Surfactant modified waste ash for the removal of chloro and nitro group substituted benzene from wastewater

Abstract

A surfactant-modified coal fly ash was developed as a multifunctional adsorbent for the removal of organic pollutants from wastewater. Sodium dodecyl sulfate (SDS) was used to modify the surface of coal fly ash (CFA). The modified CFA was characterized using Scanning Electron Microscopy (SEM), surface porosity analyzer, Thermogravimetric analysis (TGA) and Fourier transform Infrared (FTIR) spectroscopy. The results showed that loading CFA with SDS not only improved the functionality and surface morphology of the raw ash for the adsorption of organic pollutants, but also enhanced its thermal stability. The efficiency of the modified fly ash was tested in terms of removal of two non-polar organic pollutants namely chlorobenzene (CB) and nitrobenzene (NB) from aqueous phase. The maximum uptake capacity of chlorobenzene and nitrobenzene with SDS-modified coal fly ash (SCFA) was 225 mg/g and 90 mg/g respectively. The kinetic analysis was done by controlled kinetic models i.e., pseudo first and second order kinetic models. The results showed that adsorption of CB and NB onto SCFA followed a pseudo second order kinetic model. The adsorption of chlorobenzene was exothermic over the modified adsorbent while nitrobenzene showed an endothermic behavior. The isotherm analysis depicted the multilayer adsorption of both pollutants onto the surface of the surfactant modified adsorbent. This work has shown that surface modification using surfactants can be a viable option to enhance the adsorption capacity of fly ash for pollutants removal.

A comparative study of coal fly and bottom ashes as sustainable electroactive vibration damping materials

“…For both ashes, the first mass losses below 100°C were attributed to the removal of moisture. The second mass loss between 100-520°C for CFA and 100-410°C for CBA might be originated from the removal of adsorbed structural water molecules [53]. In addition, the total amounts of water were calculated to be 0.49% for CFA and 0.78% for CBA.…”

Efficient Decontamination: Caffeine/Triclosan Removal using Rice Husk in Batch and Fixed-Bed Columns

“…These treatment methods have proven to be efficient in removing both contaminants (removal = up to 80%). However, the high infrastructure and operational costs are not the only limiting factors for their use (USD 10-450/m 3 ), which is mainly in developing countries [12,15,16]. Additional disadvantages include variable reagent dosing, low mineralization (in the case of ozonation), high energy consumption (electrooxidation), and short lifespan due to saturation (membrane filtration, zero-valent iron particles).…”

“…In contrast, adsorption using husks, seeds, fibers, and other agro-industrial residues offers significant advantages [1]. Using bio-adsorbents derived from these materials could also be profitable, since their benefits include high availability (1000 million tons annually worldwide) [17], simple conditioning, and being 28% less expensive (operating and maintenance) than conventional wastewater treatments (USD 5-200/m 3 ) [16,18,19]. Moreover, their composition (minerals, lipids, polyphenols, and lignocellulosic compounds) allows them to have a variety of functional groups (hydroxyl, carbonyl, carboxyl, methylene, etc.)…”