scholarly journals Assessment of Lagos soils for some persistent organic Pollutants

2020 ◽  
Vol 22 (1) ◽  
pp. 113-122
Author(s):  
R. Alani ◽  
K. Olayinka ◽  
B. Alo
Keyword(s):  
Gas Chromatography ◽  
Organic Carbon ◽  
Carbon Content ◽  
Organic Pollutants ◽  
Soil Samples ◽  
Organic Carbon Content ◽  
Mass Selective Detector ◽  
Run Off ◽  
Selective Detector ◽  
High Concentrations

Contamination of Lagos soils with persistent, bioaccumulative and toxic micropollutants (PBTs) may not only affect the non-target species residing in the soil, but also raises the concern of the possibility of the chemicals finding their way into the Lagoon and other water courses via soil run-off and leaching. In this study, soil samples were collected from three busy areas of Lagos (Apapa, Okobaba and Iddo) and analyzed for Polychlorinated Biphenyls (PCBs), Organochlorine pesticides (OCS), and Polycyclic Aromatic Hydrocarbons (PAHs). Gas Chromatography with Mass Selective Detector (GC/MSD) was used for the analyses. Iddo had the highest percentage organic carbon content of 39.39% with highest total PAHs of 2,706.93 ng/g. The highest total PCBs of 23.63 ng/g was found at Apapa 3 which was one of the three sampling points in Apapa. PCB 74 was the onlyPCB found in all the soil samples and ranged between 3.55 ng/g and 23.64 ng/g at Apapa 1 and Apapa 2 respectively. High concentrations of the following organic compounds were also obtained at the following locations- naphthalene (1,625.10 ng/g) at Iddo; dichlorodiphenyldichloroethylene (p,p'DDE ), (117.98 ng/g) at Okobaba, and PCB 74 (23.63 ng/g) at Apapa 1. The results obtained showed that the higher the municipal activity, the higher the percentage organic carbon content. Key words: Bioaccumulative and toxic micropollutants, Gas chromatography/Mass selective detector, Persistent organic carbon, Soil organic pollutants

Ocena wpływu przygotowania próbek na uzyskiwane wyniki analiz pirolitycznych

Nafta-Gaz ◽  
2021 ◽  
Vol 77 (5) ◽  
pp. 299-312
Author(s):  
Marek Janiga ◽  
◽  
Małgorzata Kania ◽  
Agnieszka Wciślak ◽  
Karol Spunda ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Organic Carbon ◽  
Sample Preparation ◽  
Carbon Content ◽  
Ball Mill ◽  
Organic Carbon Content ◽  
Ball Mills ◽  
Pyrolysis Products ◽  
Two Samples ◽  
Analysis Error

The aim of the work, the results of which are presented in the article, was to evaluate the influence of the method of sample preparation on the results of pyrolytic analyses: RockEval, Py-GC-FID (gas chromatography with FID detector) and Py-GC-IRMS (isotope mass spectrometry with gas chromatography). Mortars and ball mills are most often used to grind the samples. Three rock samples with a higher organic carbon content (shales) and five with a lower organic carbon content (including two samples of dolomites and three of anhydrites) were prepared. The rocks were homogenized and divided into three parts. Each part was ground: by hand in a mortar, in a ball mill for 5 minutes, and in a ball mill for 15 minutes. A total of 24 RockEval analyses, 48 Py-GC-FID analyses (two pyrolysis temperatures corresponding to RockEval pyrolysis conditions) and 24 Py-GC-IRMS analyses were performed. The grinding of the samples for the RockEval analyses is insignificant. The differences in the results seem to indicate the influence of the analysis error and the nature of the sample. For the Py-GC-FID methodology, the influence of milling on the results of desorption carried out at the temperature of 300ºC for most of the tested samples can be considered insignificant and negligible. At the temperature of 500ºC, various types of samples show some correlations, but they are insufficient to reject one of the methods of sample preparation. Therefore, it is important to analyze the results comprehensively, taking into account both the group composition and the distribution of pyrolysis products. In the case of the isotopic composition analyses (Py-GC-IRMS), also no differences in δ13C values related to different types of grinding samples can be found. Summarizing, all the results show a negligible influence of the method of grinding the samples on the results of pyrolysis analyses. Nevertheless, it is important that only one method of sample preparation is used for a separate sample series.

scholarly journals Determination of soil specific surface area by water vapor adsorption: I Drying of soil samples

