Dye Wastewater Treatment Research Articles

Hybrid O3/UV/Fe process using rebar flakes waste for removal of congo red dye in wastewater

In Indonesia, textile is one of the labour-intensive industries that makes an important contribution to the national economy sectors. This industry tends to develop rapidly to meet domestic and export needs. This phenomenon increases wastewater generation from the textile industry. Textile wastewater contains dyes that are designed to be durable to resist sunlight and washing process. These properties pose a challenge to the treatment of dye wastewater. The complex structure of dye molecules is generally difficult to degrade by conventional biological processes, while the physical-chemical precipitation process will generate hazardous sludge. Therefore, alternative treatment processes for dye removal are urgently required. In this work, ozonation (O3), ozone and ultraviolet (O3/UV), and catalytic ozone coupling with ultraviolet (O3/UV/Fe) processes were tested for decolourisation of synthetic Congo red dye wastewater. Laboratory assays were carried out under various operating conditions: pH (3-7); ozonation mode (continuous, sequential); and catalyst dose (0.5-2 g/L). Ozonation in sequential mode and the utilisation of rebar flake waste from building construction project as iron catalyst presents a degree of novelty in this work. Congo red decolourisation up to 97% was achieved in less than one-hour of reaction by the continuous O3 process. Mineralisation in terms of COD reduction (50%) can be increased by either performing ozonation in sequential mode (79%) and coupling with UV irradiation (86%). Nevertheless, the effect of the iron catalyst was found to be negligible.

The Study on the Novel Complex Structure and Photocatalytic Degradation Ability of Manganese

The vigorous development of the dye industry has led to increasingly serious harm to the water environment. Currently, dye wastewater has become one of the most difficult industrial wastewater to degrade. Therefore, how to treat dye wastewater in a green and economical manner is receiving increasing attention. Photocatalytic technology has attracted much attention in the treatment of dye wastewater due to its advantages such as fast speed, no selectivity, and complete degradation. However, the current application of traditional photocatalytic materials is greatly limited due to the high recombination rate of photo generated charge carriers and the difficulty in separating and recovering powder catalysts. Therefore, it is of great significance to study the preparation and application of visible light response catalysts with high catalytic activity. The structure of the complex was characterized by X-ray single crystal diffractometer, and the manganese complex was determined by UV and IR spectroscopy, which was then used for the photocatalytic degradation of methyl orange solution.

Hybridization of magnetic MOF composites with 3D terminal carboxyl hyperbranched polymers for dye wastewater treatment

A novel adsorbent obtained by hybridization of magnetic MOFs with three-dimensional terminal carboxyl hyperbranched polymers to achieve efficient dye removal.

Preparation of a CPVC composite loose nanofiltration membrane based on plant polyphenols for effective dye wastewater treatment.

The textile industry's high-salinity wastewater presents a significant difficulty for fractioning salts and dyes. To fractionate the dyes and salts, a high-performance CPVC composite loose nanofiltration membrane (LNM) was fabricated by interfacial polymerization. The organic phase was obtained by crosslinking polyethylenimine (PEI) with tannic acid (TA) and gallic acid (GA) using TMC. The resultant composite LNM performance was enhanced by adjusting the coating parameters, which included TA and GA concentrations as well as coating time. The study examined the effects of the total content of TA/PEI and GA/PEI concentrations on the chemical structure, surface roughness, and microstructure of the selective layer of LNM using SEM, AFM, FTIR, and water contact angle measurements. It also investigated the filtration performance of the membrane's selective layer, including pure water flux, PEG800 rejection rate, and membrane fouling analysis. However, the resultant membrane treated simulated reactive black 5 (RB5) dye wastewater. When the total content of TA/PEI is 4 kg L-1, the permeability of pure water flux is high at 7.5 L per m2 per h per bar when the total content of GA/PEI is 14 kg L-1 and the pure water flux is high at 8.8 L per m2 per h per bar. The overall PEG800 rejection rates were 97-98.98%. The optimal TA : PEI ratios reached a good pure water permeability up to 6.4 L per (m2 per h per bar) with a high rejection rate of 99.69% for a ratio 1/3 to dye, and GA : PEI ratios reached a good water permeability at 5.5 and 6.5 L per (m2 per h per bar) with rejection rates of 99.21% and 98.88% for ratio 1/3 and 3.5/10.5 for simulated RB5 dye, and the NaCl retention rate gradually decreased from 4% to 3%. The resultant LNM demonstrated promising applications in dye and salt fractionation.

