Mohamed Ben Hassen

The petroleum industry plays a vital role in the economies of developing countries. Refinery wastewater pollution has increased in recent years due to the increase in the industrial and urban use of petroleum products. The present work demonstrates how textile waste can be modified into a material that can effectively remove sulfur pollutants from refinery wastewater. An economic activated carbon (AC) material was developed by using cotton spinning waste from a textile company. The chemical activation was carried out using nitric acid (HNO₃), hydrogen peroxide (H₂O₂), and potassium hydroxide (KOH). The characterization of the obtained activated carbons was performed using the SEM, BET, and FTIR techniques. The effect of the experimental adsorption condition was investigated using both bed and batch isotherms. The results show that effluent flow has the highest effect on sulfur compound adsorption. The greatest adsorption capacity of the sulfur compounds was found to be around 168.4 mg·g⁻¹. The equilibrium data were investigated using the Freundlich, Langmuir, Dubinin–Radushkevich, Tóth, and Sips isotherm models. The Langmuir model exhibited the best fit (R² = 0.98) for the sulfur compounds’ adsorption, which implies that their adsorption onto the synthesized AC was homogeneous. The kinetic data were tested with pseudo-first-order, pseudo-second-order, and intraparticular diffusion equations. The pseudo-second-order equation described the kinetic data well (R² = 0.99), indicating that this adsorption may be restricted by the chemisorption process. These properties under optimal conditions make the obtained ACs suitable for use in refinery wastewater treatment.

Cotton is one of the most-used natural fibres in the world due to its relative comfort and strength compared with other natural fibres. However, the processing of cotton for manufacturing products consumes a lot of water, while harvesting cotton uses significant amounts of pesticides. One solution to this ecological problem is to recycle cotton waste. This study investigated the effect of blending virgin cotton with two categories of denim cotton waste—sourced during the winding and dyeing processes and used in various ratios—on the quality of blended denim cotton. The study was realised in collaboration with a large manufacturer of denim fabrics in Tunisia and a producer of preparation machines in Italy and aimed to use an adequate process to recycle cotton yarn waste and to obtain fibres with acceptable quality. The research aimed at providing a solution to the great demand for denim with the use of reclaimed fabric, which accompanies the increased need for denim with a fancy effect and the obligation of denim producers to follow environmental standards required by many brands The results show that it is possible to obtain a good quality of blend yarn using virgin cotton and cotton waste even when the waste content exceeds 50%. These results are significant for textile mills. Reprocessing fibres from denim colour-processing waste has a lot of advantages, including reductions in wastewater treatment and the consumption of energy, chemicals and water. In addition, the process eliminates the need for the dyeing and finishing processes of these coloured fibres.