scholarly journals Physicochemical Characteristics, Particle Size Distribution and Total Hydrocarbon Content in Soil from Abandoned Landfill Site in Igbogene, Bayelsa state, Nigeria

2020 ◽  
Vol 24 (4) ◽  
pp. 729-734
Author(s):  
S.A. Uzoekwe ◽  
U.L. Anekwe
Keyword(s):  
Particle Size ◽  
Organic Carbon ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Total Nitrogen ◽  
Physicochemical Characteristics ◽  
Landfill Site ◽  
Total Hydrocarbon ◽  
Hydrocarbon Content ◽  
Total Hydrocarbon Content

Most household and some industrial solid wastes end up in the landfill which is the commonest means of solid waste management in many parts of Baylesa state, Nigeria. This study assessed the physicochemical characteristics, particle size distribution and total hydrocarbon content in soil samples from abandoned landfill site in Igbogene, Bayelsa state, Nigeria by collecting samples from varying distances (50m, 100m and 150m) at a depth of 0-20cm and analyzed using standard methods. Results were in the range of 5.01 – 5.34 (pH), 0.73 – 0.98 meg/100g (Exchangeable Acidity), 2.45 – 3.48 meg/100g (sodium), 0.19 – 0.31 meg/100g (potassium), 3.94 – 5.33 meg/100g (calcium), 1.52 – 2.15 meg/100g (magnesium), 9.57 – 11.49 mg/kg (nitrate), 4.18 – 5.19 mg/kg (sulphate), 6.99 – 8.85 mg/kg (available phosphorus), 8.23 – 12.60 mg/kg (total hydrocarbon content), 76.48 – 100.25 mg/kg (chloride), 5.14 – 7.59 mg/kg (ammonium), 8.83 – 8.95% (clay), 2.70 – 3.10% (silt), 87.93 – 88.35% (sand), 2.62 – 3.58% (organic carbon), 4.51 – 6.16% (organic matter) and 0.22 – 0.33% (total nitrogen). Analysis of variance (ANOVA) showed no significant deviations (p>0.05) across the various distances for all parameters except for organic carbon and matter, total nitrogen, potassium and ammonium. In addition, most of the  nutrients showed positive significant relationship at p<0.05. This suggests that at large the activities of old landfill in the study area is not influencing the soil characteristics under study. Rather the apparent decline in value away from old landfill may be due to mobility level of minerals in the soil toward the southwest direction, which the cluster analysis clearly showed. Keywords: Physicochemical Properties, Environmental Contamination, Hydrocarbon Content, Landfill

scholarly journals Aggregates reduce transport distance of soil organic carbon: are our balances correct?

2014 ◽  
Vol 11 (6) ◽  
pp. 8829-8859 ◽  
Author(s):  
Y. Hu ◽  
N. J. Kuhn
Keyword(s):  
Particle Size ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Settling Velocity ◽  
Mineral Particle ◽  
Undisturbed Soil ◽  
Coarse Aggregates ◽  
Transport Distance

Abstract. The effect of soil erosion on global carbon cycling, especially as a source or sink for greenhouse gases, has been the subject of intense debate. The controversy arises mostly from the lack of information on the fate of eroded soil organic carbon (SOC) whilst in-transit from the site of erosion to the site of longer-term deposition. Solving this controversy requires an improved understanding of the transport distance of eroded SOC, which is principally related to the settling velocity of sediment fractions that carry the eroded SOC. Although settling velocity has already been included in some erosion models, it is often based on mineral particle size distribution. For aggregated soils, settling velocities are affected by their actual aggregate size rather than by mineral particle size distribution. Aggregate stability is, in turn, strongly influenced by SOC. In order to identify the effect of aggregation of source soil on the transport distance of eroded SOC, and its susceptibility to mineralization after transport and temporary deposition, a rainfall simulation was carried out on a silty loam. Both the eroded sediments and undisturbed soil were fractionated into six different size classes using a settling tube apparatus according to their settling velocities. Weight, SOC concentration and instantaneous respiration rates were measured for each of the six class fractions. Our results indicate that: (1) 41% of the eroded SOC was transported with coarse aggregates that would be likely re-deposited down eroding hillslopes, rather than with fine particles likely transferred to water courses; (2) erosion was prone to accelerate the mineralization of eroded SOC, and thus might contribute more CO2 to the atmosphere than current estimates which often ignore potential effects of aggregation; (3) preferential deposition of SOC-rich coarse aggregates potentially causes an increase of SOC remaining in the colluvial system and a reduction of SOC flux to the alluvial or aquatic system. These findings identify a potential error of overestimating net erosion-induced carbon sink effects, and thus add an additional factor to consider when improving our current understanding of SOC erosion and deposition on hillslopes.

scholarly journals Geochemistry of Street Dust in Tyumen, Russia: Influence of Traffic Load

