Cation Exchange Capacity Values Research Articles

Internal Force Mechanism of Pisha Sandstone as a Soil Amendment to Improve Sandy Soil Structural Stability in Mu Us Sandy Land

Compounding Pisha sandstone (PSS) with sandy soil in Mu Us Sandy Land is a viable agronomical measure to effectively reduce soil erosion and improve soil quality due to the complementary characters and structures of the two materials. Aggregate stability is an important indicator to assess sandy soil erosion resistance and quality, which could be largely affected by soil surface electrochemical properties and particle interaction forces. However, the effect of the compound ratio and particle interaction forces on the aggregate stability of compound soils with Pisha sandstone and sandy soil is still unclear. Therefore, in this study, the electrochemical properties, particle interaction forces, and their effects on the aggregate stability of PSS and sandy soil at five volume ratios (0:1, 1:5, 1:2, 1:1, and 1:0) were determined to clarify the internal force mechanism of PSS to increase sandy soil structural stability in a 10-year field experiment. Experiments were measured by a combined method for the determination of surface properties and aggregate water stability. A ten-year field study revealed that the incorporation of Pisha sandstone significantly enhanced the soil organic carbon (SOC) and cation exchange capacity (CEC) (p < 0.05), while the CEC value notably increased from 4.68 to 13.76 cmol·kg−1 (p < 0.05). The soil surface potential (absolute value) and the electric field intensity gradually decreased with the increase in the Pisha sandstone content. For the compound soil particle interaction force, the addition of Pisha sandstone enhanced the van der Waals attraction force, reduced the net repulsive force between compound soil particles, and promoted the agglomeration of aeolian sandy soil. The overall trend of the aggregate breaking strength of compound soils under different addition ratios of PSS was 1:0 > 1:1 > 0:1 > 1:5 > 1:2. When the Pisha sandstone content in the compound soils was <50%, the aggregate stability was mainly influenced by compound soil particle interaction forces, and the interaction force increase was the key reason for the aggregate breakdown. When the Pisha sandstone content in the compound soils was ≥50%, the aggregate stability was affected by the combined effects of the compound soil particle composition and particle interaction forces. These results indicate that PSS addition ratios and particle interaction force are important factors affecting the structural stability of compound soils, in which the volume ratio of PSS to sandy soil of 1:2 is the appropriate ratio. Our study provides some theoretical references for further understanding of the compound soil structure improvement and sandy soil erosion control in Mu Us Sandy Land.

Organo acid-activated clays for water treatment as removal agent of Eosin-Y: Properties, regeneration, and single batch design absorber

Organoclays have been proposed as efficient removal agents for colored wastewater treatment. In this study, organo-acid-activated clays were investigated for their ability to remove eosin Y dye molecules. Firstly, the clay was acid activated using sulfuric solution at 90 °C for overnight. Secondly, the resulting materials were treated by hexadecyltetramethylammonium bromide solutions to obtain organo-acid-activated clays. Several techniques were used, such as X-ray diffraction, carbon hydrogen nitrogen analysis, silicon-29 and carbon-13 solid-state nuclear magnetic resonance, and nitrogen adsorption isotherms. The cation exchange capacity values were reduced and the specific surface area values increased from 80.1 m2/g to 183.2 m2/g during the acid activation process. The resulting organo-acid-activated clays had a similar expansion of interlayer spacing of 3.90 nm with less intercalated hexadecyltetramethylammonium surfactants, ranging from 0.80 mmol/g to 1.22 mmol/g; 13C solid NMR indicated that the intercalated surfactants exhibited different degree of conformation. Many factors, including the solid dose, solution pH, amount of intercalated surfactants, and starting eosin-Y concentrations, were studied in relation to the removal capabilities of organo acid-activated clays. Based on the Langmuir model, the removal capacity of the organo acid-activated clays ranged from a minimum of 43.5 mg/g to a maximum of 79.3 mg/g, dependent on the surfactant quantities and acid activation degree. , and the pH. The removal percentage of eosin-Y was increased from 50.5 % to 80.8 % by treating the organo acid-activated clay with HCl solution before the removal procedure. Regeneration and reuse of two selected organo acid-activated clays were carried out for seven successive cycles, and a reduction in the initial efficiency was in the range of 26.4 %–30.1 %. However, for organoclay (without acid activation), approximately 52.1 % efficiency was maintained. Using the Langmuir model and mass balance equations, a single-stage adsorber design was suggested for different dye volumes at a constant starting concentration.

