Phosphorus is a nonrenewable mineral and essential macronutrient for all living organisms. Nevertheless, sustainable utilization of phosphorous is questionable due to the low bioavailability of phosphorus. Nano formulation is a cutting-edge option to increase the bioavailability of phosphorus. If various chemical and physical techniques are available for the nano formulation, the biological route is a great concern due to its simple, eco-friendly and cost-effective nature. Among biological methods, microbial synthesis is a currently focused way due to the smart ability of microbes to synthesis nanoparticles. Microorganisms are consisted of potential materials to synthesize well-defined stable and pure phosphorus-related nanoparticles. Due to the tiny size and stability, microbially synthesized nanoparticles increase the bioavailability of phosphorus. Microbial synthesis of phosphorus-related nanoparticles is not well studied up to now and the area is open for plenty of studies. Deep discovering of the nano formulating mechanism at the genetic level is highly required for the development of nanoparticle synthesis by microbes. Scaling up the technique for mass production is required. Toxicological assessments of phosphorus-related nanoparticles are highly required before the application in the agricultural sector to confirm the safety. If in-depth studies can thorough the knowledge in the field and minimize the existing limitations, microbial synthesis of phosphorus-related nanoparticles would be revolutionized the agricultural sector.

Background / Originality Evaluating the impact of chemical and organic farming practices on soil toxic metal concentrations is crucial for soil profiling in agroecosystems. Objective This study analyzed heavy metal concentrations within soil samples obtained from paddy fields in the Anamaduwa Divisional Secretariat region. Methodology Paddy soil samples were collected from a chemically fertilized field and an organically cultivated field. Employing a random stratified sampling methodology, twenty composite topsoil specimens were gathered from each paddy field. Toxic heavy metal (Cr, Ni, Pb, As, Cd) concentrations were analyzed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The resultant data were further analyzed using the ANOVA test followed by Tukey's pairwise comparison to determine statistically significant variations among the parameters. Furthermore, Pearson correlation analysis was applied. Findings Soil samples from chemically fertilized fields exhibited notably elevated concentrations of Cr (20.09±4.91 mg/kg), Ni (8.58±2.51 mg/kg), Pb (7.15±1.57 mg/kg), and As (0.87±0.17 mg/kg). In contrast, the soil samples from fields that were organically farmed revealed significantly lower mean concentrations of Cr (12.19±3.72 mg/kg), Ni (2.72±1.58 mg/kg), Pb (2.84±1.06 mg/kg), and As (0.49±0.18 mg/kg). The ANOVA test revealed significant differences in pH, conductivity, ammonium nitrogen, potassium, and ash content, and a notable variance in the mean concentrations of Ni, As, and Cr in organic versus chemically fertilized soils (p<0.05) while organic matter and phosphate content showed no significant differences. In the chemically fertilized field, Pearson correlations indicated a strong positive correlation between potassium and heavy metals (Pb, Cr, As, Ni) (r>0.5, p<0.05). Particularly, As showed strong correlation with Cr (r=0.912, p<0.01) and Ni (r=0.862, p<0.01), while the organic field displayed moderate correlations between As and both Cr (r=0.703, p<0.05) and Ni (r=0.779, p<0.01). Cr and Ni showed significant positive correlations (r=0.911, p<0.01) in both fields. Conclusions This suggests that organic farming practices significantly affect soil heavy metal content, leading to reduced levels of these metals. Furthermore, the positive correlations observed between potassium and heavy metals as well as among heavy metals itself emphasize a common origin among them.

Even if granular media filtration effectively reduces the turbidity of water, its limited surface functionalities and physical properties may constrain its ability to effectively remove critical contaminants from water. In our research, we successfully synthesized a new type of porous material – multiple coated GO/sand (M-GO/S) by integrating ordinary river sand with gra�phite oxide (GO) for the adsorptive removal of calcium ions in terms of water softening. Prior investigations confirmed it could remove water turbidity and fluoride simultaneously. M-GO/S was characterized using microscopic and spectroscopic techniques. The results indicate the presence of an uneven coating of graphite oxide, and the nanocomposite contains oxygen�containing functional groups. Under given conditions, the M-GO/S nanocomposite demonstrated remarkable efficacy in re�moving 75% of calcium ions (a higher removal percentage than commercial coal powdered activated carbon) from simulated hard water: pH 8, 5.0 g dosage, 50 mg/L calcium ions, and 20 min contact time. The isotherm and kinetic data revealed that the adsorption mechanism primarily comprises multilayer adsorption by means of a chemical sorption process. The mecha�nism of the proposed M-GO/S nanocomposite for removing calcium ions from hard water is elucidated using (XPS) analysis. The presence of (-O-Ca-O-) chemical bonds on the surface of the nanocomposite after equilibration with calcium ions suggests the occurrence of chemical interactions between the calcium ions and oxygen-containing functional groups of the M-GO/S. Consequently, the synthesized M-GO/S nanocomposite can be identified as a promising candidate for hard water treatment. Keywords: graphite oxide, sand, water hardness, adsorption

