Recovery of phosphates(V) from wastewaters of different chemical composition

2019 ◽  
Vol 17 (1) ◽  
pp. 1071-1079 ◽  
Author(s):  
Nina Hutnik ◽  
Anna Stanclik ◽  
Krzysztof Piotrowski ◽  
Andrzej Matynia

AbstractPhosphate(V) ions were recovered from wastewaters of different chemical compositions in a continuous reaction crystallization of struvite. Two real wastewaters were represented by an effluent sample from the phosphorus mineral fertilizer industry and by liquid manure derived from a cattle-breeding farm. Two other wastewaters were prepared under laboratory conditions. Impurities present in the wastewaters caused the precipitation of solid products of distinctly different quality. The mean size of struvite crystals varied from ca. 18 to ca. 40 μm. Homogeneity within their populations, quantified by the coefficient of variation CV, varied from satisfactory (CV ca. 75%) to unfavorable (CV ca. 100%), which resulted in the elongation of necessary filtration time. Calcium ions in wastewater precipitated as amorphous hydrated calcium phosphates ACP. Their content in the products varied from 33.4 up to 73.1 mass %. Also 28.32 – 32.74 mass % of P2O5, 6.35 – 14.12 mass % of MgO and 4.35 – 16.94 mass % of CaO were confirmed in the products, together with hydroxides of some metals and salts of other impurities. Based on the chemical composition of the products derived from the investigated wastewaters, their application in agriculture as valuable mineral fertilizers is recommended.

1976 ◽  
Vol 31 ◽  
pp. 359-372 ◽  
Author(s):  
Peter M. Millman

AbstractThe contribution of meteor observations to our knowledge of meteoroids and interplanetary dust is reviewed under four headings – flux, mass distribution, physical structure and chemical composition. For lower limits of particle mass ranging from 1 g to 10−5 g the mean cumulative flux into the earth’s atmosphere varies from 2 × 10−15 to 6 × 10−9 particles m−2 s−1 (2Πster)−1, and the mean size distribution of these particles is given by log N = C – 1.3 log M, where N is the cumulative number of particles counted down to a lower mass limit M, and C is a constant. The physical structure of meteoroids in the above range is essentially fragile, with generally low mean bulk densities that tend to increase with decrease in mass. A minor fraction, about 10 or 15 per cent, with orbits lying inside that of Jupiter, have densities several times the average densities, approaching those of the carbonaceous chondrites. The mean chemical composition of meteoroids seems to be similar to the bronzite chondrites for the elements heavier than number 10, but with the probable addition of extra quantities of the light volatiles H, C and O.


2021 ◽  
Vol 50 (5) ◽  
Author(s):  
Y.J. Chen ◽  
Z.Y. Wang ◽  
C.G. Du ◽  
Z.L. Qi ◽  
Y.Q. Guo ◽  
...  

Correlations between chemical composition, enzymatic hydrolysate gross energy (EHGE), and true metabolizable energy (TME) of corn for ducks were investigated. Twenty-two corn samples were collected from various regions in 11 provinces of China. The crude protein (CP), ether extract (EE), neutral detergent fibre (NDF), Ash, gross energy (GE), dry matter (DM), amylopectin (AP), amylose (AM), total starch (TS), and AP/AM were determined for each sample. Five of the samples of corn were chosen at the mean, mean ± 1 standard deviation (SD), and mean ± 2 SD based on AP/AM. The EHGE of these samples was analysed using the pepsin-artificial small intestinal fluid enzymatic method. These five samples were also force-fed to male Cherry Valley ducks to assay their TME. Finally, correlation analyses were performed, and regression equations were established. Ash content, GE, and TS were highly related to EHGE. Univariate prediction equations were EHGE = 11.8566Ash-0.0421 (P <0.05), EHGE = 0.1535GE1.5642 (P <0.05), and EHGE = 0.1020TS1.1561 (P <0.05). The total starch, AP/AM, and ash of the chemical compositions were highly related to TME. The corresponding univariate regression equations were TME = 21.9355TS-0.0910 (P <0.05), TME = 15.6590AP/AM-0.0559 (P <0.05), and TME = 15.0778Ash0.0442 (P <0.05). The mean EHGE was equivalent to 78.5% of TME, but their correlation coefficient was low. In conclusion, chemical composition was predictive of EHGE and TME of corn samples for ducks, but the correlation of EHGE and TME was low Keywords: Cherry Valley duck, amylopectin, amylose, true metabolizable energy


2011 ◽  
Vol 236-238 ◽  
pp. 1437-1441 ◽  
Author(s):  
Hui Gao ◽  
Li Ping Zhang ◽  
Sheng Quan Liu

