Enhanced removal of cationic dye by eco-friendly activated biochar derived from rice straw

Abstract

This report deals with converting the agriculture waste (rice straw) to environmental cleaner materials (biochar) using airless pyrolysis followed by eco-friendly activation. The biochar (p-Biochar) obtained after pyrolysis step (poorly active material) was activated using wet attrition method to give m-Biochar (highly active materials). The both p-Biochar and m-Biochar were characterized in detail and utilized for MB and CV dye removal from aqueous solution. Various parameters affecting the adsorption process such as dye concentration, adsorbent dose, contact time, temperature, NaCl dose and pH were investigated. The adsorption isotherm was well fitted using Langmuir isotherm, and the maximum adsorption capacity is 90.91 and 44.64 mg/g, for MB and CV dyes, respectively. The contact time data obtained showed that the two dyes were poorly adsorbed over p-Biochar. The equilibrium was reached quickly in 15 min for MB dye and 20 min for CV dye using the m-Biochar, and removal percent was 94.45 and 92.70% for MB and CV dyes, respectively. Moreover, the kinetic isotherm presented very well fitted by pseudo-second-order model. In addition, the adsorption percent increases with further increasing the pH value. Finally, we observed that m-Biochar highly adsorbs the MB dye compared with the CV dye over all experimental conditions.

Mesoporous Carbons of Well-Organized Structure in the Removal of Dyes from Aqueous Solutions

“…Some studies on adsorbing performance of various materials for the studied dyes and the corresponding maximum adsorption capacities have been reported [ 25 , 26 , 33 , 36 , 60 , 61 , 62 , 63 , 64 , 65 , 66 ], which are listed in Table 4 . Compared with referred materials, the mesoporous carbons obtained by impregnation of well-organized silicas proved to be similar or even more efficient adsorbents.…”

Biogenic and chemically synthesized Solanum tuberosum peel–silver nanoparticle hybrid for the ultrasonic aided adsorption of bromophenol blue dye

“…Most of these techniques are expensive or ineffective for dye removal 4 . Considered to be the most preferred is the adsorption technique, due to the ease of operation, high effectiveness and design simplicity 19 , 20 . In addition, activated carbon is widely used and commercially applied for dye decontamination, due to its impressive adsorption capacity 21 , but the high cost is a big limitation for its application 22 – 24 .…”

Purification of Aqueous Media by Biochars: Feedstock Type Effect on Silver Nanoparticles Removal

“…Adsorbed nanoparticles may have formed clusters on the solid. Besides silver nanoparticles, biochar was also used in the removal of other contaminants, e.g., heavy metals [ 28 , 32 , 33 ], dyes [ 34 , 35 ], gold nanoparticles [ 10 ], antibiotics [ 36 , 37 ], and PAH [ 38 , 39 ].…”