scholarly journals Application of Langmuir and Freundlich Isotherms to Phosphate Sorption by Soils: Modelling and Effects of pH

1970 ◽  
Vol 66 (1) ◽  
Author(s):  
Oanamari ORBULEŢ ◽  
Liana KREIDER ◽  
Cristina MODROGAN ◽  
Alexandra MIRON ◽  
Giani APOSTOL ◽  
...  
Keyword(s):  
Soil Phosphorus ◽  
Freundlich Isotherm ◽  
Inorganic Phosphorus ◽  
Phosphorus Sorption ◽  
Phosphate Sorption ◽  
Freundlich Isotherms ◽  
Charged Surfaces ◽  
Effects Of Ph ◽  
Ph Range

Phosphate sorption capability is an important soil characteristic which determines the nutrients dynamics. Research studies on the chemistry of inorganic phosphorus in soil showed that in soil occur several reactions with resulting compounds; these reactions are dependent on factors like soil pH, type and quality of soil minerals, quantity of soil phosphorus and other soil properties. The work seeks to determine the equilibrium curves by using a thermodynamic study in order to determine sorption degree of phosphorus (P) on soil grains (chernozem from Teleorman area and sandy soil from Dabuleni area) using the isotherm functions Langmuir and Freundlich typically used to describe adsorption equilibrium, at a phases mass ratio soil:water of 1:5 in the pH range 59. KH2PO4 solutions were used as aqueous phases at a concentration range of 10-100. The Freundlich isotherm was more attractive than the Langmuir isotherm in describing phosphorus sorption by soil. Thus, quantifying the ratio between concentration of P adsorbed on soil and concentration of P in soil solution is an important step for describing the specific adsorption of ions on soil’s charged surfaces taking pH into account. Moreover, these simple isotherms used in describing phosphorus sorption have a significant role being useful for summarizing both the information about a given soil and the effects of a particular treatment involving the same soil.

Efficient Preconcentration of Cu2+, Zn2+ and Fe3+ with an Agarose-Schiff Base Sorbent

2007 ◽  
Vol 72 (7) ◽  
pp. 908-916 ◽  
Author(s):  
Payman Hashemi ◽  
Hatam Hassanvand ◽  
Hossain Naeimi
Keyword(s):  
Schiff Base ◽  
Metal Ions ◽  
Metal Ion ◽  
Good Accuracy ◽  
Kinetic Studies ◽  
Sample Volume ◽  
Effects Of Ph ◽  
Glass Column ◽  
High Concentrations ◽  
Ph Range

Sorption and preconcentration of Cu2+, Zn2+ and Fe3+ on a salen-type Schiff base, 2,2'- [ethane-1,2-diylbis(nitrilomethylidyne)]bis(2-methylphenol), chemically immobilized on a highly crosslinked agarose support, were studied. Kinetic studies showed higher sorption rates of Cu2+ and Fe3+ in comparison with Zn2+. Half-times (t1/2) of 31, 106 and 58 s were obtained for sorption of Cu2+, Zn2+ and Fe3+ by the sorbent, respectively. Effects of pH, eluent concentration and volume, ionic strength, buffer concentration, sample volume and interferences on the recovery of the metal ions were investigated. A 5-ml portion of 0.4 M HCl solution was sufficient for quantitative elution of the metal ions from 0.5 ml of the sorbent packed in a 6.5 mm i.d. glass column. Quantitative recoveries were obtained in a pH range 5.5-6.5 for all the analytes. The volumes to be concentrated exceeding 500 ml, ionic strengths as high as 0.5 mol l-1, and acetate buffer concentrations up to 0.3 mol l-1 for Zn2+ and 0.4 mol l-1 for Cu2+ and Fe3+ did not have any significant effect on the recoveries. The system tolerated relatively high concentrations of diverse ions. Preconcentration factors up to 100 and detection limits of 0.31, 0.16 and 1.73 μg l-1 were obtained for Cu2+, Zn2+ and Fe3+, respectively, for their determination by a flame AAS instrument. The method was successfully applied to the metal ion determinations in several river water samples with good accuracy.

scholarly journals Biochar Chemistry in a Weathered Tropical Soil: Kinetics of Phosphorus Sorption

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 295
Author(s):  
Marina Moura Morales ◽  
Nicholas Brian Comerford ◽  
Maurel Behling ◽  
Daniel Carneiro de Abreu ◽  
Iraê Amaral Guerrini
Keyword(s):  
Mineral Soil ◽  
Soil Surface ◽  
Kinetic Studies ◽  
Inorganic Phosphorus ◽  
Initial Reaction ◽  
Phosphorus Sorption ◽  
P Sorption ◽  
Published Research ◽  
Kinetics Of

