Correction to "Mesoporous Activated Carbon from Leaf Sheath Date Palm Fibers by Microwave-Assisted Phosphoric Acid Activation for Efficient Dye Adsorption".

[This corrects the article DOI: 10.1021/acsomega.2c03755.].

Mesoporous Activated Carbon from Leaf Sheath Date Palm Fibers by Microwave-Assisted Phosphoric Acid Activation for Efficient Dye Adsorption.

Remazol Brilliant Blue R (RBBR) is a common dye used in the industry, and its presence in wastewater and discharge into the environment can create a serious concern for the ecosystem and human health. Activated carbon produced from crop residues has emerged as a promising technique for removing contaminants from wastewater. In this study, leaf sheath date palm fiber-based activated carbon (LSDAC) was synthesized via phosphoric acid, H3PO4, treatment, followed by a microwave-induced carbonization process. The produced LSDAC was found to have a BET surface area of 604.61 m2/g, a Langmuir surface area of 922.05 m2/g, a total pore volume of 0.35 cm3/g, and an average pore size of 2.75 nm. The highest removal of RBBR was achieved at a solution pH of 3 (92.56 mg/g) and a solution temperature of 50 °C (90.37 mg/g). Adsorption of RBBR onto LSDAC followed the Langmuir isotherm model with a maximum monolayer capacity, Q m, of 243.43 mg/g, whereas in terms of kinetics, this adsorption system was best described by the pseudo-first-order (PFO) model. The calculated thermodynamic parameters ΔH°, ΔS°, ΔG°, and Arrhenius activation energy, E a, were 4.71 kJ/mol, 0.10 kJ/mol·K, -26.25 kJ/mol, and 5.88 kJ/mol, respectively, indicating that the adsorption of RBBR onto LSDAC was endothermic in nature, exhibited increased randomness at the solid-liquid interface, and was spontaneous and controlled by physisorption.

The effect of sand storms on acute asthma in Riyadh, Saudi Arabia.

OBJECTIVE: Major sand storms are frequent in the Middle East. This study aims to investigate the role of air particulate matter (PM) level in acute asthma in children in Riyadh, Saudi Arabia. METHODS: An aerosol spectrometer was used to evaluate PM < 10µm in diameter (PM10) and PM < 2.5 µm in diameter (PM2.5) concentrations in the air every 30 minutes throughout February and March 2012 in Riyadh. Data on children 2-12 years of age presenting to the emergency department of a major children's hospital with acute asthma during the same period were collected including their acute asthma severity score. RESULTS: The median with interquartile range (IQR) levels of PM10 and PM2.5 were 454 µg/m(3) (309,864) and 108 µg/m(3) (72,192) respectively. There was no correlation between the average daily PM10 levels and the average number of children presenting with acute asthma per day (r = -0.14, P = 0.45), their daily asthma score (r = 0.014, P = 0.94), or admission rate ( r= -0.08, P = 0.65). This was also true for average daily PM2.5 levels. In addition, there was no difference in these variables between days with PM10 >1000 µg/m(3), representing major sand storms, plus the following 5 days and other days with PM10< 1000 µg/m(3). CONCLUSION: Sand storms, even major ones, had no significant impact on acute asthma exacerbations in children in Riyadh, Saudi Arabia. The very high levels of PM, however, deserve further studying especially of their long-term effects.

Airborne Weed Pollen in Relation to Allergic Rhinitis in Riyadh, Saudi Arabia.

Aims: The study was conducted to investigate the frequently encountered allergenic pollen grains in the environment of Riyadh, Saudi Arabia as well as to determine their seasonal and annual growth pattern in the region. Study Design: Volumetric air sampling of two City sites with qualitative and quantitative comparison of data on seasonal and diurnal concentrations of weed pollen aeroallergens. Place and Duration of Study: The work was conducted in the capital City of Riyadh, Saudi Arabia and the sampling was conducted for a continuous 12 month period from January to December 2012. Methodology: Using two Burkard 7-Day Volumetric Air Sampler, airborne pollen grain for two sites in Riyadh City (City Center site in the middle of City) and Riyadh airport site (40 km away from the city) was studied. The data were collected for at least 12 months period in both sites. Results: The pollen grains from grasses, weeds and trees were identified. However, the weeds pollen dominated the pollen flora by a ratio of 70% followed by trees 20%, and grasses 10%. The major weeds pollen identified were: Amaranthus viridis, Artemisia monosperma, Atriplex nummularia, Chenopodium murale, Plantago boissieri, Ricinus communis, Rumex vesicarius and Salsola imbricata. Riyadh City Center site constituted higher percentage of total weeds (69%) compared to Riyadh airport site (31%). Conclusion: Seasonal periodicities of major allergens, reveal a trend that would help allergists and allergic patients for diagnosis and prevention.