Optimization of dye removal by diesel exhaust emission soot using response surface methodology

In this research, the synthesis of biochar from cow dung and sewage sludge and its application for the removal of organic contaminants using methylene blue (MB) as the model molecule was evaluated. Experiments were performed using different concentrations of adsorbent and MB and were optimized by a response surface methodology (RSM). Dynamic models were adjusted to the experimental data and the regeneration of the bed was studied. The results showed that the optimal conditions to favor the adsorption of MB, in a fixed bed and making a comparison between the two biochar sources, were those where an adsorbent biochar concentration of 5 g and initial MB concentration of 10 mg L −1 were used. The biochar prepared from cow dung presented the best adsorption conditions. Under these conditions, the breaking time was 172.73 min. The models of Thomas, Bohart-Adams, and Yoon-Nelson were applied for the study in fixed-bed columns and it was observed that the models were adjusted satisfactorily. Regeneration was possible for three different cycles, slightly diminishing the performance of the bed with elution of HNO 3 . These results indicate that MB bed fixed adsorption on cow dung biochar is viable and suitable for water treatment.

Section: Methodsmentioning

confidence: 99%

Section: Statistical Optimizationmentioning

confidence: 99%

Comparative study of biochar prepared from cow dung and sewage sludge and its application as an adsorbent for organic pollutants removal in water

Suárez-Vázquez

Cruz‐López

Márquez-Reyes

et al. 2021

“…[6][7][8][9][10][11] During several decades various methods for the treatment of dye-containing effluents, such as photochemical treatment, oxidation, electrochemical treatment, Ozonation, coagulation flocculation, and adsorption was found to be more effective due to its low-cost, good efficiency, insensitivity to toxic pollutants, and simplicity. [12][13][14][15][16][17][18] Metal-organic frameworks (MOFs) are highly porous organicinorganic hybrid materials, which is assembled through coordination between polytopic organic ligands (linkers) and metal nodes (secondary building units, SBUs). [19][20][21][22] MOFs offer a new platform for developing versatile materials for various applications in energy storage, chemical sensor, drug delivery, catalysis, luminescence, optics, and separations.…”

Section: Introductionmentioning

confidence: 99%

“…Thus, necessary wastewater treatment must be conducted for discharge and even either recycling or reuse of water 6–11 . During several decades various methods for the treatment of dye‐containing effluents, such as photochemical treatment, oxidation, electrochemical treatment, Ozonation, coagulation flocculation, and adsorption was found to be more effective due to its low‐cost, good efficiency, insensitivity to toxic pollutants, and simplicity 12–18 …”

Section: Introductionmentioning

confidence: 99%

TMU‐24 (Zn‐based MOF) as an advance and recyclable adsorbent for the efficient removal of eosin B: Characterization, equilibrium, and thermodynamic studies

Samimi

Safari

2022

Zn-based TMU-24 as a metal-organic framework (MOF), containing amidefunctionalized pores was prepared by a facile and efficient strategy. The obtained TMU-24 was illustrated to be efficient adsorbents for the eosin B removal from an aqueous solution. Due to their large surface area, stability, tunability, and porosity of the TMU-24, as well as π-π and hydrophobic interactions, hydrogen bonding formation between the dye and the MOF ligands, the fabricated sorbents showed fast adsorption kinetics (9 min) and high adsorption capacity. The effect of important factors such as pH, amount of adsorbent, contact time, and desorption conditions to achieve the optimal removal conditions was investigated. The optimum condition was pH = 6, absorbent dosage 4 mg and contact time 9 min. The adsorption results match with those of the Langmuir model and the pseudo-second-order kinetics, suggesting that eosin B was adsorbed to the adsorbent in monolayers due to its chemical affinity. The maximum adsorption capacity of TMU-24 for the removal of eosin B was 370.37 mg/g. Thermodynamic parameters suggested that the adsorption procedure is spontaneous and exothermic. TMU-24 exhibited excellent reusability (6 cycles) and had potential in the treatment of dyes polluted wastewater.

“…Besides, interaction effects within variables are overlooked and as such, a true optimal point is never attained. To overcome these limitations, several studies have considered the optimization of transesterification reactions using statistical RSM (e.g., central composite design [CCD], Box–Behnken design [BBD]) to maximize the biodiesel yield 31–34 . Hereof, RSM is a vigorous statistical technique for describing the interactions among input parameters with output variables 35,36 .…”

Section: Introductionmentioning

confidence: 99%

Modeling and global optimization of biodiesel synthesis using hybrid response surface methodology‐crow search algorithm: Case study of papaya seed waste oil utilization

Hossain

Sultana

Taher

et al. 2021

Biodiesel is potential renewable and clean energy, which can be produced form wide range of waste materials. This study employs a hybrid response surface methodology (RSM) and crow search algorithm (CSA) as novel tool for global optimization of transesterification reaction parameters to maximize biodiesel synthesis from papaya seed‐derived waste oil. Catalyst (NaOH) dose, methanol to oil molar ratio (M:O), and reaction time were considered independent factors, while biodiesel yield was taken as a dependent variable. The experimentally produced biodiesel was characterized by gas chromatography–mass spectrometry analysis. The experiments were developed based on RSM with Box–Behnken design matrix, which was subsequently used for modeling, optimization and model validation. Initially, a quadratic regression model was developed following RSM technique, correlating the transesterification reaction parameters and biodiesel yield. Afterward, the CSA coupled with RSM approach was employed to assess the global optimization. A highest biodiesel yield of 99.48% was attained with a catalyst (NaOH) dose of 0.5 wt%, M:O of 8.5:1 at a reaction time of 40 min. The results acquired by RSM‐CSA were also compared with the results achieved by desirability function‐based optimization technique. Further, the optimal set for maximizing biodiesel yield was validated experimentally with an error margin of 2.0%. These observations indicate that the hybrid RSM‐CSA is an efficient and economic approach to optimize the process conditions for biodiesel production from alternative sources.