Citrus lemon leaf powder as a biosorbent for the removal of liquid phase toxic metals from textile effluent

Citrus lemon leaf powder (CLLP) is used as a biosorbent for the removal of toxic metals from textile effluent in a batch process. The biosorbent of CLLP is cost-effective and holds excellent potential for the removal of toxic metals. The textile effluent is one of the major sources of toxic metals that contaminate the river and groundwater. The main objective of this research is to purify the textile effluent and to reduce the toxicity of cadmium [Cd(II)(L)], lead [Pb(II)(L)], nickel [Ni(II)(L)], zinc [Zn(II)(L)], and copper [Cu(II)(L)]. Besides, it intrigues the effect of various factors/parameters like pH, dosage content, and contact time of metals. It is found that in 50 ml of effluent, 80%–90% of the toxic metals could be removed by 2.0 g of the citrus lemon leaves powder. The results obtained through experimental data are examined by the various isotherms like Langmuir, Freundlich, Temkin, Dubinin–Radushkevich, Harkins–Jura, and Jovanovic. The adsorption data fitted well to Langmuir isotherms. The regression coefficient value is greater than 0.9. The absorbed RL of Langmuir isotherm for all cases is around 0–1, which is a favorable one. In the cases of adsorptions, the parameters such as ‘n’ falling in the range of 1–10 indicate favorable sorption. The results show that CLLP could be used as a low-cost biosorption process for the removal of metals from textile effluent.