starting from the readly available N-melhyl-N-(1-phenyl-3-R-pyrazol-5-yl)-2-nitrobenzamides (1a,b), the pyrazoles, 4-aeetyl substituted 2a,b, were prepared in high yield. Reduction of 2a gave the amino derivative 4a, which was eyclized to the desired pyrazolo[3,4-c][1,5]benzodiazo-cin-10(11H)one (5a). Compound 2b afforded 5b directly. Compound 5b was also prepared by the action of phosphorus oxychloride on N-methyl-N-(1,3-diphenylpyrazol-5-yl)-2-acetamido-benzamide (6b).

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.

The effect of iron on the biodegradation of natural dissolved organic matter

2016

Iron (Fe) may alter the biodegradation of dissolved organic matter (DOM), by interacting with (DOM), phosphorus (P) and microbes. We isolated DOM and a bacterial community from boreal lake water and examined bacterial growth on DOM in laboratory experiments. Fe was introduced either together with DOM (DOM-Fe) or into bacterial suspension, which led to the formation of insoluble Fe-precipitates on bacterial surfaces (Fe coating). In the latter case, the density of planktonic bacteria was an order of magnitude lower than that in the corresponding treatment without introduced Fe. The association of Fe with DOM decreased bacterial growth, respiration, and growth efficiency compared with DOM alo…