Form Of P2O5 Research Articles

Influence of sulfur ions on the glass-forming ability and structure of silicate-phosphate glasses

The aim of the study was to analyze the structure of two groups of glasses: first sulfur-free from the SiO2-P2O5-K2O-MgO system and second sulfur-containing from the SiO2-P2O5-K2O-MgO-SO3 system with various network formers content in the form of P2O5 and SiO2. The sulfur speciation in the sulfur-bearing glasses was also determined. The sulfur-containing glasses were obtained under reducing conditions. The bulk composition of the glasses was confirmed by X-Ray Fluorescence Spectroscopy. The amorphous nature of the samples was verified using XRD analysis. The structure of the materials was studied with the 29Si and 31P MAS NMR and XAS spectroscopic techniques. It was found that the addition of sulfur increased the ability of glasses with higher amounts of P2O5 to form. XAS spectra demonstrate that S-bearing glasses contain sulfur in the reduced form as S2-. The 31P and 29Si MAS NMR spectra did not detect P-S and Si-S linkages.

Stabilized sewage sludge: Sanitary aspects and potential for conversion to biosolids

The improvement of wastewater treatment techniques is of crucial importance for effluent quality, but it also results in an increased amount of waste sludge. Dehydrated sludge contains organic matter and nutrients, and therefore it can be used in agriculture and bioremediation, but it is considered a potential source of environmental pollution. As the sludge analyzed in the research does not contain impermissible levels of organic and inorganic pollutants, the aim of the research was to examine microbiological, particularly sanitary, aspects and potential for its further use. Microbial diversity was determined by the standard serial dilution technique and selective media, and sanitary quality indicators (total coliforms, fecal coliforms, Escherichia coli and Salmonella spp.) were determined by the MPN method. The abundance of fungi, actinomycetes, and bacteria (ammonifiers, spore-forming bacteria and Pseudomonas spp.) indicate possibilities for further use of the sludge. The chemical analysis included the following parameters: total nitrogen (N), phosphorus in the form of P2O5 (available P), organic carbon (C), C/N ratio, pH, and water content. The chemical composition indicates the potential of sewage sludge to be used as a soil fertilizer, but its C/N ratio is not adequate to enable successful conversion to biosolids by the composting process. The obtained results indicate a significant level of microbiological contamination, which was most pronounced in the centre of the stabilized sludge pile. The research showed the necessity to conduct further studies on the microbial diversity and sanitary aspects of sewage sludge for proper waste sludge management.

Soil-dwelling arthropods as indicators of erosion in a South African grassland habitat

Soil erosion is a natural process that drives the formation of lowland terrains in mountainous regions. Its role in ecosystem degradation has been strongly debated, due to the significant effect it has on a range of land types. Soil arthropods have been used as indicators of several disturbance types. However, little is known about arthropods in eroded sites in South Africa. The aim of this study was to identify possible indicators of erosion in the Golden Gate Highlands National Park, South Africa, and to determine differences in soil-dwelling arthropod assemblages found in non-rehabilitated and rehabilitated sites over a 24-month period. A total of 5661 soil arthropods were sampled during the study, with the highest species richness recorded in non-rehabilitated eroded sites. A higher number of unique arthropod species were recorded from the non-rehabilitated sites compared to other site types. Overlaps in assemblage structure between site types differed, dependent on site locality. IndVal results, based on species fidelity and specificity in the given habitats, indicated a single strong indicator, the mite Speleorchestes meyerae Theron and Ryke, 1969, for the non-rehabilitated eroded sites. Linear model analyses of site richness with mineralogy identified the significance of phosphorus (in the form of P2O5) in eroded sites. Given these results, soil mineralogy in conjunction with soil arthropod richness of eroded sites could be used to investigate the effect of erosion and form a basis for future study in soil biodiversity and function.

