Novel Wastewater Treatment by Using Newly Prepared Green Seaweed-Zeolite Nanocomposite

Experimental investigation of Cd (II) ion adsorption on surface-modified mixed seaweed Biosorbent: A study on analytical interpretation and thermodynamics

Despite advancements in wastewater treatment technologies, heavy metal contamination, especially cadmium (Cd), severely threatens human health and ecosystems. The purpose of this work is to compare the removal of Cd (II) ions from aqueous solutions by chemically modified mixed seaweed biosorbent (CMSB) and physically modified mixed seaweed biosorbent (PMSB). BET, SEM, EDAX, FTIR, and XRD techniques characterized the mixed seaweed biosorbents before and after adsorption. They are well-known for their sustainability, affordability, and biodegradability. The BET study revealed that CMSB had a surface area of 19.682 m2/g, while PMSB had a lower surface area of 14.803 m2/g. The optimum adsorption conditions were a temperature of 303 K, pH of 6.0, and biosorbent dosages of 1 g/L for CMSB and 2.5 g/L for PMSB. For CMSB and PMSB, the most efficient contact times were 40 and 80 min, respectively. The Langmuir model was demonstrated to be the best fit for the experimental data when compared to other isotherm models, with a coefficient of determination, or R2, of 0.9713 and a maximum monolayer capacity of 151.2 mg/g and 181.6 mg/g for physical and chemical activated mixed seaweed biomass. There was a significant relationship between the R2 values of chemically modified and physically modified biomass. The findings demonstrate that pseudo-second-order kinetics more accurately represent the adsorption process than pseudo-first-order and Elovich models. Thermodynamic experiments validated the endothermic, spontaneous and favourable characteristics of the removal process. According to the results of the current study, PMSB and CMSB may be used as effective adsorbents to remove Cd (II) from aqueous solutions.

Accessible Eco-Friendly Method for Wastewater Removal of the Azo Dye Reactive Black 5 by Reusable Protonated Chitosan-Deep Eutectic Solvent Beads

A novel approach to enhance the utilization of low-cost and sustainable chitosan for wastewater remediation is presented in this investigation. The study centers around the modification of chitosan beads using a deep eutectic solvent composed of choline chloride and urea at a molar ratio of 1:2, followed by treatment with sulfuric acid using an impregnation accessible methodology. The effectiveness of the modified chitosan beads as an adsorbent was evaluated by studying the removal of the azo dye Reactive Black 5 (RB5) from aqueous solutions. Remarkably, the modified chitosan beads demonstrated a substantial increase in adsorption efficiency, achieving excellent removal of RB5 within the concentration range of 25-250 mg/L, ultimately leading to complete elimination. Several key parameters influencing the adsorption process were investigated, including initial RB5 concentration, adsorbent dosage, contact time, temperature, and pH. Quantitative analysis revealed that the pseudo-second-order kinetic model provided the best fit for the experimental data at lower dye concentrations, while the intraparticle diffusion model showed superior performance at higher RB5 concentration ranges (150-250 mg/L). The experimental data were successfully explained by the Langmuir isotherm model, and the maximum adsorption capacities were found to be 116.78 mg/g at 298 K and 379.90 mg/g at 318 K. Desorption studies demonstrated that approximately 41.7% of the dye could be successfully desorbed in a single cycle. Moreover, the regenerated adsorbent exhibited highly efficient RB5 removal (80.0-87.6%) for at least five consecutive uses. The outstanding adsorption properties of the modified chitosan beads can be attributed to the increased porosity, surface area, and swelling behavior resulting from the acidic treatment in combination with the DES modification. These findings establish the modified chitosan beads as a stable, versatile, and reusable eco-friendly adsorbent with high potential for industrial implementation.

