This work focuses on exploiting the naturally occurring microbial calcium carbonate precipitation
catalyzed by microbial consortia within lakes and oceans biogeochemistry for carbon dioxide removal
from atmosphere. In this work, Bacillus subtilis OQ119616 was used for carbon dioxide sequestration
in equi-molar concentrations into Bacillus-induced calcium carbonate precipitation (BICCP). As this
process requires alkaline media, urea degradation by urease and nitrogen fixation were traced.
BICCP has been formed from calcium salts in the following order: chloride > nitrate > acetate > citrate.
However, conversion efficiency percentage (CE%) of calcium salts to CaCO3 exhibited a different
attitude of citrate > acetate > chloride > nitrate. Calcium citrate is excluded from consideration. Acetate,
however, is the most efficient salt; it significantly exhibited the highest CE%, with the least cost and
highest economic feasibility. The wide range in quantities, efficiency and feasibility indicates the
importance of the salt anion in BICCP. In addition, BICCP exhibited applicability in healing concrete
cracks, improving field capacity of sand soil and the subsequently improved seed germination of Vicia
faba. BICCP was also accompanied by adsorption of heavy metals as partial purging of waste/sewage
water for hygiene/reuse. Bacillus subtilis exhibited the ability to perform MICP, utilizing various calcium
salts in the following order: chloride > acetate > nitrate > citrate. However, acetate is the most efficient
salt of calcium to be converted to calcium carbonate precipitate by B. subtilis, as it exhibited the
highest conversion efficiency percentage (g/g %), with the least cost and highest economic feasibility.
Carbon dioxide removal (CDR) occurs at simultaneous equity to CaCO3 precipitation at mole/mole
ratios. Economic feasibility (US$/m3) showed that BICCP may be applicable in CDR for cleansing carbon
dioxide inside closed systems and for environmental safety. The bacterially induced CaCO3 proved
successful applicability in improving the field capacity of sand soil and growth of V. faba, healing
concrete cracks and sorption of heavy metals for depolluting sewage/wastewater for hygiene reuse.
BICCP could repair concrete cracks of 1–2 mm wide in 7 days by 210 * 106 cells/mL. Adsorption of heavy
metals (Pd, Zn, Cd and Cu) for partial removal of contaminants in/from waste/sewage water for hygiene
reuse.

Recent increases in the release of untreated water containing cationic dyes have led to significant environmental issues in ecosystems. Many industries contribute to this pollution by discharging water containing various organic pollutants, including crystal violet (CV). Therefore, a novel hybrid mesoporous sulfur-doped copper oxide embedded in Cu-alginate-derived carbon micro-beads (SCO@CACBs) adsorbent was developed for CV-decolorization through batch and fixed-bed columnar techniques. Comparative studies on the effectiveness of CV removal using CACBs and SCO@CACBs under different conditions such as pH, stirring time, amount of sorbent, initial CV concentration, and temperature were conducted. The results demonstrated that the optimal CV removal reached up to 99 % at neutral pH conditions (pH of 7), with an adsorption capacity of 87 mg/g through a batch approach. The CV adsorption process was analyzed using various methods, including adsorption isotherms, kinetics, thermodynamics, zeta potential measurements, and density-functional theory (DFT) calculations. Langmuir (R² = 0.995) and pseudo 2nd order (R² = 0.998) models most agree with experimental CV-adsorption data. Thermodynamic parameters indicated that CV adsorption is spontaneous, favorable, and endothermic. The columnar adsorption tests showed that the adsorption capacity of SCO@CACBs varied from 83.6 to 71.3 mg/g as the flow rate varied from 2 to 6 mL/min and 81.5–115.6 mg/g as the adsorbent mass varied from 1 to 4 g. The Thomas and Yoon-Nelson models fitted the breakthrough curves. The adsorbent maintained high removal efficiency (about 93 %) after five reuse cycles through batch and fixed-bed columnar approaches. Notably, the SCO@CACBs showed over 96 % efficiency in removing CV dye from actual agricultural and textile wastewater samples using batch and column setups. Thus, SCO@CACBs is an effective sorbent for removing CV dye from water contaminated by natural sources.

Biodegradable naturally occurring adsorbents derived from waste precursors are essential for water sustainability. This study investigates using modified cellulose nanostructure (m-CNS) with thiols from wood pulp as a waste source to remove Cr(VI) ions from aqueous solution under different conditions, such as temperature, initial dye concentration, and contact time. The equilibrium adsorption of Cr(VI) is assessed at various temperatures (30, 40, and 50 °C) and concentrations (10, 20, 30, 40, and 50 mg L⁻¹). The m-CNS is detected by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and dispersive X-ray spectroscopy (EDS). Experiments are being carried out to investigate the removal of Cr(VI) ions in equilibrium state. The results showed that the highest percent removal of Cr(VI) ions was 95.95% at pH = 4.0 and after a relatively short adsorption time (80 min). The experimental data is presented using a diverse range of seven isotherm models. There are four models with two parameters: Freundlich, Langmuir, Dubinin-Radushkevich, and Temkin. In addition, three models with three parameters, namely the Redlich-Peterson, Sips, and Toth models, are employed to analyze the experimental adsorption data comprehensively. The depth of our analysis is further enriched using six error functions: the chi-square test (χχ2), the sum of squares of the errors (SSE), the derivative of Marquard’s percent standard deviation (MPSD), the average relative error (ARE), the sum of absolute errors (EABS), and the coefficient of determination. Unlike the Dubinin-Radushkevich isotherm, linear and non-linear regression procedures produced equivalent results for two-parameter isotherms at different temperatures. This is especially noteworthy since the Freundlich, Langmuir, and Temkin isotherms, which provided the greatest fit to the data, are frequently utilized in isotherm modeling and adsorption research. Three-parameter isotherms yielded conflicting linear and non-linear model findings across different temperatures. Furthermore, the findings show that the most optimum error function for prediction was χχ2.