The case was carried out to study the variance of fiber feature, chemical composition and pulping property between heartwood and sapwood of poplar I-69. As results showed, the mean fiber length in heartwood and sapwood of poplar I-69 were 770 and 1146µm separately, with the length-to-width ratio of 42.56 vs 51.76, and the wall-to-lumen ratio of 0.40 vs 0.59, respectively. The heartwood of poplar I-69 differed from sapwood in contents of chemical compositions, with holocellulose of 82.65% vs 81.35%, α- cellulose of 42.83% vs 42.82% and lignin of 18.01% vs 21.68%, respectively. Both the heartwood and sapwood of poplar I-69were suitable for pulping material. By investigating pulp yield and Kappa number, it was proven that the caustic soda dosage and the duration of reaction temperature were major factors influencing KP pulping properties of poplar I-69 sapwood. Under the same technical conditions of pulping, the pulp of the poplar I-69 sapwood was lower in Kappa number and higher in yield and in viscosity compared with those of heartwood. The tensile index, tear index and burst index of paper made by sapwood were higher than those made by heartwood. The sapwood of poplar I-69 showed overall better pulping aptitude in comparison with heartwood.


Agriculture ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 467 ◽  
Author(s):  
Artur Przywara ◽  
Francesco Santoro ◽  
Artur Kraszkiewicz ◽  
Anna Pecyna ◽  
Simone Pascuzzi

We report the experimental results of tests aimed at assessing the effects of different settings on the mean radius of mineral fertilizer distribution using a disc fertilizer spreader. Our aim was to improve the performance of fertilizer distribution in sustainable agriculture. Three types of mineral fertilizers with different physical characteristics, commonly used in agriculture, were considered: urea, calcium ammonium nitrate and ammonium sulfate. A complete randomization method based on a four-factor experimental model was used to study the influence of the functional and operational parameters on the mean radius of fertilizer spread. Fixed model analysis of variance showed that fertilizer type, vane configuration and disc angular velocity explained 91.74% of the variance of the spread mean radius, while linear multiple regression analysis highlighted that the fertilizer dust fraction and disc angular velocity had an overall effect of 82.72%, the former showing an inverse correlation as high as 72.77%.


2018 ◽  
Vol 2 (95) ◽  
pp. 26-29
Author(s):  
O.S. Gavrishko ◽  
Yu.M. Olifir ◽  
T.V. Partyka

The results of studies of the change in redox potential in the profile of light gray forest surface-gleyed soil on variants with long-term agricultural use without applying fertilizers and mineral fertilizer system solely compared with the soil under the forest are presented. On the basis of the conducted analyzes it was established, that soil tillage without fertilizer application and with mineral fertilizer solely has a different effect on ROP in the profile. In the soil without fertilization (control) as compared to the forest a moderate oxidizing (514 mV) and slightly oxidizing (437 mV) processes are happening. Prolonged application of mineral fertilizers to the soil (N65R68K68) significantly reduced the redox potential of all genetic horizons compared with forest and control without fertilizers. For the given fertilizer system the highest values of ROP were obtained in arable HEgl and underarable HEgl layers: 426 mV and 416 mV respectively. Redox potential sharply decreases with the depth to 398-311 mV, which characterizes processes occurring in the soil profile, as weakly reducing and close to moderately reducing.


Author(s):  
H.M. Hospodarenko ◽  
◽  
I.V. Prokopchuk ◽  
K. P. Leonova ◽  
V.P. Boyko

The productivity of agricultural crops is the most variable and integral indicator of their vital activity, which accumulates their genetic potential, soil fertility, weather conditions and components of agricultural technology. Soybean under optimal growing conditions (the reaction of the soil is close to neutral, sufficient phosphorus and potassium nutrition, the use of nitraginization) assimilates from the air about 70 % of the total nitrogen requirement. Therefore, it is believed that it is enough to apply only a starting dose of nitrogen fertilizers (20–40 kg/ha a. s.), to get a high yield with good indicators of grain quality. The results of studies of the influence of long-term (8 years) application of different doses and ratios of fertilizers in field crop rotation on podzolized chernozem in the conditions of the Right -Bank Forest-Steppe of Ukraine on the yield and quality of soybean seeds preceded by spring barley were presented. It was found that crop yields could be increased by 18–77 % owing to different doses, ratios and types of fertilizers. The highest indicators of seed yields for three years of the research (3,02 t/ha) were obtained under the application of mineral fertilizers at a dose of N110P60K80 per 1 ha of crop rotation area, including under soybean – N60P60K60. Exclusion of the nitrogen component from the complete fertilizer (N60P60K60) reduced its yield by 26 %, phosphorus – by 17, and potassium by 11 %. There was no significant decrease in soybean yield in the variant of the experiment with a decrease in the proportion of potassium in the composition of complete mineral fertilizer (N60P60K30) for three years of study. The largest mass of 1000 soybean seeds was formed at doses of N60К60 fertilizers, and their protein content — under the application of complete mineral fertilizer in doses of N60P60K60 and N60P60K30.