2021 ◽  
Author(s):  
Dmitriy Moskovchenko ◽  
Roman Pozhitkov ◽  
Dzhamilya Ukarkhanova
Keyword(s):  
Particle Size ◽  
Organic Carbon ◽  
Particle Size Distribution ◽  
Carbon Content ◽  
Size Distribution ◽  
Road Dust ◽  
Traffic Load ◽  
Anthropogenic Sources ◽  
Emission Spectrometry ◽  
Organic Carbon Content

Abstract The article presents the results of studying the composition of road dust in Tyumen, a large city in Western Siberia. On roads with different traffic intensities, 50 dust samples were taken, in which the particle size distribution, pH, and organic carbon content were determined. The content of 62 major and trace elements was studied using atomic emission spectrometry (AES-MS) и inductively coupled plasma spectrometry (ICP-MS). It was revealed that the dust has an alkaline reaction pH = 7.4 - 10.2, low organic carbon content (0.07 - 2.9%). The particle size distribution is dominated by particles PM = 100-250. The content of small particles (PM <2 and PM2-10) representing the greatest environmental hazard is minimal on roads with an average traffic intensity. Studies have shown that the main road dust pollutants in Tyumen are Ni, Sb, Cr, Zn, Co. The average geoaccumulation index (Igeo) values ​​are ranked as Ni (2.2) > Sb (1.5) > Cr (1.3) > Zn (0.4) > Co (0.4) > Cu (0.2). The contamination evaluation through enrichment factor (EF) calculation showed that road dust is highly enriched in Ni and significantly in Cr and Sb. More than 80% of Zn, Co, Cu and more than 90% of Ni, Sb, Cr come from anthropogenic sources. By the content of Ni and Cr, Tyumen surpasses all cities of the Earth where similar studies were carried out. The high Ni content is associated with the composition of local soils and roadways, increased content in vehicle exhaust gases, and abrasion of metal parts. Calculations of the total pollution indices (IPI and Zc) showed that the level of road dust pollution in most of Tyumen's territory is average, moderately hazardous.

scholarly journals Influence of particle size distribution, organic carbon, pH and chlorides on washing of mercury contaminated soil

Chemosphere ◽  
2014 ◽  
Vol 109 ◽  
pp. 99-105 ◽  
Author(s):  
Jingying Xu ◽  
Dan B. Kleja ◽  
Harald Biester ◽  
Anders Lagerkvist ◽  
Jurate Kumpiene
Keyword(s):  
Particle Size ◽  
Organic Carbon ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Contaminated Soil

Effect of Process Parameters on the Particle Size Distribution of Paclitaxel Nanocrystals

2020 ◽  
Vol 12 (2) ◽  
pp. 137-146
Author(s):  
Gannimitta Arvind ◽  
Srinivas Prathima ◽  
Atla Venkateshwar Reddy
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Response Surface ◽  
Size Distribution ◽  
Process Parameters ◽  
Physicochemical Characteristics ◽  
Precipitation Method ◽  
Influence Of Process Parameters ◽  
Predicted Values ◽  
Two Phases

The main intention of this work was to study the effect of process variables on the particle size distribution of paclitaxel nanocrystals. Paclitaxel nanocrystals were prepared by using anti-solvent precipitation method. Box Behnken design was used to optimize the process parameters including the Ratio (v/v) of two phases (A), Ulatrasonication time in min (B) and Surfactant concentration (%w/v) (C). A response surface methodology comprising 17 runs was carried out to optimize the nanocrystal formulation of paclitaxel. Two dependent variables particle size and polydispersity index (PDI) were identified as responses. Polynomial equations and response surface curves were used to relate the dependent and independent variables. The optimization model predicted a mean particle size of 147.653 nm and PDI of 0.1706 with A, B and C levels of 5, 15 min and 0.03% w/v respectively. The observed values were in close agreement with the predicted values. The optimized batches of nanocrystals were analyzed by FTIR, DSC and XRPD techniques. The optimized batch revealed irregular morphology as assessed by transmission electron microscopy and was crystalline as determined by thermal analysis and XRPD studies. Paclitaxel nanocrystals exhibited a considerable increase in solubility as well as dissolution rate in comparison with the pure drug. The present work thoroughly explored the influence of process parameters on the physicochemical characteristics of the produced drug nanocrystals.

The mechanisms of organic carbon protection and dynamics of C-saturation in Oxisols vary with particle-size distribution

2017 ◽  
Vol 68 (5) ◽  
pp. 726-739 ◽  
Author(s):  
I. F. Souza ◽  
L. F. J. Almeida ◽  
G. L. Jesus ◽  
M. Kleber ◽  
I. R. Silva
Keyword(s):  
Particle Size ◽  
Organic Carbon ◽  
Particle Size Distribution ◽  
Size Distribution
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