Effect of Textile Effluent on Nutrient and Heavy Metals Uptake by Rice (Oryza sativa L.)

Abstract

This study evaluated the effects of textile effluent—an increasingly common irrigation source in Bangladesh’s garment-industry regions—on nutrient acquisition, heavy-metal uptake, and associated health risks in rice (Oryza sativa L.). Six irrigation and fertiliser treatments were applied: T1 (control), T2 (recommended fertiliser dose with fresh water), T3 (50% RDF + 25% effluent), T4 (50% RDF + 50% effluent), T5 (50% RDF + 75% effluent), and T6 (50% RDF + 100% effluent). Rice grains from T2 exhibited the highest nutrient concentrations and uptake, whereas T4—representing 50% textile effluent—produced comparable values across most nutrients. Heavy-metal accumulation varied by treatment, with T6 showing the greatest concentrations of Zn, Cu, Fe, and Mn, and T3 and T2 exhibiting the highest levels of Ni and Cr, respectively; Cd and Pb were not detected. Uptake patterns followed the order Fe > Mn > Zn > Cu > Ni > Cr. While moderate effluent use (T4) supported nutrient acquisition without excessive heavy-metal loading, higher effluent proportions substantially increased metal accumulation in grains, raising concerns about chronic dietary exposure. Elevated Fe, Mn, Zn, and Ni levels—if accumulated beyond permissible limits—pose potential risks related to oxidative stress, neurotoxicity, and long-term metabolic disturbances in humans. The findings suggest that integrating 50% textile effluent with reduced fertiliser inputs can support rice production in water-scarce regions, but careful monitoring of heavy-metal concentrations is essential to minimise food-safety risks and protect public health.