High Cation Exchange Capacity Research Articles

Effects of aging processes on spent mushroom Substrate-Derived Biochar: Adsorption characteristics of Cd(II) and Cr(VI)

To explore how chemical, physical and biological process impact the adsorption capacity of biochar for cations and anions, five kinds of spent mushroom substrate biochars including PB (carbonized Auricularia auricula substrate at 600 °C for 6 h), NB (Aged PB at 25 °C and 40 % moisture for 12 mon), AB (PB treated with 20 % mixed acid solution at 70 °C for 6 h), FB (PB subjected to 16 freeze–thaw cycles between − 20 °C and 25 °C) and MB (PB incubated with microbes from contaminated soil for 15 cycles) were prepared under simulated conditions, the internal mechanisms were revealed. Results showed that all aging processes caused a variation in crystal quantity and structure on different biochar. AB, NB and MB had higher hydrophilicity and polarity, and more positive charges than PB. Moreover, AB and MB had a higher cation exchange capacity (CEC) (70.7 and 75.3 cmol/kg) and more oxygen-containing functional groups than PB. MB has the maximum adsorption capacity for Cd(II) (24.2 mg/g), followed by PB (23.5 mg/g), FB (22.7 mg/g), NB (22.2 mg/g), and AB (22.0 mg/g). Langmuir model better described the Cd(II) adsorption onto NB, FB, and PB, while Freundlich better described AB and MB. As for Cr(VI), the maximum adsorption capacity followed the order: MB (24.1 mg/g) > AB (23.7 mg/g) > FB (23.5 mg/g) > PB (23.0 mg/g) > NB (22.7 mg/g). Langmuir model was better for Cr(VI) adsorption onto FB and PB, while Freundlich was better for AB, NB and MB. The pseudo-first-order kinetic model fits for Cd adsorption by FB，while the pseudo-second-order kinetic model fit for the adsorption of Cd and Cr by other biochars. The adsorption of Cr by all biochars was significantly related to the content of lactone group. Acidification and organic acids from microorganisms increased the pHPZC values of AB and MB, which was not conducive to the adsorption of Cd. The surface fragmentation of FB caused by the freezing and thawing process promoted its adsorption of Cd.

MINERALOGIA, GEOQUÍMICA, FERTILIDADE E ORIGEM DOS SEDIMENTOS DE PRAIA (BARRA EM PONTAL) DAS BACIAS DOS RIOS PURUS E JURUÁ NOS TERRENOS DO ESTADO DO ACRE

The Acre state is in the southwestern part of the Brazilian Amazon region with an area of 164.123.738 km2 and a low population density (5.52 inhabitants/km2 for 2021). The geological context is mainly related to recent units that outcrop at the Acre basin and associated with the Solimões Formation, besides old alluvial terraces that follow main drainages. The Solimões Formation comprises fossil-bearing clayey siltstones intercalated to fine sandstones. The old alluvial terraces are composed by sand, silt, clay, and occasionally fossil fragments. The area of the Acre state is crossed by two main hydrographic basins: The Purus and Juruá rivers in the eastern and western part, respectively. Both rivers are the so-called “white-water rivers”. They exhibit a typical dendritic drainage pattern and are extremely meandering what give rise to lakes formed after abandoned meanders. During dry season, several beaches (point bars) are exposed on river‘s meanders, frequently used for swimming but also playing a very important role in the small-scale agriculture. These beaches are also used for planting corn (Zea-Mays) and beans (Vigna unguiculata (L) Walp). The main purpose of this work is to investigate the mineralogical and geochemical aspects of those beach sediments to understand their high fertility and to identify their primary source. Fourteen stations were selected for sampling purposes throughout the river valley close to BR-364 highway. Laboratory analyses were carried out as follow: grain sizes, x-ray diffraction, scanning electron microscopy and optical microscopy of heavy minerals concentrates; sediment whole chemistry (major and traces elements analyses including rare-earth elements) by means of ICP-MS; macronutrients (P, Mg, Ca, and K) besides available Na and Al and organic matter. The river sediments are mainly fine-grained, angular sub-angular and selected moderately. Mineralogical assemblage is represented by quartz, clay minerals (smectite, illite and kaolinite) and feldspars (K-feldspars and albite). The heavy minerals contents ranged from 0.5 to 4.6% and are mainly represented by zircon, epidote, kyanite, tourmaline, garnet, rutile, apatite, staurolite, ilmenite and hematite. Chemical results shown that the sediments are mainly composed by SiO2, besides minor amounts of Al2O3, Fe2O3, K2O, CaO and MgO, what is compatible with mineralogical composition. High SiO2 contents are mainly related to quartz and Al2O3 contents reflects the presence of clay minerals. Contents for alkaline and alkali-earths are relatively high for such beach environment related to feldspars and smectites. P2O5 is related to apatite and can also be adsorbed on smectite. Fe2O3 contents are mainly associated to smectite and a minor amount to ilmenite and hematite, the most common opaque minerals found in the beach sediments. Strong correlation coefficients were observed between Al2O3 and most major and trace elements, except for Zr, Hf, Ni and As. On the other hand, strong negative correlation was obtained between SiO2 and major and trace elements what points to the importance of smectites as scavenger of trace elements in such environment. The chemical results were compared with the mean of the Upper Crust and post-Archean Australian Shales (PAAS) and show that they are impoverished in MgO, CaO, Na2O and K2O in comparison with the former and MgO, in comparison with the latter. Such impoverishment is higher in samples enriched on sand fraction. The same comparison was carried out with the Chinese Changliang and Huanghe river sediments, showing impoverishment in CaO and MgO in comparison with the Changjiang River and MgO, CaO, Na2O and Sr, in comparison with the Huanghe River. The small value obtained for the Chemical Index of Alteration (CIA) shows that these sediments have experienced small degree of chemical weathering and consequently, physical weathering has prevailed in the source area. The beach sediments also exhibit high immature index as evidenced by the following very low rations: SiO2 / Al2O3 (11,64) and K2O/ Na2O (2,08). Rare-earth elements were normalized to the Upper Crust and to the PAAS patterns. They show similar patterns of LREE depletion and HREE enrichment. On the other hand, normalized to the chondrites present enrichment in LREE and horizontalization of the HREE, with similar standards of distribution between each other, presenting typical Eu negative anomalies of granitic and intermediary nature rocks. Analytical results for macronutrients exhibited high concentrations for P, Mg, Ca and K, and low contents of available Na and Al. Organic matter contents in below 1%. The sediments show high cation exchange capacity, base saturation over 70% and low Na and Al saturation. Accordingly, those sediments can be interpreted as representing a redistribution of the recent Miocene sediments (Solimões Formation) and the own sediments that were deposited in old alluviums. Chemical and mineralogical characteristics with a silty granulometry indicate that beach sediments are like the eutrophic cambisols.