Acid-free activation process of Vyatka – Kama phosphate in the presence of nitrogen-and potassium-containing salts

The work describes the production of complex fertilizers of prolonged effect on the basis of acid-free processing of phosphate rock of the Vyatka-Kama Deposit. The authors investigated the influence of chemical composition of salts and mass ratio between salt and phosphate components on the degree of activation of the phosphorite flour of the Vyatka-Kama Deposit (VKPF) during its treatment with solutions and suspensions of nitrogen-containing mineral salts and potassium chloride. It has been determined that the content of available form of P2O5 in phosphorite increases by 1.5-2 times, and the greatest activating effect is provided by ammonium salts. The use of preliminary mechanical activation of VKPF, in the method investigated, provides the increase in the content of available form of P2O5 by 11–13 %. The mechanism of interaction of the main minerals of phosphorite with salt additives (ammonium sulfate, ammonium nitrate, ammonium chloride, carbamide, potassium chloride) is proposed. The dynamics of changes in the content of ammonium nitrogen in fertilizer compositions at each stage of the process has been determined. The method for producing complex fertilizers based on phosphorite flour of the Vyatka-Kama Deposit has been developed and patented.

Effect of Phosphorus Fertilization on Dry matter Accumulation and it's Remobilization in Oil seed Flax (Linum usitatissimum L.) under rainfed condition

This experiment was carried at Qlyasan Research Station. Faculty of Agricultural Sciences, University of Sulaimani, during 2016-2017 to study the effect of four levels of phosphorus fertilizer in the form of P2O5 (0 control, 100, 200 and 300 kg P2O5ha-1) on two oilseed flax varieties (Poland and Syria local) dry matter and Phosphor accumulation and their translocation from source to sink . Results showed that Poland variety with the 200kg P2o5 ha-1 in all studied parameters significantly being higher than Syria local, and other levels of P2O5 fertilizer. Compared to control 200kg P2O5 increased DM accumulation at 50% anthesis by (44.48 and 27.04%), DM translocation efficiency by (24.46and 38.19 %), Contribution of leaves DM to final grain by (53.57 and 44.060%), P accumulation in vegetative tissues at 50% anthesis by (69.59 and 81.65 %), P translocation efficiency by (51.85 and 70.02%), leaf P contribution to final grain by (50.69 and 73.63%), also at maturity increased biological yield by (27.16 and 29.72%), and increased grain yield by (20 and 27%) for Poland and Syria local respectively, with no significant increment above that level. In both varieties at 50% anthesis the leaves DM were increased and reached peak at 200kg P2O5ha-1 but as the plant reached maturity the leaves DM significantly lower by ten times than stem DM+NG. These results suggest that 1.The leaves in oil seed flax are the major DM and P contributor to grain after anthesis whereas the stem and NG are the stronger demand for DM and P post anthesis.2. Variety of Poland under the 200kgP2O5 ha-1 could be suitable for grain yield under rainfed condition in Sulaimani province.

Effect of phosphorus and gibberellic acid on growth and yield of grape (Vitis vinifera L.)

The experiment was conducted during 2017–18 in Kombetlar village of Kirkuk Province, Iraq. The aim of this study was to evaluate the effect of phosphorus and gibberellic acid on growth and yield of grape (Vitis vinifera L.). The first factor in this experiment was phosphorus in the form of P2O5 with three levels (0, 5 and 10 g/l) supplied through phosphatic fertilizer containing 46% phosphorus. The second factor was three levels (0, 100 and 200 ml/l) of gibberellic acid concentrations. The experiment was laid out in completely randomized block design with three replications and one grapevine was assumed as one plot. The results of this study showed significant effects of phosphorus and gibberellic acid on leaf area, chlorophyll content, carbohydrates, cluster number, cluster weight, fruit number, juice intensity, total soluble solids and total acidity of grape.