Dyes Wastewater Treatment Technology

Dyes Wastewater Treatment Technology

Intermolecular interactions in mixed dye systems and the effects on dye wastewater treatment processes.

Dye wastewater discharge is a critical concern across textiles, paper, cosmetics, and other industries. This study explores the impact of dye-dye interactions on chemical coagulation and ultrafiltration process. Using basic and reactive dyes, representing cationic and anionic compounds, the intricate interplay between these dyes was examined through spectroscopic analysis. Remarkably, interactions between dyes of opposite charges exhibited significant effects on both techniques. Electrostatic attractions played a key role. Positive coagulant hydrolysates selectively attracted negative dyes, while negatively charged membranes effectively captured positive dyes. Combining dyes with opposite charges resulted in enhanced removal efficiency, addressing challenging dyes collectively. This discovery offers a novel approach to improving dye removal, utilizing opposite-charged dye mixtures can tackle stubborn dyes unmanageable by conventional methods.

Carbon dots as potential candidate for photocatalytic treatment of dye wastewater.

Water is the utmost important element for the existence of life. In recent decades, water resources have become highly contaminated by a variety of pollutants, especially toxic dyes that are harmful to both living beings and environment. Hence, there is an urgent need to develop more effective methods than traditional wastewater treatment approaches for treatment of hazardous dyes. Herein, we have addressed the various aspects related to the effective and economically feasible method for photocatalytic degradation of these dyes employing carbon dots. The photocatalysts based on carbon dots including those mediated from biomass have many superiorities over conventional methods such as utilization of economically affordable, non-toxic, rapid reactions, and simple post-processing steps. The current study will also facilitate better insight into the understanding of photocatalytic treatment of dye-polluted wastewater for future wastewater treatment studies. Additionally, the possible mechanistic pathways of photocatalytic dye decontamination, several challenges, and future perspectives have also been summarized.

A green dye wastewater treatment process: Complex extraction of Telon yellow 4R from dye wastewater and its application in nylon fabric dyeing

AbstractComplex extraction, which has the characteristics of high efficiency and selectivity of chemicals, has unique advantages in dye wastewater treatment. In the paper, a green closed‐loop dye wastewater treatment route for dyeing industry is re‐evaluated by studying the complex extraction and stripping of Telon yellow 4B, and dyeing test of regenerated dye. FT‐IR characteristic peaks of the initial organic phase and the regenerated organic phase are consistent, and the dye can be migrated from the loaded organic phase to the aqueous phase after stripping. The concentration of dye in the aqueous phase and extraction conditions have a significant effect on extraction rate, especially the aqueous‐organic phase ratio and the pH value of the aqueous phase. Meanwhile, the stripping conditions have a marked impact on stripping rate, among which NaOH dosage is an important factor. The regenerated dye solution and the freshly prepared dye solution at same concentration have the same color shade and K/S value, and the color fastness of dyed fabrics is all above Grade 4. High extraction rate, high stripping rate, excellent reusability of regenerated organic phase, and the dyeing performance of the regenerated dye prove that complex extraction is a green dye wastewater treatment process with the practical feasibility.

Z-Scheme heterojunction WO3/ZnIn2S4 solar absorber for wastewater remediation

Z-Scheme heterojunction, recognized as one of the optimal methods for the separation of electrons and holes, is extensively applied in the domain of photocatalytic. Leveraging the Z-Scheme heterojunction for photocatalytic and solar interfacial water evaporation presents a promising solution for the purification of dye wastewater and the mitigation of organic pollutant accumulation on traditional solar absorbers. In this study, WO3/ZnIn2S4 heterojunction was synthesized through a two-step solvothermal method, and resulting WO3/ZnIn2S4, which rested on a flexible substrate Ti mesh, possessed the dual functionality of interfacial water evaporation and photocatalytic treatment of dye wastewater, which not only water evaporation rate for WO3/ZnIn2S4 reached 1.26 kgꞏm−2ꞏh−1 but also the Z-Scheme heterojunction WO3/ZnIn2S4 empowered it to effectively degrade dye wastewater, with a degradation rate of Rhodamine B up to 98.6%. The harmonization of these two functionalities effectively circumvented the issue of secondary pollution commonly associated with dye wastewater treatment. This study effectively integrates photocatalysis into a cutting-edge solar-driven interfacial evaporation system, effectively expanding the capabilities of a multifunctional solar absorber and introducing novel applications for zero-discharge dye wastewater treatment.