Co-pyrolysis of alkali-fused fly ash and corn stover to synthesize biochar composites for remediating lead-contaminated soil

Fly ash (FA) is mainly composed of silica, alumina, and other metal oxide components, and has a positive stabilizing effect on soil heavy metals. Biochar composites produced from FA and corn stover (CS) can improve its remediation performance. Therefore, a batch of biochar composites (alkali-fused FA-CS biochars, ABs), synthesized via co-pyrolysis of CS and alkali-fused FA (AFFA) at different temperatures of 300, 500, and 700 °C (AB300-1, AB500-1, and AB700-1) and CS to AFFA mass ratios of 10:1, 10:2, and 10:5 (AB500-1, AB500-2, and AB500-5), was used to remediate lead (Pb)-contaminated soil. Compared with pristine biochars (BCs), ABs were enriched with oxygen-containing functional groups (Si–O–Si and Si–O) and aromatic structures. The ABs prepared at lower pyrolytic temperature (≤500 °C) and lower ratio of CS to AFFA (10:1) showed higher yield and stability. The contents of Toxicity Characteristic Leaching Procedure (TCLP)-extractable Pb and DTPA-CaCl2-triethanolamine (DTPA)-extractable Pb were generally lower in the soils amended with ABs than BCs. Compared with other ABs such as AB300-1, AB500-2, AB500-5, and AB700-1, the soil amended with AB500-1 had lower contents of TCLP and DTPA-extractable Pb (24% reduction), exhibiting superior performance in stabilizing Pb in the soil. The gradual decrease of DTPA-extractable Pb content in the soil with increasing dosage of AB500-1 amendments suggests that AB500-1 facilitated the conversion of bioavailable Pb to the stable and less toxic residual fractions. Specifically, the highest percentage of residual fraction of Pb in soil amended with AB500-1 was 14%. Correlation analyses showed that the soil DTPA-extractable Pb content decreased with the increase of soil pH and cation-exchange capacity (CEC) value. ABs stabilize Pb in the soils mainly via electrostatic attraction, precipitation, cation-π interaction, cation exchange, and complexation. These findings provide insights for producing functionalized biochar composites from industrial waste like FA and biomass waste for remediating the soils polluted by heavy metals.

A comparative study on the Cs adsorption/desorption and structural changes in different clay minerals.

We investigated the structural changes in clay minerals after Cs adsorption and understood their low desorption efficiency using an ion-exchanger. We focused on the role of interlayers in Cs adsorption and desorption in 2:1 clay minerals, namely illite, hydrobiotite, and montmorillonite, using batch experiments and XRD and EXAFS analyses. The adsorption characteristics of the clay minerals were analyzed using cation exchange capacity (CEC), maximum adsorption isotherms (Qmax), and radiocesium interception potential (RIP) experiments. Although illite showed a low CEC value, it exhibited high selectivity for Cs with a relatively high RIP/CEC ratio. The Cs desorption efficiency after treatment with a NaCl ion exchanger was the highest for illite (74.3%), followed by hydrobiotite (45.5%) and montmorillonite (30.3%); thus, Cs adsorbed onto planar sites, rather than on interlayers or frayed edge sites (FESs), is easily desorbed. After NaCl treatment, XRD analysis showed that the low desorption efficiency was due to the collapse of the interlayer-fixed Cs, which tightly narrowed the interlayers' hydrobiotite due to the ion exchange of divalent cations (Mg2+ or Ca2+) into the monovalent cation (Na+). Moreover, EXAFS analysis showed that hydrobiotite formed inner-sphere structures after NaCl desorption, indicating that it was difficult to remove Cs from NaCl desorption due to the collapsed hydrobiotite and montmorillonite interlayers as well as the strong bonding in FESs of illite. In contrast, chelation desorption using oxalic acid effectively dissolved the narrowed interlayers of hydrobiotite (98%) and montmorillonite (85.26%), enhancing the desorption efficiency. Therefore, low desorption efficiency for Cs clays using an ion exchanger was caused by the collapsed interlayer due to the exchange between monovalent cation and divalent cation.