1987 ◽  
Vol 59 (2) ◽  
pp. 63-65
Author(s):  
Raina Niskanen ◽  
Väinö Mäntylahti
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Mineral Soil ◽  
Clay Content ◽  
Fine Sand ◽  
Water Vapor Adsorption ◽  
Soil Samples ◽  
Organic Carbon Content ◽  
Clay Sample

Drying of three mineral soil samples (clay content 4—58 %, organic carbon content 1—5 %) equilibrated at 75.5 % relative humidity was studied. The soils were dried in an oven at +50°C, +70°C and + 105°C for 4 and 8 hours and in a desiccator over pure concentrated H2SO4 and P2O5. Drying over desiccants for 8 hours removed less water than drying at + 50°C. Drying over desiccants for 3—7 days was as efficient as drying at +70°C, for 14—24 days as efficient as 4 hours of drying at + 105°C. Eight hours of drying at + 105°C seemed to be too drastic, because it caused a greater weight loss in the clay sample of 5 % organic carbon content than did prolonged desiccant-drying. Drying at + 70°Cremoved as much water from fine sand which contained 4 % clay as prolonged desiccant-drying.

scholarly journals Status of molybdenum in soils of Palghar district of Maharashtra

2019 ◽  
Author(s):  
S. S. Hadole ◽  
R. N. Katkar ◽  
P. A. Sarap ◽  
S. R. Lakhe ◽  
Shamna K. Muhammed
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Negative Correlation ◽  
Surface Soil ◽  
Soil Samples ◽  
Molybdenum Content ◽  
Organic Carbon Content ◽  
Nutrient Index ◽  
Index Value ◽  
Positive Significant Correlation

The surface soil samples representing six tehsils were collected from Palghar district during 2015-16. The available molybdenum content in soil varied from 0.01 to 0.65 mg Kg-1 with nutrient index value was found 1.93. In Palghar district 30 percent soil samples were deficient in available molybdenum. However, positive significant correlation between available molybdenum with pH (r=+0.714**) whereas, significantly negative correlation with organic carbon content (r= -0.815**) was observed.

Dynamics of selected chemical and microbiological properties changes in soils after application of ultra-fine powdered calcium carbonate – incubation studies

2020 ◽  
Author(s):  
Karolina Woźnica ◽  
Michał Gąsiorek ◽  
Justyna Sokołowska ◽  
Agnieszka Józefowska ◽  
Tomasz Zaleski
Keyword(s):  
Calcium Carbonate ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Soil Properties ◽  
Carbon Content ◽  
Buffer Capacity ◽  
Microbial Biomass Carbon ◽  
Soil Samples ◽  
Organic Carbon Content ◽  
Biomass Carbon

<p>Soil acidification is a serious problem on a global scale, about 30% of land surface is occupied by acidic soils (pH≤ 5.5). Recent research indicates, that more than 50% of arable soils in Poland have too low pH. Acid soils are characterised the ability to mobilize toxic metals and increased plant uptake as well as decreased microbial activity in the soil. Progressive acidification leads to degradation of soils and caused that they are marginal for agricultural production. Soil acidification is a naturally occurring process, but only when natural factors are supported by intensive human activity, especially by nitrogen fertilisers application, intensive degradation is observed. Traditionally method to increase soil pH is the application of lime materials e.g. calcite, burnt lime or dolomite. The liming efficiency depends on lime material type (primarily chemical form of calcium compounds), the neutralising value, lime application method, soil properties and the particle size distribution of lime. The aim of this research was to determine the rate of action and influence of ultra-fine powdered calcium carbonate on selected chemical and microbiological soil properties.</p><p>The incubation studies were conducted on the three soils (G1, G2 – silt loam and G3 – sandy loam). Soil samples were taken from the 0-20 cm layer. Soil properties were measured after 7, 14, 30, 60 and 120 days of incubation. The liming factor was ultra-fine powdered calcium carbonate with particle size distribution < 0.08 mm. The application dose was calculated for 0.5 soil hydrolytic acidity. In the soil samples pH<sub>KCl</sub>, buffer capacity, microbial biomass carbon and dissolved organic carbon content were measured.</p><p>Application of lime caused an increase of pH value in all studied soils. The highest increase of the pH<sub>KCl </sub>was noted between 0 to 7<sup>th</sup> day of incubation. Afterward, the pH<sub>KCl </sub>decreased slowly for the soil G1 and G2. However, in the soil G3 significantly decreased just after 7<sup>th</sup> to 14<sup>th </sup>day, and afterward, the pH<sub>KCl</sub> decreased slowly to the end of the incubation period. As a result of liming long-term changes in soil buffer capacity were not noted. The studied soils were characterised by the higher buffer capacity in alkaline than in acidic range. The microbial biomass carbon content was varied during the incubation in all studied soils. The dissolved organic carbon content increased during the incubation, starting from the 7<sup>th</sup> to the 120<sup>th</sup> day of incubation for G2 and G3 soils and from 14<sup>th </sup>to last day of incubation for G1 soil. Application of lime caused an increase of the dissolved organic carbon content in all studied soils. These studies show that application of ultra-fine powdered calcium carbonate is an effective and fast way to improve soil properties.</p>

