scholarly journals Calculating pH from EC and SAR values in salinity models and SAR from soil and bore water pH and EC data.

Soil Research ◽  
1990 ◽  
Vol 28 (6) ◽  
pp. 1001 ◽  
Author(s):  
CW Robbins ◽  
WS Meyer
Keyword(s):  
Soil Ph ◽  
Soil Salinity ◽  
Field Method ◽  
Soil Extract ◽  
Subsurface Water ◽  
Calibration Data ◽  
Exchangeable Sodium ◽  
Solution Ph ◽  
Simple Method ◽  
Water Ph

Currently used soil salinity models do not contain a mechanism for including exchangeable sodium effects on soil pH. A method is needed that allows pH calculation from the sodium adsorption ratio (SAR) or exchangeable sodium percentage (ESP) and electrical conductivity (EC) data. This study developed a simple method for calculating saturated soil paste and aqueous solution pH from SAR (or ESP) and EC data and compared the results with measured values from a number of soils and subsurface waters. The equation pH =A+{B*(SAR)1/2/(1+C*EC)} estimated soil pH from EC and SAR or ESP values. When rewritten as: SAR or ESP={(pH-A)(1 + C*EC)/B)2, the SAR or ESP was estimated from pH and EC data. By using shallow bore (well) water and soil extract data from the Murray Basin, values were determined for the scalar terms A, B and C. These values differed among subsurface water and soil types, however, the range of each scalar was reasonably small. It was found that a range of at least 2.5 pH units in the calibration data was necessary to obtain reliable regression between predicted and measured pH and SAR or ESP values. When these conditions were met, the predicted results were satisfactory. These relationships provide a method for pH calculation in soil salinity models which takes into account soil EC and sodium effects. They also provide a rapid field method to estimate SAR or ESP from easily obtainable EC and pH data. Further research is needed to define the factors that determine the values of A, B and C.

SOIL AND SOLUTION pH AND SODIUM:CALCIUM RATIO: EFFECTS ON CATION EXCHANGE PROPERTIES OF A SODIUM-SATURATED CHERNOZEMIC SOIL

1984 ◽  
Vol 64 (1) ◽  
pp. 139-146
Author(s):  
THERON G. SOMMERFELDT
Keyword(s):  
Cation Exchange ◽  
Soil Ph ◽  
Irrigation Water ◽  
Polynomial Equation ◽  
Exchangeable Sodium Percentage ◽  
Exchangeable Sodium ◽  
Solution Ph ◽  
Chernozemic Soil ◽  
Sodium Percentage ◽  
Exchange Properties

The effects of soil and solution pH and Na:Ca ratio in solution on the exchangeable Na, Ca, and (Na + Ca) of a Na-saturated Dark Brown Chernozemic soil were studied. At soil pH 9.0, the exchangeable Na, Ca, and (Na + Ca) were 14.5, 25.4, and 21.8% greater than at soil pH 6.0. Solution pH (6.0–9.0) had small but statistically significant effects on the amount of Na and Ca adsorbed by the soil. The logarithm of exchangeable sodium percentage (ESP) was related to the Na fraction in the solution by a polynomial equation, log ESP = 0.93 [Na/(Na + Ca)]2 + 0.16 [Na/(Na + Ca)] + 0.82. Not only is replacement of exchangeable Na with Ca important in the reclamation of this soil, should it become sodic and have a high pH, but also lowering of its surface charge, through lowering of its pH, would be an important factor in its reclamation. It appears impractical to reduce soil pH by applying acidified irrigation water. Acidic amendments such as gypsum and sulfur may be more suitable. Key words: Cation exchange, solution pH, soil pH

Interrelations between soil pH measurements in various electrolytes and soil solution pH in acidic soils

Soil Research ◽  
1991 ◽  
Vol 29 (4) ◽  
pp. 483 ◽  
Author(s):  
RL Aitken ◽  
PW Moody
Keyword(s):  
Ionic Strength ◽  
Soil Solution ◽  
Soil Ph ◽  
Low Ph ◽  
Acidic Soils ◽  
Solution Ph ◽  
Ph Measurements ◽  
The Best Approximation ◽  
Water Ph ◽  
The Difference