AKILLI MALZEMELER VE İLERİ BİYOMEDİKAL UYGULAMALARI: HNT VE HNT-POLİMER KOMPOZİTLERİ

The aluminosilicate clay minerals (Al2Si2O5(OH)4·nH2O) known to exist in nature are called halloysite nanotubes (HNTs). HNTs, which are found in layered, spherical, flat and other forms, can be obtained naturally as well as synthetically. HNTs with an outer diameter of 50 nm and a length ranging from 500 to 1000 nm have a hollow and nanotube-shaped structure. It has natural deposits in Brazil, Turkey, New Zealand, China, the United States, Korea, Japan, and France, and it is a low-cost material that can be obtained through ore purification. Thanks to their high surface area, large pore volume, rheological properties, high interactions, and high binding capacities with biopolymers, HNTs are used in a wide range of areas. For example, HNTs have become a frequently used material in environmental applications such as wastewater treatment and removal of organic contaminants and dyes. It is also used in the production of nanoelectronics and nanocomposites, catalytic studies, flame retardants in make-up materials, forensic sciences and biomedical fields. The specific properties of HNT used in the biomedical field lead to numerous applications. In this review, it is aimed to present the advantages of HNTs for use in drug delivery systems, immune therapy, anti-infection applications, cancer therapy, bioimaging, biosensing applications, tissue engineering applications, implants and hygiene-cosmetics materials.

A green cross-linking method for the preparation of renewable three-dimensional graphene sponges for efficient adsorption of Congo red dye

Graphene-based materials possess significant potential for the treatment of dye wastewater due to their exceptional adsorption properties toward stubborn pollutants. However, their utilization is hindered by high preparation costs, low yields, environmental pollution during synthesis, and challenges in regenerating the adsorbent. This study proposes a novel approach to address these limitations by developing nitrogen-doped three-dimensional (3D) polyvinyl alcohol cross-linked graphene sponges (N-PGA) using a cross-linking method with ammonium carbonate. This method offers a relatively mild and environmentally friendly approach. Ammonium carbonate serves as both a reducing and modifying agent, facilitating the formation of the intrinsic structure of N-PGA and acting as a nitrogen source. Meanwhile, polyvinyl alcohol (PVA) is utilized as the cross-linking agent. The results demonstrate that N-PGA exhibits a favorable internal 3D hierarchical porous structure and possesses robust mechanical properties. The measured specific surface area (BET) of N-PGA was as high as 406.538 m2·g–1, which was favorable for its efficient adsorption of Congo red dye molecules. At an initial concentration of 50 mg·L–1, N-PGA achieved an impressive removal rate of 89.6% and an adsorption capacity of 112 mg·g–1 for Congo red (CR) dye. Furthermore, it retained 79% of its initial adsorption capacity after 10 cycles, demonstrating excellent regeneration performance. In summary, the synthesized N-PGA displays remarkable efficacy in the adsorption of CR dye in wastewater, opening up new possibilities for utilizing 3D porous graphene nanomaterials as efficient adsorbents in wastewater treatment.

Magnetic photocatalytic nano-semiconductors prepared from carbon quantum dots compounded with copper ferrate and their application in dye wastewater treatment

To investigate new and potent photocatalytic materials for organic pollutants, in this work, copper ferrate (CuFe2O4) nanoparticles were synthesized by sol-gel combustion method and then combined with the microwave synthesis method to prepare CQDs/CuFe2O4, which was used for the degradation of methylene blue (MB) dye. Firstly, scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence spectroscopy (PL), UV–visible diffuse reflectance spectroscopy (UV–vis DRS), and electrochemistry were employed to validate the composite effect of CQDs/CuFe2O4. The MB removal (99.86%) was maximized under the optimal conditions (1.5% CQDs/CuFe2O4, 10 mg/L, pH 7.0). Meanwhile, the recycling performance after magnet adsorption and recovery and the effects of carbon quantum dots (CQDs) dosing (0.5% ∼ 3%), dye concentration (10 mg/L ∼ 30 mg/L), and pH (3.0 ∼ 11.0) on the degradation of MB dye by the CQDs/CuFe2O4 system were comprehensively investigated. Finally, based on the findings of the free radical scavenging experiments, the photocatalytic mechanism is proposed that the high catalytic activity of CQDs/CuFe2O4 is owed to its high specific surface area, narrow bandgap, and multiple active sites. On account of the introduction of the CQDs, the rate of electron mobility is improved and carrier complexation is reduced. In conclusion, the present work provides an effective photocatalytic system for removing organic pollutants by CQDs/CuFe2O4 composites at room temperature under neutral conditions.

