In-situ toxicity assessment of pulp and paper industry wastewater on Trigonella foenum-graecum L: Potential source of cytotoxicity and chromosomal damage

Abstract

This work aimed to study in-situ toxicity assessment of pulp and paper industry wastewater on Trigonella foenum-graecum L. Physico-chemical analysis of wastewater revealed high pH (8.1), total suspended solids, total dissolved solids, biochemical oxygen demand and chemical oxygen demand (89, 2160, 8670 and 25600 mg L−1 , respectively), electrical conductivity (2156 ms cm−1), and heavy metal (mg L−1) contents as Fe (79.61), Zn (49.06), Cu (6.07), Cd (6.07), Mg (19.66), and Ni (6.43), which were higher than compare to control The major pollutants detected via GC–MS analysis were hexadecanoic acid, octadecanoic acid, nonacosane, and β-sitosterol trimethylsilyl ether. UV–Vis spectrophotometry and Fourier transform infrared spectroscopy analyses of the wastewater confirmed the presence of residual organic and inorganic pollutants. The cytotoxicity and genotoxicity of the wastewater for plants were also assessed and revealed chromosomal and cytological aberrations in wastewater-treated T. foenum-graecum L. The accumulation of metals in and the effects of such accumulation on the physiology of T. foenum-graecum L. plants irrigated with wastewater were also studied, and it was concluded that antioxidant enzyme activity, chlorophyll, protein content, and dry weight were reduced in wastewater irrigated T. foenum-graecum L. plants compared to those in the control (fed with normal water). Scanning and transmission electron microscopy analyses of plant roots, root nodules, and stomata revealed the accumulation of heavy metals on the surfaces and in tissues. The present study highlights the urgent necessity of proper treatment of paper and pulp industry wastewater before their disposal into water bodies to control the damage to environment and aquatic life.