Phytoremediation of Textile Effluent from Navi Mumbai MIDC Zone Using Eichhornia crassipes (Water Hyacinth)

Abstract

Textile effluents from industrial hubs such as Navi Mumbai MIDC are complex, chemically diverse wastewaters characterized by high organic loads (COD, BOD), suspended and dissolved solids (TSS, TDS), synthetic dyes, and trace heavy metals. In this study, the phytoremediation potential of Eichhornia crassipes (water hyacinth) was evaluated under controlled laboratory-scale batch conditions. Raw effluent was treated in 10-L reactors containing 300 g fresh biomass per unit, with parallel plant-free controls. Water quality parameters including pH, COD, BOD₅, TSS, TDS, dissolved oxygen (DO), colour, and selected heavy metals (Cr, Fe, Zn) were monitored at 0, 7, 15, and 30 days. After 30 days, treatment systems demonstrated substantial improvements in effluent quality: COD decreased from 1200 ± 35 to 360 ± 22 mg/L (70%), BOD₅ from 500 ± 20 to 140 ± 12 mg/L (72%), and TSS from 600 ± 28 to 120 ± 10 mg/L (80%), whereas control systems exhibited only minor reductions. Dissolved oxygen increased from 0.6 ± 0.05 to 4.2 ± 0.15 mg/L in planted systems, and pH shifted toward neutrality. Heavy metals showed significant removal from water (Cr, Fe, Zn: 70–76%), with roots accumulating higher concentrations than shoots (Cr: 420 mg/kg⁻¹; Fe: 5200 mg/kg⁻¹; Zn: 350 mg/kg⁻¹), indicating root-mediated sequestration and rhizofiltration as primary mechanisms. The combined effects of physical filtration, rhizosphere-enhanced microbial degradation, and adsorption/uptake of organics and metals highlight the efficacy of E. crassipes as a low-cost, environmentally benign treatment option. These findings support the application of water hyacinth for pre-treatment or polishing of textile effluents in industrial zones, offering potential to enhance the performance of centralized effluent treatment plants.