Constructed wetlands as sustainable solutions for textile effluent treatment: a review

Constructed Wetlands (CWs) have emerged as a promising technology for the effective remediation of wastewater, including textile effluent, and provide an alternative water source for various activities. Several bacterial populations are critical in degrading and decolorizing noxious dyes within CWs. However, enzymes are considered highly efficient biological catalysts utilized to speed up degradation reactions within CWs for the removal of different dyes from textile wastewater. The obtained macrophytic biomass acts as a raw material to develop different bioresources such as biofertilizers, biofuels, bioenergy, animal feed, biochar, recovery of various nutrients and pharmaceutical compounds, etc. Several macrophytes utilized in CWs have great nutritional and pharmaceutical values. Further, the production of biofuels from biomass feedstock has been extensively investigated to develop an alternative fuel for reduced dependence on fossil fuels. Additionally, strong, robust, and air-dried stem strands of macrophytes obtained during the treatment process can be utilized as an alternative structural resource. The resultant sludge and other solid, biosolid, and semi-solid materials may produce heat or electricity, biogas, or be transformed into organic manure or fertilizers. This review highlights the potential of CWs for textile wastewater treatment and the generation of various value-added products for the circular economy. The role and potential of microbial populations and their enzymes during the treatment process are also discussed briefly.