Synthesis and Characterization of Nanocomposite Hydrogels Based on Poly(Sodium 4-Styrene Sulfonate) under Very-High Concentration Regimen of Clays (Bentonite and Kaolinite).

The aim of this work was to synthesize and study the functional properties of polymer-clay nanocomposite (PCNCs) based on poly(sodium 4-styrene sulfonate) (NaPSS) and two types of clay in the dispersed phase: bentonite and kaolinite, in order to advance in the development of new geomimetic materials for agricultural and environmental applications. In this study, the effect of adding high concentrations of clay (10-20 wt. %) on the structural and functional properties of a polymer-clay nanocomposite was evaluated. The characterization by infrared spectroscopy made it possible to show that the PCNCs had a hybrid nature structure through the identification of typical vibration bands of the clay matrix and NaPSS. In addition, scanning electron microscopy allowed us to verify its hybrid composition and an amorphous particle-like morphology. The thermal characterization showed degradation temperatures higher than ~300 °C with Tg values higher than 100 °C and variables depending on the clay contents. In addition, the PCNCs showed a high water-retention capacity (>2900%) and cation exchange capacity (>112 meq/100 g). Finally, the results demonstrated the ability of geomimetic conditioners to mimic the structure and functional properties of soils, suggesting their potential application in improving soil quality for plant growth.

Spatial variability of clay minerals in a semi-arid region of Turkiye

Clay minerals are the source of many chemical and physical properties that influence the provision of soil-based ecosystem services. This study aimed to identify the most significant soil characteristics contributing to the spatial variability of clay minerals in a semi-arid region of Turkiye. Additionally, the study assessed the predictive capabilities of Classification and Regression Tree (CART), Random Forest Regression (RF) and eXtreme Gradient Boosting Regression (XGBoost) in estimating soil clay mineral content. Smectite+vermiculite (SMVR) was the most abundant clay mineral in the study area, followed by illite and kaolinite. Hyperparameter tuning significantly improved model accuracy, with root mean square error (RMSE) reductions ranging from 2.53% to 97.3%. The machine learning algorithms demonstrated varying performances in spatial prediction accuracy. The RF model achieved the lowest RMSE (8.587%) and the highest R2 values (0.796) for predicting SMVR. The XGBoost outperformed other models for kaolinite (RMSE: 4.814%, R2:0.713) and illite (RMSE:7.368%, R2:0.613). Exchangeable cations, particularly magnesium (Mg) and calcium (Ca), were identified as crucial factors influencing the spatial distribution of clay minerals. Among these, M concentration had the strongest influence on predicting both SMVR (38.1%) and illite (26.3%). Conversely, for kaolinite prediction, Ca concentration played the most significant role (38.7%), followed by Mg (19.93%). In conclusion, this study demonstrates the effectiveness of machine learning models, particularly XGBoost which achieved the lowest RMSE for all clay minerals investigated. These models offer a valuable tool for predicting clay mineral content in the Kazova Plain. The findings highlight the importance of parent material, weathering processes, and specific soil properties, such as exchangeable cations, in shaping clay mineral distribution. This knowledge not only contributes to a deeper understanding of soil formation in semi-arid environments but also practical applications. For instance, by predicting the abundance of SVMR, known for its high cation exchange capacity land managers can develop targeted strategies for optimizing fertilizer application in the Kazova Plain.