Ninety soil samples (81 surface, 9 subsurface) were collected from eastern Queensland and soil pH (1:5 soi1:solution) was measured in each of deionized water (pH,), 0.01 M CaCl2, 0-002 M CaCl2 and 1 M KCl. Soil solution was extracted from each soil after incubation for 4 days at the 10 kPa matric suction moisture content, and pH (pHss) and electrical conductivity were measured. The objectives of this work were to investigate interrelationships between soil pH measurements in various electrolytes and soil solution pH in a suite of predominantly acidic soils. Although the relationships between pHw and pH measured in the other electrolytes could be described by linear regression, the fitting of quadratic equations improved the coefficients of determination, indicating the relationships were curvilinear. The majority of soils exhibited variable charge characteristics (CEC increases with soil pH) and the curvilinear trend is explained on this basis. At low pH, the difference between pH, and pH measured in an electrolyte will be small compared with the difference at higher pH values because, in general, at low pH, soils will be closer to their respective PZSE (pH at which electrolyte strength has no effect). Of the electrolytes used, pH measured in 0.002 M CaCl2 gave the closest approximation to pHs,. However, when soils with ionic strengths greater than 0.018 M were selected (predominantly cultivated surface soils), pH in 0.01 M CaCl2 gave the best approximation to pHss. For predicting pHss, the ionic strength of the electrolyte will need to be matched to that of the soils studied. For a suite of soils with a large range in soil solution ionic strength (as in this study), it is preferable to measure pHss directly.

Evaluation of fresh and aged clam processing wastes as potential agricultural liming materials for coastal area vegetable production soils

2008 ◽  
Vol 88 (4) ◽  
pp. 559-569 ◽  
Author(s):  
Josée Owen ◽  
Serge LeBlanc ◽  
Patrick Toner ◽  
Cargèle Nduwamungu ◽  
Erica Fava
Keyword(s):  
Soil Ph ◽  
Soil Extract ◽  
Germination Index ◽  
Lepidium Sativum ◽  
Vegetable Production ◽  
Ph Change ◽  
Application Rates ◽  
Processing Wastes ◽  
Water Ph ◽  
Loam Soil

Clam canning in New Brunswick generates 1800 t of clam processing wastes (CPW) annually. Thirty-year-old stockpiles of CPW must now be remediated to satisfy environmental regulations. This study examined fresh and aged CPW as potential agricultural liming materials for acidic coastal vegetable production soils. Clam processing wastes were ground to three size fractions (< 0.250 mm, 0.250 to < 1.00 mm, 1.00 to < 2.00 mm) and analyzed for calcium carbonate equivalent (CCE). They were then mixed with two soils of contrasting textures at three rates, in duplicate, and then placed in a control-plus-factorial pot experiment, with commercial agricultural lime of fine texture (< 0.250 mm) as reference. During an 8-wk incubation, soil water pH and electrical conductivity (EC) were monitored biweekly. At 4 and 8 wk, a soil extract germination test was conducted using cress (Lepidium sativum L.) as an indicator plant. CPW of < 1 mm raised soil pH with effectiveness increasing as particle size decreased. Application rates in function of the fineness to induce a given pH change (ΔpH) could be obtained using prediction graphs with high coefficients of determination (r2: 0.84 to 0.97). The average EC in all treatments to the end of the incubation period was < 2 dS m-1, indicating that salt stress is not a risk following CPW application to soil, since even sensitive crops are capable of withstanding such an EC. Seeding could take place between 4 and 8 wk after the CPW application to loamy sand with no adverse effect on germination index. In the loam soil, this period could safely be shortened. Key words: Clam, liming, soil pH, soil EC, cress, germination index

scholarly journals A Comparative Study of Hydroxyapatite Coating Produced with Plasma Electrolytic Oxidation and Hydrothermal Treatment on Titanium Alloys: Ti6Al4V and Ti6Al7Nb for Dental Implants

2018 ◽  
Author(s):  
Elinor Nahum ◽  
Svetlana Lugovskoy
Keyword(s):  
Dental Implants ◽  
Plasma Electrolytic Oxidation ◽  
Water Solution ◽  
Thickness Gauge ◽  
Solution Ph ◽  
Ti Alloys ◽  
Electrolytic Oxidation ◽  
Water Ph ◽  
Mechanical Properties And Corrosion ◽  
Plasma Electrolytic