Influence of phosphorus from phosphogypsum on the initial hydration of Portland cement in the presence of superplasticizers

Phosphogypsum is widely used for the total or partial substitution of natural gypsum in the production of Portland cement. However, contaminants from the phosphogypsum, such as chemicals that contain phosphorus, may affect the performance of the binder, especially when it is applied to concrete that uses chemical admixture. The goal of this study is to evaluate the impact of successive increments of Na2HPO4 on the hydration of cements that are produced with low or high phosphorus concentrations in the presence of ether–polycarboxylate–based (PCE) and sulfonated–naphthalene–formaldehyde–based (SNF) superplasticizers. Two binders with the same clinker size were produced in the laboratory with natural (phosphorus–free) gypsum and phosphogypsum (contaminated). The isothermal calorimetry and thermogravimetry (TG/DTG) techniques were used to evaluate the heat flow behavior and the formation of portlandite at the end of the induction period (Pi), at the maximum heat flow (Pmax), and at the final 72-h stage (P72). The results indicate that the greatest impact on hydration occurs at phosphorus concentrations between 0.83% and 1.64% in the form of P2O5 in the phosphogypsum and especially at a concentration of 1.13%. Nonetheless, in all cases, the formation of portlandite after 72 h is very similar.

Physico-Chemical Quality of Lake Kyoga at Selected Landing Sites and Anthropogenic Activities

Lake Kyoga, one of the great African lakes in Uganda is facing an increasing pressure from human activities yet there is limited information on water quality of the lake. Therefore this study determined selected physico-chemical parameters of Lake Kyoga at some landing sites (Kayei, Acholi inn, Waitumba, Masindi port) and anthropogenic activities (boat dock, waste site, garden, fishing). The parameters included temperature, pH, water flow rate, dissolved oxygen (DO), nitrite (NO2-) and phosphate (PO4-P). The American Public Health Association (APHA) and Water Watch Australia protocols, standard meters, Merck’s rapid test kits and timing of a float were used to measure the parameters. The results showed that the mean temperature, pH, DO, and PO4-P significantly (p < 0.05) varied across the anthropogenic activities. On the other hand, only temperature, pH and flow rate varied significantly (p < 0.05) across the landing sites. Lake Kyoga water flow rates were the fastest at Masindi port (0.031 m/s) and the least in Waitumba (0.021 m/s) governed by river inflow and surface vegetation cover. The mean pH (6.73 - 7.15) and DO (10.15 - 13.50 mg/l) of the lake at all the study sites were within the Environmental Protection Agency (EPA) standard values of 5.5 - 8.5 and ≥9.0 mg/l respectively. These mean pH and DO values reflect more or less neutral waters which are equally well saturated with oxygen at all the landing sites. However, areas close to the waste sites had the least oxygen levels (10.15 mg/l) followed by gardens (11.82 mg/l) while fishing areas were the most saturated with oxygen (13.50 mg/l). On the other hand, temperature (25.06°C - 25.76°C) and (0.13 - 0.49 mg/l) levels in the study sites were above EPA standards of 25°C and ≤0.03 mg/l respectively signifying warmer waters and sewage pollution at the sites. Fortunately, the NO2- levels were within the EPA drinking water guideline of 0.5 mg/l. The orthophosphates (PO4-P) were highest in the waste sites (0.35 mg/l), followed by gardens (0.24 mg/l) and least in the fishing areas (0.12 mg/l). However, phosphates in the form of P2O5 were higher than the EPA standard value (0.5 mg/l) at Kayei (0.55 mg/l) and Acholi inn (0.55 mg/l) landing sites as well as at waste sites (0.80 mg/l) and gardens (0.55 mg/l) pointing to high nutrient (phosphorus) input at these sites. The high concentrations of nitrites in Lake Kyoga at the investigated anthropogenic activities and landing sites plus phosphate amounts close to waste sites and gardens including Kayei and Acholi inn landing sites call for vigilance in protection of Lake Kyoga through optimized planning. Hence, National Environment Management Authority should ensure proper sewage management in Lake Kyoga catchment to avoid discharge of untreated sewage into the lake. The authority should also regulate waste dumping and cultivation around the lake so as to reduce nutrient (phosphorus) enrichment.