Application of zeolite based nanocomposites for wastewater remediation: Evaluating newer and environmentally benign approaches

The presence of heavy metal ions and emerging pollutants in water poses a great risk to various biological ecosystems as a result of their high toxicity. Consequently, devising efficient and environmentally friendly methods to decontaminate these waters is of high interest to many researchers around the world. Among the varied water treatment and desalination means, adsorption and photocatalysis have been widely employed. However, the discussion and analysis of the use of zeolite-based composites as adsorbents are somehow minimal. The porous aluminosilicates (zeolites) are excellent candidates in wastewater treatment owing to various mechanisms of pollutants removal that they possess. The purpose of this review is thus to provide a synopsis of the current developments in the fabrication and application of nanocomposites based on zeolite as adsorbents and photocatalysts for the extraction of heavy metals, dyes and emerging pollutants from wastewaters. The review goes on to look into the effect of weight ratio on photocatalyst, photodegradation pathways, and various factors that influence photocatalysis and adsorption.

Polyaniline/Glauconite Nanocomposite Adsorbent for Congo Red Dye from Textile Wastewater

Glauconite (Gl), a naturally occurring clay material, was utilized as an affordable and ecologically friendly adsorbent to explore its capturing capacity towards Congo red (CR) dye from textile industrial waste effluent. To improve adsorption and removal effectiveness, a modification technique utilizing polyaniline (PAN) was investigated. An X-ray diffractometer (XRD), a scanning electron microscope (SEM), and Fourier transformer infrared (FTI-R) were applied as strong familiar characterization techniques for all used adsorbents. The effects of starting concentration, contact duration, adsorbent dose, pH, and temperature on the adsorption process were also studied. The reusability of the adsorbent was studied over four adsorption cycles. The results show that PAN modification of Gl enhances the effectiveness of CR elimination. The clearance efficiency of raw and modified glauconite at 25 °C and pH 7 was 77% and 91%, respectively. The kinetics and isotherms of Congo red dye adsorption were investigated using batch studies to determine the impacts of various experimental conditions. The maximum adsorption capacity of the glauconite/polyaniline (Gl/PAN) nanocomposite rose from 11.9 mg/g for Gl to 14.1 mg/g in accordance with the isotherm analysis, which shows that the Langmuir isotherm properly characterizes the experimental data. The pseudo-second-order model (R2 = 0.998) properly expresses the experimental data. The reusability research proved that the adsorbents may be reused effectively. The overall results suggest that the modified Gl by PAN might be used as a low-cost, natural adsorbent for eliminating CR color from textile effluent.

Adsorption Mechanism and Electrochemical Characteristic of Methyl Blue onto Calcium Ferrite Nanosheets

A rapid combustion process was applied to prepare CaFe2O4 nanomaterials using CaBr2·xH2O and Fe(NO3)3·9H2O as raw materials and CaFe2O4 nanomaterials were characterized by SEM, TEM, VSM, XRD, and FTIR techniques. The results showed that the prepared nanomaterials had a sheet-like structure, and for larger adsorption capacity of dyes, CaFe2O4 nanosheets prepared at 700°C for 2 h with average grain size was 93.3 nm, a thickness of 8.4 nm, and the saturation magnetization of 8.15 emu/g were employed as adsorbate for the removal of methyl blue (MB). The adsorption performance of MB onto CaFe2O4 nanosheets was investigated; CaFe2O4 nanosheets displayed favorable adsorption capacity, and the adsorption conformed to the pseudo-second-order model and the Freundlich model, which demonstrated that the adsorption process of MB on CaFe2O4 nanosheets belonged to multilayer chemisorption process. When the pH value reached 3, the adsorption capacity of MB by CaFe2O4 nanosheets kept maximum value of 478.07 mg/g; and after 5 regenerations, the removal efficiency of MB was reduced to 59.06% of the first time. The electrochemical behavior of MB onto the nanosheets was evaluated through CV in conjunction with EIS. The CaFe2O4 nanosheets revealed a promising prospect for the adsorption of dyes.