Electrospun chitosan-based nanofibres for removal of phenols from drinking water

Abstract

Chitosan-based nanofibres were synthesized using a fibre electrospinning technique and tested for the removal of 3-methyl-4-nitrophenol from aqueous solutions. The downside of chitosan-based materials is swelling. In this study, it was found that the addition of polyisoprene not only improved the electrospinning ability of chitosan but also reduced the swelling of the nanofibres by 50%. The adsorption studies of 3-methyl-4-nitrophenol on the chitosan-based nanofibres were conducted in a batch process. The nanofibres were found to remove up to 90% of 3-methyl-4-nitrophenol with an adsorption reduction capacity of 12% at each cycle of reusability test. The reduction capacity was associated with the chemical interaction of the adsorbate and the adsorbent. This indicated that the nanofibres can effectively remove 3-methyl-4-nitrophenol from water for at least 3 cycles. The adsorption efficiency improved as the degree of cross-linking was reduced and the adsorption mechanism followed the Freundlich isotherm suggesting that the adsorption of 3-methyl-4-nitrophenol occurred in different layers on the surface of the nanofibres. The degree of crosslinking of the electrospun nanofibres with glutaraldehyde was found to affect theadsorption capacity. Nanofibres with different degrees of crosslinking were used to study the effect of pH, adsorbent dose, and initial concentration.

Microwave-assisted synthesis of coal fly ash-based zeolites for removal of ammonium from urine

“…Adsorption kinetics are crucial as they provide information about the reaction pathways. 48 The exchange of ammonium ions on coal fly ash, clinoptilolite and the synthesized zeolitic products was modeled using pseudo first order and pseudo second order kinetics. The rate constants were calculated from the slope and intercept of the graph ( Fig.…”

“… 53 Moreover, Freundlich isotherms describes the formation of the multiple layers on the surface of the adsorbent. 48 The constants were calculated from the slope and intercept of the graph ( Fig. 7 ).…”

Recent advances in dye and metal ion removal using efficient adsorbents and novel nano-based materials: an overview

“…The ndings revealed signicant adsorption capacity reached 90% for at least 3 consecutive cycles. 184 Cellulose based adsorbents (CBA) are considered promising and cost-effective for removing dyes and metal ions from water. 185,186 Because of the abundance of hydroxyl, carboxyl, and phenolic groups throughout the backbones of cellulose, CBA have the ability to bind contaminants effectively.…”

“…The findings revealed significant adsorption capacity reached 90% for at least 3 consecutive cycles. 184 …”

Chemically Exfoliated Titanium Carbide MXene for Highly Sensitive Electrochemical Sensors for Detection of 4-Nitrophenols in Drinking Water

“…Generally, aromatic molecules containing nitrogen derivatives are more carcinogenic to ecosystems, including both nonliving and living systems. Among specific interests in the nitrated phenol family, such as 2-nitrophenol (2-NP), 3-nitrophenol (3-NP), and 4-nitrophenol (4-NP), the latter one has been identified as the most serious toxic phenolic derivative. − 4-NP has critical effects on the growth and metabolism of living organisms, including humans, specifically causing methemoglobinemia, liver and kidney injuries. − Because of its continuous exposure, causing drowsiness, cyanosis, lethargy, and nausea, the environmental protection agency (EPA) categorizes the limit of 4-NP in drinking water to be less than 0.43 μM. − , Therefore, the development of rapid, continuous, selective, and trace-level detection of 4-NP from all sources especially water is required. At present, many approaches including traditional methods such as spectroscopy, fluorimetry, electrophoresis, high-performance liquid chromatography (HPLC), chemiluminescence, competitive flow assays, and electrochemical methods have been applied for qualitative and quantitative identification of pollutants specifically 4-NP. ,, Among the different analytical methods, electrochemical techniques are of current interest because of its rapid response, cost-effectiveness, simple operation, and importantly, its potential in real-time and in-field monitoring.…”