Taking Advantage of Disposal Bamboo Chopsticks to Produce Biochar for Greenhouse Crop Cultivation

Biochar is a value-added product that can be used for many purposes, particularly for environmental and agricultural purposes. In this study, pyrolysis at 450–500 °C was used to upgrade urban waste such as disposable bamboo chopsticks (DBCs) into biochar. The properties of DBC biochar were analyzed, and the biochar was subsequently used to cultivate Romaine lettuce to assess its potential as a soil amendment. Its properties, including specific surface area (SSA), pore size, pore volume, pH, cation exchange capacity (CEC), contents of carbon (C), hydrogen (H), nitrogen (N), oxygen (O), macronutrient content, and the atomic ratio of H/C, O/C, (O+N)/C, and C/N, were analyzed. The experimental pots consisted of four treatments, each with ten replicates: unamended soil (TC), soil amended with 10% (w/w) vermicompost (TV), soil amended with 10% vermicompost mixed with 1.5% biochar (TVB1.5), and soil amended with 10% vermicompost mixed with 2.5% biochar (TVB2.5). Fundamental physicochemical soil properties and plant yield (plant height, leaf width, number of leaves, and fresh weight) were investigated. The results indicated that the DBC biochar was neutral (pH 6.80) and had a high CEC (10.86 cmol/kg), 66.80% C, 3.76% H, 25.93% O, and 0.61% N. It had mesopores (39.077 Å), a large SSA (0.542 m2/g), and a pore volume of 0.005 cc/g. The biochar exhibited high aromaticity and hydrophobicity. Based on these results, the DBC biochar has the potential to be used as a soil amendment: it significantly enhances soil quality and increases plant yields. The application of 2.5% biochar resulted in the highest yield. Doi: 10.28991/ESJ-2024-08-03-07 Full Text: PDF

Biochar – a sustainable soil conditioner for improving soil health, crop production and environment under changing climate: a review

Land degradation and climate change, two intricately intertwined phenomena, demand appropriate management solutions to effectively tackle the escalating issues of food and nutritional security. In this context, the realm of agriculture confronts formidable challenges in its pursuit of soil resource reclamation, improving water quality, mitigating climate change, and maintaining soil and natural resources for posterity. Central to these aspirations is the preservation of an optimum organic matter, serving as a linchpin threshold is crucial for protecting the physical, chemical, and biological integrity of the soil, while simultaneously sustaining agricultural productivity. To address these multifaceted challenges, the introduction of diverse organic amendments has emerged as a crucial strategy. Noteworthy among these is the application of biochar, which functions as a soil conditioner capable of bolstering soil health, mitigating the impact of climate change, and securing global food security. Biochar is a carbon-enriched substance produced through pyrolysis of assorted biomass waste. It has a larger surface area, higher cation exchange capacity, and an extended carbon storage capability. The strategic integration of biochar production and subsequent soil application engenders an array of benefits, encompassing the amelioration of soil physical properties, augmented retention and the availability of nutrients, and the enhancement of biological activity, resulting in higher agricultural yields and societal benefits through the curtailment of soil to atmosphere greenhouse gas emissions. Additionally, biochar demonstrates its efficacy in the realm of environmental restoration by serving as a medium for extraction and elimination of heavy metals, which often pervade aquatic ecosystems and soil matrices. This review addressed the need for biochar production, characterization, soil health, the possibility for environmental restoration, and crop yield fluctuations owing to climate change.

