Char from Spent Tire Rubber: A Potential Adsorbent of Remazol Yellow Dye

Abstract

A char produced from spent tire rubber showed very promising results as an adsorbent of Remazol Yellow (RY) from aqueous solutions. Spent tire rubber was submitted to a pyrolysis process optimized for char production. The obtained char was submitted to chemical, physical, and textural characterizations and, subsequently, applied as a low-cost adsorbent for dye (RY) removal in batch adsorption assays. The obtained char was characterized by relatively high ash content (12.9% wt), high fixed-carbon content (69.7% wt), a surface area of 69 m2/g, and total pore volume of 0.14 cm3/g. Remazol Yellow kinetic assays and modelling of the experimental data using the pseudo-first and pseudo-second order kinetic models demonstrated a better adjustment to the pseudo-first order model with a calculated uptake capacity of 14.2 mg RY/g char. From the equilibrium assays, the adsorption isotherm was fitted to both Langmuir and Freundlich models; it was found a better fit for the Langmuir model to the experimental data, indicating a monolayer adsorption process with a monolayer uptake capacity of 11.9 mg RY/g char. Under the experimental conditions of the adsorption assays, the char presented positive charges at its surface, able to attract the deprotonated sulfonate groups (SO3−) of RY; therefore, electrostatic attraction was considered the most plausible mechanism for dye removal.

Thermochemical Conversion Processes as a Path for Sustainability of the Tire Industry: Carbon Black Recovery Potential in a Circular Economy Approach

“…The obtained results are in accordance with previous studies that addressed the production of char from scrap tire rubber as potential adsorbent of Remazol Yellow dye [44]. In that study, the authors showed, for example, an increase in the fixed carbon content close to 70%, while the ash content reached 12.9% [56]. In our study, the mass loss reached 63.42% at 300 • C and 67.56% at 400 • C (Table 2), which also meets the results of the tests carried out by Nogueira et al (2019).…”

“…In our study, the mass loss reached 63.42% at 300 • C and 67.56% at 400 • C (Table 2), which also meets the results of the tests carried out by Nogueira et al (2019). According to them, the TGA curves indicate a mass loss slightly higher than 60% for the temperature range between 380 and 450 • C [56]. In conclusion, the high content of fixed carbon verified in the samples produced at 400 • C shows that the potential of this material produce carbon black is very promising.…”

“…Clean Technol. 2022, 4, FOR PEER REVIEW 12 showed, for example, an increase in the fixed carbon content close to 70%, while the ash content reached 12.9% [56]. In our study, the mass loss reached 63.42% at 300 °C and 67.56% at 400 °C (Table 2), which also meets the results of the tests carried out by Nogueira et al (2019).…”

Advancement in recycling waste tire activated carbon to potential adsorbents

“…The main reason due to the distinctive behavior of the adsorption is the ionization of the compound. Nogueira et al [77] prepared effective adsorbents from waste tire rubber for remazol yellow dye removal from aqueous solution. The produced sample was characterized by relatively high ash content (12.9% wt), high fixed-carbon content (69.7% wt), a surface area of 69 m 2 /g, and total pore volume of 0.14 cm 3 /g.…”

Alternative Materials for the Enrichment of Biogas with Methane

“…As waste materials, chars obtained from the pyrolysis of rubber tires have great potential [30], the same as adsorbents produced from biomass [31][32][33]. In addition, these chars were reported to exhibit reasonable adsorption properties for the cleaning of wastewater of iron [34], drugs [35], and dyes [36]. Although commercial carbon materials can be developed especially for the process of methane separation from the CH 4 /CO 2 mixture (or with other components such as NH 3 , H 2 S, and N 2 ), the cost of such an adsorbent is high in comparison to by-products of utilization processes or waste products from food production.…”