scholarly journals Effects of soil components, solution chemical properties, and temperature on Cu(II) adsorption by alluvial acid soil: A case study in Southwest China

2021 ◽  
Author(s):  
Bangzheng Ren ◽  
Yong Wu ◽  
Hongtao Li ◽  
Zailin Chen ◽  
Junlong Xu
Keyword(s):  
Organic Matter ◽  
Adsorption Capacity ◽  
Manganese Oxides ◽  
Acid Soil ◽  
Clay Fraction ◽  
Bulk Soil ◽  
Chemical Extraction ◽  
Experimental Conditions ◽  
Selective Chemical ◽  
Soil Components

Abstract The specific soil components such as soil organic matter, Fe and Mn oxides exert a significant influence on Cu(II) adsorption in soil. In the present study, clay fraction was separated from an alluvial acid soil, Then the selective chemical extraction method was used to remove the specific components in the bulk soil and clay fraction. Adsorption experiments showed that the adsorption capacity of the clay fraction of Cu(II) is greater than that of the bulk soil, regardless of whether it is treated by selective chemical extraction or not. Compared with untreated soil samples, after the removal of organic matter by H2O2, Kd decreased by a maximum of 82.8% for the bulk soil and 73.5% for the clay fraction. After the removal of manganese oxides by NH2OH·HCl, Kd decreased by a maximum of 68.1% for the bulk soil and 73.2% for the clay fraction. However, after the removal of free iron oxides by dithionite-citrate-bicarbonate, Kd increased by a maximum of 422% for the bulk soil and 195.5% for the clay fraction. Kd increased by 4263.3% when the initial pH increased from 2 to 3.5 and, then, increased to 6. The amount of Cu(II) adsorbed did not change significantly. Within a range greater than 6, the increased Cu(II) adsorption may be due to the precipitation of Cu(II). When the concentration of NaNO3 changes from 0.01 to 0.1 M, the adsorption capacity decreased by a maximum of 36%, Kd decreased by a maximum of 84.3%. The presence of foreign ions decreased Cu(II) adsorption; their order of effect on Cu(II) adsorption is Na+ < K+ < Mg2+ < Ca2+ for cations and NO3− < SO42− ≈ Cl− for anions. The adsorption of Cu(II) was an endothermic and spontaneous process under the experimental conditions.

Influence of removal of organic matter and iron and manganese oxides on cadmium adsorption by red paddy soil aggregates

RSC Advances ◽  
2015 ◽  
Vol 5 (110) ◽  
pp. 90588-90595 ◽  
Author(s):  
Zhongwu Li ◽  
Bin Huang ◽  
Jinquan Huang ◽  
Guiqiu Chen ◽  
Chang Zhang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Paddy Soil ◽  
Manganese Oxides ◽  
Soil Aggregates ◽  
Cadmium Adsorption ◽  
Soil Components ◽  
Cd Adsorption ◽  
Iron And Manganese ◽  
Red Paddy Soil

Different soil components in various aggregates were selectively removed for evaluating their influence on Cd adsorption.

scholarly journals Simulation of methane adsorption in diverse organic pores in shale reservoirs with multi-period geological evolution

2021 ◽  
Author(s):  
Shangbin Chen ◽  
Chu Zhang ◽  
Xueyuan Li ◽  
Yingkun Zhang ◽  
Xiaoqi Wang
Keyword(s):  
Organic Matter ◽  
Pore Size ◽  
Adsorption Capacity ◽  
Thermal Evolution ◽  
Methane Adsorption ◽  
Storage Site ◽  
Pressure Sensitivity ◽  
Adsorption Characteristics ◽  
Shale Reservoirs ◽  
Organic Pores

AbstractIn shale reservoirs, the organic pores with various structures formed during the thermal evolution of organic matter are the main storage site for adsorbed methane. However, in the process of thermal evolution, the adsorption characteristics of methane in multi type and multi-scale organic matter pores have not been sufficiently studied. In this study, the molecular simulation method was used to study the adsorption characteristics of methane based on the geological conditions of Longmaxi Formation shale reservoir in Sichuan Basin, China. The results show that the characteristics of pore structure will affect the methane adsorption characteristics. The adsorption capacity of slit-pores for methane is much higher than that of cylindrical pores. The groove space inside the pore will change the density distribution of methane molecules in the pore, greatly improve the adsorption capacity of the pore, and increase the pressure sensitivity of the adsorption process. Although the variation of methane adsorption characteristics of different shapes is not consistent with pore size, all pores have the strongest methane adsorption capacity when the pore size is about 2 nm. In addition, the changes of temperature and pressure during the thermal evolution are also important factors to control the methane adsorption characteristics. The pore adsorption capacity first increases and then decreases with the increase of pressure, and increases with the increase of temperature. In the early stage of thermal evolution, pore adsorption capacity is strong and pressure sensitivity is weak; while in the late stage, it is on the contrary.

scholarly journals Mixed Oxide Layered Double Hydroxide Materials: Synthesis, Characterization and Efficient Application for Mn2+ Removal from Synthetic Wastewater