Nutrient content in olive leaves through sustained irrigation with treated wastewater

Water scarcity is posing a major challenge to sustainable development. This issue will become more pressing as the global population grows, living standards rise, food habits evolve, and the effects of climate change intensify, resulting in rising temperatures globally. Reusing treated wastewater reduces effluent discharge into natural water bodies while also providing a reliable water source for applications that do not require high-quality water. A field trial was conducted on plots where olive trees grow. Two water treatment scenarios were investigated: one with a conventional water source as the control and one with treated wastewater as an alternative.Soil and irrigation water were characterized in the study regions, and chlorophyll, macro and micronutrients in olive leaves were analyzed. Soils treated to long-term wastewater irrigation had considerably higher electrical conductivity, total nitrogen, potassium, sodium, magnesium, zinc, and cation exchange capacity values than control. Notably, control soils had much greater levels of zinc and phosphorus than treated wastewater-irrigated soils. Except for phosphorous content (greater in plants from treated wastewater irrigated plots) and zinc content (lower in plants from treated wastewater irrigated plots), no significant variations in nutrients evaluated occurred for crops. In general, when comparing irrigation with reclaimed wastewater to irrigation with fresh water, no negative influence on tree performance was detected over time. Nevertheless, it's crucial to consider the potential risk of soil salinization associated with the consistent use of this water for irrigation.

MAPPING THE SALINITY STATUS OF AGRICULTURAL SOILS BETWEEN KIRIKHAN-KUMLU IN THE EASTERN MEDITERRANEAN REGION OF TURKEY WITH GEOGRAPHIC INFORMATION SYSTEMS (GIS)

In this study, it was aimed to determine the salinity status of agricultural soils between Kırıkhan-Kumlu in the Eastern Mediterranean region of Turkey by mapping with Geographic Information Systems (GIS). For this purpose, a total of 60 soil samples were taken from 0–20 and 20–40 cm depths and from 30 different points to represent the agricultural soils of Kırıkhan-Kumlu region in the Eastern Mediterranean region of Turkey. In the soil samples, pH, cation exchange capacity (CEC) and exchangeable cation (ECC) values were determined to determine some soil properties. Total salt, salinity class, sodium adsorption rate (SAR), exchangeable sodium percentage (ESP) and soluble cations (Na, Ca and Mg) were determined to determine the salinity status of the soils. According to the results of the research; as a result of the analysis carried out to determine the salinity status of the soils; pH values were determined between 6.91–7.98; total salt content between 0.02–0.13%; SAR values between 0.023–0.044 me/100 gr; ESP values between 0.35–2.96%; soluble Na content between 0.019–0.034 me/100 gr; soluble Ca content between 0.018–0.245 me/100 gr and soluble Mg content between 0.037–0.113 me/100 gr. In addition, by applying the ESP-SAR regression relationship of the soils, it was revealed that the soils tended to alkalize towards the lower layers. The salinity values obtained as a result of the study were transferred to the Geographic Information Systems (GIS) environment and interpolated by Kriging method and a salinity map of the study area was created. In conclusion, as a result of the research conducted in the soils of the study area in the Eastern Mediterranean region, it was determined that all of the agricultural soils of Kırıkhan-Kumlu region were classified as non-saline and that the soils did not have any problems in terms of salinity.

Evolving dynamics of insect frass fertilizer for sustainable nematode management and potato production.

