The feasibility of date seed ash, a low-cost agricultural by-product in Oman, for the removal of boron from aqueous solution was investigated. The aim of this study was to understand the mechanism that governs boron removal from seawater using date seed ash as an adsorbent in batch adsorption experiments. The effects of adsorbent dose, contact time, and temperature on boron removal were tested. A surface study of the date seed ash was investigated using scanning electron microscope, energy-dispersive X-ray spectroscopy, and Fourier transform infrared. Thermogravimetric-analysis, specific area using Brunauer, Emmett and Teller method, and particle density were also obtained. The maximum removal efficiency of boron was around 47% at neutral pH. The application of date seed ash is a promising adsorbent for boron removal where it can be used as pretreatment before reverse osmosis desalination process. This will increase the stability of membranes, minimize the membrane scaling, and ultimately reduce the operating cost.

Material build-up on membrane surfaces is one of the vital challenges faced by Reverse Osmosis operations, leading to many operational and maintenance issues. To date, several modeling studies are dealt with flow behavior and concentration patterns for cross-flow membrane operations. However, the relative fouling propensities of top and bottom membrane surfaces are never addressed in any study for narrow channels filled with ladder-type spacers. In the present work, fluid flow patterns through different spacer configurations are visualized using ANSYS FLUENT by varying the dimensionless filament spacing, L (ratio of top or bottom filament spacing and channel height). Results clearly indicate that the average shear stress values at the top membrane surface are always higher (3–8 times) than that at the bottom membrane surface, but the mass transfer coefficient for the two walls yielded approximately similar average values having low to moderate filament spacings of L ≤ 3 (SP22 and SP33), indicating similar fouling propensities of membrane surfaces. Further increase in filament spacing with L ≥ 4 (SP44 and SP66), the average mass transfer coefficient for the top membrane indicated a sharp decline, suggesting high fouling propensity compared to bottom membrane which is not a desirable feature. Among the four spacer arrangements studied, SP44 (with L = 4) was found to be the optimal arrangement, yielding moderate pressure drop with nearly equal/higher area weighted values of mass transfer coefficient for the two walls and would lead to lower and equal fouling tendencies for top and bottom membrane surfaces, respectively.

Anecdotal evidence suggests that households burn plastics to manage waste and help satisfy their energy demand. To examine the prevalence, extent, and reasons for using plastic waste as household fuel, we report on a survey with 1018 key informants from cities in 26 countries in the Global South. Informants were purposively selected due to their familiarity with the living conditions in their communities. One-third of respondents reported being aware of plastic waste burning, with some reporting that their households engaged in this practice. Analyses of the data reveal significant correlations of plastic waste burning with both supply factors, such as, the massive amount of waste generated (p = 0.000), expensive clean fuels (p = 0.004), and demand factors, including self-management of waste (p = 0.000). Expanding essential public waste management services and implementing programs that enhance the affordability of clean energy technologies, especially among marginalized and low-income communities, could reduce this health- and environment-damaging practice.

The viscosity of slag from an operating integrated gasification combined cycle (IGCC) plant utilising petroleum coke and a synthetic petcoke slag with the same composition made from chemical grade oxides in a reducing environment for gasification application were investigated in this study. A high temperature rotating bob-type viscometer was used to measure viscosity between temperatures of 1250–1375 °C. Natural and synthetic ash had similar viscosities above 1300 °C in this study. The viscosity was predicted by using FactSage, a thermodynamic modelling software, in conjunction with different viscosity models, available in the open literature. Percentage deviations of predicted viscosities from different models with experimentally measured values ranged from about 41 to 151%. Crystallisation of the slag was noted in SEM-EDS (scanning electron microscopy– energy dispersive spectroscopy) and FactSage results. Solid phases from FactSage predictions were used to modify the Kalmanovitch–Frank model with the Roscoe method. It predicted the viscosity of the slag accurately between 1250 and 1375 °C. Average percentage deviation from measured natural ash viscosity was about 11%.