Electricity generation and oxidoreductase potential during dye discoloration by laccase-producing Ganoderma gibbosum in fungal fuel cell

Color chemicals contaminate pure water constantly discharged from different points and non-point sources. Physical and chemical techniques have certain limitations and complexities for bioenergy production, which motivated the search for a novel sustainable production approaches during dye wastewater treatment. The emerging environmental problem of dye decolorization has attracted scientist's attention to a new, cheap, and economical way to treat dye wastewater and power production via fungal fuel cells. Ganoderma gibbosum was fitted in the cathodic region with laccase secretion in the fuel cell. At the same time, dye water was placed in the anodic region to move electrons and produce power. This study treated wastewater using the oxidoreductase enzymes released extracellularly from Ganoderma gibbosum for dye Remazol Brilliant Blue R (RBBR) degradation via fungal-based fuel cell. The maximum power density of 14.18 mW/m2 and the maximum current density of 35 mA/m2 were shown by the concentration of 5 ppm during maximum laccase activity and decolorization of RBBR. The laccase catalysts have gained considerable attention because of eco-friendly and alternative easy handling approaches to chemical methods. Fungal Fuel Cells (FFCs) are efficiently used in dye treatment and electricity production. This article also highlighted the construction of fungal catalytic cells and the enzymatic performance of fungal species in energy production during dye water treatment.

Preparation and characterization of Ag3PO4@g-C3N4 photocatalysts for dye wastewater treatment under visible-light irradiation

Ag3PO4@g-C3N4 photocatalyst was successfully prepared via a workable liquid phase deposition strategy. The Ag3PO4 particles were anchored intimately on the surface of g-C3N4 by the chemical bonding interactions. The obtained Ag3PO4@g-C3N4 heterojunction catalysts exhibit outstanding enhanced photodegradation performance and good stability for the removal of organic pollutants rhodamine B (RhB) and methyl orange (MO). And the as-synthesized Ag3PO4@g-C3N4 also displayed excellent stability for the photodegradation activity of RhB and MO in wastewater, and the performance remained above 90% after six cycles. The significant improvement of photocatalytic performance is attributed to the hereojunction structures derived from the interaction between Ag3PO4 and g-C3N4. The mechanism of the photocatalytic removal of RhB and MO dye was also investigated by the capture experiments and ESR spectra. Based on the research results, a new simple and feasible way for the preparation of Ag3PO4@g-C3N4 photocatalyst is provided for the degradation of organic pollutants in wastewater.

In situ bridges of nano-titanium dioxide constructed in MXene self-cleaning loose nanofiltration membranes for dye wastewater treatment

It has been a longstanding problem to combat the oxidation process of MXene membranes. Here, we propose a strategy to construct nano bridge defect repair loose nanofiltration membrane with the help of MXene oxidation. The oxidation kinetics of Ti3C2Tx was investigated in both model and experimental aspects. The acid solution leads to aggregation and smaller d-spacing. However, the oxidation of MXene was accelerated in alkaline solution via reaction with hydroxyl anions resulting in a hydrophilic MXene membrane surface. The water permeability of the pH = 12-Ti3C2Tx membrane increased to a maximum value of 26.5 L·m−2·h−1·bar−1 together with a high rejection (98 %) of Janus green B (JGB). Titanium dioxide, which was in situ formed by oxidation of MXene, gives the membrane self-cleaning properties under UV light. The water recovery ratio was as high as 96.6 %. To further study the mechanism of in situ oxidation of MXene to form nano-titanium dioxide, the oxidation stages were analyzed which revealed that the in-situ oxidation process involved three different oxidations stages. This research offers a new perspective on MXene membrane design, paving the way for a new method of in situ nano bridge defect repair loose MXene nanofiltration membrane.

Room-temperature aqueous synthesis of MOF-808(Zr) for selective adsorption of dye mixtures

ZrIV-based metal–organic frameworks (MOFs) featuring distinguished water stability, large surface area, and intriguing functionalities have immense potential for practical usage. However, conventional MOF synthesis approaches generally require high reaction temperatures and organic solvents to initiate and template the nucleation and growth, hindering sustainable and cost-effective manufacturing and application of Zr-based MOFs. In this study, a scalable, room-temperature and aqueous synthesis of MOF-808—a Zr-MOF extensively explored as an adsorbent in both academic and industrial sectors—was reported. A rational use of water/formic acid (FA) as a green co-solvent enabled the formation of Zr6-cluster in an aqueous phase, thereby facilitating subsequent coordination with H3BTC to yield well-crystallized MOF-808. The effects of the water/FA volume ratio, the total solvent volume, and reaction time on the physicochemical properties of MOF-808 were studied. The optimized synthesis conditions (FA/water = 2.7:8.1, and reaction time = 24 h) resulted in the synthesis of MOF-808 with good hydrophilicity, excellent stability, high surface area, and weak positive charges. Moreover, this synthesis approach was successfully upscaled, yielding 11.5 g of MOF-808 at a magnification factor of 48. Notably, MOF-808-V10.8 exhibited an impressive adsorption capacity for Congo Red (ca. 1500 mg/g) and demonstrated selective fractionation of dye mixtures, suggesting their potential application in dye wastewater treatment. This methodology is expected to provide guidance for aqueous and scalable fabrication of Zr-MOFs towards water-related environmental applications.