The phosphorus (P) chemistry of biochar (BC)-amended soils is poorly understood. This statement is based on the lack of published research attempting a comprehensive characterization of biochar’s influence on P sorption. Therefore, this study addressed the kinetic limitations of these processes. This was accomplished using a fast pyrolysis biochar made from a mix of waste materials applied to a highly weathered Latossolo Vermelho distrofico (Oxisol) from São Paulo, Brazil. Standard method (batch method) was used. The sorption kinetic studies indicated that P sorption in both cases, soil (S) and soil-biochar (SBC), had a relatively fast initial reaction between 0 to 5 min. This may have happened because adding biochar to the soil decreased P sorption capacity compared to the mineral soil alone. Presumably, this is a result of: (i) Inorganic phosphorus desorbed from biochar was resorbed onto the mineral soil; (ii) charcoal particles physically covered P sorption locations on soil; or (iii) the pH increased when BC was added SBC and the soil surface became more negatively charged, thus increasing anion repulsion and decreasing P sorption.

scholarly journals Optimum three-point linkage set up for improving the quality of soil spectra and the accuracy of soil phosphorus measured using an on-line visible and near infrared sensor

2009 ◽  
Vol 103 (1) ◽  
pp. 144-152 ◽  
Author(s):  
A.M. Mouazen ◽  
M.R. Maleki ◽  
L. Cockx ◽  
M. Van Meirvenne ◽  
L.H.J. Van Holm ◽  
...  
Keyword(s):  
Near Infrared ◽  
Soil Phosphorus ◽  
Infrared Sensor ◽  
On Line ◽  
Set Up

A Study on Adsorption Ammonia Nitrogen of Diatomite Modified by Microwave

2012 ◽  
Vol 602-604 ◽  
pp. 1211-1214
Author(s):  
Zhi Wen Luo ◽  
Zhong Chen ◽  
Su Hong Liu
Keyword(s):  
Adsorption Process ◽  
Freundlich Isotherm ◽  
Nitrogen Adsorption ◽  
Microwave Treatment ◽  
Ammonia Nitrogen ◽  
Ammonia Adsorption ◽  
Freundlich Isotherms ◽  
Adsorption Capacities ◽  
The Impact ◽  
Modified Diatomite

Diatomite was modified by microwave treatment to increase their utilization value, using modified diatomite to treat ammonia-nitrogen wastewater. The experiment indicated that adsorption process of modification of the modified time by microwaves and microwave power is the impact of ammonia adsorption of the main factors. Through modification experiments by raising the capacity of diatomite adsorption ammonia nitrogen, adsorption of ammonia nitrogen increase over one time. Langmuir and Freundlich isotherms were used to fit and the experimental results show that the modified diatomite adsorption onto ammonia nitrogen accords with Langmuir and Freundlich isotherm. The maximum theoretical adsorption capacities are 5.81083mg/g.

scholarly journals Influence of soil pH on inorganic phosphorus sorption and desorption in a humid brazilian Ultisol

2005 ◽  
Vol 29 (5) ◽  
pp. 685-694 ◽  
Author(s):  
Shinjiro Sato ◽  
Nicholas Brian Comerford
Keyword(s):  
Soil Ph ◽  
Ph Value ◽  
Tropical Soils ◽  
Inorganic Phosphorus ◽  
Phosphorus Sorption ◽  
Tropical Regions ◽  
P Sorption ◽  
Phosphorus Desorption ◽  
P Desorption ◽  
P Bioavailability

Liming is a common practice to raise soil pH and increase phosphorus (P) bioavailability in tropical regions. However, reports on the effect of liming on P sorption and bioavailability are controversial. The process of phosphorus desorption is more important than P sorption for defining P bioavailability. However few studies on the relationship between soil pH and P desorption are available, and even fewer in the tropical soils. The effects of soil pH on P sorption and desorption in an Ultisol from Bahia, Brazil, were investigated in this study. Phosphorus sorption decreased by up to 21 and 34 % with pH increases from 4.7 to 5.9 and 7.0, respectively. Decreasing Langmuir K parameter and decreasing partition coefficients (Kd) with increasing pH supported this trend. Phosphorus desorption was positively affected by increased soil pH by both the total amount of P desorbed and the ratio of desorbed P to initially sorbed P. A decreased K parameter and increased Kd value, particularly at the highest pH value and highest P-addition level, endorsed this phenomenon. Liming the soil had the double effect of reducing P sorption (up to 4.5 kg ha-1 of remaining P in solution) and enhancing P desorption (up to 2.7 kg ha-1 of additionally released P into solution).