Mineralogy and geotechnical properties of alkaline-activated kaolin with zeolitic tuff and cement kiln dust as landfill liners

Mixtures of variable proportions of kaolin, quartz sand, zeolitic tuff, and cement kiln dust were blended while adding an 8 M sodium hydroxide (NaOH) solution to allow alkali-activation of kaolin and achieve the optimum strength. This study investigated the mineralogy, microstructure, and geotechnical properties of the prepared mixtures. The aim was to produce a sustainable, environmentally friendly landfill liner. The samples were compacted in stainless steel molds to a maximum dry density and optimum moisture content, extruded from the molds, and left to cure in an oven at varying temperatures from 40°C to 80°C for 24 h. The investigations included XRD, SEM, unconfined compressive strength, and hydraulic conductivity tests. Test results showed the development of a hydroxysodalite binder due to the alkali reaction of kaolin, which caused an increase in strength ranging from 20 to 25 MPa depending on the curing temperature. Alkaline activation was effective even at temperatures as low as 40°C. A mixture of 100 units of kaolin, 45 units of sand, 45 units of zeolitic tuff, and 10% by weight cement kiln dust (CKD) with an 8 M sodium hydroxide activator was found to best achieve the required strength and hydraulic conductivity of 10−9 m/s for the landfill liner. The zeolitic tuff with high cation exchange capacity, available in the mixture, absorbs contaminants in the leachate and prevents pollution of the groundwater. The use of cement kiln dust contributes to enhancing strength and solving an acute environmental problem.

Synthesis of geopolymer powder and beads based on red clay waste for the adsorption of methyl orange dye from aqueous solutions: Characterization, application of response surface methodology, and cost analysis

The current research focuses on the valorization of red clay waste (RCW) to develop alumino-silicate geopolymer binders (GPP) and geopolymer spheres obtained from GPP powder modified with sodium alginate (Alg/GPP). GPP and Alg/GPP were applied in the environmental field for the retention of methyl orange (MO) from an aqueous solution. The raw material and the synthesized geopolymers were characterized by various physico-chemical methods. The results of XRF, XRD, and FTIR confirmed the successful synthesis of GPP and Alg/GPP, while the SEM/EDX findings revealed the homogeneous surface of the adsorbents. A significant specific surface area was detected for GPP (73.56 m2/g) and Alg/GPP (91.24 m2/g) with a high cation exchange capacity around 122 meq/100g for GPP and 185 meq/100g for Alg/GPP. The removal process was performed using the response surface methodology according to the Box-Behnken design, optimizing the retention efficiency of MO by different factors, including temperature, initial concentration, solution pH, and contact time. The obtained data was treated through the analysis of variance (ANOVA) and fitted by a quadratic polynomial model based on multiple regression analysis. In an acidic medium at 45 °C, the optimal conditions for MO retention were estimated to be 120 mg/L of MO concentration in 55 min using GPP and 180 mg/L of MO concentration in 20 min using Alg/GPP. The pseudo-second-order kinetics were more appropriate for describing the MO removal onto GPP and Alg/GPP adsorbents. The Langmuir model identified a high retention capacity of MO around 94.78 mg/g via GPP and 224.85 mg/g via Alg/GPP. The thermodynamic data confirmed that the elimination of MO dye onto GPP and Alg/GPP adsorbents was endothermic, favorable, and spontaneous. This study provided insights into the valorization of composite materials based on solid waste in dye retention, which can potentially be employed in wastewater treatment.

Applying coal char to cattle pens for sustainable agriculture in the semiarid US High Plains

AbstractApplying high carbon (C) additive to cattle pens and land application of the resultant manure mix offers a potential strategy for optimizing manure and soil management while mitigating environmental concerns. An experiment was conducted in western Nebraska from 2019 to 2022 to evaluate the effect of adding coal char (∼290 g C kg−1 by wt.) on feedlot manure's properties and stability and the interacting effect of manure‐char on crop yields in a corn (Zea mays L.)–dry bean (Phaseolus vulgaris L.)–corn rotation. Treatments in the crop field included manure from pens with or without char (each at 34 and 68 Mg ha−1; low and high rate), urea at 100% recommended nitrogen (N) rate with or without 45 Mg char ha−1, and a control. Applying char to pens kept them drier following snowfall events. The high surface area and cation exchange capacity of char improved soil and manure nutrient retention. The 100% urea‐N plus char treatment had a greater corn yield than the low‐rate char–manure mix or high‐rate manure in 2020. In 2021, there was a trend for higher bean yields with the high char–manure rate treatment than the control. In 2022, all the fertilized treatments had greater grain yields than the control. A one‐time high‐rate char–manure mix or manure application could replace 314 kg N ha−1 and 90 kg P2O5 ha−1 over 2 years without any yield penalty. This study underscores the synergy between char and manure or chemical fertilizers to improve nutrient balance and supply, ultimately enhancing crop production.