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4089
Author(s):  
Cristina Modrogan ◽  
Simona Cǎprǎrescu ◽  
Annette Madelene Dǎncilǎ ◽  
Oanamari Daniela Orbuleț ◽  
Eugeniu Vasile ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Layered Double Hydroxides ◽  
Synthetic Wastewater ◽  
Precipitation Method ◽  
Metallic Ions ◽  
Materials Synthesis ◽  
Experimental Conditions ◽  
Edx Analysis ◽  
Co Precipitation ◽  
Double Hydroxides

Magnesium–aluminum (Mg-Al) and magnesium–aluminum–nickel (Mg-Al-Ni) layered double hydroxides (LDHs) were synthesized by the co-precipitation method. The adsorption process of Mn2+ from synthetic wastewater was investigated. Formation of the layered double hydroxides and adsorption of Mn2+ on both Mg-Al and Mg-Ni-Al LDHs were observed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometry (EDX) analysis. XRD patterns for prepared LDHs presented sharp and symmetrical peaks. SEM studies revealed that Mg-Al LDH and Mg-Al-Ni LDH exhibit a non-porous structure. EDX analysis showed that the prepared LDHs present uniformly spread elements. The adsorption equilibrium on these LDHs was investigated at different experimental conditions such as: Shaking time, initial Mn2+ concentration, and temperatures (10 and 20 °C). The parameters were controlled and optimized to remove the Mn2+ from synthetic wastewater. Adsorption isotherms of Mn2+ were fitted by Langmuir and Freundlich models. The obtained results indicated that the isotherm data fitted better into the Freundlich model than the Langmuir model. Adsorption capacity of Mn2+ gradually increased with temperature. The Langmuir constant (KL) value of Mg-Al LDH (0.9529 ± 0.007 L/mg) was higher than Mg-Al-Ni LDH (0.1819 ± 0.004 L/mg), at 20 °C. The final adsorption capacity was higher for Mg-Al LDH (91.85 ± 0.087%) in comparison with Mg-Al-Ni LDH (35.97 ± 0.093%), at 20 °C. It was found that the adsorption kinetics is best described by the pseudo-second-order model. The results indicated that LDHs can be considered as a potential material for adsorption of other metallic ions from wastewater.

scholarly journals Adsorption Characteristics and Controlling Factors of CH4 on Coal-Measure Shale, Hedong Coalfield

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 63
Author(s):  
Weidong Xie ◽  
Meng Wang ◽  
Hongyue Duan
Keyword(s):  
Organic Matter ◽  
Adsorption Capacity ◽  
Mineral Composition ◽  
Shale Gas ◽  
Total Content ◽  
Coal Measure ◽  
Gas Reservoirs ◽  
Quartz Content ◽  
Adsorption Characteristics ◽  
Adsorbed Gas

Adsorbed gas is one of the crucial occurrences in shale gas reservoirs; thus, it is of great significance to ascertain the adsorption capacity of shale and the adsorption characteristics of CH4. In this investigation, the Taiyuan–Shanxi Formations’ coal-measure shale gas reservoir of the Carboniferous–Permian era in the Hedong Coalfield was treated as the research target. Our results exhibit that the shale samples were characterized by a high total organic carbon (TOC) and over to high-over maturity, with an average TOC of 2.45% and average Ro of 2.59%. The mineral composition was dominated by clay (62% on average) and quartz (22.45% on average), and clay was mainly composed of kaolinite and illite. The Langmuir model showed a perfect fitting degree to the experimental data: VL was in the range of 0.01 cm3/g to 0.77 cm3/g and PL was in the range of 0.23–8.58 MPa. In addition, the fitting degree depicted a linear negative correlation versus TOC, while mineral composition did not exhibit a significant effect on the fitting degree, which was caused by the complex pore structure of organic matter, and the applicability of the monolayer adsorption theory was lower than that of CH4 adsorption on the mineral’s pore surface. An apparent linear positive correlation of VL versus the TOC value was recorded; furthermore, the normalized VL increased with the growth of the total content of clay mineral (TCCM), decreased with the growth of the total content of brittle mineral (TCBM), while there was no obvious correlation of normalized VL versus kaolinite, illite and quartz content. The huge amount of micropores and complex internal structure led to organic matter possessing a strong adsorption capacity for CH4, and clay minerals also promoted adsorption due to the development of interlayer pores and intergranular pores.

scholarly journals Impacts of soil moisture level and organic matter content on growth of two Juncus species and Poa pratensis grown under acid soil conditions

Weed Research ◽  
2019 ◽  
Vol 59 (6) ◽  
pp. 490-500
Author(s):  
W Kaczmarek‐Derda ◽  
M Helgheim ◽  
J Netland ◽  
H Riley ◽  
K Wærnhus ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Poa Pratensis ◽  
Acid Soil ◽  
Organic Matter Content ◽  
Matter Content ◽  
Moisture Level ◽  
Soil Conditions ◽  
Soil Moisture Level
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