scholarly journals Effects of pH and Aeration on Sclerotium rolfsii sacc. Mycelial Growth, Sclerotial Production and Germination

2018 ◽  
Vol 7 (3) ◽  
pp. 123-129 ◽  
Author(s):  
Fakher Ayed ◽  
Hayfa Jabnoun-Khiareddine ◽  
Rania Aydi-Ben-Abdallah ◽  
Mejda Daami-Remadi
Keyword(s):  
Mycelial Growth ◽  
Sclerotium Rolfsii ◽  
Dry Weight ◽  
Ph Values ◽  
Effects Of Ph ◽  
Ph Range ◽  
Sclerotial Development ◽  
Sclerotial Germination

Sclerotium rolfsii is one of the devastating soilborne fungus responsible for significant plant losses. The effects of pH and aeration on pathogen mycelial growth, sclerotial production and germination were investigated for three Tunisian isolates. Optimal mycelial growth occurred at pH 6 for Sr2 and Sr3 isolates and at pH 6-7 for Sr1. Dry mycelial growth was optimum at pH values ranging between 4 and 7. Sclerotial initiation started on the 3rd day of incubation at all pH values tested and mature sclerotia were formed after 6 to 12 days. Optimal sclerotial production was noted at pH 5. The dry weight of 100 sclerotia varied depending on isolates and pH and occurred at pH range 4-7. At pH 9, mycelial growth, sclerotial production and dry weight of 100 sclerotia were restricted. The optimum sclerotial germination, noted after 24 h of incubation, varied depending on isolates and pH and occurred at pH 4-9. Mycelial growth was optimum in aerated plates with a significant isolates x aeration treatments interaction. Sclerotial initiation occurred at the 3rd day of incubation and mature sclerotia were observed after 6-9 days. Sclerotial development was very slow in completely sealed plates and dark sclerotia were produced only after 15 days of incubation. The highest sclerotial yields were noted in aerated plates. The highest dry weight of 100 sclerotia for Sr1 isolate was recorded in ½ sealed, no sealed and completely sealed plates, while for Sr2, it was noted in ½ and ⅔ sealed plates. For Sr3, the maximum dry weight of 100 sclerotia was recorded in ½, ⅔ and completely sealed plates. Germination of S. rolfsii sclerotia, after 24 h of incubation, did not vary significantly depending on aeration treatments and ranged from 90 to 100% for all isolates.

scholarly journals Impact of Partially Treated Wastewater on Downstream Water Quality of Notwane River in Botswana

2018 ◽  
pp. 1-9
Author(s):  
Gilbert K. Gaboutloeloe ◽  
Gugu Molokwe ◽  
Benedict Kayombo
Keyword(s):  
Water Quality ◽  
Pearson Correlation ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Treated Wastewater ◽  
Nitrate N ◽  
River Stretch ◽  
Ph Range ◽  
The Impact

The impact of partially treated wastewater on the water quality of Notwane river stretch in the Gaborone region of Botswana was investigated. Water samples collected at effluent discharge point and three other sampling sites downstream were analyzed for pH, temperature, Biological Oxygen Demand (BOD5), Ammonia-nitrogen (Ammonia-N) and Nitrate-nitrogen (Nitrate-N). Sampling was conducted bi-weekly between February 2013 and April 2013. The ranges of measured parameters were:  pH (7.6-8.5), temperature (22-23ºC), BOD5 (11.2-27.0 mg/l), Ammonia-N (2.4-60.5 mg/l), Nitrate-N (20.6-28.6 mg/l). Analysis of variance, Games-Howel multiple comparisons and Pearson correlation were used to separate variable means. The results signal river non-point pollution due to runoff inflow of organics mainly from land use and domestic waste dumping by nearby dwellings. Temperature, BOD5, and pH range values were all within the Botswana Bureau of Standards (BOBS) limit while the maximum Ammonia-N and Nitrate-N were above BOBS limit by 50.5 mg/l and 6.6 mg/l, respectively. Regulations on indiscriminate waste dumping and discharge standards adherence should be enforced.

scholarly journals Adsorption of UV254 in Kerian River water onto ZeliacTM: Analysis using linear and non-linear forms of isotherm models

2017 ◽  
Vol 19 (1) ◽  
pp. 74-81 ◽  
Keyword(s):  
River Water ◽  
Function Analysis ◽  
Low Cost ◽  
Error Function ◽  
Linear Regression Analysis ◽  
Freundlich Isotherm ◽  
Linear Analysis ◽  
Isotherm Models ◽  
Freundlich Isotherms ◽  
Non Linear