The Influence of Chemical Fertilizers on the Effectiveness of Biochar in Mitigating Cadmium Mobility in Soil

The focus of this study was to explore how various fertilizers influence the movement of cadmium in soil treated with biochar. The research utilized a strong acid sandy loam soil from Chanthaburi Province, naturally rich in organic matter with moderate cation exchange capacity and low nitrogen, potassium, phosphorus, sulfate, salinity and chloride levels. The soil was purposely contaminated with 50 mg kg-1 of cadmium and treated with biochar derived from water hyacinth through pyrolysis at 450°C for an hour. This biochar displayed moderate alkalinity, high organic matter, phosphorus, potassium, and cation exchange capacity, but low nitrogen content. Analytical techniques like Scanning Electron Microscopy and Fourier-Transform Infrared Spectroscopy were employed to study the surface characteristics of the biochar. The cadmium adding soil was blended with 10% biochar and various chemical fertilizers at a 0.04% ratio. Diethylenetriamine pentaacetate (DTPA) extraction was used to assess the bioavailability of cadmium to plants in the soil, while sequential extraction was conducted to identify the different forms of cadmium present in the soil. The study revealed distinct effects of different fertilizers on cadmium mobility. Fertilizers like 46-0-0 and 0-3-0 caused a transformation of cadmium from stable to less stable forms, increasing the bioavailability of cadmium to plants. Conversely, fertilizers such as 15-15-15, 0-0-50, 0-0-60, and 0-52-34 shifted cadmium from less stable to more stable forms, resulting in decreased cadmium extracted by DTPA. Other fertilizers showed no significant impact on cadmium mobility in the soil. A stepwise linear regression analysis highlighted that nitrogen content, potassium content, and electrical conductivity were influential factors affecting cadmium mobility.

Spatial variation in iodine content with relation to soil physicochemical properties in lower Himalayan region

Topography of a place has a significant impact on soil characteristics that ultimately influence soil iodine levels. Lower Himalayan region (LHR) in Pakistan has a wide range of climatic and geological variations. Hence, an investigation was conducted to analyze the iodine concentration and other physicochemical properties of soils in two LHR districts, Haripur and Mansehra. Spatial analysis indicated a decrease in iodine levels in the mountainous regions in comparison to the flat portions of LHR. Soil samples obtained from different locations across Haripur had a stronger affinity for iodine due to variations in solubility and adsorption of iodine to soil clay components, which can be attributed to lower pH, higher organic matter, and a higher cation exchange capacity (CEC). In contrast to the plains of Haripur, elevated locations in the Mansehra district had decreased levels of iodine, along with a higher soil pH and reduced soil organic matter. The soil erosion and depletion of soil micronutrients in the hilly region of Mansehra may be attributed to the unfavorable soil conditions and excessive precipitation. Presence of clay, iron (Fe), and aluminum (Al) in the soil led to a rise in iodine levels. Iodine concentrations exhibited an inverse relationship with soil acidity. Study revealed a direct correlation between soil iodine levels and their cation exchange capacity (CEC) and clay content. This study aims to gather fundamental data for the chosen regions of LHR to address illnesses caused by iodine deficiency.

Mapping of volcanic soil chemical properties with digital soil mapping after the prolonged eruption of Mt. Sinabung (2013-2020)

Volcanic soils in Indonesia cover an area of about 5.4 million ha and around 2.7 million ha in Sumatra. The prolonged eruptions of Mt. Sinabung in North Sumatra from 2013 to today eject pyroclastic materials, which blanketed and altered the soil surface. As a result, volcanic soil formed from these pyroclastic deposits. This study aims to map the chemical properties of volcanic soils after the prolonged eruption of Mt. Sinabung from 2013-2020. Thirty-four soil samples were collected at a depth of 0-20 cm according to the grid sampling system with an interval of 1x1 km covering an area of about 4,500 ha. Regression kriging (RK) was applied to predict the soil’s chemical properties and distribution spatially. The soil samples were air dried, sieved, and analyzed to determine soil pH (H2O and KCl), available, potential and retention P, organic carbon, total nitrogen, cation exchange capacity (CEC), and exchangeable basic cations. Soil pH (H2O) ranges from very acidic to neutral (4.14-6.52) and very acidic to acidic pH (KCl) (3.89-5.26), low to very high available-P (3.46-382.01 ppm), potential-P very low to very high (3.76-230.26 mg 100g-1), P-retention is categorized as very high (90-99%). The organic Carbon range from low to very high (1.73-13.05%), low to high total nitrogen (0.13-0.60%), low to high cation exchange capacity (11.78-97.71 cmolc kg-1), and exchangeable base cations are categorized as high with K values (1.60-2.98 cmolc kg-1). Na (3.72-7.45 cmolc kg-1) and Mg (5.79-12.15 cmolc kg-1) were categorized as high and Ca very low (0.039-0.157 cmolc kg-1). The estimated area of soils with pH between 4 and 5 is about 424.85 ha, and soils with pH between 5 and 6 covered an area of approximately 3,964.81 ha. Our findings suggest that persistent eruptions of Mt. Sinabung supply new plant nutrition, which can enrich and increase soil fertility in the future.

