Removal Of Dyes In Wastewater Treatment Research Articles

Chitosan‐Carbon Aerogel for Efficient Removal of Methylene Blue Dye: Synthesis, Characterization, Adsorption Mechanism and Antimicrobial Therapies

AbstractChitosan‐carbon aerogel was synthesized via a facile and eco‐friendly method and characterized for its structural and morphological properties. The composite exhibits remarkable adsorption kinetics and a high potential for removing Methylene Blue (MB) dye, attributed to its enhanced surface area, porous structure, and active functional groups. The adsorption capacity of chitosan‐carbon aerogel increased from 38 to 86.8 mg/g as the pH was raised from 2 to 7. The maximum MB adsorption capacity increased from 22 to 632 mg/g as the initial MB concentration increased from 25 to 2000 mg/L. The saturation adsorption capacity of the chitosan‐carbon aerogel was 668 mg/g. After five reuse cycles, the removal efficiency dropped from 89 % to 73.1 %. Antibacterial tests showed that the width of the inhibition zone for S. enterica was 16.2 ± 0.38 mm, indicating similar antibacterial activity for both chitosan and chitosan‐carbon aerogels. These findings underscore the potential of chitosan‐carbon aerogel as a sustainable and cost‐effective solution for dye removal in wastewater treatment.

Utilization of macadamia nutshell-derived activated carbon for enhanced congo red adsorption

This study addresses the challenge of removing Congo red (CR) from aqueous solutions using activated carbon (AC) derived from macadamia nutshells (MNS). A unique two-step carbonization and pyrolysis process was employed to produce MNS-AC with high surface area and porosity. Key experimental variables, including initial CR concentration, contact time, and pH, were systematically varied in batch mode. Results indicated that the modified AC achieved significantly higher removal percentages compared to unmodified charcoal. At pH 2.0 and an initial dye concentration of 50 mg L−1, CR removal reached 97.48 % for MNS-AC3. The maximum adsorption capacity (qmax) of 58.29 mg g−1 was observed at an initial dye concentration of 200 mg L−1. The pseudo-second-order kinetic model closely matched the experimental data, and equilibrium data analysis using Langmuir and Dubinin-Radushkevich (D-R) isotherm models provided excellent fits. This research demonstrates the potential of using industrial biomass waste to develop sustainable solutions for dye removal in wastewater treatment.

Utilization of Sidoarjo Volcanic Mud as Heterogeneous Catalyst in Persulfate Oxidation Process

Advanced Oxidation Processes (AOP), such as persulfate oxidation is a promising contaminant removal agent for treating wastewater. In this study, Sidoarjo volcanic mud (VM) was applied as heterogeneous catalyst to support the persulfate oxidation process for Congo Red (CR) dye removal. The Sidoarjo volcanic mud is known to have a high iron content, making it a potential catalyst in AOP. This study was conducted under conditions of pH 2, CR 50 mg/L, and catalyst dosage 0.5 g/L and effective reaction volume of 300 mL. This experiment was conducted by comparing three types of catalysts: unmodified volcanic mud (UVM), impregnated volcanic mud (Fe-IVM), and calcined volcanic mud (CVM). The methods were carried out by comparing two methods, namely simultaneous and sequential. The obtained CR removal values for UVM, Fe-IVM, and CVM catalysts were 83.73%, 78.86%, 51.96% for simultaneous and 84.75%, 81.72%, and 87.69% for sequential method. Whereas the UVM catalyst has the highest CR removal value with a lower adsorption value of 16.89%. The production of sulfate radical analyzed by comparing the oxidation process of homogeneous and heterogeneous catalysts. It was shown that the application of VM catalyst as heterogeneous catalyst is very promising for dye removal in wastewater treatment.

Adsorption of methyl red from aqueous solution using Bali cow bones (Bos javanicus domesticus) hydrochar powder

Beef consumption produces a lot of bone waste. Here, We prepared Bali cow bones-based hydrochar material (BCBHP) using the hydrothermal carbonization (HTC) method. The resulting BCBHP material was then characterized using XRD, FTIR, FESEM-EDX, and BET-BJH. Next, the BCBHP was applied to adsorb methyl red in water samples. Adsorption was carried out using a bath system. Adsorption of methyl red persisted optimum for 30 min at pH 6 at 303.15 K, with a capacity of 7.2 mg g−1. The Zeta potential of BCBHP is −24.4 mV suggesting a higher electrostatic attraction between methyl red dye and BCBHP surface. Methyl red adsorption fitted with pseudo-second-order kinetics model. Adsorption of Methyl red dye on BCBHP follows the Freundlich isotherm model and is well described by a heterolayer adsorption pattern. Thermodynamic studies show that adsorption processes are spontaneous, exothermic, and chemisorption reactions. Moreover, BCBHP has an excellent reusability performance that could be used as a promising adsorbent for dye removal in wastewater treatment.

