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PublicationValorization of face mask waste as an adsorbent for cationic dye adsorption(Desalination Publications, 2023)The increasing environmental pollution caused by the disposal of untreated dye-containing effluent and face mask wastes in landfills has become a significant concern. To address this issue, this work focuses on the utilization of face mask wastes as alternative adsorbents for the adsorption of malachite green (MG) dye. These adsorbents offer advantages such as ease of operation, cost-effectiveness, high efficiency, and ready availability. In this study, the raw face mask wastes (RFM) undergo a thermal treatment process in a furnace at 800°C for 21 h before conducting the adsorption tests. The Fourier-transform infrared spectroscopy analysis revealed the presence of various functional groups, including alkane, alkene, alcohol, and carbonyl, in both the treated face mask adsorbent (TFMA) and RFM. The scanning electron microscopy with energy-dispersive X-ray spectroscopy analysis displayed the surface morphologies of RFM as a porous and homogeneous carbon sorbent structure, while TFMA exhibited a heterogeneous and flaky structure. Energy-dispersive X-ray spectroscopy analysis indicated that RFM primarily consisted of carbon elements, followed by oxygen and calcium elements, whereas TFMA predominantly comprised calcium and oxygen elements with a limited amount of carbon. The adsorption experiments, considering various parameters such as initial dye concentration (1,000–1,200 mg/L) and contact time (5–1,500 min), demonstrated that increasing the contact time and initial concentration led to an enhanced adsorption capacity. The maximum adsorption capacity of 2,127 mg/g confirmed the effectiveness of TFMA as an adsorbent for MG. Thermodynamic analysis revealed that the adsorption process was spontaneous and endothermic. The isotherm and kinetic studies showed a good fit between the adsorption data and the Brunauer–Emmett–Teller and pseudo-second-order models as evidenced by high R2 values and low error function values, suggesting a heterogenous adsorption of MG on TFMA.
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PublicationEffects of different biomass on the properties of Pleurotus Djamor eco-friendly foam(EDP Sciences, 2023)Plastic waste and polyurethane foam are major sources of pollution that threatens environmentsâ biodiversity. The objective of the study is to create an eco-friendly foam from Pleorotus djamor mycelium, rice husk and sugarcane bagasse. The mushroom industryâ s overabundance of materials, like oyster mushrooms and biomass, has provided an alternative method to make foam that could be beneficial for the environment. The biomass, consisting of rice husk and sugarcane bagasse, both of which are necessary for the production of foam, was evaluated as a substrate. Pleurotus djamor was inoculated on both substrates and test was done on both produced foams. Mechanical tests showed that rice husk foam had higher hardness and less springy than sugarcane bagasse foam. The morphology of both foams was analyzed using a scanning electron microscope (SEM), and the results show that sugarcane bagasse foam is denser than rice husk foam.
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PublicationEffect of molasses-based wastewater irrigation on the rice yield and heavy metals uptake by Oryza sativa: a field study(AIP Publishing Ltd., 2023)The molasses-based effluent discharge contains significant amount of nutrients (e.g. Fe, Mg, K), which has potential use as an organic fertilizer to fit into the waste-to-wealth plan. Apart from that, the presence of toxic heavy metals content should not be underestimated as it could somehow end up in the rice grains and into the food chains. Thus, in this present work, the concentrations of Al, Cr, Cu and Ni in paddy crops from three different plots irrigated with the molasses-based effluent from an ethanol distillery; Control Plot, Plot 1 (repeatedly irrigated) and Plot 2 (irrigated for the first time) were investigated. All the heavy metals were found to be within the limits indicated by the Food and Agriculture Organization (FAO) for the reuse of wastewater for cultivation, Standard B in the Fifth Schedule, Environmental Quality (Industrial Effluent) Regulations 2009, and the Malaysia Ground Water Quality Standard (MGWQS) for Agricultural 2019 by the Department of Environment Malaysia. The results postulated that the rice yield in Plot 2 was higher compared to the other plots. The study also revealed that the concentrations of the heavy metals in the paddy plants decreased when mobilized from the roots to the rice grains for all sampling plots (p < 0.05). The bioconcentration factor (BCF) for Cu and Ni showed the highest values of 2.01 and 4.89, respectively in Plot 1. As the heavy metals concentration in wastewater were within the allowed limit, metals present in the paddy plant parts could be mobilized from the metals readily present in the soil. These results indicated that the molasses-based distillery’s effluent could be a source of plant nutrients as the rice yields improved and have potential to be used for paddy irrigation, as long as it is contained from leaching into water reservoirs.xc
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PublicationSynthesis and characterization of green phenolic resin with olive oil mill wastewater(SpringerOpen, 2023)Olive oil mill wastewater (OMW), a by-product of the olive oil industry, each year is generated millions of tons all over Mediterranean countries. Uncontrolled disposal of the OMW leads to massive environmental problems including soil and water pollution. In this experimental study, the OMW was used to partly replace clean water for getting prepared formaldehyde solution. Then, phenol and formaldehyde solutions were synthesized under alkali conditions to obtain more green phenol–formaldehyde (PF) resin. The effect of the OMW substitution level on the chemical and thermal properties of PF resin was examined by the Fourier transform infrared (FT-IR) spectral and thermogravimetric (TGA) analysis, respectively. Moreover, the bonding strength of each PF resin was evaluated under dry and wet conditions. It was found that FT-IR measurements showed that the PF resin containing various amounts of the OMW had a chemical structure very similar to the PF resin. The thermogravimetric analysis demonstrated that the low‐molecular‐weight organics in the OMW had negatively affected the thermal stability of the modified PF resins. In addition, the wood samples bonded with the PF resin containing up to 30 wt% OMW met the minimum requirements of interior and exterior bonding performance according to standard EN 12765. The OMW could be replaced by clean water up to 30 wt% for the production of green phenolic resin.
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PublicationMulti-technique investigation on the surface interaction of diatomaceous earth with organic phase change material: experimental and molecular dynamics aspects(Elsevier, 2023)To promote diatomaceous earth (DE)-based phase change composite as green energy building materials, this paper bridges the studies of experimental and molecular dynamics (MD) focusing on the absorption effect of phase change materials (PCMs). Octadecanoic acid (OA) was selected as PCMs and DE as supporting material for the fabrication of composite PCMs at different loading ratios; effect on thermal properties and porosity of the composite PCMs were further investigated by MD simulation. In consonance with ATR-FTIR and XRD analyses, the highest loading ratio (DEOA-4) was proven to absorb a high amount of PCMs, with excellent thermal stability and chemical compatibility. DEOA-4 exhibited higher latent heat storage capacity of 52.67 J/g, with a loading ratio and loading efficiency of 32.13 and 32.98 %. Besides, MD simulation showed that increasing the OA loading would decrease the fractional free volume of DEOA models, resulting in a limited mobility of PCMs molecules, as confirmed by self-diffusion coefficient at room and melting temperatures. Experimental and computational studies revealed that pore-filling process plays an imperative role during PCMs absorption. An adequate amount of loading ratio can potentially enhance the pore-filling process, maximize the efficiency of the performances, and promote the development of green energy in concrete structures.