Tunable Colloidal Properties of Lauramidopropyl Betaine and Li Co-modified Montmorillonite in Ethanol/Water.

Montmorillonite (Mt) is a hydrophilic clay mineral with a generally high cationic exchange capacity and a remarkable swellability in water. Yet the application of Mt in cosmetics, paints, polymer nanocomposites, drug delivery systems, and tissue engineering are limited due to its unfavorable swelling and dispersion in alcohol/water mixtures. Improving the swellability and dispersibility of Mt in mixtures of ethanol and water remains challenging. Here, we showed that the swellability and dispersibility of Mt in ethanol/water could be significantly enhanced when lithium-Mt (Li-Mt) was intercalated by zwitterionic surfactant lauramidopropyl betaine (LPB). The binding mechanism of the LPB intercalate to Li-Mt originated from a combination of van der Waals forces, ion-dipole interaction, and electrostatic attraction. Due to the synergistic effect of Li+ and LPB, the comodified Mt (LPB-Li-Mt) exhibited excellent swellability, dispersibility, and rheological properties. The structure, morphology, zeta potential, dispersibility, and gel-forming performance of LPB-Li-Mt can be modulated by the concentrations of ethanol in ethanol/water mixtures. When the ethanol concentration increased to 75% v/v ethanol solution, the free swelling of LPB-Li-Mt remained above 80%. The results from X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray photoemission spectrometry, and small-angle X-ray scattering confirmed the full exfoliation of LPB-Li-Mt at 75% (v/v) ethanol solution. The formation of a stable colloidal LPB-Li-Mt dispersion in a mixture of ethanol/water might be derived from the association between water molecules and the Li+, the hydrophobic interaction, and the ion-dipole of ethanol with the LPB molecules. The findings provide a guide for improving dispersion and swelling of Mt and modified ones in water-miscible organic solvents.

Variation of Geochemical Properties of Soils in Tropical Lowland Rainforests in Sri Lanka

Tropical lowland rainforests (TLRFs) of Sri Lanka are considered as diverse ecosystems which play a vital role in climate change mitigation. In recent years, increasing deforestation leads to diminishing their potential ecosystem roles. For efficient forest conservation, knowledge of both above- and below-ground characteristics of TLRFs is required. Currently, above-ground information on TLRFs is sufficiently available but the details on the below-ground characteristics are limited. Therefore, this study was carried out to investigate pedo-geochemical properties of lowland rain forests of Kanneliya (KDN) and Pitadeniya, (PTD) in Sri Lanka. Four sampling plots with 1 ha in size (KDN1, KDN2, PTD1 and PTD2) were established, selecting altitudes of 117, 174, 509, and 618 m asl, respectively. Five representative near-surface (up to 25 cm) samples were collected from each plot for the investigation. Soil pH, electrical conductivity (EC), and cation exchange capacity (CEC) were measured while soil organic matter (SOM) content was determined by (i) Walkey-Black (WB) and (ii) Loss on ignition (LI) methods. Data were analysed by ANOVA and means were compared using Duncan‘s test. All measured parameters were significantly different (P<0.05) among the sampling plots. Soil pH and EC values were ranged between 3.43– 3.78 and 0.28–0.44 dS m-1, respectively. The highest CEC was recorded in PTD2 (11.09±3.44 cmol(+)/kg) whereas the lowest was in PTD1 (5.31±1.26 cmol(+)/kg). The highest SOM was recorded in PTD1 (17.71±4.42% in WB, 18.04±3.98% in LI) whereas the lowest was noted in PTD2 (5.81±3.07% in WB, 8.21±2.13% in LI). According to the comparison made between WB and LI methods, LI method recorded higher SOM content. The actual SOM and volatilizable water in hygroscopic mineral fractions might be the reason for the higher values in LI method. All acquired data were compared with standard interpretation data and accordingly, soils of the measured TLRFs are acidic, non-saline and non-reduced with sufficient soil aeration. Even though, TLRF vegetation produce high amount of biomass, soil CEC and SOM contents are low in the study area due to rapid microbial decomposition and absorption of dense vegetation. There was no linear relationship between measured parameters and altitude. Overall, measured soil chemical properties can be considered as ideal indicators of TLRFs conservation and therefore, it needs to be correlated with above-ground properties for understanding the behaviour of TLRFs responding to conservation strategies. 
 Keywords: Forest conservation, Soil chemical properties, Soil organic matter content, Tropical lowland rainforest

Organic Amendments to Short Rotation Coppice (SRC) Plantation Affect Species Richness and Metal Accumulation of Spontaneously Growing Herbaceous Plants