Valorization of spent brewery yeast biosorbent with sonication-assisted adsorption for dye removal in wastewater treatment

The effluent of textile industries containing synthetic dyes contributed to substantial pollution to water bodies. The biosorption process of Congo Red dye was successfully performed by integrating ultrasonication in the adsorption step with spent brewery yeast as a novel and renewable biosorbent. The adsorption process was hindered when ultrasonication was employed together with the biosorbent, indicating that desorption process had occurred. The adsorption process showed that 4 g/L of biosorbent was the optimum dosage for adsorption of 50 mg/L of Congo Red dye, and that the adsorption equilibrium fitted to the Langmuir model, with kinetics best fitted with pseudo-second order model. The maximum capacity of the adsorption was 52.6 mg/g, showing the potential of spent brewery yeast to aid in removing wastewater pollutants. Maximal Congo Red dye recovery (100%) was achieved in the sonication-assisted desorption studies using 0.01M NaOH as the eluting agent. The ultrasonication effects contributed to the efficient recovery of dye and good conversion of spent brewery yeast to biosorbent can be beneficial for treating pollution from textile wastewater.

Hydrothermally engineered Ni–CuC hybrid nanocomposites: Structural and morphological investigations with potential fuel catalytic applications

Increasing travel demand, incomplete combustion of fuel in an engine, vehicle exhaust emissions such as NOx, CO and particular matter and global warming urge the fuel modification methods by using nano additives and alternative fuel. Suitable preparation method, characterization and fuel additive application of nickel-copper-carbide nanocomposite (Ni–CuC NC) have been rarely reported due to lack of research. On this ground, the present research illustrated the synthesis of nickel-copper bimetallic nanoparticles (Ni–Cu BNPs) with copper chloride (CuCl 2 ) and nickel nitrate (Ni(NO 3 ) 2 ·6H 2 O) salt precursors in the presence of sodium hydroxide (NaOH). Followed by the reinforcement of calcium carbide (CaC 2 ) with Ni–Cu BNPs to prepare Ni–CuC nanocomposite via hydrothermal approach. Structural composition and morphological analysis of the Ni–CuC nanocomposite was studied by XRD and SEM respectively. Physical and combustion fuel properties were investigated at 20, 40, 60 and 80 ppm concentration of Ni–Cu BNPs and Ni–CuC nanocomposite respectively for fuel-efficiency. Flash and fire point of diesel fuel in the absence of additives was observed as 78 and 82 °C respectively. Whereas, 80 ppm fuel blend of Ni–CuC and Ni–Cu show a remarkable decrease in flash point up to 69 and 72 °C respectively. The decreasing trend for fire point observed up to 72 and 74 °C respectively. A tremendous recorded decrease in kinematic viscosity was 1.51 and 1.75 m 2 /s with Ni–CuC and Ni–Cu. Ni–Cu BNPs and Ni–CuC nanocomposite in term of fuel efficiency and environment friendly emission could be recognized as potential candidates in diesel. Future work on Ni–Cu BNPs and Ni–CuC nanocomposite as fuel additives for enhancing fuel or biofuel parameters as a photocatalyst for various dye removal in wastewater treatment, as sensing agent in sensing technology as well as for chemical reaction catalysis could be encouraged. • Ni–Cu and Ni–CuC are prepared by fast and low-cost hydrothermal method. • Structural and morphological analysis of Ni–CuC NC was observed with XRD and SEM. • Ni–CuC show better effects on physio-chemical properties of diesel than Ni–Cu. • Ni–CuC blend show decreased flash and fire point values of 70 and 72 °C at 80 ppm. • Ni–CuC decreased the diesel's viscosity up to 1.51 mm 2 /s.

Study on Organic Dye Removal in Wastewater Treatment and Purification Technology Using MgWO4@Carbon Quantum Dot Composite Photocatalyst

Study on Organic Dye Removal in Wastewater Treatment and Purification Technology Using MgWO4@Carbon Quantum Dot Composite Photocatalyst

Porous carbon-based MgAlF5·1.5H2O composites derived from carbon-coated clay presenting super high adsorption capacity for Congo Red

Carbon and clay-based composites have great potential to be applied as sorbents for dye removal in wastewater treatment. Existing sorbent materials suffer from high cost and relatively low capacity. The key to solve this problem is to develop new composites as adsorbents. Here, we report a newly developed porous carbon-based MgAlF5·1.5H2O nanocomposites derived from carbon-coated palygorskite via a single-step HF etching for the first time. Structural and compositional evolution of a series of samples occured by subtly tuning of HF doses. Our results highlight the significantly enhanced adsorption capacity of Congo Red wastewater (4261.0 mg/g), which is approximately 7 and 123 times that of porous carbon (572.0 mg/g) and carbon-coated palygorskite (34.4 mg/g), respectively. The enhanced adsorption property is attributed to chemisorption mechanism between MgAlF5·1.5H2O and Congo Red via two Al atoms binding to two O atoms of the –SO3− group. The corresponding adsorption energy was calculated to be −1.01 eV. In this work, porous carbon-based MgAlF5·1.5H2O adsorbents possess the characteristics of super high adsorption capacity, low cost and no pH dependence, which meets the environmental, economical and engineering requirements for wastewater dye removal, especially, for wastewater treatment under emergency circumstances.