Ti and Ti alloys are materials usually used in contact with hard tissue for applications such as artificial joints and dental implants. Ti6Al4V is a very common alloy used for dental implants, owing to its good mechanical properties and corrosion resistance. Nevertheless, because of uncertainties regarding the toxicity of vanadium and its influence on the human body, other Ti alloys containing no vanadium and retaining suitable properties are used. In this work Ti6Al4V and Ti6Al7Nb were oxidized in a water solution of calcium acetate (Ca(CH3COO)2) and calcium glycerophosphate (Ca(PO4CH(CH2OH)2) by Plasma Electrolytic Oxidation (PEO) for 20 minutes and then were hydrothermally treated (HTT) in water (pH=7) and in potassium hydroxide (KOH) solution (pH=11) for 2 hours at 200&deg;C in a pressurized reactor. The surface morphologies, elemental composition and phase components were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-Ray Diffraction (XRD), respectively. The surface roughness was measured by Atomic Force Microscope (AFM) and thickness measurements were made by SEM and thickness gauge. Also, corrosion tests were made to evaluate the corrosion behavior of the two alloys. The aim of this study is to compare two viable Ti alloys, Ti6Al4V and Ti6Al7Nb, and to attain on their surface hydroxyapatite (HA) coating improving the osseointegration, as it simulates a human bone.

scholarly journals Evaluation of active sludge and aquatic ferns usage for removal of zinc in a biological wastewater treatment system

2019 ◽  
pp. 39-44
Author(s):  
Amir Hajiali ◽  
Lacramioara Diana Robescu
Keyword(s):  
Ph Value ◽  
Reaction Times ◽  
Treatment Method ◽  
Operating Conditions ◽  
Industrial Scale ◽  
Reactor Performance ◽  
Solution Ph ◽  
Active Sludge ◽  
Simple Method ◽  
Aquatic Fern

In this research capability of biological treatment method via active sludge and aquatic fern evaluated in different operating conditions and they were optimized in order to remove Zn (II). A simple reactor performance for treatment of model and real wastewater on laboratory and semi-industrial scale was investigated. This refining process proceeded with special attention to the effect of solution pH-value, pollutant concentration, absorbent concentration and reaction time. The batch semi-industrial scale reactor represented over 90 % removal efficiency under pH-value of 6 and 5-5.5 for aquatic ferns and active sludge, respectively. Effective reaction times represented various durations for aquatic ferns and active sludge with respect of 120 minutes and 90 minutes. The two biological masses had the best performances with 6 g/l for aquatic ferns and 5 g/l for active sludge. In the presence of 5 ppm of Zn (II) as the objective heavy metal, both absorbents had over 93.2 % removal efficiencies. While obviously laboratory-scale attempts introduced higher acceptable reduction efficiencies via this economic applicable treatment method. Additionally, economic considerations clarified feasibility of this recommended simple method.

scholarly journals Soil Salinity Variations in an Irrigation Scheme during a Period of Extreme Dry and Wet Cycles

Soil Systems ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 35 ◽  
Author(s):  
Sheyda Chamaki ◽  
Saleh Taghvaeian ◽  
Hailin Zhang ◽  
Jason G. Warren
Keyword(s):  
Soil Salinity ◽  
Chemical Properties ◽  
Soil Classification ◽  
Severe Drought ◽  
Exchangeable Sodium Percentage ◽  
Exchangeable Sodium ◽  
Irrigation Scheme ◽  
Sodium Percentage ◽  
Food And Feed ◽  
Global Population

Salinization of irrigated lands is a major challenge towards supplying required food and feed to meet the needs of an increasing global population. In this study, the changes in soil salinity and several other chemical properties were investigated in an irrigation scheme during a period that experienced severe drought followed by above-normal precipitation. Soil salinity, represented by the electrical conductivity (EC) of the saturated paste extract, decreased for the top layers and increased for the bottom layers during the study period, suggesting some level of leaching had occurred. However, the change in the average EC of top 1.5 m of the soil was not statistically significant. The change in exchangeable sodium percentage (ESP) was not significant over the study period either. In contrast, average pH and calcium concentrations increased and decreased significantly during the study period, respectively. EC and ESP data were used in soil classification. The percentage of all sampled sites classified as saline was 60 at the beginning of the dry–wet period, but dropped to 50% at the end of this period. All tested parameters were temporally stable, preserving their spatial rank during the study period.