Excess potentially toxic metals (PTMs) in soils require ad hoc approaches to salvage. Hence, this study explored the shoot accumulation of cadmium (Cd), lead (Pb), and zinc (Zn) by herbaceous plants growing under previously established Salix and Populus clones Short Rotation Coppice (SRC) with compost and sewage sludge applications in an abandoned metallurgical site, Podlesí, Czech Republic; PTM decontamination of soils. Soils within the SRC experimental site and outside considered as control were analyzed for their chemical properties by multi-analytical techniques. Shoots of spontaneously growing herbaceous plants under trees in the site and without trees in control were determined for pseudo-total Cd, Pb, and Zn contents. Moderately to slightly acid soils, high cation exchange capacity, and C/N ratio supported mineralization and relative mobility of total Cd (7.7–9.76), Pb (1541–1929), and Zn (245–320 mg kg−1) in soils. Although soil amendments improved chemical properties, compost application supported higher species richness than sewage sludge. Over 95% of plants accumulated Cd and Zn above the WHO threshold and green fodder in the Czech Republic, with 36% Pb above the regional limit (40 mg kg−1). Approximately 100, 50, and 6% of herbaceous species had Cd, Pb, and Zn accumulation, respectively, higher than published average upper limits in plants (0.2 Cd, 10 Pb, and 150 Zn mg kg−1). Dicots recorded higher Cd content, Tenacetum vulgare (L.), Hypericum maculatum (Crantz), and Cirsium arvense (L.); Stachys palustris (L.), Lamium perpereum (L.), and Campanula patula (L.) for Pb; Glechoma hederaceae (L.), C. patula, and C. arvense for Zn in all treatments. Appropriate soil amelioration of SRC-supported PTM mobility and excess herbaceous species shoot accumulation, growth, and richness.

Synthesis and evaluation of aromatic stationary phases based on linear solvation energy relationship model for expanded application in supercritical fluid chromatography

In the last decade, the separation application based on aromatic stationary phases has been demonstrated in supercritical fluid chromatography (SFC). In this paper, four aromatic stationary phases involving aniline (S-aniline), 1-aminonaphthalene (S-1-ami-naph), 1-aminoanthracene (S-1-ami-anth) and 1-aminopyrene (S-1-ami-py) were synthesized based on full porous particles (FPP) silica, which were not end-capped for providing extra electrostatic interaction. Retention mechanism of these phases in SFC was investigated using a linear solvation energy relationship (LSER) model. The aromatic stationary phases with five positive parameters (a, b, s, e and d+) can provide hydrogen bonding, π-π, dipole-dipole and cation exchange interactions, which belong to the moderate polar phases. The LSER results obtained using routine test solutes demonstrated that the aforementioned interactions of four aromatic stationary phases were influenced by the type and bonding density of the ligand, but to a certain extent. Furthermore, the LSER data verified that the S-1-ami-anth column based on full porous particles silica had higher cation exchange capacity (d+ value), compared to the commercialized 1-AA column (based on the ethylene-bridged hybrid particles). The relationship between the d+ value and SFC additive was quantitatively proved so as to regulate electrostatic interaction reasonably. This value was greatly increased by phosphoric acid, slightly increased by trifluoroacetic acid and formic acid, but significantly reduced by ammonium formate and diethylamine. Taking the S-1-ami-naph column as an example, better peek shape of the flavonoids was obtained after the addition of 0.1 % phosphoric acid in MeOH while isoquinoline alkaloids were eluted successfully within 11 min after adding 0.1 % diethylamine in MeOH. Combined with the unique π-π interaction and controllable electrostatic interaction, the aromatic stationary phases in this study have been proven to have expandable application potential in SFC separation.

KARAKTERISASI INDIKATOR KESESUAIAN LAHAN KOMODITI NANAS LOKAL (Ananas comosus) KABUPATEN MAJENE

Indonesia boasts a high biodiversity, intricately linked to the various ecosystems within its territories. In Majene Regency, West Sulawesi Province, for instance, there is a unique commodity in the form of pineapple, locally known as 'pondang'. One of the efforts to preserve this unique pineapple commodity is to understand the characteristics of the cultivation land that has sustained it over time. This research aimed to characterize the land in the cultivation areas of Majene's local pineapple as fundamental information for farmers to comprehend the plant growth ecosystem and manage the land optimally. The research utilized purposive random sampling based on the cultivation locations of Majene's local pineapple. Observations revealed that the cultivation land conditions for Majene's local pineapple had an average temperature ranging from 25.65 to 29.75 ºC, rainfall between 1,488.05 and 2,820.50 mm, with humidity ranging from 63.38 to 89.00%. Additionally, soil fertility conditions in the research locations indicated high nutrient retention, as shown by slightly acidic to neutral soil pH values and high Cation Exchange Capacity (CEC), although some available nutrients indicated very low to low soil fertility levels, such as potassium. Soil management significantly influenced nutrient availability, soil salinity, and alkalinity in the research locations.

