Removal of methylene blue from aqueous solution using sediment obtained from a canal in an industrial park

Efficient adsorption of tetracycline in aquatic system by thermally-treated sediment

The disposal of dredged sediment is a considerable challenge for environmental protection and resource utilization. In this study, the dredged sediment was thermally-treated to prepare as adsorbent and utilized for tetracycline adsorption. Sediments based adsorbents under different pyrolysis temperature and atmosphere (N₂ and limited oxygen) were obtained and 600 °C and N₂ atmosphere (600AN) exhibited maximum TC adsorption capacity (15.45 mg/g). SEM, N₂ adsorption-desorption isotherm, XRD, FTIR and XPS analysis suggested larger pore volume, relatively higher surface area, effective pore size distribution and abundant surface functional groups were the main reasons. Moreover, the influence of key adsorption parameters, including adsorbent dosage, initial pH, coexisting ions, ionic strength, contact time, initial TC concentration and ambient temperature had also been investigated. Results revealed that TC adsorption by 600AN were more consistent with pseudo-second order kinetic and Freundlich isothermal models. Combined with characterization results, which reasonably inferred that the adsorption mechanisms of 600AN were mainly involved pore-filling effect, hydrogen bonding interaction and π-π EDA interaction. This work has provided a low-cost, high efficiency and promising method for the dredged sediment reduction and resource recovery.

Removal of Methylene Blue Dye from Wastewater Using Periodiated Modified Nanocellulose

The study was focused on the preparation and characterizations of sodium periodate-modified nanocellulose (NaIO4-NC) prepared from Eichhornia crassipes for the removal of cationic methylene blue (MB) dye from wastewater (WW). A chemical method was used for the preparation of NaIO4-NC. The prepared NaIO4-NC adsorbent was characterized by using X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscope (SEM), energy-dispersive X-ray (EDX), and Brunauer–Emmett–Teller (BET) instruments. Next, it was tested to the adsorption of MB dye from WW using batch experiments. The adsorption process was performed using Langmuir and Freundlich isotherm models with maximum adsorption efficiency (qmax) of 90.91 mg·g−1 and percent color removal of 78.1% at optimum 30 mg·L−1, 60 min., 1 g, and 8 values of initial concentration, contact time, adsorbent dose, and solution pH, respectively. Pseudo-second-order (PSO) kinetic model was well fitted for the adsorption of MB dye through the chemisorption process. The adsorption process was spontaneous and feasible from the thermodynamic study because the Gibbs free energy value was negative. After adsorption, the decreased values for physicochemical parameters of WW were observed in addition to the color removal. From the regeneration study, it is possible to conclude that NaIO4-NC adsorbent was recyclable and reused as MB dye adsorption for 13 successive cycles without significant efficient loss.

Valorization of Date Pits as an Effective Biosorbent for Remazol Brilliant Blue Adsorption from Aqueous Solution

In this work, the adsorption of Remazol Brilliant Blue (RBB) over raw date pits (RDPs) as an inexpensive adsorbent has been examined. In addition, all parameters such as the adsorbent mass, solution pH, RDP particle size, RBB initial concentration, and temperature on the adsorption of RBB influencing the adsorption procedure were studied to provide fundamental information of the adsorption equilibrium. The characterization of RDP material is investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). Based on the calculation, the kinetic rate of the adsorption was well modeled by pseudo-second-order and Langmuir isotherm. Surface functional groups of RDP have substantially been influenced by the adsorption characteristics of RBB. The capacity of the adsorption has achieved 105 mg/g and a removal efficiency of 90.4% at 1.5 g/L RDP mass, 40 mg/L initial dye concentration, pH 2, temperature of 328 K, 40 µm particle size, and contact time of 50 min. The capacity of the adsorption could reach 198 mg/g by increasing the ionic strength of RBB solution. Desorption tests showed that RDP adsorbent has the disadvantage of losing efficiency while reusing for many cycles. However, it still abundant and inexpensive. Therefore, RDP can be used as a potential low-cost bioabsorbent for the elimination of RBB from wastewater.

Adsorption Studies on the Removal of Textile Effluent over Two Natural Eco-Friendly Adsorbents

This study investigates the possibility of applying an adsorption process using two abundant natural minerals M1 and M2. Without pretreatment or activation, the adsorbents were used to treat real textile wastewater samples (collected from Fez city, Morocco). As a cost-effective alternative, these materials were characterized by different analyses, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray fluorescence (XRF). Chemical oxygen demand (COD) and biological oxygen demand (BOD) were used to characterize the textile wastewater. Additionally, the influence of operating conditions (contact time, adsorbent dosages, and pH) was evaluated. Results show that the adsorption process takes place quickly, reaching the equilibrium at 90 and 160 min for M1 (88% COD) and M2 (79% COD). Both materials show a higher affinity to Cr (39%) and lower affinity to Cu (28%). A pseudo-second-order kinetic model provides the best fit to the experimental adsorption data. Germination tests indicate a low toxicity after the adsorption process. Performance of both materials was compared with that of other literature studies.

Valorization of Oued Sebou Natural Sediments (Fez-Morocco Area) as Adsorbent of Methylene Blue Dye: Kinetic and Thermodynamic Study

The objective of this study is to evaluate the efficiency of methylene blue removal using Oued Sebou sediments as an adsorbent. The presence of carboxyl functional group demonstrated by infrared (IR) analysis of the sediment favorized the methylene blue (MB) adsorption. Sediment collected from Oued Sebou could remove the most MB molecules at pH 8. The Freundlich model described suitably the adsorption process. The experimental measured enthalpy (ΔH) and entropy (ΔS°) are 118.1 kJ mol−1 and 395.2 J mol−1 K−1, respectively, indicating that the reaction was endothermic with an increase of randomness at the solid/liquid interface during the adsorption. The kinetics of MB adsorption by sediment were adequately fitted to the pseudo-second-order model. Experimental results showed that the adsorption capacity of the methylene blue dye depends on the solution pH, the initial dye concentration, the adsorbent mass, the sediment particle diameter, and the temperature of the reaction medium. The removal efficiency of the MB molecules reaches 100% after 60 minutes under the optimum conditions.

Valorization of Oued Sebou Natural Sediments (Fez-Morocco Area) as Adsorbent of Methylene Blue Dye: Kinetic and Thermodynamic Study

The objective of this study is to evaluate the efficiency of methylene blue removal using Oued Sebou sediments as an adsorbent. The presence of carboxyl functional group demonstrated by infrared (IR) analysis of the sediment favorized the methylene blue (MB) adsorption. Sediment collected from Oued Sebou could remove the most MB molecules at pH 8. The Freundlich model described suitably the adsorption process. The experimental measured enthalpy (ΔH) and entropy (ΔS°) are 118.1 kJ mol−1 and 395.2 J mol−1 K−1, respectively, indicating that the reaction was endothermic with an increase of randomness at the solid/liquid interface during the adsorption. The kinetics of MB adsorption by sediment were adequately fitted to the pseudo-second-order model. Experimental results showed that the adsorption capacity of the methylene blue dye depends on the solution pH, the initial dye concentration, the adsorbent mass, the sediment particle diameter, and the temperature of the reaction medium. The removal efficiency of the MB molecules reaches 100% after 60 minutes under the optimum conditions.