Sorption of the Pesticide Aldicarb by Soil: Its Mobility Through a Saturated Medium in the Presence of Dissolved Organic Matter

1988 ◽  
Vol 23 (2) ◽  
pp. 253-269 ◽  
Author(s):  
P. Lafrance ◽  
L. Ait-ssi ◽  
O. Banton ◽  
P.G.C. Campbell ◽  
J.P. Villeneuve
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Content ◽  
Humic Substances ◽  
Soil Column ◽  
Soil Samples ◽  
Saturated Soil ◽  
Organic Carbon Content ◽  
Treated Soil ◽  
Dissolved Humic Substances

Abstract Adsorption characteristics of the radiolabeled pesticide aldicarb (2-methyl-2-(methyl-14C-thio)-propionaldehyde-O-methycarbamoyO-oxime) on loamy sand and its mobility through a water-saturated soil column were studied. This study emphasizes the effect of soil organic carbon content and of dissolved humic materials on the sorption characteristics of aldicarb. Dissolved humic substances at 25 mg/L present a very small binding affinity for aldicarb (“association constant” ≈ 20 [nmol/g carbon]/[nmol/g water]) and do not significantly affect the sorption rate for this pesticide. Freundlich isotherms were determined for aldicarb sorption on the original soil (% o.c. = 2.2) and on soil samples treated to reduce the initial soil organic carbon content (% o.c. = 0.8). If linear isotherms are assumed, the adsorption coefficient KD is nearly three-fold higher for the original soil than for the treated soil samples. The ratios of the KD values obtained for adsorption in the presence and in the absence of dissolved humic substances (25 mg/L) were 1.3 and 1.4, respectively, for the original and for the treated soil samples: this indicates that humic substances could modify only slightly aldicarb transport in soil. Effluent concentration profiles for the movement of the radiolabeled pesticide through a 30-cm long saturated soil column indicate a retardation factor R = 1.4. This R value is related to hydrolysis product of aldicarb, since no detectable parent compound was found in the column effluent. Results showed 45% loss of the initial radioactivity applied on the soil column: this could be attributed to irreversible adsorption and to biodegradation of the pesticide compounds.

scholarly journals Source Rock Characteristic of Sargelu and Kurrachine Formations from the Selected Wells in Northern Iraq

2021 ◽  
Vol 54 (2A) ◽  
pp. 60-74
Author(s):  
Arwa M. S. Al-Dolaimy
Keyword(s):  
Gas Chromatography ◽  
Organic Matter ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Carbon Content ◽  
Source Rock ◽  
Total Organic Carbon Content ◽  
Organic Carbon Content ◽  
Northern Iraq ◽  
Rock Eval

A total of 56 cuttings samples of Sargelu and Kurrachine formations from different wells (Ain Zalah, Baiji, and Jabal Kand) in northern Iraq have been investigated in this study. Both the Sargelu and Kurrachine formations were examined using Rock-Eval pyrolysis to assess the richness of organic matter and thermal maturity level. The Sargelu Formation Have Total Organic Carbon wt.% ranged from 0.22–2.52 wt.%, average 1.26 wt.% in Ain Zalah Well, and between 0.57–8.90 wt.%, average 2.95 wt.% in Baiji Well, and between 0.81–11.80 wt.%, average 5.01wt.% in for Kand Well. It is considered a potential source rock based on total organic carbon content. total organic carbon wt. % in Ain Zalah and Kand in the Kurrachine Formation is considered poor source rock with a total organic carbon content of 0.17, 0.39 wt. %, respectively, while in Baiji Well is considered moderate source rock with total organic carbon content 0.53 wt. %. The Rock-Eval data are not always sufficient to define the kind of organic matter through the use of the van Krevelen diagram because HI and OI are affected by both matrix mineralogy and the kerogen mixture. For accurate assessments of the source rocks, gas chromatography has been relied on, which provides a direct indication of the kerogen type as well as the type of hydrocarbons that kerogen can generate during maturity. Gas chromatography analysis indicates that all selected samples contained type II kerogen. The highest value of the TAS/ (MAS+TAS) ratio was found in Ain Zalah samples (Sargelu Formation), and this result indicates the occurrence of an aromatization process with increasing thermal maturation.