Potato production faces major challenges from inadequate soil fertility, and nematode infestation, yet synthetic fertilizers and nematicides are costly and harmful to the environment. This study explored the potential of chitin-fortified black soldier fly-composted organic fertilizer (BSFCOF) as a multipurpose organic fertilizer amendment for enhancing potato yield and suppressing potato cyst nematodes (PCN). The BSFCOF was applied at a rate equivalent to 150 kg N ha-1 and fortified with chitin from black soldier fly pupal exuviae at inclusion rates equivalent to 0.5, 1, 2, 3, 4 and 5% chitin. Data were collected on potato growth characteristics, PCN population densities, and soil chemical properties for two growing cycles. Results showed that chitin fortified BSFCOF significantly improved potato growth parameters, chlorophyll concentration, marketable tuber yield and number of marketable tubers. The marketable tuber yield achieved using chitin-fortified BSFCOF was 70 - 362%, and 69 - 238% higher than the values achieved using unfertilized soil during the first and second growing cycles, respectively. Soil amendment with chitin-fortified BSFCOF significantly reduced the number of cysts per 200 g soil-1, number of eggs and J2 per cyst-1, eggs g-1 soil and reproduction rate by 32 - 87%, 9 - 92%, 31- 98% and 31 - 98%, respectively. The PCN suppression increased with chitin inclusion rates. There were significantly higher values for soil pH, ammonium nitrogen, nitrate nitrogen, available phosphorus, calcium, magnesium, potassium, and cation exchange capacity in soil amended with BSFCOF compared to unamended soil. This study demonstrates that BSFCOF fortified with 5% chitin is an effective soil enhancer with multiple benefits, including improved soil fertility, potato performance, and effective management of potato cyst nematodes.

Seasonal quality and statistical assessment of physicochemical properties and base saturation of Hadejia-Nguru wetland soils, Northwest/Eastern Nigeria

Abstract The evaluation of Hadejia-Nguru wetland soils was carried out for two consecutive dry seasons. Standard analytical techniques were adopted to analyze the samples and statistical models were used to assess the spatial and temporal distribution of the parameters selected. The average pH values of the soil samples were mostly alkaline, and all the measured values were also within the approved standards. Experimental results revealed a significantly positive correlation between Ca and Mg for both seasons as indicated by the p-values and a high coefficient of determination (R2) for both metals with cation exchange capacity (CEC) values as the predictors. The regression analysis showed that the changes in CEC and pH levels in the soil were dependent on changes in Ca and Mg content of the soil. The data obtained showed that the increase in pH is directly proportional to the CEC and base saturation of the soils. A higher percentage of Ca than other cations (Mg, K and Na) was observed from the base saturation of the soils. The pH, base saturation, and CEC levels in the soils are suitable for most crops grown in the area, which has the potential to support a wide range of crops with further exploration.

Using mid-infrared spectroscopy as a tool to monitor responses of acidic soil properties to liming: case study from a dryland agricultural soil trial site in South Australia

Soil acidification is an issue for agriculture that requires effective management, typically in the form of lime (calcium carbonate, CaCO3), application. Mid infrared (MIR) spectroscopy methods offer an alternative to conventional laboratory methods, that may enable cost-effective and improved measurement of soil acidity and responses to liming, including detection of small–scale heterogeneity through the profile. Properties of an acidic soil following lime application were measured using both MIR spectroscopy with Partial Least Squares Regression (MIR-PLSR) and laboratory measurements to (a) compare the ability of each method to detect lime treatment effects on acidic soil, and (b) assess effects of the different treatments on selected soil properties. Soil properties including soil pH (in H2O and CaCl2), Aluminium (Al, exchangeable and extractable), cation exchange capacity (CEC) and organic carbon (OC) were measured at a single field trial receiving lime treatments differing in rate, source and incorporation. Model performance of MIR-PLSR prediction of the soil properties ranged from R2 = 0.582, RMSE = 2.023, RPIQ = 2.921 for Al (extractable) to R2 = 0.881, RMSE = 0.192, RPIQ = 5.729 for OC. MIR-PLSR predictions for pH (in H2O and CaCl2) were R2 = 0.739, RMSE = 0.287, RPIQ = 2.230 and R2 = 0.788, RMSE = 0.311, RPIQ = 1.897 respectively, and could detect a similar treatment effect compared to laboratory measurements. Treatment effects were not detected for MIR-PLSR-predicted values of CEC and both exchangeable and extractable Al. Findings support MIR-PLSR as a method of measuring soil pH to monitor effects of liming treatments on acidic soil to help inform precision agricultural management strategies, but suggests that some nuance and important information about treatment effects of lime on CEC and Al may be lost. Improvements to prediction model performance should be made to realise the full potential of this approach.

The effect of sulphur supplementation on cadmium phytotoxicity in wheat and lettuce: changes in physiochemical properties of roots and accumulation of phytochelatins.

