scholarly journals Performances of nanofiltration on industrial phosphoric acid purification

2014 ◽  
Vol 10 (2) ◽  
pp. 2218-2229
Author(s):  
Hassen Nasri ◽  
Raja Ben Amar

Phosphoric acid production is of major importance to the Tunisian economy. However, the quality produced is not suitable for other than agricultural use due to mineral and organic impurities. In this study, the purification of industrial phosphoric acid with a maximum P2O5 concentration of 25% was achieved by nanofiltration.  Six solutions of different P2O5 concentration were used. The removal of organic (total carbon) and inorganic impurities such as magnesium, iron, chrome, zinc, cadmium and vanadium, were studied.The performances of nanofiltration (NF) Nadir NP 30 membrane were determined in terms of permeate flux and P2O5 and impurities retention taking into account the effect of transmembrane pressure, P2O5 concentration and membrane prea-treatment by purified phosphoric acid solution.Results showed that for the industrial 25% P2O5 acid solution, the use of NF membrane achieved a retention of 87.35%, 86.73%, 87.57%, 78.41% and 73.17%, respectively, for iron, aluminum, chrome, magnesium, vanadium and organic matter (kerogen and humic acids) under a pressure of 20 bar. P2O5 permeation increased with the increase of its concentration in the acidic feed solution. The best permeation is provided by 25% P2O5 feeding acid solution which is of almost 98%.

1969 ◽  
Vol 17 (4) ◽  
pp. 287-300
Author(s):  
Juan Amedée Bonnet ◽  
Fernando A. Villamil

Research was undertaken with the purpose of shortening time without affecting accuracy of the Dyer modified method for the determination in soils, of phosphoric acid, lime and potash soluble in 1 per cent citric acid solution. A short method is recommended for the lime determination based on the Chapman's method (4) for the precipitation of calcium oxalate in acid solutions (pH 3.9-4.2) in the presence of iron, aluminum, titanium, manganese, magnesium and phosphates. A short method is recommended for the phosphoric acid determination. Results are analyzed statistically by Student's method. Several of the colorimetric methods recommended for the phosphoric acid determination are also discussed.


Author(s):  
V. А. Shevchenko ◽  
A. V. Nefedov ◽  
A. V. Ilinskiy ◽  
А. Е. Morozov

Long-term observations of the drained soil of peat-podzolic-gley light loam on ancient alluvial sands state on the example of the meliorative object "Tinky-2" showed that under the influence of agricultural use in the soil, the organic matter mineralization processes are accelerated. During the drainage process, the soil evolutionarily suffered the following changes: the peat layer was compacted, humified and mineralized, which was a reason of the transformation them into the humus horizon. Based on the monitoring studies results it was established that during 21 intensive use years the peat layer thickness was decreased by 74.5% and amounted to 5.51 inch, which in the following 20 years was decreased to a layer of 1.18 inch, and for another 14 years it became a homogeneous humus horizon containing difficulty identifiable plant remains. For half a century, the bulk density increased by 6 times and the total moisture capacity of the soil decreased by 3.6 times. Other indicators were changed significantly. So, the ash content by 2016 increased from 11.2% to 52.7%. It was a reason of the plough-layer decreasing and it mixes with the mineral sand horizon during plowing. It should also be noted that the total nitrogen content in the soil decreased by 1.13%, and total carbon by 15.3% from 1982 to 2016. The dynamics of changes in the soil acidity, phosphorus and potassium content is associated with the introduction of calcareous, organic and mineral fertilizers in the 1980s. The unsystematic exploitation of such soils leads to decrease in the agricultural products productivity and increase in energy costs. When planning these soils usage in agricultural production, it is necessary to develop and implement modern melioration technologies and techniques aimed to increase soil fertility.


Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 493
Author(s):  
Amine Charfi ◽  
Fida Tibi ◽  
Jeonghwan Kim ◽  
Jin Hur ◽  
Jinwoo Cho

This study aims to investigate the effect of operational conditions on organic fouling occurring in a direct contact membrane distillation (DCMD) system used to treat wastewater. A mixed solution of sodium alginate (SA) and bovine serum albumin (BSA) was used as a feed solution to simulate polysaccharides and proteins, respectively, assumed as the main organic foulants. The permeate flux was observed at two feed temperatures 35 and 50 °C, as well as three feed solution pH 4, 6, and 8. Higher permeate flux was observed for higher feed temperature, which allows higher vapor pressure. At higher pH, a smaller particle size was detected with lower permeate flux. A mathematical model based on mass balance was developed to simulate permeate flux with time by assuming (i) the cake formation controlled by attachment and detachment of foulant materials and (ii) the increase in specific cake resistance, the function of the cake porosity, as the main mechanisms controlling membrane fouling to investigate the fouling mechanism responsible of permeate flux decline. The model fitted well with the experimental data with R2 superior to 0.9. High specific cake resistance fostered by small particle size would be responsible for the low permeate flux observed at pH 8.


Author(s):  
Laslo Šereš ◽  
Ljubica Dokić ◽  
Bojana Ikonić ◽  
Dragana Šoronja-Simović ◽  
Miljana Djordjević ◽  
...  

Cross-flow microfiltration using ceramic tubular membrane was applied for treatment of steepwater from corn starch industry. Experiments are conducted according to the faced centered central composite design at three different transmembrane pressures (1, 2 and 3 bar) and cross-flow velocities (100, 150 and 200 L/h) with and without the usage of Kenics static mixer. For examination of the influence of the selected operating conditions at which usage of the static mixer is justified, a response surface methodology and desirability function approach were used. Obtained results showed improvement in the average permeate flux by using Kenics static mixer for 211 % to 269 % depending on experimental conditions when compared to the system without the static mixer. As a result of optimization, the best results considering flux improvement as well as reduction of specific energy consumption were obtained at low transmembrane pressure and lower feed cross-flow rates.


2013 ◽  
Vol 788 ◽  
pp. 152-155
Author(s):  
Tomáš Bakalár ◽  
Milan Búgel ◽  
Henrieta Pavolová ◽  
Gabriel Müller

The influence of transmembrane pressure on the permeate flux, and the critical and limiting fluxes in microfiltration of two sorbents Bentonite a natural sorbent, montmorillonite based clay and Lewatit S1468 a synthetic sorbent, styrene-divinylbenzene based copolymer were studied. An asymmetric single-channel inorganic ceramic membrane based on α-Al2O3 was used. The experimental data were obtained by continuous microfiltration equipment. According to the results the limiting flux ranged from 37 to 70 l.m-2.h-1 for Bentonite suspensions. It was not possible to estimate the limiting flux for Lewatit S1468 suspension.


2013 ◽  
Vol 65 (4) ◽  
Author(s):  
Muhammadameen Hajihama ◽  
Wirote Youravong

Tuna cooking juice is a co-product of tuna canning industry. It riches in protein, currently used for production of feed meal as well as protein hydrolysate. The finish products are usually in the form of concentrate, produced by evaporation process. However, evaporation is energy consumable process and the salt content level of the concentrate is often over the standard, thus required additional process for lowering salt content e.g. crystallization. The use of membrane technology, therefore, is of interest, since it required less energy and footprint compared with evaporation and is also able to reduce salt content of the concentrate. The aim of this study were to employ and select the membrane filtration process, and optimize the operating condition for protein concentration and desalination of tuna cooking juice. The results indicated that nanofiltration (NF) was more suitable than the ultrafiltration (UF) process, regarding the ability in protein recovery and desalination. The NF performance was evaluated in terms of permeation flux and protein and salt retentions. The protein and salt rejections of NF were 96 % and 5 %, respectively. The permeate flux(J) increased as transmembrane pressure (TMP) or cross flow rate (CFR) increased and the highest flux was obtained at TMP of 10 bar and CFR of 800 L/h. Operating with batch mode, the permeate flux was found to decrease as protein concentration increased, and at volume concentration factor about 4, the protein concentration  about 10% while salt removal was aproximately 70 % of the initial value. This work clearly showed that NF was successfully employed for concentration and desalination of protein derived from tuna cooking juice.


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