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Hydrogen-rich syngas from palm empty fruit bunch has been produced using CaO and bentonite as absorbent and catalyst. The gasification process is carried out at 550–750 °C at atmospheric pressure in the fixed bed gasifier with steam to biomass ratio (S/B) of 0–2.5 and Ca/C ratio of 0–2. The results showed that CaO only acts as $\mathrm{CO}_2$ absorbent during the process. Increasing the ratio of Ca/C and S/B has increased the concentration of $\mathrm{H}_2$ and absorption of $\mathrm{CO}_2$ in the syngas. The addition of CaO did not significantly increase the production of $\mathrm{CH}_4$ and CO in the syngas. The $\mathrm{H}_2$ concentration reaches about 78.16 vol% at 700 °C and Ca/C 2.

Nitrogen dioxide is one of the primary air contaminants that can cause severe ecological and human health effects. This study used the Ozone Monitoring Instrument (OMI) sensor aboard AURA satellite to analyze the spatial and temporal variations of VCDtrop (Tropospheric vertical Columnar density) NO2 concentration in Sumatra, Indonesia, during 2012–2020. Based on the seasonal characteristics, the VCDtrop NO2 amounts in the east part of Sumatra were higher in the dry season and slightly lower in the wet season. The increasing trend was recorded in some provinces; North Sumatra, Riau, South Sumatra, and Lampung with the accumulation rate around 8–9 × 1015 molecules/cm2 from 2012 to 2014. Higher VCDtrop NO2 concentrations were associated with an increase in population size. As a whole, this finding can be useful to arrange air pollution management associated with population growth in urban areas. [ABSTRACT FROM AUTHOR]

The increasing demand for clean water, driven by population growth, urbanization, and industrial activities, has led to significant challenges in public health, the economy, and the environment. Effective water purification technologies are essential to address this issue. This study explores using polyethersulfone (PES) polymer-based membranes reinforced with titanium dioxide (TiO2) nanoparticles for antifouling applications. The membranes were fabricated using an electric field treatment method. Scanning Electron Microscopy (SEM) revealed a pore size distribution between 1,170 μm and 7,122 μm, demonstrating that this method can be adjusted to create membranes with specific filtration characteristics. Atomic Force Microscope (AFM) analysis showed surface roughness between 150 and 500 nm, indicating that the membrane's surface morphology can be customized to improve performance. Mechanical testing showed that the tensile strength of the membranes varied with the addition of TiO2: the pure PES membrane (TI0) had a tensile strength of 2.12 MPa, while the TI1 membrane (20 % PES, 1 % TiO2) exhibited a decrease to 1.84 MPa. The TI2 membrane (30 % PES, 1 % TiO2) showed an increase in tensile strength to 3.86 MPa, confirming the reinforcing effect of TiO2 on the membrane's mechanical properties. Clean Water Permeability (CWP) testing indicated flux values of 2558.9 L/m²•h•bar for TI0, 1263.1 L/m²•h•bar for TI1, and 2763.9 L/m²•h•bar for TI2, highlighting the optimal balance of mechanical strength and permeability in TI2. The PES/TiO2 composite membrane, made using an electric field method, shows promise for water filtration due to its enhanced permeability, providing an efficient solution for water treatment. [ABSTRACT FROM AUTHOR]

Molecular imprinting technology is a promising technique for creating recognition elements for selected compounds and has been successfully applied for synthesis of environmental pollutants such as simazine. Simazine is a pesticide ingredient that is commonly used in agriculture, which has devastating effects on the environment if used excessively. Molecularly imprinted polymer (MIP) provides cavities to form a particular space generated by removing the template when the polymer has formed. In this study, MIP using simazine as template had been made by the cooling-heating method and used as a material potentiometric sensor for detecting simazine. A template (simazine) was incorporated into a pre-polymerization solution that contains a methacrylic acid as functional monomer, an ethylene glycol dimethacrylate as cross linker, and benzoyl peroxide as initiator. Characterization was performed by scanning electron microscope (SEM) and fourier transforms infra-red (FTIR). The FTIR spectra of the MIP showed that the peaks of amine group decrease significantly, indicating that the simazine concentration decreases drastically. Characterization by SEM images showing the broadest pore size distribution with the highest number of pores in the MIP prepared under the heating time of 150 min. The MIPs therefore could be applied as a simazine sensor.

The effect of ceramic filter composition on improving the quality of produced water by reducing total dissolved solids (TDS), barium, and phenol for reverse osmosis (RO) treatment was investigated in the present work. The ceramic filters were fabricated using a residue catalytic cracking (RCC) unit spent catalyst with and without activation, clay, and Dioscorea hispida starch (DHS), at various compositions. The result showed that the optimum removal of TDS, barium, and phenol in produced water was achieved at a flow rate of sample 7 L/min and an operating time of 90 min. Ceramic filter with the composition of 60% spent catalyst without activation: 37.5% clay: 2.5% DHS reduced 34.84% TDS, 27.97% barium, and 71.11% phenol. While, the ceramic filter with a composition of 37.5% activated spent catalyst: 60% clay: 2.5% DHS was removed 51.44% TDS, 27.93% barium, and 85.29% phenol from produced water. The next steps of treatment of filtrates of the ceramic filter using reverse osmosis (RO) membrane showed that the permeate met the Indonesian standard for oil and gas wastewater. In addition, adsorption of TDS, barium, and phenol from produced water was dominated by clay composition in the ceramic filter. [ABSTRACT FROM AUTHOR]

This present study contribute to provide a simple technology to early detect the phenomenon of spontaneous coal combustion. A new prototype is designated to detect the CO gas formation as a product of initial coal oxidation. Moreover, several parameters including coal quality, coal weight sample, ambient temperature, and air flow were employed to investigate the effects of each parameter to the CO formation time. The results show that the coal characterisation have a significant effect in the CO formation time where the coal having a higher fixed carbon and high grass calorific values provide the high liability of spontaneous coal combustion. However, these finding only occurred in low weight sample where in the high coal weight sample only fixed carbon plays the main role in determining the CO formation time. Furthermore, the prototype ambient temperature become the important parameter in the boosting of CO formation time where airflow only enhance the CO formation time in low temperature condition (below 29°C). Moreover, these findings opens a new sight in coal management, especially in Indonesia, where controlling the coal and atmosphere temperature could effectively prevent the spontaneous coal combustion especially in coal stockpile. Nevertheless, the other factor including airflow and coal weight sample also need perfect controlling because all of these factors potentially create a perfect environment to combust the coal spontaneously. [ABSTRACT FROM AUTHOR]