ABSTRACT
In the present study, nanocellulose was extracted from palm leaves to synthesize nanocellulose/chitosan nanocomposites for the removal of dyes from textile industrial wastewater. Nanocellulose is of interest in water purification technologies because of its high surface area and versatile surface chemistry. Following bleach, alkali, and acid treatments on palm leaves, nanocellulose is obtained as a white powder. The produced nanocellulose was investigated. The adsorption capacity of chitosan, nanocellulose, and novel synthetic nanocellulose/chitosan microbeads (CCMB) for direct blue 78 dye (DB78) removal was studied. A series of batch experiments were conducted in terms of adsorbent concentration, mixing time, pH, dye initial concentration, and nanocellulose concentration in synthetic microbeads. The CCMB was characterized by using physicochemical analysis, namely Brunauer-Emmett-Teller (BET), scanning electron microscope (SEM), zeta potential analysis, and Fourier-transform infrared spectroscopy (FTIR). It was found that the surface area of synthetic CCMB is 10.4 m2/g, with a positive net surface charge. The adsorption tests showed that the dye removal efficiency increases with an increasing adsorbent concentration. The maximum removal efficiencies were 91.5% and 88.4%, using 14 and 9 g/L of CCMB-0.25:1. The initial dye concentrations were 50 and 100 mg/L under acidic conditions (pH = 3.5) and an optimal mixing time of 120 min. The equilibrium studies for CCMB-0.25:1 showed that the equilibrium data were best fitted to Langmuir isothermal model with R2 = 0.99. These results revealed that nanocellulose/chitosan microbeads are an effective eco-adsorbent for the removal of direct blue 78 dye and provide a new platform for dye removal.
ABSTRACT
Dysphagia aortica is a rare aetiology of dysphagia resulting from an abnormality in thoracic aorta that causes extrinsic compression on the oesophagus. Dysphagia aortica includes aortic aneurysm, aortic dissection or even tortuous aorta and is seldom considered in the differential diagnosis of dysphagia. Herein, we report a 30-year-old man with Behcet's disease who presented with rapid progressive dysphagia and diagnosed as dysphagia aortica caused by saccular aortic aneurysm complicated by large para-aortic haematoma compressing the oesophagus. The case reveals the importance of early and proper identification of the rare causes of dysphagia in young adults with complaint of dysphagia and history of recurrent oral and genital ulcers in absence of obvious cardiovascular diseases.
