School environment may have an impact on children’s health, but few studies have focused on indoor comfort factors such as temperature, humidity, and noise in relation with potential effects on children’s health. Our cross-sectional study used data from the European Schools Indoor Pollution and Health Observatory Network in Europe (SINPHONIE) project to assess children’s allergy, asthma-like symptoms, and flu-like symptoms in relation with classroom comfort and environmental factors. The study used self-reported data from three questionnaires to identify classroom conditions and student health outcomes for 280 students. We used backwards variable selection and unconditional logistic regression to assess the outcome-environment relationship while controlling for demographics, family history of allergy, and home exposures. We found increased risks for allergy and flu-like symptoms associated with hot classrooms in the heating season, increased risks for asthma-like symptoms associated with noisy classrooms, and a protective effect for allergy associated with good outdoor air quality. Romanian classrooms rely on natural ventilation, which may contribute to increased temperature and humidity in the heating season. Further research warrants the use of SINPHONIE’s measurement data to validate our findings.

The microbial production of fumaric acid by Rhizopus arrhizus NRRL 2582 has been evaluated using soybean cake from biodiesel production processes and very high polarity (VHP) sugar from sugarcane mills. Soybean cake was converted into a nutrient-rich hydrolysate via a two-stage bioprocess involving crude enzyme production via solid state fermentations (SSF) of either Aspergillus oryzae or R. arrhizus cultivated on soybean cake followed by enzymatic hydrolysis of soybean cake. The soybean cake hydrolysate produced using crude enzymes derived via SSF of R. arrhizus was supplemented with VHP sugar and evaluated using different initial free amino nitrogen (FAN) concentrations (100, 200, and 400 mg/L) in fed-batch cultures for fumaric acid production. The highest fumaric acid concentration (27.3 g/L) and yield (0.7 g/g of total consumed sugars) were achieved when the initial FAN concentration was 200 mg/L. The combination of VHP sugar with soybean cake hydrolysate derived from crude enzymes produced by SSF of A. oryzae at 200 mg/L initial FAN concentration led to the production of 40 g/L fumaric acid with a yield of 0.86 g/g of total consumed sugars. The utilization of sugarcane molasses led to low fumaric acid production by R. arrhizus, probably due to the presence of various minerals and phenolic compounds. The promising results achieved through the valorization of VHP sugar and soybean cake suggest that a focused study on molasses pretreatment could lead to enhanced fumaric acid production.

The devastating health effects of particulate matter (PM₁₀) exposure by susceptible populace has made it necessary to evaluate PM₁₀ pollution. Meteorological parameters and seasonal variation increases PM₁₀ concentration levels, especially in areas that have multiple anthropogenic activities. Hence, stepwise regression (SR), multiple linear regression (MLR) and principal component regression (PCR) analyses were used to analyse daily average PM₁₀ concentration levels. The analyses were carried out using daily average PM₁₀ concentration, temperature, humidity, wind speed and wind direction data from 2006 to 2010. The data was from an industrial air quality monitoring station in Malaysia. The SR analysis established that meteorological parameters had less influence on PM₁₀ concentration levels having coefficient of determination (R ²) result from 23 to 29% based on seasoned and unseasoned analysis. While, the result of the prediction analysis showed that PCR models had a better R ² result than MLR methods. The results for the analyses based on both seasoned and unseasoned data established that MLR models had R ² result from 0.50 to 0.60. While, PCR models had R ² result from 0.66 to 0.89. In addition, the validation analysis using 2016 data also recognised that the PCR model outperformed the MLR model, with the PCR model for the seasoned analysis having the best result. These analyses will aid in achieving sustainable air quality management strategies.

