Sustainable environmental remediation approach for biocide removal from water medium: a model biosorption study using activated biological waste.

Within the scope of sustainable environmental remediation approach, a biosorbent prepared from the waste of coastal plant with chemical activation was used to effectively remove malachite green as a common biocidal agent from water environment in this work. The biocide treatment ability of activated biosorbent was interpreted through the characterization, optimization, equilibrium, thermodynamic, and kinetic studies. The characterization research showed that the biosorbent has an uneven surface and various active groups for the retention of biocide molecules. Langmuir isotherm was found to be the most appropriate model for the experimental equilibrium data. The maximum monolayer biosorption capacity was obtained as 103.834 mg g under the optimum conditions (time of 6 h, pH of 4, temperature of 25 °C, biosorbent amount of 10 mg, and biocide concentration of 15 mg L). The biosorption system was determined to be spontaneous and exothermic in thermodynamic aspect. The experimental kinetic data were best described by the pseudo-second-order model. All these results indicated that the activated biological residue could be used as an environmentally friendly and effective biosorbent for the biocide removal from water environment in a sustainable way.