Intensive sulphur fertilisation has been reported to improve the nutrient balance and growth of Cd-exposed plants, but the reasons of this phenomenon and the role of sulphur compounds in the resistance to cadmium are unclear. We investigated sulphur supplementation-induced changes in the surface properties of roots and the level of thiol peptides (PCs) in Cd-stressed Triticum aestivum L. (monocots clade) and Lactuca sativa L. (dicots clade) grown in nutrient solution. The combination of three sulphur (2mM S-basic level, 6 or 9mM S-elevated levels) and four cadmium (0, 0.0002, 0.02 or 0.04mM Cd) concentrations was used. The physicochemical parameters of the roots were determined based on the apparent surface area (Sr), total variable surface charge (Q), cation exchange capacity (CEC) and surface charge density (SCD). In Cd-exposed plants supplied with sulphur, a different character and trend in the physicochemical changes (adsorption and ion exchange) of roots were noted. At the increased sulphur levels, as a rule, the Sr, CEC, Q and SCD values clearly increased in the lettuce but decreased in the wheat in the entire range of the Cd concentrations, except the enhanced Sr of wheat supplied with 6mM S together with elevated (0.0002mM) and unchanged (0.02, 0.04mM Cd) value of this parameter at 9mM S. This indicates a clade-specific and/or species-specific plant reaction. The 6mM S appears to be more effective than 9mM S in alleviation of the cadmium's toxic effects on roots. It was found that at 0.02 and 0.04mM Cd, the use of 6mM S limits the Cd accumulation in the roots of both species in comparison with the basic S fertilisation. Moreover, PC accumulation was much more efficient in wheat than in lettuce, and intensive sulphur nutrition generally induced biosynthesis of these chelating compounds. Physicochemical parameters together with quantitative and qualitative assessment of thiol peptides can be important indicators of the efficiency of root system functioning under cadmium stress. The differences between the species and the multidirectional character of the changes are a result of the involvement of a number of multi-level mechanisms engaged in the defence against metal toxicity.

Delineation of Soil Physical and Chemical Properties of Mahisagar District of Gujarat, India

The successful implementation of sustainable agriculture practices relies on maintaining a favorable physical and chemical environment in the soil. This study aimed to assess the soil properties of Mahisagar district in Gujarat, focusing on both physical and chemical aspects. A total of 180 surface soil samples (0-15 cm depth) were collected from cultivated fields in six talukas during April-May 2018. Key indicators, including bulk density, particle density, porosity, moisture-holding capacity (MWHC), electrical conductivity (EC2.5), pH2.5, free lime, organic carbon, and cation exchange capacity (CEC), were analyzed to provide a comprehensive understanding of the soil's characteristics. The results indicated that mean bulk density and particle density value of the soils of Mahisagar district was 1.32 and 2.53 Mg m-3 respectively, while porosity with a mean value of 47.97 per cent. The overall range of MWHC was with a mean value of 45.97 per cent. The soils of Mahisagar district were high in organic carbon content and non-calcareous in nature with alkaline in reaction. The mean EC2.5 value in the soils of Mahisagar district was (0.38 dS m-1). The mean CEC value was 24.47 cmol (p+) kg-1. among the exchangeable cations Ca++ and Mg++ was dominance in soil, while water soluble ions Cl- and Mg++ were found in higher proportion in Mahisagar district of Gujarat.

Shale Characterization Methods Using XRD, CEC, and LSM: Experimental Findings

Shale characterization is essential for understanding its potential as a hydrocarbon reservoir and for optimizing hydraulic fracturing operations. In this study, we evaluate the effectiveness of three methods for shale characterization: X-ray diffraction (XRD), cation exchange capacity (CEC), and linear swell meter (LSM). The study was conducted on a set of shale samples from a specific location. The samples were analyzed using XRD to determine their mineralogy, CEC to measure their ion exchange capacity, and LSM to assess their swelling properties. The results indicate that Clay stabilizers and KCl salt together perform much better. The concentrations of different additives can have a positive/negative effect on swelling. CEC values can be determined for each formation with the statistical method determined by using XRD results. Overall, the study highlights the potential of using a combination of XRD, CEC, and LSM for comprehensive shale characterization.

Variations in soil physico-chemical properties, soil stocks, and soil stoichiometry under different soil layers, the major forest region Liupan Mountains of Northwest China.