Understanding interaction mechanisms between polycyclic aromatic hydrocarbons (PAHs) and soil-washing agents can help in choosing efficient agents which are able to desorb and solubilize PAHs. This study investigated interaction mechanisms between pyrene and four washing agents including: two dissolved organic matters (DOM) F-DOM and CRC-DOM, and two commercial bio-based surfactants BBE-1000 and Supersolv using fluorescence spectroscopy combined with multivariate curve resolution alternating regression (MCR-AR). The efficiencies of these washing agents in removing PAHs from the soil were tested in a soil washing experiment. Pyrene showed π-π interactions with F-DOM and no interaction with CRC-DOM. This could be attributed to the more aromatic structures in F-DOM compared to CRC-DOM. The two DOMs were inefficient in soil washing which might be attributed to the relatively weak effect of π-π interactions in releasing PAHs from the soil. Interaction mechanisms between pyrene and the bio-based surfactants were elucidated with MCR-AR, which resolved three spectroscopically active species from pyrene emission spectra as a function of pyrene and bio-based surfactants concentrations. These species resembled pyrene emission in a polar and nonpolar microenvironment, respectively and of an excimer. Concentration profiles retrieved by the model for the three species showed that, below the critical micelle concentration (CMC), Supersolv created more nonpolar interactions with pyrene compared to BBE-1000. In soil washing, Supersolv showed the highest efficiency in extracting PAHs from the soil. This highlighted the importance of nonpolar interactions in desorbing PAHs from soils, which could then be solubilized in micelles. This study demonstrated the potential of fluorescence spectroscopy combined with the MCR-AR model for selecting efficient soil-washing agents.

The highly unbalanced nature of bio-oil composition poses a serious threat in terms of storage and utilization of bio-oil as a viable fuel in engines. So it becomes inevitable to study the variations in physicochemical properties of the bio-oil during storage to value its chemical instability, for designing stabilization methodologies. The present study aims to investigate the effects of storage stability of bio-oil extracted from pyrolyzing Calophyllum inophyllum (CI) deoiled seed cake on the engine operating characteristics. The bio-oil is produced in a fixed bed reactor at 500 °C under the constant heating rate of 30 °C/min. All the stability analysis methods involve an accelerated aging procedure based on standards established by ASTM (D5304 and E2009) and European standard (EN 14112). Gas chromatography-mass spectrometry was employed to analytically characterize the unaged and aged bio-oil samples. The results clearly depict that stabilizing Calophyllum inophyllum bio-oil with 10% (w/w) methanol improved its stability than that of the unstabilized sample thereby reducing the aging rate of bio-oil to 0.04 and 0.13 cst/h for thermal and oxidative aging respectively. Engine testing of the bio-oil sample revealed that aged bio-oil samples deteriorated engine performance and increased emission levels at the exhaust. The oxidatively aged sample showed the lowest BTE (24.41%), the highest BSEC (20.14 MJ/kWh), CO (1.51%), HC (132 ppm), NOx (1098 ppm) and smoke opacity (34.8%).

Removal of intracellular water in microbial cells remains a key issue for sludge disposal, and here, a novel method of enzymatic treatment with two enzymes, lysozyme and protease, was employed. Total internal reflection fluorescence microscope (TIRF) was applied to image the bacteria in sludge and quantify the evolution of sludge bacteria for the first time. The ratio of dead/live bacterial cells was always higher in the presence of lysozyme than in the presence of protease, indicating that lysozyme has higher activity in inducing bacterial cell degradation and releasing intracellular water. The compositions of extracellular polymeric substances (EPS) were further measured, and the results show that the dewatering performance of sludge is correlated both to the release of cell contents and the variations in EPS composition during cell degradation. Moreover, kinetic analysis demonstrated that the enzyme-catalyzed reaction was substantially completed within 1 h, i.e., the reaction was quite rapid during the first 1 h, and thereafter, it gradually reduced to stability. The mechanism of enzymatic treatment of sludge explored in this study thus not only enhanced the understanding of sludge deep dewatering but also provided significant methodological clues for the disposal of sludge.

Magnetite (Fe₃O₄) nanoparticle-encapsulated mesoporous carbon nanocomposite was fabricated from Fe-based metal–organic framework (MOF) (MIL-102) through carbonization. It was found that Fe-based MOF (MIL-102) is a potential precursor for the fabrication of hexagonal mesoporous carbon nanodisk functionalized with Fe₃O₄ nanoparticles. The obtained nanocomposite was characterized by XRD, FT-IR, N₂ adsorption and desorption, FE-SEM and HRTEM techniques. As a Fenton-like solid catalyst for phenol degradation, Fe₃O₄ nanoparticle-encapsulated mesoporous carbon showed greater catalytic activity for the production of hydroxyl radical from the decomposition of H₂O₂ and it accomplished 100% phenol and 82% total organic carbon (TOC) conversion, within 120 min of reaction. This enhanced catalytic performance was due to confined access for the pollutant to the iron oxide nanoparticles provided by mesopores in carbon shell. Bare Fe₃O₄ nanodisk shows poor catalytic performance in the degradation of phenol, and it obviously reveals the significance of the mesoporous carbon support for iron oxide nanoparticles.