Self-assembled MXene-based nanocomposites via layer-by-layer strategy for elevated adsorption capacities

The chemical modification and organized self-assembly of MXene-based nanocomposites demonstrate critical importance to a wide range of material applications. Herein, we have investigated the preparation of new hierarchical core-shell type MXene-based composite materials for high-efficient dye removal in wastewater treatment via layer-by-layer (LbL) strategy. From the carboxyl functionalization of the MXene material, the negative functional groups were obtained on the surface of the shell composite layer. Carboxyl functionalized MXene materials are immersed in polyimide and polyacrylic acid solution respectively, which leads to formation of shell structure on the surface of MXene layer. Alternating self-assembly processes in the solutions of the polyimide and polyacrylic acid polymers are investigated until the desired number of shell layers is fabricated around MXene layer structures. Finally, the core-shell nanocomposites were characterized by morphological and spectral techniques, demonstrating that the core-shell nanocomposites have more reaction sites and mesoporous structures. The as-obtained core-shell nanocomposites were evaluated with well adsorption capacities via three kinds of dyes. Thus the study of MXene based composites assembled by LbL provides a new choice for the application of MXene composite nanomaterials in wastewater treatment.

Advances in Studies on the Adsorption of Dyes in Wastewater Using Mesoporous Materials

Due to their large surface areas, high pore volumes, relatively even distributions of pore sizes, surfaces enriched with unsaturated groups and orderly long-range structures, the mesoporous materials have been widely applied in industries such as chemical, biomedical, environmental protection and functional materials. In recent years, many scientists have demonstrated that the mesoporous molecular sieves have better adsorption of dyes in wastewater. This paper reviews the applications of different types of mesoporous adsorbents for removal of dyes in wastewater. It also presents the challenges and prospects in using the mesoporous materials for dye removal in wastewater treatment.

Removal of basic dyes from aqueous solution by low-cost adsorbent: Wood apple shell ( Feronia acidissima)

The adsorption of two basic dyes, methylene blue (MB) and crystal violet (CV) on wood apple shell (WAS) were investigated using a batch adsorption technique. A series of experiments were undertaken in an agitated batch adsorber to assess the effect of the system variables such as solution pH, dye concentration and temperature. Removal of dyes was observed to be most effective at higher pH. Freundlich and Langmuir isotherm models were applied to the equilibrium data. The results showed that Langmuir equation fits better than the Freundlich equation. It was observed that the WAS adsorbent showed higher adsorption capacity for crystal violet (130 mg/g) than methylene blue (95.2 mg/g). The FTIR studies indicate that the interaction of dye and WAS surface is via the nitrogen atoms of the adsorbate and oxygen groups of the adsorbent. The adsorption of dyes onto WAS proceeds according to a pseudo-second-order model. Thermodynamic parameters such as free energy (Δ G°), enthalpy (Δ H°) and entropy (Δ S°) were also calculated. The studies show that WAS, a lignocellulosic inexpensive material, can be an alternative to other expensive adsorbents used for dye removal in wastewater treatment.

Physical and chemical regeneration of zeolitic adsorbents for dye removal in wastewater treatment

Natural zeolite and synthetic zeolite, MCM-22, were employed as effective adsorbents for a basic dye, methylene blue, removal from wastewater. Two methods, Fenton oxidation and high temperature combustion, have been used for regeneration of used materials. It is found that MCM-22 exhibits equilibrium adsorption at 1.7 × 10 −4 mol g −1, much higher than the adsorption of natural zeolite (5 × 10 −5 mol g −1) at initial dye concentration of 2.7 × 10 −5 M and 30 °C. Solution pH will affect the adsorption behaviour of MCM-22. Higher solution pH results in higher adsorption capacity. The regenerated adsorbents show different capacity depending on regeneration technique. Physical regeneration by high temperature combustion will be better than chemical regeneration using Fenton oxidation in producing effective adsorbents. Regeneration of MCM-22 by high temperature treatment can make the adsorbent exhibit comparable or superior adsorption capacity as compared to the fresh sample depending on the temperature and time. The optimal temperature and time will be 540 °C and 1 h. The Fenton oxidation will recover 60% adsorption capacity. For natural zeolite, regeneration can not fully recover the adsorption capacity with the two techniques and the regenerated natural zeolites by the two techniques are similar, showing 60% adsorption capacity of fresh sample. Kinetic studies indicate that the adsorption follows pseudo-second-order kinetics.