Liupan Mountains are an important region in China in the context of forest cover and vegetation due to huge afforestation and plantation practices, which brought changes in soil physio-chemical properties, soil stocks, and soil stoichiometries are rarely been understood. The study aims to explore the distribution of soil nutrients at 1-m soil depth in the plantation forest region. The soil samples at five depth increments (0-20, 20-40, 40-60, 60-80, and 80-100 cm) were collected and analyzed for different soil physio-chemical characteristics. The results showed a significant variation in soil bulk density (BD), soil porosity, pH, cation exchange capacity (CEC), and electric conductivity (EC) values. More soil BD (1.41 g cm-3) and pH (6.97) were noticed in the deep soil layer (80-100 cm), while the highest values of porosity (60.6%), EC (0.09 mS cm-1), and CEC (32.9 c mol kg-1) were reflected in the uppermost soil layer (0-20 cm). Similarly, the highest contents of soil organic carbon (SOC), total phosphorus (TP), available phosphorus (AP), total nitrogen (TN), and available potassium (AK) were calculated in the surface soil layer (0-20 cm). With increasing soil depth increment a decreasing trend in the SOC and other nutrient concentration were found, whereas the soil total potassium (TK) produced a negative correlation with soil layer depth. The entire results produced the distribution of SOCs and TNs (stocks) at various soil depths in forestland patterns were 0→20cm > 20→40cm > 40→60cm ≥ 60→80cm ≥ 80→100 cm. Furthermore, the stoichiometric ratios of C, N, and P, the C/P, and N/P ratios showed maximum values (66.49 and 5.46) in 0-20 cm and lowest values (23.78 and 1.91) in 80-100 cm soil layer depth. Though the C/N ratio was statistically similar across the whole soil profile (0-100 cm). These results highlighted that the soil depth increments might largely be attributed to fluctuations in soil physio-chemical properties, soil stocks, and soil stoichiometries. Further study is needed to draw more conclusions on nutrient dynamics, soil stocks, and soil stoichiometry in these forests.

Improving the BRIS Soil management and practices for growing roselle (Hibiscus sabradiffa L.)

Beach ridges with interspersed swales (BRIS), commonly referred to as BRIS soil or sandy soil, are extensively distributed along the eastern coast of Peninsular Malaysia. Despite the challenging nature of the lowland agricultural soil, characterised by its sandy texture and sterility, agricultural activities on BRIS soils have experienced an upward trend in recent times. The objective of this study was to conduct a literature review on the challenges and possibilities of roselle (Hibiscus sabdariffa L.) growth in the BRIS soil environment. Soil concerns can be classified into three categories: physical, chemical, and biological. The soil in BRIS is characterised by its acidic nature and low CEC values, with sand content occasionally reaching as high as 95 percent. Significant challenges associated with sandy soil conditions encompass soil water repellency (SWR), soil compaction, surface crust formation, soil erosion, low fertility, and Cation Exchange Capacity (CEC) value, as well as nutrient leaching into the groundwater, leading to pollution. The roselle plant is currently being commercially cultivated in the state of Terengganu as a substitute for tobacco in BRIS soil. This is due to the plant's exceptional aeration and deep root zone. However, owing to its diminished fertility, its output is restricted. This book concentrates on the challenges related to BRIS soil and environmental concerns, including issues such as inadequate nutrient levels, weak soil structure, and excessive drainage. This review comprehensively elucidates the management strategies for sandy soil in the context of agricultural operations and evolving climatic conditions, thereby contributing to the advancement of research on the prospective cultivation of roselle.

Impacts of Biochar Treatments on Some Soil Properties and Micronutrient Availability

The application of biochar as a soil amendment has been recognized as an environmentally friendly and highly efficient strategy for restoring the fertility of the soil and increasing agricultural productivity. In this study, the impacts of Senna tora biochar treatments on soil properties and micronutrient availability in the farmlands of Misau, Bauchi State, Nigeria, were investigated. A complete randomized design replicated three times, which included control soil (no biochar/0 day), 30 days, and 60 days of biochar treatments, was adapted based on the fact that incubation time affects biochar application in soil. After treatments, the biochar was removed and the soil samples from each treatment were analyzed for pH, soil bulk density (BD), cation exchange capacity (CEC), organic carbon (OC) and micronutrient levels using various analytical methods. The results of the analysis show pH, OC and CEC values increased significantly (p ≤ 0.05) from 6.66 to 7.89, 3.40 to 3.90 g/kg and 5.16 to 7.29 cmol/kg respectively, while BD decreased significantly from 1.56 to 1.48 g/cm3 after 60 days of biochar treatment. The levels of Mn, Cu and Zn increased from 188.25 to 286.12 mg/kg, 14.38 to 41.88 mg/kg and 68.63 to 140.19 mg/kg respectively, while levels of Fe decreased from 9460.00 to 4782.73 mg/kg after 60 days of biochar treatments. Application of Senna tora biochar has generally led to a significant improvement in the fertility of the soil. It is therefore recommended that Senna torabiochar be used in the field to demonstrate its practical application.

