Nascent Rice Husk as an Adsorbent for Removing Cationic Dyes from Textile Wastewater

Abstract

We assessed the applicability of rice husk (RH) to remove cationic dyes, i.e., methylene blue (MB) and crystal violet (CV), from water. RH thermally treated at 75 °C showed a higher adsorption capacity than that at high temperatures (300–700 °C). For a suitable CV-adsorption model, a pseudo-first-order model for MB adsorption was followed by the kinetics adsorption process; however, a pseudo-second-order model was then suggested. In the qt versus t1/2 plot, the MB line passed through the origin, but that of CV did not. The Langmuir isotherm model was better than the Freundlich model for both dye adsorptions; furthermore, the adsorption capacity for MB and CV was 24.48 mg/g and 25.46 mg/g, respectively. Thermodynamically, the adsorption of both MB and CV onto the RH was found to be spontaneous and endothermic. This adsorption increased insignificantly on increasing the solution pH from 4 to 10. With an increasing dosage of the RH, there was an increase in the removal percentages of MB and CV; however, adsorption capacity per unit mass of the RH was observed to decrease. Therefore, we conclude that utilizing RH as an available and affordable adsorbent is feasible to remove MB and CV from wastewater.

The Use of Bilberry Leaves (Vaccinium myrtillus L.) as an Efficient Adsorbent for Cationic Dye Removal from Aqueous Solutions

“…The bioadsorbent dose effect on the adsorption capacity and the dye removal efficiency is depicted in Figure 6 . The increase of adsorbent dose from 1 to 5 (mg L −1 ), generated an ever-increasing available adsorption sites number which led to an increase in removal efficiency [ 1 , 64 , 65 ]. Meanwhile, many of this adsorption sites remain unsaturated and aggregation or agglomeration of adsorbent particle may occur [ 23 , 66 ] and the adsorption capacity decrease from 37.46 to 8.67 (mg g −1 ).…”

Adsorption and coagulation in wastewater treatment – Review

“…The Langmuir model was the best model for this study, and based on the Dubinin-Radushkevich model, ammonium was physically adsorbed on MCRH. Quansah et al (2020) used rice husk utilization for removing methylene blue (MB) and crystal violet (CV). The rice husk used varying dosage in the range of 0.05-1.0 g with the initial concentration of 300 mg L À1 (MB) and 400 mg L À1 (CV).…”

Production of chemically and microwave activated hazelnut husk as an adsorbent for dye contaminated wastewaters

“…Therefore, the general conclusion made on the improvement of MB adsorption in alkali environment can alter depending on the origin, and the treatment of the raw material. On the other hand, MB removal efficiencies in the pH range of 2 or 4 to 10 were regarded as insignificant [26,33]. Additionally, keeping the original pH of the solution prevents the consumption of the chemicals used in pH regulation.…”

“…Temperature increase results in an increase in the adsorption capacity of pollutants in endothermic reactions and a decrease in exothermic reactions [34]. The MB adsorption on the heat-, chemical-or microwave-treated organic wastes has been mostly stated as an endothermic process [12,16,26,[31][32][33][34][35].…”