Author(s):  
Fesenko, H.

Purpose. Increasing the uniformity of distribution of mineral fertilizers and other bulk materials due to the stability of their feed from the body to the spreading working bodies using the top feeder. Methods. The following methods are used to achieve this aim: the method of comparing the differences between individual groups of fertilizers, the method of analyzing the properties of a new technical system, the method of functional inventiveness, and the methods of theoretical and analytical mechanics. Results. The traction body of the conveyor of the upper feed of the body fat body machine for mineral fertilizers and other bulk materials was substantiated and the relationship between the height of its scrapers and the distance between them was established, as well as the nature of the mineral fertilizer pressure on the curvilinear wall of the body. In addition, the design of the advanced body fertilizer spreader is justified, which ensures a stable flow of fertilizers from the body due to the improvement of the top feeder. Conclusions. Because of the conducted researches, the advantages of machines equipped with top feeder are found. They create the conditions for the forced feeding mineral fertilizers and other loose materials from the container to the distribution bodies, which is a prerequisite for their evenness on the surface. With this, the imperfection of known machines with the top feeder constrains their introduction into agricultural production. On this account, a more thoroughly constructed solution of the body feeder of the top feed is substantiated, in which the conveyor provides a stable supply of fertilizers from the body with reduced energy consumption during operation. Keywords: analysis, feed, upper device, conveyor, stability, fertilizers, flow ability, body.


1994 ◽  
Vol 59 (6) ◽  
pp. 1301-1304
Author(s):  
Jaroslav Nývlt ◽  
Stanislav Žáček

Lead iodide was precipitated by a procedure in which an aqueous solution of potassium iodide at a concentration of 0.03, 0.10 or 0.20 mol l-1 was stirred while an aqueous solution of lead nitrate at one-half concentration was added at a constant rate. The mean size of the PbI2 crystals was determined by evaluating the particle size distribution, which was measured sedimentometrically. The dependence of the mean crystal size on the duration of the experiment exhibited a minimum for any of the concentrations applied. The reason for this is discussed.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ali Pouryousef ◽  
Erfan Eslami ◽  
Sepehr Shahriarirad ◽  
Sina Zoghi ◽  
Mehdi Emami ◽  
...  

Abstract Objectives The current study aimed to evaluate the effects of Ficus carica latex on the treatment of cutaneous leishmaniasis (CL), induced by Leishmania major. A 5% topical gel with F. carica latex was prepared. BALB/c mice were infected by inoculation of amastigotes form of L. major. Thirty BALB/c mice were divided into five groups, where the first group was treated daily, the second group twice per day, and the third group every other day with the 5% topical gel, for 3 weeks. The sizes of the lesions were measured before and during the course of treatment. Results Although the mean size of lesions in the mice group treated with the 5% F. carica gel, especially in the group receiving daily treatment, was less than the mean size of the lesions in the control group, yet, the differences was not statistically significant (p > 0.05). The findings of the current study demonstrated that the 5% F. carica latex with a 3-week course of treatment had no considerable effect in recovery or control of CL induced by L. major in the murine model. Using higher concentration of F. carica latex and with longer treatment lengths may increase its efficacy in the treatment of CL.


Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 653
Author(s):  
Shereef Bankole ◽  
Dorrik Stow ◽  
Zeinab Smillie ◽  
Jim Buckman ◽  
Helen Lever

Distinguishing among deep-water sedimentary facies has been a difficult task. This is possibly due to the process continuum in deep water, in which sediments occur in complex associations. The lack of definite sedimentological features among the different facies between hemipelagites and contourites presented a great challenge. In this study, we present detailed mudrock characteristics of the three main deep-water facies based on sedimentological characteristics, laser diffraction granulometry, high-resolution, large area scanning electron microscopy (SEM), and the synchrotron X-ray diffraction technique. Our results show that the deep-water microstructure is mainly process controlled, and that the controlling factor on their grain size is much more complex than previously envisaged. Retarding current velocity, as well as the lower carrying capacity of the current, has an impact on the mean size and sorting for the contourite and turbidite facies, whereas hemipelagite grain size is impacted by the natural heterogeneity of the system caused by bioturbation. Based on the microfabric analysis, there is a disparate pattern observed among the sedimentary facies; turbidites are generally bedding parallel due to strong currents resulting in shear flow, contourites are random to semi-random as they are impacted by a weak current, while hemipelagites are random to oblique since they are impacted by bioturbation.


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