Adsorption Isotherm of Carbon Microparticles Prepared from Pumpkin (Cucurbita maxima) Seeds for Dye Removal

Abstract

This study aims to evaluate the adsorption isotherm of carbon microparticles prepared from pumpkin (Cucurbita maxima) seeds for adsorbing curcumin (as a model of dye). The results were derived and compared using the kinetics approach based on several standard adsorption isotherm models, namely the Langmuir, Temkin, Freundlich, and Dubinin-Radushkevich models. The second aim is to evaluate the effects of carbon particle size (from 100 to 1000 mm) on the adsorption characteristics. The experimental results showed that the adsorption on the surface of carbon microparticles occurred in monolayer with a physical phenomenon. This is because the active areas are located only on the outer surface of carbon and no surface structure in the carbon is available. This is confirmed by the fact that the produced carbon has less porosity and the pores themselves are mostly produced from the release of inorganic contents during carbon synthesis, while the amount of inorganic content is very less. The confirmation of the adsorption profile was also achieved by testing various sizes of carbon microparticles. Smaller particles have direct impacts on the improvement of adsorption capacity, which is due to the existence of a larger surface area, a larger number of adsorption sites, and additional cooperative adsorption, i.e. adsorbate-adsorbate interaction. Understanding the adsorption phenomena occurring on carbon particles is useful for further developments and applications, such as those of catalysts and adsorbents, especially concerning the production of carbon materials from organic waste.

A review of biomaterial as an adsorbent: From the bibliometric literature review, the definition of dyes and adsorbent, the adsorption phenomena and isotherm models, factors affecting the adsorption process, to the use of typha species waste as adsorbent

“…Some techniques such as photocatalytic degradation [32][33][34], sonochemical degradation [35][36][37], cation exchange membranes [38][39][40], electrochemical degradation [41][42][43], solar Acid orange 165 60 [29] Basic blue 7 100 [29] Basic blue 81 205 [29] Basic violet 16 90 [29] Basic yellow 21 171 [29] Direct orange 62 150 [29] Congo red 96 [30] Crystal violet 10 [14] Methylene blue 50 [31] photo-Fenton [44][45][46], biological process [28,47,48], adsorption [49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66], solar photo-Fenton and biological processes [67], and Fenton-biological treatment [68] have been used for the wastewater treatment to remove the dyes from wastewater....…”

“…The adsorbent-grade activated carbon is one of the issues due to its cost-prohibitive [90]. Many researchers, in response, have been attempting to find out some affordable and locally available chemical substitutes from natural sources as the alternative to the traditional carbon adsorbent [49][50][51][52][53]58,59,61]. The employmet of biomasses and plant-derived biomaterials has been one of the great interests, including several materials:…”

Biochar from Agricultural Waste for Soil Amendment Candidate under Different Pyrolysis Temperatures

“…Other choices for solving the problems regarding organic waste have been well-documented, such as converting the organic waste into carbon that can be used as adsorbents. Several examples of carbon production from organic waste are available, including pineapple peel waste (Nandiyanto et al, 2020b), rice husk (Fiandini et al, 2020), pumpkin seeds (Nandiyanto, 2020), typa and grass (N'diaye et al, 2022), soursop peel (Nandiyanto et al, 2020c), and dragon fruit peel (Nandiyanto et al, 2020d). Different from other reports, here, this study converts durian seeds into biochar through the pyrolysis process.…”

Removing Cobalt ions from Industrial Wastewater Using Chitosan

“…When the value of 1/n is less than one, this indicates (a normal adsorption). When 1/n values are greater than one, this indicates (a cooperative adsorption) [33,34]. The data in Table 2 show the adsorption of Co (II) on CS follows the Freundlich model ( R 2 =0.937 ).…”