Comparative study of zinc addition effect on thermal properties of silicate and phosphate glasses

The aim of the study was an analysis of two groups of glasses from the SiO2–P2O5–K2O–CaO–MgO system with various content of network formers in the form of P2O5 and SiO2, modified by the addition of ZnO. Their effect on glass-forming ability, glass transition effect, crystallization process and the kind of crystallizing phases was examined using DSC and XRD methods. It was observed that in both matrixes, the addition of ZnO decreases the glass transition temperature (T g). The lower T g values observed in the phosphate matrix glasses and the accompanying higher values of the changes in molar heat capacity (Δc p) in contrast to the silicate matrix glasses may be considered an indicator of the degree of the reconstruction of their amorphous structure, which facilitates the process of their crystallization. It was found that the crystallizing products of the silicate matrix glasses were silicates and phosphates whose structure contained zinc. In the phosphate matrix glasses, it was observed that zinc inhibited the crystallization of silicate phases.

Interaction of Rhizobium and Pseudomonas with Wheat (Triticum Aestivum L.) in Potted Soil with or Without P2O5

The effect of inoculation of Rhizobium or Pseudomonas, or both, in the presence and absence of phosphorus pentoxide (P2O5) fertilizer on wheat yield was tested. The experiment was conducted outdoors in potted soil during two consecutive years under natural conditions. Rhizobial strain (Thal 8-chickpea nodulating bacteria) and Pseudomonas strain (54RB), both indigenous P solubilizers were applied in broth culture at seedling stage. Fertilizer in the form of P2O5 was an additional treatment applied at sowing time. Results revealed that inoculation of Pseudomonas strain in presence of phosphorus (P) fertilizer increased yield up to 41.8% when it was compared with only P fertilizer applied. Co-inoculation of Rhizobium and Pseudomonas strains with the P2O5 treatment however resulted in increased grains yield by 10% over the P2O5 treatment alone. It is inferred that inoculation with Rhizobium and Pseudomonas combined with P2O5 is not only environmentally beneficial but also economically sound and productive, with wheat yield increases of 10% to 42%.

The effects of N and P additions on microbial N transformations and biomass on saline-alkaline grassland of Loess Plateau of Northern China

Microbial nutrient transformation plays an important role in regulating nitrogen (N) and phosphorus (P) cycling in terrestrial ecosystems. Soil N and P contents also control microbial nutrient transformations. However, there is still dispute on how N and P additions affect microbial activity and N transformations. A field experiment was conducted to examine the effects of N and P on microbial N transformations and biomass in saline-alkaline grassland in Loess Plateau of northern China during growing season in 2009. N was added at a rate of 10gNm−2 y−1 in the form of NH4NO3. P was added at a rate of 5g P m−2 y−1 in the form of P2O5−. We measured the in situ net ammonification rate (Ramm), and nitrification rate (Rnit) once a month from May to October; we also measured potential soil microbial biomass carbon (MBC), nitrogen (MBN), and potential microbial respiration (MR) once a month in laboratory. ResultsDuring the whole growing seasons, P addition significantly stimulated soil inorganic N pool, soil extractable C, soil extractable N pool, Rmin, and the metabolic quotient (qCO2) from the estimates of microbial respiration and microbial biomass carbon, and there was no effect on peak aboveground biomass, MBC, MBN and MR during the whole growing seasons in 2009. N addition significantly increased peak aboveground biomass, inorganic N pool, Rmin, MBN, MR, and qCO2, decreased soil extractable C and the ratio of MBC/MBN, and there was no effect on soil extractable N and MBC during the growing season in 2009. P addition increased the soil net N mineralization rate and N addition not only increased the soil net N mineralization rate but also increased microbial biomass N. We observed that P induced a decreased soil inorganic N pool, but N addition directly increased soil inorganic N pool, how to balance the quantity of N and P additions in agriculture system is an important technique in agriculture harvest in the future in Loess Plateau of Northern China.

Mechanochemical activation of ordinary phosphorite powder of Central Kyzylkum mixed with urea nitrate and ammobium carbonate salts

Grinding of ordinary phosphorite powder of Central Kyzylkum with urea nitrate and ammonium carbonate salt to the particles size less than 0.16 mm is shown leading to significant increase in content of consumable by plants form of P2O5 in the products.