<p>The composite media, Zeliac<sup>TM</sup> was developed with the initial aim to provide low cost adsorbent with promising adsorption capacity. This study was conducted to investigate the removal of UV absorbance at 254 nm (UV<sub>254</sub>) in Kerian river water using Zeliac<sup>TM</sup> as the media. Batch experiments study was carried out to determine the optimum removal of UV<sub>254</sub> by Zeliac<sup>TM</sup>. The experimental data were fitted to Langmuir and Freundlich isotherms to investigate the adsorption mechanism. The results from batch study exhibit that Zeliac<sup>TM</sup> is capable to remove 74.4% UV<sub>254</sub> at the dosage of 7g/100 ml. Linear isotherm analysis suggests that the best fitting linear line is Freundlich isotherm with R<sup>2</sup> values of 0.9294 indicating multilayer adsorption. Similarly, non-linear regression analysis reveals that the adsorption of UV<sub>254</sub> by Zeliac<sup>TM</sup> is attributed by physisorption. The non-linear Freundlich isotherm gives a better fit to the adsorption of UV<sub>254</sub> than Langmuir isotherm with R<sup>2</sup> values of 0.9488. The results are supported with low values of X<sup>2</sup>, ARE, HYBRID and MPSED from the error function analysis.&nbsp; Additionally, it is noted that the linear analysis overestimates the constant parameters’ values for Freundlich isotherm, which cause larger errors as estimated by the error function analysis. Hence, non-linear analysis is more appropriate in explaining the batch experiment data.</p>

scholarly journals QUALITY EVALUATION OF SOME BOTTLED WATERS AVAILABLE IN IRAQI MARKET

2021 ◽  
Vol 25 (4) ◽  
pp. 13-22
Author(s):  
Mohammed A. Rashid ◽  
◽  
Nagam O. Kariem ◽  
Keyword(s):  
Quality Evaluation ◽  
Trade Mark ◽  
International Standards ◽  
The Other ◽  
Fecal Coliforms ◽  
Physical Chemical ◽  
Trade Names ◽  
Ph Range ◽  
Physical And Chemical

This study was intended to evaluate the quality of some bottled waters available in Iraqi market, by testing their physical, chemical and biological characteristics. These samples produced by four companies during the period of December- 2016 to April-2017. The selected companies had the biggest sells and were under the trade names of AlluLua, Ala, Alwafi, and Venesia. The results showed that most bottled waters samples characteristics were in compliance with Iraqi and international standards, with some superiority in water quality for the trade mark Allulua upon the other companies, but the trade mark Ala was at the end of the list of quality rank. All the tested samples showed clean bacteriological results for coliforms as pollution indicators and fecal coliforms (all tests MPN was less than 1.1). The other physical and chemical characteristics showed pH range of 6.21 ~ 7.7, TDS of 12.81 ~ 126.88 mg/L, Ca of 0.24 ~ 25.5 mg/L, Mg of 3.2 ~ 13.1 mg/L, Na of 0.92 ~ 23 mg/L, K of 0 ~ 0.39 mg/L, Hardness of 3.8 ~ 38.2 mg/L, and chloride of 3.55 ~ 35.5 mg/L.

EFFECTS OF pH AND NITROGEN SOURCES ON GROWTH OF MICROCYSTIS AERUGINOSA KÜTZ.

1962 ◽  
Vol 8 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Jack McLachlan ◽  
P. R. Gorham
Keyword(s):  
Growth Inhibition ◽  
Microcystis Aeruginosa ◽  
Nitrate Nitrogen ◽  
Nitrogen Sources ◽  
Cesium Chloride ◽  
Potassium Nitrate ◽  
Degree Of Ionization ◽  
Ph Values ◽  
Effects Of Ph ◽  
Ph Range

Microcystis aeruginosa Kütz. (strain NRC-1) grew equally well throughout the pH range 6.5 to 10 when provided with suitable media. Toxicity of tris(hydroxymethyl)aminomethane (TRIS) towards the alga was found to decrease as the pH decreased and could be correlated with the degree of ionization of the TRIS molecule. Other organic buffers examined were either toxic at all concentrations and pH values tested or promoted lysis. When TRIS was used as a buffer, higher concentrations of cesium chloride and potassium nitrate were tolerated without growth inhibition at pH 6.5 than at 7.5. In the presence of TRIS, Microcystis grew equally well with nitrate, ammonium, or urea as nitrogen sources. Eight out of 20 amino compounds examined served as nitrogen sources in TRIS-buffered medium, but growth was poorer than with nitrate nitrogen.

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