The Influence of Adjusting Spray Solution pH on the Efficacy of Saflufenacil

2013 ◽  
Vol 27 (3) ◽  
pp. 445-447 ◽  
Author(s):  
Jared M. Roskamp ◽  
William G. Johnson
Keyword(s):  
Ammonium Sulfate ◽  
Weight Reduction ◽  
Seed Oil ◽  
Dry Weight ◽  
Final Solution ◽  
Solution Ph ◽  
Field Corn ◽  
Spray Solution ◽  
Initial Ph ◽  
Water Ph

Saflufenacil solubility and efficacy has been shown to be influenced by carrier water pH. This research was conducted to determine if altering the pH of a solution already containing saflufenacil would influence the efficacy of the herbicide. Saflufenacil at 25 g ai ha−1was applied to field corn in carrier water with one of five initial pH levels (4.0, 5.2, 6.5, 7.7, or 9.0) and then buffered to one of four final solution pH levels (4.0, 6.5, 9.0, or none) for a total of twenty treatments. All treatments included ammonium sulfate at 20.37 g L−1and methylated seed oil at 1% v/v. Generally, saflufenacil with a final solution pH of 6.5 or higher provided more dry weight reduction of corn than saflufenacil applied in a final pH of 5.2 or lower. When applying saflufenacil in water with an initial pH of 4.0 or 5.2, efficacy was increased by raising the final solution pH to either 6.5 or 9.0. Conversely, reduction in corn dry weight was less when solution pH of saflufenacil mixed in carrier water with an initial pH of 6.5 or 7.7 was lowered to a final pH of 4.0. When co-applying saflufenacil with herbicides that are very acidic, such as glyphosate, efficacy of saflufenacil may be reduced if solution pH is 5.2 or lower.

Lime loss rates from arable and grassland soils

1998 ◽  
Vol 131 (4) ◽  
pp. 455-464 ◽  
Author(s):  
B. J. CHAMBERS ◽  
T. W. D. GARWOOD
Keyword(s):  
Organic Matter ◽  
Soil Ph ◽  
Agricultural Land ◽  
Negative Relationship ◽  
Organic Matter Content ◽  
Matter Content ◽  
N Fertilizer ◽  
Exchangeable Ca ◽  
Water Ph ◽  
Loss Rates

Lime loss rates were determined for 11 agricultural soils across England (1987–92) under arable cropping (six sites) and grassland management (five sites), receiving commercial rates of fertilizer inputs. Lime additions in the range 0–1500 kg ha−1 CaCO3 (250 kg ha−1 CaCO3 increments) were made annually to the sites. Soil pH (water and 0·01 m CaCl2) and exchangeable calcium concentrations were measured annually. The annual lime loss rates were calculated as the amount of lime needed to maintain the initial site pH or exchangeable Ca concentrations.Lime loss rates based on soil water pH varied between 40 and 1270 kg ha−1 CaCO3, on the basis of CaCl2 pH between 0 and 1370 kg ha−1 CaCO3, and exchangeable Ca between 0 and 1540 kg ha−1 CaCO3. There was a positive relationship between the lime loss rate (based on water pH) and initial soil pH value (r=0·75; P<0·01), and a negative relationship with soil organic matter content (r=0·63; P<0·05) was based on soil pH, organic matter content and nitrogen (N) fertilizer input. Lime loss rates were approximately double those predicted by previous models developed in the 1970s, reflecting the greater quantities of inorganic N fertilizer now being applied to agricultural land.

Direct, simultaneous measurement of chloramphenicol and its monosuccinate ester in micro-samples of plasma by radial-compression liquid chromatography.

1987 ◽  
Vol 33 (10) ◽  
pp. 1814-1816 ◽  
Author(s):  
A el-Yazigi ◽  
A Yusuf ◽  
A Al-Humaidan
Keyword(s):  
Sodium Succinate ◽  
Acetic Acid Solution ◽  
Internal Standard ◽  
Peak Height ◽  
Radial Compression ◽  
Solution Ph ◽  
Liquid Chromatograph ◽  
Simple Method ◽  
Micron Particle ◽  
Total Analysis

Abstract A simple method of simultaneous analysis for chloramphenicol and chloramphenicol succinate in 10-microL samples of plasma is described. We injected the plasma samples directly into a radial-compression liquid chromatograph equipped with a precolumn module and a C18 insert. A mixture of acetic acid solution (pH 3)/acetonitrile (75/25, by vol) was used as mobile phase, at a flow rate of 4 mL/min. We separated the compounds in a 10-micron (particle size) C18 cartridge with a radial compression separation system and detected them in the effluent at 280 nm. The peak height for both compounds was linearly (r greater than 0.9993) related to concentration over the range investigated, 1-50 mg/L. We also performed the analysis with use of an internal standard (methylprednisolone) and obtained equally good results (r greater than 0.9995). We observed no interference from other antibiotics or drugs in the assay, and the inter- and intra-run precision at different concentrations was good (CV, 0 to 5.6%). We analyzed microsamples of plasma from an infant treated for meningitis with chloramphenicol sodium succinate intravenously. Total analysis time for each sample was less than 8 min.

Sign in / Sign up

Export Citation Format

Share Document