Influence of azolla, grass, water hyacinth, and peanut residues in amending soil properties

An incubation experiment was undertaken to evaluate the effects of azolla, grass, water hyacinth, and peanut residues for amending some soil properties. The experiment was laid out in pots comprising 7 treatments, viz. T1: Control, T2: Azolla (Azolla pinnata) @ 100 g/pot, T3: Grass (Phleum pretense) @ 100 g/pot, T4: Water hyacinth (Pontederia crassipes) @100 g/pot, T5: Peanut (Arachis hypogaea) @ 100 g/pot, T6: Azolla @ 50 g/pot + Water hyacinth @ 50 g/pot, and T7: Peanut@ 50 g/pot + Grass @ 50 g/pot. The results revealed that peanut treated soils (T5) played an important role in enhancing soil properties significantly (p < 0.05) and the values of soil organic carbon (SOC), pH, nitrogen, moisture content and cation exchange capacity (CEC) reached at an optimum level to support microbial growth over a year. Biodivers. Conserv. Bioresour. Manag. 2023, 9(2): 57-64

Tetracycline adsorption/desorption by raw and activated Tunisian clays

Clay-based adsorbents have applications in environmental remediation, particularly in the removal of emerging pollutants such as antibiotics. Taking that into account, we studied the adsorption/desorption process of tetracycline (TC) using three raw and acid- or base-activated clays (AM, HJ1 and HJ2) collected, respectively, from Aleg (Mazzouna), El Haria (Jebess, Maknessy), and Chouabine (Jebess, Maknessy) formations, located in the Maknessy-Mazzouna basin, center-western of Tunisia. The main physicochemical properties of the clays were determined using standard procedures, where the studied clays presented a basic pH (8.39–9.08) and a high electrical conductivity (446–495 dS m−1). Their organic matter contents were also high (14–20%), as well as the values of the effective cation exchange capacity (80.65–97.45 cmolckg−1). In the exchange complex, the predominant cations were Na and Ca, in the case of clays HJ1 and AM, while Mg and Ca were dominant in the HJ2 clay. The sorption experimental setup consisted in performing batch tests, using 0.5 g of each clay sample, adding the selected TC concentrations, then carrying out quantification of the antibiotic by means of HPL-UV equipment. Raw clays showed high adsorption potential for TC (close to 100%) and very low desorption (generally less than 5%). This high adsorption capacity was also present in the clays after being activated with acid or base, allowing them to adsorb TC in a rather irreversible way for a wide range of pH (3.3–10) and electrical conductivity values (3.03–495 dS m−1). Adsorption experimental data were studied as regards their fitting to the Freundlich, Langmuir, Linear and Sips isotherms, being the Sips model the most appropriate to explain the adsorption of TC in these clays (natural or activated). These results could help to improve the overall knowledge on the application of new low-cost methods, using clay based adsorbents, to reduce risks due to emerging pollutants (and specifically TC) affecting the environment.

Determining relative values of pH, CECe, and OC in agricultural soils using functional enhanced derivative spectroscopy (FEDS0) method in the mid-infrared region