Electrocatalytic Degradation of Rhodamine B on the Sb-Doped SnO2/Ti Electrode in Alkaline Medium.

To realize efficient electrocatalytic degradation of organic compounds in alkaline wastewater, an Sb-doped SnO2/Ti electrode was fabricated and employed for the removal of Rhodamine B (RhB), and the electrocatalytic oxidation performance of this electrode was assessed in an alkaline medium. In an alkaline solution (pH 11), the complete fading of 50 mg·L-1 RhB could be achieved after 150 min of degradation, the removal efficiency of the chemical oxygen demand reached 56.1% at 300 min, and the degradation process of RhB followed the pseudo-first-order kinetic model very well. Under the attack of hydroxyl radicals, partial RhB was degraded to low-molecular-weight organic acids through N-demethylation and the destruction of the conjugated chromophore. Various techniques including scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and cycle voltammetry were used to examine the changes in the morphology and structure, as well as the activity of the Sb-doped SnO2/Ti electrode before and after use. The Sb-doped SnO2/Ti electrode could be reproduced in batches, and each electrode was reused up to eight times without a significant decrease in degradation ability; the leaching amount of antimony was significantly lower than the national emission standard. The electrocatalytic oxidation of the dye wastewater sample was also performed with the desired results, indicating that electrochemical oxidation is a very promising technology for the treatment of alkaline dye wastewater using a Sb-doped SnO2/Ti electrode.

Properties and Mechanism of Fe–Cu–AC Microelectrolysis for Treatment of Typical Dye Wastewater

Properties and Mechanism of Fe–Cu–AC Microelectrolysis for Treatment of Typical Dye Wastewater

Prospects of green adsorbent produced from avocado seed via hydrothermal carbonization for treatment of dye wastewater

The adsorption process is a highly effective operational technique for dye removal from industrial wastewater. At present, the commercial adsorbents employed for removing dyes are manufactured via a slow pyrolysis process, which is time-consuming and requires more energy. Hydrothermal carbonization, on the other hand, is a highly efficient alternative method of synthesizing adsorbents that consumes less time and energy while producing effective adsorbents. This study synthesized adsorbents from avocado seeds via hydrothermal carbonization, followed by chemical activation. The adsorption study revealed that the avocado seed adsorbent has the highest color removal of 80 % using 3.5 g/L of adsorbent at acidic pH under optimized conditions. In conclusion, hydrochar from the avocado seed is a potential green adsorbent for the treatment of dye wastewater.

Photocatalytic treatment of landfill leachate using CaTiO3 nanoparticles

Perovskite Calcium titanate (CaTiO3)is a versatile material that can be used in several applications, such as biomedicine, electronic devices, photocatalysis, and wastewater treatment.In this study, CaTiO3nanoparticles were synthesized using the sol–gel method at 600 °C with the help of tetra butyl titanate, calcium nitrate, and citric acid as chelating agents. FESEM and TEM analysis shows the synthesized nanoparticle has particle sizes of less than 26.23 and 23.71 nm respectively with a bandgap of 3.57 eV. By using DTA, TGA, XRD, FESEM, TEM, EDX, and UV–Vis, the thermal, structural, and optical properties were examined. Several studies examined the photocatalytic capabilities of CaTiO3for the photocatalytic treatment of simulated dye solution and wastewater produced by the textile industry. In this study, the CaTiO3 nanoparticles are used in the photocatalytic treatment of landfill leachate. The results are promising, showing a 72 % reduction in chemical oxygen demand (COD),a 43.62 % decrease in colour,a 41.75 % improvement in turbidity, 59.01 % removal of total dissolved solids, and35.71 % removal of NH3-N from the landfill leachate under the optimum condition of 33 W UV irradiation for 8 h at a catalyst dose of 3.33 g/L and a pH of 6. After nano-photocatalytic treatment, the percentages of Cr, Ni, and Zn removed are 52.30 %, 63.46 %, and 87.50 %, respectively.