Modeling of water hyacinth growth and its role in heavy metals accumulation from unoperated old Ganga canal at Haridwar, India

The present study aimed to investigate the annual potential of water hyacinth (WH; Eichhornia crassipes) macrophyte in an un-operated/abandoned stretch of the upper Ganga canal at Haridwar, India. The study covered a 25 km long and 100 m wide stretch of the old Ganga canal which exhibits a huge WH growth every year. For this, standard field and laboratory methods were adopted to estimate the WH biomass density (Kg/m²), and heavy metals dynamics between canal water and macrophyte biomass. Results showed that the average annual density of WH biomass was 5.538 kg/m² with significant (P < 0.05) heavy metals (HMs) accumulation as 1.50 mg/Kg dw of Cd, 0.21 of mg/Kg dw of Cr, 2.19 mg/Kg dw of Cu, 28.54 mg/Kg dw of Fe, 20.79 mg/Kg dw of Mn, and 9.39 mg/Kg dw of Zn, respectively. Using a polynomial cubic model, the annual trends of WH growth and HMs accumulation in both water and biomass were also simulated. The developed models showed good R² and error validation results that support the prediction criteria. The findings of this study revealed that WH’s growth in the un-operated stretch of the old Ganga canal located at Haridwar has high HMs accumulation and biomass production potentials. Graphic abstract: [Figure not available: see fulltext.]