Exploring time-dependent seawater desalination capacity of terracotta clay soil and coconut shell charcoal

A study assessed the effectiveness of two locally available materials, terracotta clay soil, and coconut shell charcoal, as desalination membranes. The research also explored the impact of exposure time on the desalination process. The study employed a 3 × 3 factorial experiment using a Randomized Complete Block Design (RCBD) with three replications. It compared three different desalination membranes: pure clay, pure charcoal, and a combination of clay and charcoal in a 2:3 ratio. Additionally, three exposure times of seawater to the membranes were examined: 4 h, 8 h, and 12 h. The findings revealed that the different desalination membranes significantly affected (p < 0.05) the salinity level and the treated seawater's sodium and chloride ions content. Notably, clay soil demonstrated higher effectiveness in desalinating water than charcoal and the combination of clay and charcoal. However, the exposure time to the membranes did not significantly affect any of the parameters studied. Based on these results, it is evident that clay soil possesses the potential to serve as a desalination membrane, attributed to its higher Cation Exchange Capacity (CEC) and efficiency in reducing salinity. Future research could investigate ways to improve the efficiency of this material, study the effects of various parameters on the desalination process, and explore scaling up the desalination process for large-scale water production. Overall, this study contributes to developing cost-effective and sustainable methods for providing clean water to areas facing limited access to fresh water.

Pengaruh Pemberian Biochar Terhadap Perubahan Sifat Kimia Tanah Vertisol dan Pertumbuhan Kacang Hijau (Vigna radiata L.)

Vertisols are soils that have a high cation exchange capacity but tend to have a low organic matter content. Meanwhile, nutrients availability in vertisol tends to be low because these elements are bound by clay particles, so the nutrient availability is limited for plantsThe aim of this research is to investigate the influence of rice husk biochar and corn cob biochar application on the changes in chemical properties of Vertisol soil and the vegetative growth of mung bean (Vigna radiata L.). The study was conducted using a Randomized Complete Block Design (RCBD) with an experimental approach. There were 8 treatments repeated 6 times, resulting in a total of 48 experimental units. The rice husk biochar (P) treatments included the control without rice husk biochar (BSP0), rice husk biochar at a rate of 60 g/kg soil (150 tons/ha) + 2.5 kg soil (BSP1), rice husk biochar at a rate of 30 g/kg soil (75 tons/ha) + 2.5 kg soil (BSP2), and rice husk biochar at a rate of 15 g/kg soil (37.5 tons/ha) + 2.5 kg soil (BSP3). The corn cob biochar (J) treatments included the control without corn cob biochar (BTJ0), corn cob biochar at a rate of 60 g/kg soil (150 tons/ha) + 2.5 kg soil (BTJ1), corn cob biochar at a rate of 30 g/kg soil (75 tons/ha) + 2.5 kg soil (BTJ2), and corn cob biochar at a rate of 15 g/kg soil (37.5 tons/ha) + 2.5 kg soil (BTJ3). The research data were analyzed using Analysis of Variance (ANOVA) at a significance level of 5%. Significant differences between treatments were further analyzed using the Duncan's New Multiple Range Test (BNJ) at a significance level of 5%. The soil analysis was carried out at the Soil Physics and Soil Chemistry Laboratories, Faculty of Agriculture, Universitas Mataram. The results of the research showed that biochar application influenced the chemical properties of the soil (pH, Cation Exchange Capacity, Organic-C) and the growth of mung bean plants in Lombok's Vertisol soil. Biochar did not have a significant effect on the height of mung bean plants at 7 and 14 days after planting (DAP), but it had a significant effect at 21, 28, and 35 DAP. However, the application of biochar did not significantly affect the number of leaves and dry weight of mung bean plants.

Additional of Organic Amendments in the Soil to Increase the Various Crop Yield: A Review

Agricultural production is threatened by the scarcity of current natural resources, an increasing total population, climatic change, and degraded soils. To feed the world's growing population, development strategies must be implemented that sustainably increase agricultural production while at the same time reducing the negative impacts of the activities. A number of amendments are currently being researched to improve the structure and fertility of soils. The properties of organic materials (biochar (BC), husk, and compost) were examined. The properties of BC have a large specific surface area, are highly porous, and have a high cation exchange capacity (CEC). These amendments could be used to slow down the continuous soil degradation and maintain soil productivity while facing global challenges. While the environmental effects have been extensively studied, the extent to which they can contribute to long-term intensification has yet to be determined. This review aims to contribute to the topic by providing a concise summary that combines both environmental evidence and agronomic considerations.