Soils are a vital and non-renewable natural resource that provide the nutrients and adequate conditions for plants growth, as well to support several economic activities. Optical spectroscopy has emerged as a reliable technique for determining multiple physicochemical properties of organic and inorganic species in agricultural industries, that employs mathematical and statistical tools to develop new methodologies of spectral analysis easily implementable in remote and in-field applications. This is the case of the Functionally-enhanced derivative spectroscopy (FEDS and FEDS0), which uses operational transformations to extract hidden information from overlapping optical signals generated by the diverse components of solid and liquid matrices. In this study, an algorithm based on FEDS has been applied for optical analysis of agricultural soils in the spectral range from 1200 to 675 cm−1, to estimate chemical properties related to nutritional and fertility state of 65 soil samples used for planting of cotton, yuca (Manihot Esculenta), and banana in Bolivar and Cordoba departments in Colombia. The results demonstrate that it is possible to establish a correlation between the Pearson’s coefficient obtained from two FEDS0 spectra associated to ATR-FTIR signals (rF > - 0.85), and their relative values of effective cation exchange capacity, pH and organic carbon content, with a ratio of performance to deviation higher to 2.0 in all cases (RPD > 2.0). This is possible due to high dependence of optical signal with CECe values, which are in turn conditioned by pH level and OC content in the soil samples considered.

The Comparation of Water Saturation Approaches to Reveal a Low Resistivity Reservoir Potential Case in Gumai Formation, South Sumatra Basin

The LRLC reservoir zone has been identified in SN-3 well, at the DAP-1 interval on Gumai Formation. This interval has a low resistivity value from 3-5 ohm.m and the drill stem test (DST) results show oil with gas without water. This study is objected to identify the causes of LRLC reservoir in gumai formation and finding a suitable sw calculation method. Some data such as well logs, reports, cores, and XRD are used to calculate petrophysical parameters such as Vsh, Phie, and Sw, and would be validated by DST data. Water saturation (Sw) calculations from Archie and the CEC method (Waxman Smits, Dual Water, Juhasz) were performed and the results were compared. The results showed that the main cause of the DAP-1 interval LRLC zone was the presence of clay minerals consisting of mixed layers (Illite/smectite). These clay minerals will be associated with high cation exchange capacity (CEC) values, with the value 70 (meq/100g), which can increase conductivity and reduce resistivity values. Based on lumping the more optimistic results of sw calculation from Waxman Smits Sw method (Sw based on CEC method). The DST data on the SN-3 well does not have water test data, so the calculation of the Sw value that is close to the Swirr value is considered the most suitable Sw for the low resistivity reservoir conditions of the Gumai Formation in the study area. The best practice for low resistivity reservoir for suitable petrophysical calculation is necessary to pay attention to the rock lithology conditions, the presence of mineral clay, and determining suitable Sw appropriate to the reservoir conditions

Effects of Seasonal Variation on some Soil Chemical Properties under Different Land Use in Santa Barbara, Bayelsa State-Nigeria

A study was carried out to examine the effect of seasonal variation on some soil chemical properties under different land-use in Nembe, Bayelsa State-Nigeria. The objective was to evaluate changes in soil nutrient contents in both wet and dry seasons. A total of eighteen soil samples were collected at 0-30 cm depths in August, 2017 (Wet Season) and March, 2018 (dry season) in natural forest, oil palm plantation and arable land-use and analyzed for pH, soil organic carbon (SOC), total nitrogen (N), available phosphorus (P), exchangeable cations (Ca, Na, K and Mg), and cation exchange capacity (CEC) using standard analytical methods. Results showed that soil pH was highest (4.2) under oil palm plantation in the wet season, while high content of N 0.52 mg/kg was recorded during the wet season in all the thee-land use. Organic carbon was highest 1.69 mg/kg in natural forest, followed by 1.39 and 1.04 mg/kg for oil palm plantation and arable land use. Maximum value of P 0.22 mg/kg was observed under natural forest during the dry season, and the minimum was recorded under arable land use during the wet season. The concentration of exchangeable Ca was highest 0.3 mg/kg in the oil palm plantation, while Na was highest 2.19 mg/kg for natural forest, 1.26 and 1.06 mg/kg for oil palm plantation and arable land use. The CEC values of the soils in the natural forest were moderately high, followed by oil palm plantation and arable land use in the wet season; whereas low CEC values were observed across the three-land use in the dry season. The study concluded that soil nutrients were more available during the wet season than in the dry season in the various land use, probably due to adequate soil moisture availability in the wet season that facilitates soil nutrient release, this implies that chemical properties of soils were influenced by seasonal changes which could in turn affect agricultural production. It is recommended that crop production is encouraged in the wet season than in the dry season so as to utilize more availability of soil nutrients.