scholarly journals Seasonal changes in organic carbon content in post-arable forest soils

2019 ◽  
Vol 70 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Paweł Dłużewski ◽  
Katarzyna Wiatrowska ◽  
Michał Kozłowski
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Seasonal Changes ◽  
Forest Stand ◽  
Soil Samples ◽  
Organic Carbon Content ◽  
Forest Age ◽  
Mineral Surface ◽  
Autumn And Winter ◽  
Precipitation And Temperature

Abstract The purpose of this work is to determine seasonal changes in the organic carbon content in the mineral topsoil horizon of the Dystric Brunic Arenosols currently used as forest. In addition, the influence of forest age on the soil organic carbon (SOC) content in the A horizon was analyzed. The paper presents the results of studies on temporal changes in the SOC content in the mineral surface horizon of 55-year-old (Sk2) and 13-year-old forest (Sk5) in 2013 and 2014. Soil samples were collected from A horizon once a month between April 2013 and March 2015. Based on the conducted studies, clear seasonal differentiation of the SOC content was observed. Higher contents of SOC in the A horizon of the analyzed soils occurred in the autumn and winter months, and were lower in spring and summer. For Sk2 soil, higher SOC values were observed in autumn and then in winter, which on average were 11.08 g·kg−1 and 9.61 g·kg−1 respectively, while lower in spring and summer (8.85 g·kg−1 and 8.83 g·kg–1 respectively). Also in the mineral topsoil horizon of Sk5 soil, higher SOC contents were recorded in autumn and winter (8.07 g·kg−1 and 7.27 g·kg−1 respectively), and lower in spring and summer (6.19 g·kg−1 and 6.57 g·kg−1 respectively). The periodicity of SOC content in plots studied was related to the seasonality of precipitation and temperature. The research also showed that the age of the forest stand influences significantly the content of organic carbon in the A horizon. Higher content of SOC was observed in the A horizon of the 55 years old forest stand (average 9.69 g·kg−1) than on the 13 years old (7.02 g·kg−1).

scholarly journals GIS-based Fertility Assessment and Mapping for Agricultural Research Station, Tandur, Telangana, India

2021 ◽  
pp. 289-296
Author(s):  
Kasthuri Rajamani ◽  
C. Sudhakar ◽  
N. Hari ◽  
M. Venkata Ramana
Keyword(s):  
Organic Carbon ◽  
Soil Fertility ◽  
Carbon Content ◽  
Agricultural Research ◽  
Soil Samples ◽  
Research Station ◽  
Organic Carbon Content ◽  
Fertility Status ◽  
Agricultural Research Station ◽  
Soil Fertility Status

This study was conducted to determine the soil fertility status of the Agricultural Research Station, Tandur of Professor Jayashankar Telangana State Agricultural University (PJTSAU), Vikarabad District, Telangana. To identify the soil sampling points, GPS device was used and collected total of 60 soil samples on grid-based method at a depth of 0–15 cm. The collected samples were analyzed for pH, EC, OC, N, P2O5, K2O, Zn, Cu, Fe and Mn status by following standard methods in the laboratory of Regional Agricultural Research Station, Palem, PJTSAU, Nagarkurnool District of Telangana, and Arc-GIS software was used further to prepare soil fertility maps. Around 37.5% of samples fall in neutral pH, whereas 62.5% samples were found as moderately alkaline reactions and entire farm soils were non-saline. Among the analyzed soil samples, 37.29% samples were in low organic carbon content, and rest of the samples i.e.,62.71% have medium organic carbon content and total samples were low in available N content (< 280 kg ha-1). The analyzed farm samples were medium to high in available phosphorus and potassium (28.67 & 71.33 % of P2O5 and 16.96 & 83.04 % of K2O respectively) content. In contrast, the micronutrients (Zn, Cu, Fe & Mn) exceeded their sufficiency level and suggested for amelioration measures to enhance research efficacy in the farm and to build future research strategies based on the determined soil fertility status.

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