In this present work, the sorption of crystal violet (CV) pigment from laden aqueous solution carried out via ultrasound-assisted. The sorption of CV on activated charcoal was performed in the existence and absence of ultrasound. Using of combined ultrasound/activated charcoal process gave high CV decolorization than using sorption or sonolysis alone because of the synergistic process achieved in this combined system. Experiments were performed at different initial pigment concentration and temperature. The sorption isotherms were achieved by the Freundlich, Langmuir, DeR and Temkin isotherm model. The sorption of CV onto activated charcoal demonstrated more suitable for Langmuir than the Freundlich isotherm model. The maximum monolayer sorption capacity was 50.1 mg/g. The thermodynamic parameters, namely the entropy, Gibbs free energy and enthalpy of the CV sorption process were determined. The enthalpy and free energy indicate an exothermic, feasible and spontaneous process. It has been shown that the proposed combined ultrasound/activated charcoal process may be useable in the treatment of pigment solution from textile wastewater.

Introduction

Wastewater effluents discharged from various sorts of enterprises, for the most part, contain several organic toxins and dangerous substances which are destructive to aquatic life. The effluent released from different ventures, for example, paint, textiles, leather, and paper in the industry. dyestuff fabricating are very shaded wastewater which makes serious environmental concerns everywhere throughout the world (Shirsath et al., 2015). Crystal violet (CV) is an artificial basic cationic pigment, which in aqueous solution makes violet dye, an affiliate of the triphenylmethane classify and it broadly utilized in cloth coloring productions. It uses for treatment dermatology problems, biological tint, treatment of animals and preservative to hens nurture to diminish the spread of hurtful bacteria. (Jain et al., 2010). The cationic pigments are more poisonous than the anionic pigments because these can simply react negatively charged cells membrane shells and can pass into cells and converge in the cytoplasm. The CV is a confirmed effective carcinogen, poisonous to mammalian cells and mitotic toxic. Subsequently, this pigment are containing wastewater must be treated before being released into the getting waterway. In a request to release pigments from wastewater different treatment forms. For example ozonation (Muthukumar et al., 2004), coagulation (Marou
sek et al., 2019), ultrafiltration (Majewska-Nowak et al., 1989), oxidization (Kim et al., 2004),electrochemical (Gupta et al., 2007), photocatalytic degradation (Sun et al., 2010) and sorption (Sun et al., 2010). Amongst of these techniques, sorption has been found to be efficient and inexpensive comparing to other methods for removal of pigments, containing dyes and other colorants owing to cost low, its ease operation, design and insensitivity to toxic various materials.