Adsorption of Direct Red 23 dye from aqueous solution by means of modified montmorillonite nanoclay as a superadsorbent: Mechanism, kinetic and isotherm studies

Seyedeh Mahtab Pormazar,Arash Dalvand 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.12

A novel adsorbent of modified nanoclay was synthesized by covering of alum on the montmorillonite nanoclay (Al/nanoclay). Al/nanoclay was applied as an efficient superadsorbent to remove Direct Red 23 (DR23) from colored wastewater. The adsorbent was characterized by Fourier transform infrared spectroscopy, energy-dispersive Xray spectroscopy, and zeta potential analysis. The effects of various operating parameters, such as contact time, initial dye concentration, adsorbent dose, pH and ionic strength on the performance of adsorption, have been studied. The adsorption experiments showed that pH has an obvious effect on the adsorption efficiency and the highest percentage of DR23 dye removal was observed at pH 2. Zeta potential measurement confirmed that the adsorption mechanism is ascribed to electrostatic interaction between sulfonic groups of the anionic dye and the positive surface charge of the adsorbent. The pseudo-second-order kinetic model and the Langmuir isotherm were found to best describe the DR23 adsorption and the maximum monolayer adsorption capacity at the conditions of pH 2 and the adsorbent dose of 0.05 g/L was 2,500mg/g. The findings recommend that Al/nanoclay can be successfully used for DR23 dye removal from the colored wastewater.

Modeling of heterogeneous fenton process using catalyst produced from date palm waste for dye removal: Catalyst characterization and process optimization

Moslemi Faeze,Ehrampoush Mohammad Hassan,Mehralian Mohammad,Dalvand Arash 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.11

This study evaluated the efficiency of the heterogeneous Fenton process using magnetic activated carbon catalyst produced from date palm waste in removing direct dye from aqueous solutions. The experimental runs and optimal conditions for the effect of contact time, solution pH, catalyst dose, and persulfate dose were determined based on the Box-Behnken design under response surface methodology (RSM). FTIR, FESEM, XRD, EDS, BET, and VSM analyses were used to investigate the characteristics of the catalyst. The analysis of variance (ANOVA) verified that the selected statistical model with R2 0.95, p-value<0.0001, and F-value 58.67 was significant. The results of optimal conditions showed that at a dye concentration of 50 mg/L, catalyst dose 0.96 g/L, persulfate dose 9.7 mM, pH 7 and contact time 84 min, maximum removal efficiency of DR80, DB80, DBw103 and COD was 92.69, 97.07, 73.85, and 60%, respectively. After five cycles of catalyst regeneration, the results showed that the catalyst could be utilized several times effectively for dye removal.

Application of photoelectro-fenton process modified with porous cathode electrode in removing resistant organic compounds from aquatic solutions: modeling, toxicity and kinetics

Reza Ali Fallahzadeh,Mohammad Hassan Ehrampoush,Mohsen Nabi Meybodi,Mohammad Taghi Ghaneian,Arash Dalvand,Fariborz Omidi,Mohammad Hossein Salmani,Hossien Fallahzadeh,Amir Hossein Mahvi 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.6

The presence of antibiotics in the environment as persistent micropollutants, due to their widespread consumption, has increased the concerns about the harmful effects of these compounds on human and animal health. Advanced oxidation processes are one of the most effective methods to remove these types of organic pollutants. In this study, amoxicillin (AMX) removal in a modified photoelectro-Fenton (PEF) reactor in which porous stainless steel was used as a cathode electrode, and the ability of air injection into its center to produce H2O2 was investigated. A graphite anode electrode equipped with iron rings was used to increase the electrochemical reaction surface and produce iron ions. The effect of current density, time, and electrolyte concentration on AMX removal efficiency was evaluated by Box-Behnken design method. Subsequently, the effect of AMX concentration variable and pH on removal efficiency was investigated. Finally, the chemical oxygen demand (COD) removal efficiency, toxicity, and effluent activity from the PEF reactor were investigated. The results showed that the modified photoelectro-Fenton process could have efficiency of 99% to remove AMX, in 20min using current density of 36 mA/cm2 and 16mM/L electrolyte concentration. Reducing pH and AMX concentration increased the removal efficiency. The PEF process can completely remove the COD in 58 min. Also, toxicity studies indicated an effective reduction in the effluent. This modified reactor improves the efficiency of the PEF process, which, in addition to the 99% removal of AMX, provides a proper function for COD removal, reducing the toxicity properties of the effluent.

