Biosorption behavior of acid orange 7 dye onto Cucumis sativus peel biochar and its effect on growth of Triticum aestivum

The application of cucumber peel biochar (CPB) for sorption of acid orange 7 (AO7) dye from aqueous solution has been assessed in this investigation. The adsorption process was systematically studied under different conditions including pH, exposure period, dye concentration, sorbent amount, temperature, and particle size of CPB. Maximum 96% removal of AO7 dye was observed at pH 2 by CPB with 80 mg/L AO7 dye concentration. Langmuir model appears to be the better one for experimental results description with 11.21 mg/g sorption ability. Kinetic results were well explained by pseudo-second order model. The negative value of Delta H-0 (-37.296 kJ mol(-1)) reflected exothermic behavior of process. CPB showed >38% adsorption ability of AO7 dye up to 5 cycles. Phytotoxic investigation showed that CPB treated AO7 dye solution enhanced growth and biochemical parameters of Triticum aestivum seeds. The seedling length and vigor index of wheat seeds showed following order: Control > AO7 dye solution treated with CPB treated > AO7 dye solution. Hence, CPB, profusely available as an agricultural waste can be applied as a cost-effective and ecofriendly sorbent for making dye containing wastewater reusable.