Tartaric Acid Modified Rice Hull as a Sorbent for Methylene Blue Removal

Abstract

<b>Problem statement:</b> Improper dye discharge from various industries such as textile, paper, cosmetic and plastics into receiving streams can be one of the sources towards water pollution. The release of these effluents not only causes various disruptions in the ecosystems, but also poses hazard effect as most of the dyes are highly toxic, mutagenic and carcinogenic in nature. <b>Approach:</b> To prepare an inexpensive and efficient sorbent by chemically modifying rice hull for the removal of Methylene Blue (MB) which is predominantly used in coloring acrylic fiber. Batch experiments were carried out for the removal of MB from aqueous solution by using Tartaric Acid Modified Rice Hull (TARH). Parameters studied include effect of pH, contact time, initial dye concentration and agitation rate and sorption isotherm. <b>Results:</b> From the results, the percentage uptake of MB increased with increasing contact time and agitation rate. Based on the linear regression correlation coefficient, R², the system under study is more appropriately described by the pseudo-second order model. Maximum sorption capacity calculated from the Langmuir model is 25.0 mg g^-1 for MB. <b>Conclusion:</b> The study has shown the effectiveness of TARH in the removal of MB, a basic dye from synthetic solutions

Biosorption of methyl blue onto tartaric acid modified wheat bran from aqueous solution

“…From the results listed in Table 1, it can be seen that the kinetic data could be described well by the pseudo-second order rate equation which was based on the assumption that the rate limiting step may be the chemical sorption or chemisorptions involving valency forces through sharing or exchange of electron between adsorbent and adsorbate [29]. This result was accordant with previous report [19]. However, Hu et al .…”

“…From the results in Table 2, the correlation coefficients values (R 2 ) were found to be in the range of 0.9605 to 0.9998 for two models; it could be concluded that the adsorption isotherm of MB on modified wheat bran followed the Langmuir and Freundlich models. Applicability of both isotherms to adsorption of dyes by treated spent bleaching earth, activated carbons and agricultural wastes have been reported previously [19,32-34]. …”

“…The adsorption capacity of modified wheat bran for MB is about 1.6 times higher than that of unmodified wheat bran, and it has higher removal efficiency for basic dye than some other biosorbents [19,24]. The presence of carboxyl groups in modified wheat bran is believed to be primarily responsible for the adsorption of MB.…”

“…The presence of carboxyl groups in modified wheat bran is believed to be primarily responsible for the adsorption of MB. Previous investigations have also postulated that the adsorption of positively charged species is due to the presence of binding sites such as carboxyl and hydroxyl groups on the surface [19,25,26]. …”

“…Thus, there has been intensive research exploring the potential of alternative low-cost materials as sorbents for dyes. For this purpose in recent years, various biological and industrial by-products have been investigated intensively for their ability to remove dye from aqueous solution, as they can be obtained readily and are in great abundance, such as corncob [5], chitosan [6], waste coir pith [7], giant duckweed [8], powdered peanut hull [9], coccinea berries [10], trees’ leaves [11], eggshell [12], modified clays [13], fly ash [14], beer brewery waste [15], natural zeolite [16], bentonite [17], rice bran [18] and rice hull [19]. Among these materials, some biosorbents have shown extraordinary properties for dye removal.…”