The textile industry is one of the oldest sectors globally, significantly contributing to water pollution—reportedly around 20%—which raises environmental concerns. Recent initiatives are aiming to address these issues through the adoption of environmentally-friendly practices, particularly focusing on the removal of synthetic dyes from wastewater. With the rapid growth of the industry and mutations due to climate change, efficient treatment methods for dye-laden wastewater have become critically necessary.
Research has highlighted sustainable approaches, such as the use of enzymes and agricultural biowastes for dye adsorption. Among the methods explored is the utilization of waste materials, such as orange peel, to create porous carbons and composites, which are effective adsorbents for cationic dyes like methylene blue (MB) and crystal violet (CV). This paper examines the synthesis of these adsorbents, their characterization, and their efficiency in removing dyes under various conditions.
Studies revealed the adsorption performance of porous carbon (PC) and ZnO nanorods@PC (ZnO-NR@PC) derived from orange peel is both environmentally sustainable and economically feasible. These materials have shown maximum adsorption capacities for MB and CV of 74.45 mg/g and 74.89 mg/g, respectively. Influencing factors such as pH, contact time, and initial dye concentrations were investigated, with optimal removal achieved at alkaline conditions (pH=10).
The adsorption process follows the pseudo-second-order kinetics with the Langmuir isotherm model fitting the data well, indicating monolayer adsorption onto surface sites. Thermodynamic analyses confirmed the adsorption of MB and CV dyes is both spontaneous and endothermic. Key to the adsorption mechanism were electrostatic interactions, π-π stacking, and ion exchange, underlining the effectiveness of the synthesized materials.
Experimental methods involved characterizing the adsorbents via XRD, FT-IR, BET, and TEM analyses to assess their physical and chemical properties, confirming the successful production of porous structures suitable for dye adsorption. Notably, the synthesized material displayed stability, achieving around 90% removal efficiency after five cycles of use.
Data also suggested the composites’ utilization not only improves the treatment of hazardous wastewater but also aligns with the push for greener technologies within the textile industry. Promisingly, even real wastewater samples exhibited high removal percentages, confirming the applicability of these materials beyond laboratory settings.
Currently, the textile industry is exploring the integration of enzymatic processes as another eco-friendly approach to manage dye waste. Enzymes such as cellulases, laccases, and lipases are being assessed for their potential to replace traditional chemical processes not only for dye removal but also enhancing the overall sustainability of textile operations.
Industry findings advocate for the application of enzymes over conventional methods, which often involve harsh chemicals detrimental to the environment. The biotechnological methods show promise for lowering operational costs and minimizing environmental impact, indicating a shift toward sustainability.
Both studies on dye adsorption and enzyme applications point to the textile industry's transformative potential when adopting sustainable practices. Future research is recommended to investigate other bio-waste materials and enzyme combinations to broaden the scope of sustainable treatment technologies.