Design of a Fixed-Bed Column with Vegetal Biomass and Its Recycling for Cr (VI) Treatment

Abstract

The aim of this work is to design a fixed-bed column with vegetal biomass of Eichhornia crassipes and the process of recycling it for treatment via the adsorption of water loaded with chromium (VI). In the first stage, the relationship between the fixed-bed density and the microparticle density is calculated, giving a model for the design of the fixed bed. Using this model, two systems for the treatment of Cr (VI)-contaminated water were designed and built. The vegetable biomass at three particle diameters of 0.212 mm, 0.30 mm and 0.45 mm was evaluated in the removal of Cr (VI) from water using the designed fixed-bed systems, giving the best removal of Cr (VI) with the lowest size particles and allowing the validation of the proposed model with the Thomas model. The incorporation of iron into the biomass allowed for the treatment of near 2.0 L of polluted solution, removing around 90% of Cr (VI), while it was only possible to treat nearly 1.5 L when using raw biomass, removing around 80% of Cr (VI). The recycling of the biomass was achieved via the elution of Cr (VI) with EDTA, permitting the reuse of the material for more than five treatment cycles.

The Design of a Process for Adsorbing and Eluting Chromium (VI) Using Fixed-Bed Columns of E. crassipes with Sodium Tripolyphosphate (TPP)

“…The Thomas constant was found to be 0.055 mL/mg•min, indicating the chemisorption rate of Cr(VI) into the EC-PPT biomass. The modified biomass has a Cr(VI) adsorption rate of 0.035 mL/mg•min, which is higher than the unmodified biomass but lower than that of the EC-PPT biomass (2), which reached a rate of 0.061 mL/mg•min. The better behavior of the modified biomass in the adsorption of Cr(VI) is evident.…”

“…The better behavior of the modified biomass in the adsorption of Cr(VI) is evident. Table 6 shows the fitted parameters for EC-PPT biomass (2).…”

“…Aquatic plants: The roots and leaves of the aquatic plant E. crassipes were taken from the Juan Amarillo wetland in the city of Bogotá D.C. The aim was to obtain particle diameters of 0.212 mm (it should be less than 0.212 mm for better contact between particle and contaminate [1,2]).…”

“…For this reason, there is a need to find suitable ways to treat water in an efficient way in the industrial sector, where most of the pollution occurs. One suitable method of treating industrial wastewater is through fixed-bed column systems, coupled with a process of reutilizing waste biomasses [1][2][3].…”

The Design of a Sustainable Industrial Wastewater Treatment System and The Generation of Biohydrogen from E. crassipes

“…The presence of hydroxyl (OH) and carboxyl (COOH) groups facilitates cation exchange with heavy metals. These groups were evidenced using FTIR tests [1][2][3][4][5][6]. Continuous treatment systems with fixed biomass have been used to purify water by exposing it to cellulose.…”