Continuous biosorption of acid red 27 azo dye by Eichhornia crassipes leaves in a packed-bed column

Abstract

In this work, the biosorption behavior of acid red 27 (AR27) dye using Eichhornia crassipes leaves (LECs) in a packed-bed column was investigated by varying relevant operational parameters and assessment of mathematical models. Results showed that the zero-charge point of LECs was 2.37 and that optima pH and volumetric flux of the influent solution for AR27 biosorption were 2.0 and $$56.5\ \hbox {L}/\hbox {m}^{2}\cdot \hbox {h}$$ 56.5 L / m 2 · h , respectively. The maximum specific and volumetric biosorption capacities were observed at influent AR27 concentrations and with LEC bed heights ranging between 50 and 400 mg/L and 2 and 8 cm, respectively. It was also found that if LEC bed height was increased and volumetric flux and AR27 concentration of the influent solution decreased, service and saturation time increased. Modeling results revealed that the Thomas, bed depth service time, Yoon–Nelson, dose-response, and logistic models accurately described the dynamic performance of the packed-bed column in terms of pH, AR27 concentration, and volumetric flux of influent AR27 solution, as well as that of LEC bed height. The findings revealed that LECs exhibited remarkable potential for the biosorption of AR27 from aqueous solutions in a packed-bed column and could potentially be useful for the treatment of AR27-laden wastewater.

Continuous successive cycles of biosorption and desorption of acid red 27 dye using water hyacinth leaves as an effective, economic, and ecofriendly biosorbent

“…A 75 mg/L AR27 test solution was prepared by diluting the AR27 stock solution with deionized water. Its pH was adjusted with 0.1 M HCl to 2.0 which is the optimum for AR27 biosorption by LEC in a continuous system with a packed-bed column reactor [25]. The AR27 concentration was determined at 520 nm in a Thermo Scientific UV-Vis Evolution 201 spectrophotometer (Thermo Fisher Scientific, Waltham, MA, USA) [23].…”

“…The 200-mesh stainless steel sieves prevented biosorbent loss. The LEC packed-bed porosity (ε b ) and density (ρ b ) were ~25% and 0.188 g/cm 3 , respectively [25].…”

“…The up-flow mode was used and the volumetric flux was 56.5 L/m 2 •h. According to Ramírez-Rodríguez et al [25], these operating conditions were deemed optimal for continuous AR27 biosorption in the LEC packed-bed column as they realized the highest experimental AR27 biosorption capacity and the longest column service time. Effluent samples were collected at regular intervals and their residual AR27 concentrations were measured.…”

“…Previous studies showed that the leaves of water hyacinth (Pontederia crassipes) (LEC) effectively biosorb AR27 dye from aqueous solutions in both batch and continuous systems [23][24][25]. In addition, this dye can be recovered with 100% desorption efficiency from the loaded LEC biomass by using 0.025 M NaHCO 3 as the eluent/desorbent.…”

Remediation of nitrate contaminated groundwater using a simulated PRB system with an La–CTAC–modified biochar filler

“…These results demonstrate that the height of the filler in the PRB column significantly affects the adsorption of NO 3 − from groundwater on the column. This behavior is attributed to the larger the mass of filler in the column as the height of the filler increases, thereby augmenting the filler surface area and the number of active binding sites available for NO 3 − adsorption (Ramírez-Rodríguez et al, 2021). Consequently, the reaction time between the NO 3 − and biochar materials in the PRB column is longer, and thus, diffusion into the adsorbent is deeper.…”