Camel whey protein (CWP) offers various health benefits, including immune enhancement, anti-inflammatory, anticancer, and antibacterial properties. It also possesses antioxidant activity. However, its limited efficacy and stability restrict its broader application. Metal–organic frameworks (MOFs) are crystalline materials composed of multiple organic groups and metal ions, known for their unique structural properties. In this study, we aimed to synthesize and evaluate the biological activity of a CWP-Co-MOF conjugate. The structural characterization of the synthesized materials was conducted using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) analysis. The comparison of the XRD and FTIR patterns of ZIF-67, CWP and CWP-Co-MOF conjugate indicate successful conjugation of CWP with ZIF-67, confirming the structural integrity of the conjugate. The EDX maps further corroborate the effective conjugation of CWP with ZIF-67. The conjugated CWP-MOF nanoparticles (NPs) exhibited promising antioxidant activity, as assessed by the DPPH assay. Furthermore, they showed more potent anti-inflammatory effects in LPS-induced BV2 microglial cells and superior anticancer activity against HepG2 and Caco-2 cell lines, as determined by the MTT assay and flow cytometry, compared to free CWP. Additionally, the CWP-MOF-NPs exhibited enhanced antimicrobial properties and increased efficacy as an anti-biofilm agent against pathogenic bacteria.

This work lies in the integration of a one-micron-gap gold electrode with SnO₂ nanowires, enhancing electric field intensity and interfacial charge transfer. This configuration enables highly sensitive gas detection at a low operating temperature of 50◦C. The study presents a SnO₂ nanowire-based gas sensor featuring a novel onemicron-gap electrode configuration for enhanced sensitivity and selectivity in detecting atmospheric pollutants such as NO₂, H₂S, H₂, and CO. The SnO₂ nanowires were synthesized via thermal evaporation, with the electrode gaps created using focused ion beam (FIB) technology. The fabricated sensor demonstrated efficient gas response characteristics, particularly for NO₂ at 2 ppm and H₂S at 5 ppm, across a range of low temperatures (RT - 350◦C). At an operating temperature of 50◦C, the sensor responded quickly to NO₂, with a response time of 105 s and a recovery time of 121 s. The sensor demonstrated a response time of 147 s and a recovery time of 147 s for H₂S at 5 ppm. The high surface-to-volume ratio of SnO₂ nanowires, combined with the concentrated electric field of the narrow-gap electrodes, facilitated rapid charge transfer and efficient gas adsorption. These results underline the potential of this configuration for low-power, high-sensitivity gas sensing applications. The plasmonic changes in micro-gold electrodes upon exposure to NO₂, H₂S, CO, and H₂ gases enhance the gas sensor’s selectivity by modulating the localized electric field and charge transfer at the electrode surface. The results demonstrate a promising approach for low-power, high-performance gas sensing using optimized electrode geometry.

In this study, a controlled citrate-based reduction process for uniform Au nanoparticles (AuNPs) nucleation on defect-engineered reduced graphene oxide (rGO) to enhance active sites and CH4 interaction was introduced. AuNPs/rGO sensor achieves high sensitivity at low temperatures with superior selectivity to CH4. The AuNPs/ rGO nanocomposite was synthesized via a modified Hummer’s method, followed by citrate-based reduction, resulting in the effective nucleation of AuNPs on rGO. Comprehensive structural and morphological made by various characterization tools confirmed the successful formation and uniform distribution of AuNPs on rGO sheets. The gas sensing performance was evaluated at various operating temperatures, demonstrating that AuNPs enhance CH4 sensing, and enable detection at a low operating temperature of 150 ◦C. They facilitate faster response/recovery times of 53 s/21 s and boost selectivity over other gases such as H2 and CO. The improved sensor performance is attributed to the increased active adsorption sites and improved transfer efficiency of the charge due to the presence of AuNPs. The sensor exhibited excellent repeatability, highlighting its potential for practical applications in environmental monitoring and industrial safety. The work suggests that AuNPs/rGO nanocomposites are promising materials for the development of efficient and reliable CH4 gas sensors. The sensor response was evaluated concerning both temperature and humidity variations at an operating temperature of 150 ◦C. A 1 % Rh variation had the same impact on the sensor response as 52.9 ppm CH₄, while a 1 ◦C temperature change corresponded to an equivalent response shift of 27.05 ppm CH₄.

Background and Objective: Forensic entomotoxicology examines how toxins affect the development of arthropods that feed on decaying bodies, which can influence post-mortem interval (PMI) calculations. This research focuses on the impact of ZnCoS nanoparticles (NPs) on the decomposition stages of rat carcasses and their effects on Dermestes maculatus; a species of forensic relevance. Materials and Methods: Thirty albino rats were assigned to control and treatment groups, receiving different doses of ZnCoS NPs. The decomposition was observed daily for a month, with arthropods collecting regularly. The development rates and structural changes in Dermestes maculatus were examined using light microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Results: Exposure to ZnCoS NPs resulted in a 22–33 hour delay in the PMI for specific insect species. Structural damage, especially to the wings of Dermestes maculatus, was evident, showing signs of apoptosis. These findings indicate that ZnCoS NPs alter both insect growth and the rate of decomposition. Conclusion: ZnCoS NPs have a notable impact on decomposition and PMI estimation, underscoring the importance of further forensic investigation into nanoparticle toxicity. SEM and TEM proved an efficiency in conducting postmortem toxicological analyses.