Centella asiatica commonly referred as Gotukola, is recognized for its extensive application in traditional medicine owing to its remarkable health benefits. This study investigated the differences in pH, ash content, moisture content, and in vitro antioxidant potential among three prevalent vine-type morphotypes of Centella asiatica: Wel Gotukola, Meerigima Gotukola, and Yodha Gotukola, indigenous to Sri Lanka. Centella asiatica plants of the same age (100 days) at their first harvestable matured stage, were randomly collected from domestic gardens in Gampaha District, Sri Lanka. Three replicates of each morphotype were sampled. Moisture and ash content were analyzed using the standard AOAC method, and pH was measured using the potentiometric method. DPPH (2,2-Diphenyl-1-picrylhydrazyl) radical scavenging capacity assay was used to determine the antioxidant activity. To thoroughly compare antioxidant potential among morphotypes, the ANOVA test was utilized followed by post-hoc Tukey HSD tests. Following results were obtained for the average moisture content of Wel Gotukola (83.41% ± 1.16%), Yodha Gotukola (74.33% ± 2.23%), and Meerigama Gotukola (79.46% ± 1.89%), alongside average ash content of Wel Gotukola (11.60% ± 1.02%), Yodha Gotukola (13.12% ± 2.57%), and Meerigama Gotukola (12.17% ± 2.01%). Additionally, an average pH of Wel Gotukola (6.00 ± 0.21), Yodha Gotukola (5.75 ± 0.25), and Meerigama Gotukola (5.98 ± 0.14) was observed. The antioxidant activity of Centella asiatica extracts exhibited concentration dependent increases in radical scavenging capacity. Notably, the DPPH radical scavenging potency, denoted by the minimum IC50 value, exhibited significant variations across different Gotukola varieties (p<0.05): Wel Gotukola (6.4 ± 0.54 µg/ml), Yodha Gotukola (8.56 ± 0.35 µg/ml), and Meerigama Gotukola (7.0 ± 0.75 µg/ml). Post-hoc Tukey tests showed antioxidant activity was significantly higher in Wel Gotukola compared to that of Meerigama and Yodha Gotukola morphotypes (p<0.05). Furthermore, Wel Gotukola demonstrated the highest average pH, moisture content, and the lowest mineral content. Conversely, Yodha Gotukola exhibited the lowest pH, moisture content, and the highest ash content. These findings underscore the potential of chemical parameters in elucidating the distinctive attributes of the three Gotukola varieties. Specifically, the significantly higher antioxidant potential observed in Wel Gotukola suggests its potential as an optimal candidate for herbal product development. This study imparts valuable insights into optimizing the therapeutic efficacy of formulations based on the specific Centella asiatica employed in such endeavours.

This research focuses on the synthesis of a novel adsorbent, a sand/graphene oxide composite with five layers of graphene oxide coating, referred to as S-GO5. The primary aim of this study is to assess the potential suitability of S-GO5 as a molecular sieving material via the adsorption of Methylene blue (MB) dye and 2-methyl-4-chlorophenoxyacetic acid (MCPA) pesticide molecules. The composite is created through a stepwise deposition of graphene oxide onto river sand using a thermal annealing process. Characterization studies conducted with scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FT-IR) reveal a non-uniform graphene oxide coating on the sand's surface and the incorporation of oxygenated functional groups within the composite structure. The study compares the adsorption capacity of S-GO5 with other sorbent materials like activated carbon, graphene oxide, and sand, for the removal of MB dye and MCPA. For the analysis of MB dye and MCPA adsorption, UV visible spectroscopy (665 nm) and high-performance liquid chromatography (HPLC) methods were employed respectively. The optimization studies for MB adsorption on S-GO5 revealed that the ideal conditions are a concentration of 5 mg/L, a dosage of 0.09 g, a contact time of 20 minutes, at pH 9. Focusing on the adsorption of MCPA onto the S-GO5, the optimum concentration, dosage, and contact time were 75 mg/L, 0.05 g, and 105 minutes respectively, at neutral pH values. The investigation of adsorption equilibrium isotherms indicated that the Freundlich model best describes the adsorption process, with high correlation coefficients for both MB and MCPA. Additionally, adsorption kinetics analysis suggests a pseudo-second-order model best fits the data, indicating a chemical sorption mechanism governing the adsorption process. It is evident that MB (98.6%) has a significantly higher adsorption capacity on S-GO5 compared to MCPA (53.3%). The adsorption capacity values of MB, and MCPA were 52. 861 mg/g and 4.7316 mg/g respectively. Despite MB having a cationic charge and MCPA being either neutral or negatively charged in solution, the S-GO5 composite demonstrates a remarkable adsorption capacity for both compounds. This suggests that the synthesized composite could be a promising solution for molecular sieving material, owing to the removing positively charged molecules (MB) as well as negatively charged (MCPA) pesticide contaminants from water.