Application of photo-electro oxidation process for amoxicillin removal from aqueous solution: Modeling and toxicity evaluation

Reza Ali Fallahzadeh,Amir Hossein Mahvi,Mohsen Nabi Meybodi,Mohammad Taghi Ghaneian,Arash Dalvand,Mohammad Hossein Salmani,Hossien Fallahzadeh,Mohammad Hassan Ehrampoush 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.5

The recent increase in the global consumption of antibiotics has led to faster entry of these pollutants into the environment as well as an increase in public concern about its impact on ecosystem and human health. Generally, due to high toxicity of antibiotics, biological methods are not used to treat these pollutants; therefore, advanced oxidation processes are recommended to treat and reduce the toxicity of the wastewater. In this study, we evaluated the efficacy of photo-oxidation (P) and electro-oxidation (E) processes in the removal of amoxicillin (AMX) from wastewater, either as integrated or separate processes. Moreover, the effect of variables, including current density (2-100 mA/cm2), reaction time (2-120 min), and electrolyte concentration (100-1,000mg/l) on antibiotic removal efficiency were investigated by Box Behnken design under response surface methodology, and optimal conditions were determined for pollutant removal. Then, the effect of AMX concentration and pH variables on the removal efficiency was investigated. The COD removal efficiency was also evaluated under optimal conditions, and eventually the toxicity and bioavailability of the effluent from the combined Photo-Electro oxidation process (PE) were examined. The optimal conditions for variables, including current density, reaction time, and electrolyte concentration for removal efficiency of 62.4%, were 94 mA/cm2, 95 min and 997mg/l, respectively. Investigating the Amoxicillin and pH variables showed that by reducing the contaminant concentration and pH, the antibiotic removal efficiency increased. The toxicity and bioavailability of the final effluent show the reduction of both parameters in the PE reactor effluent. The PE process can provide an appropriate function to reduce the toxicity and antibacterial properties of effluent by removing more than 60% of amoxicillin and 30% of COD from wastewater.

Application of amine-functioned Fe3O4 nanoparticles with HPEI for effective humic acid removal from aqueous solution: Modeling and optimization

Seyedeh Mahtab Pormazar,Mohammad Hassan Ehrampoush,Mohammad Taghi Ghaneian,Mehdi Khoobi,Parvaneh Talebi,Arash Dalvand 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.1

Humic acids are one type of natural organic matter and precursors of chloro organic compounds that cause a major problematic issue for water treatment plants. In the present study, Hyperbranched polyethylenimine (HPEI) was grafted onto Fe3O4 nanoparticles for HA adsorption from aqueous solution. Fe3O4@HPEI nanoparticles were characterized via TEM, SEM, FTIR, XRD, VSM, and BET analysis. The effects of various operational parameters including initial HA concentration, pH, adsorbent dose, contact time and ionic strength on the HA removal were assessed. According to the obtained statistical model, the optimal condition was acquired at the initial HA concentration 79mg/L, adsorbent dose 0.128 g/L, pH 3 and contact time 29 min, which up to 97.27% HA were adsorbed by Fe3O4@HPEI that was close to the predicted result by the model (95.6%) that confirmed the validity of the selected model. The adsorption data were fitted to the pseudo-second-order kinetic and Freundlich isotherm. Thermodynamic parameters indicated that the adsorption process was spontaneous and endothermic. The fabricated Fe3O4@HPEI nanoparticles could be repeatedly utilized as a suitable adsorbent to remove HA from the aqueous environment.