A novel magnetic heavy metal adsorbent was prepared via diethylenetriamine (DETA) modification on magnetic hydrothermal carbon, with glucose and sugar-containing waste water as the carbon source. The prepared materials were characterized by FT-IR, SEM, TEM, EDXRF, TGA, elemental analysis, XPS, and magnetic moment determination. In this paper, the adsorption mechanism of the modified and unmodified adsorbents was well discussed. Four kinds of waste water (watermelon juice, expired sprite, sugar-pressing waste water, and confectionary waste water) were employed to produce heavy metal ion adsorbents; the chemical properties of hydrothermal carbon derived from the proposed sources were analyzed as well. The maximum uptake capacity for Cu²⁺, Pb²⁺, and Cd²⁺ of the adsorbent produced from glucose was 26.88, 103.09, and 25.38 mg g⁻¹, respectively. After 5 cycles, the adsorption ability was still well preserved. This work represents an efficient new direction for the treatment of heavy metal ions in water and the reuse of sugar-containing waste water. Graphical abstract The schemetic of DETA-modified magnetic carbon preparing from sugar-containing wastewater

The aquatic risk assessment of pesticides in tropical areas has often been disputed to rely on toxicity data generated from tests performed with temperate species. Given the differences in ecosystem structure between temperate and tropical ecosystems, test species other than those used in temperate regions have been proposed as surrogates for tropical aquatic effect assessments. Freshwater shrimps, for example are important components of tropical freshwater ecosystems, both in terms of their role in ecosystem functioning and their economic value. In the present study, available toxicity data of (tropical and sub-tropical) freshwater shrimps for insecticides and fungicides were compiled and compared with those available for Daphnia magna and other aquatic invertebrates. Freshwater shrimps appeared to be especially sensitive to GABA-gated chloride channel antagonist and sodium channel modulator insecticides. However, shrimp taxa showed a moderate and low sensitivity to acetylcholinesterase inhibiting insecticides and fungicides respectively. Implications for the use of freshwater shrimps in tropical pesticide effect assessments and research needs are discussed.

Various properties of soil affect the partition of organic contaminants within, and conversely, the properties of the organic contaminants also directly affect their partition behavior in soil. Therefore, understanding the effects of various properties of soil on the partition of organic contaminants favors subsequent assessment and provides soil remediation methods for policymakers. This study selected pentachlorophenol (PCP), a common hydrophobic ionizable organic compound in contaminated sites worldwide, as the target contaminant. The effects of pH, organic matter, and the combination of both, on PCP adsorption/desorption behavior in soil were investigated. Phosphoric acid and potassium hydroxide were used as buffer solutions to modify the soil pH by the batch and column extraction methods. A common retail organic fertilizer and fulvic acid were selected as additives to manipulate the soil organic content. Modifying the pH of the soil samples revealed that acidic soil exhibited a greater PCP adsorption rate than alkaline soil. The amount of PCP desorption increased regardless of pH of the in situ contaminated soil. The adsorption of PCP increased with increasing amount of organic additive. However, addition of fulvic acid yielded different results compared to the addition of organic fertilizer. Specifically, the organic fertilizer could not compete with the in situ contaminated soil in PCP adsorption, whereas fulvic acids increased the PCP dissolution to facilitate adsorbing contaminant adsorption. The combined effect of pH modification and organic matter addition provides additional PCP adsorption sites; therefore, adding the organic fertilizer to decrease the soil pH elevated the PCP adsorption rates of the laterite, alluvial, and in situ contaminated soil samples. The study results revealed that both pH and organic matter content are crucial to PCP adsorption/desorption in soil. Therefore, the effects of soil pH and organic matter should be considered in facilitating PCP treatment for soil remediation.