Textile Dyeing Wastewater Research Articles

Mitigating pollutants in textile dye wastewater with Aloe vera (L.) Burm. f. and Abelmoschus esculentus (L.) Moench: A study on treatment efficacy

Textile wastewater, particularly those containing dyes, presents significant threats to environmental quality and human health. This study assessed the efficacy of Aloe vera (L.) Burm. f. and Abelmoschus esculentus (L.) Moench (Okra) in removing pollutants from textile dye effluent collected in Dindigul, Tamil Nadu. The effluent samples were treated with varying doses of phyto-coagulants (0.02 g, 0.04 g, 0.06 g, 0.08 g, 0.10 g, and 0.12 g), as well as isolated polysaccharides from Aloe vera and Okra, to identify optimal strategies for reducing color, Total Dissolved Solids (TDS), and Chemical Oxygen Demand (COD). The findings revealed that the phyto-coagulants, particularly Okra polysaccharides, significantly reduced pollution levels, achieving a 90 % reduction in color, 96 % reduction in TDS, and 82 % reduction in COD. To further understand the mechanism of pollutant removal, GC–MS, FTIR, and Zeta potential analyses were conducted. This study highlights the effectiveness of natural coagulants in mitigating environmental pollution and preventing the entry of harmful chemical contaminants into the food chain. The study supports the potential of Aloe vera and Okra as sustainable and eco-friendly solutions for addressing the environmental challenges posed by textile wastewater pollution.

Comparative treatment of textile dye wastewater with chemical coagulants and bacterial exopolysaccharides

Traces of chemical coagulants, such as alum, commonly used in wastewater treatment, remain in the water effluent and also result in secondary sludge that is difficult to treat. On the other hand, Extracellular Polymeric Substances (EPS) are safer and can be used as alternative bio flocculants. A study was hence done to compare the effectiveness of the treatment of Reactive Black 5 (RB5) textile wastewater with chemical coagulants and bacterial EPS. The jar test method was used to treat the wastewater with Alum and Polyferrous Sulphate (PFS) at varied pH (2–10) and respective dose concentrations. EPS was produced by bacteria isolated from cotton gin trash soil collected from Kitui ginnery in Kenya. EPS treatment was done at 30 °C for 72 h. EPS-producing bacteria isolates were identified by molecular analysis. The chemically and EPS-treated wastewater was analyzed for color, Total Dissolved Solids (TDS), and Chemical Oxygen Demand (COD). Respective color and TDS removal capacity by PFS and alum were (86.1% and 42.18%) and (85.1% and 69%) at their optimal conditions of (pH 7 and 100 mg/L) and (pH 7 and 140 mg/L). Similarly, PFS and alum reduced COD by 27.25% and 26.65%. Respective dye removal by YEAK2 −5 and YEPD K2 −2 EPS was 69.1% and 85.7%. However, YEPD K2 −2 and YEAK2 −5 EPS caused a respective rise of TDS by 40.14% and 67.17%. The respective reduction of COD by YEPD K2 −2 and YEAK2 −5 EPS was 56.25% and 54.24%. The chemically and EPS-treated wastewater met the National Environment Management Authority (NEMA) limits. The YEPD K2 −2 and YEAK2 −5 isolates were both identified as Bacillus sp. GC–MS and FTIR analysis results indicated that the two EPS were heteropolysaccharides composed of different sugar derivatives and hydroxyl as the main functional group. The results for treatment of the dye wastewater by Alum, PFS, and EPS were therefore comparable. The bacterial EPS bio flocculants can therefore serve as effective and cleaner substitutes to the alum and PFS chemical coagulants.

Occurrence and Ecological Risk Assessment of Highly Toxic Halogenated Byproducts during Chlorination Decolorization of Textile Printing and Dyeing Wastewater.

Textile printing and dyeing wastewater is a substantial source of highly toxic halogenated pollutants because of the chlorination decolorization. However, information on the occurrence and fate of the highly toxic halogenated byproducts, which are produced by chlorination decolorization of the textile printing and dyeing wastewater, is very limited. In this study, the occurrence of six categories of halogenated byproducts (haloacetic acids (HAAs), haloacetonitriles (HANs), N-nitrosamines (NAs), trihalomethanes, halogenated ketones, and halonitromethanes) was investigated along the full-scale treatment processes of textile printing and dyeing wastewater treatment plants. Furthermore, the ecological risk of the halogenated byproducts was evaluated. The results showed that the total concentration of halogenated byproducts increased significantly after chlorination. Large amounts of HAAs (average 122.1 μg/L), HANs (average 80.9 μg/L), THMs (average 48.3 μg/L), and NAs (average 2314.3 ng/L) were found in the chlorinated textile wastewater, and the results showed that the generations of HANs and NAs were positively correlated with the BIX and β/α index, indicating that the HANs and NAs might form from the microbial metabolites. In addition, HAAs and HANs exhibited high ecological risk quotients (>1), suggesting their high potential ecological risk. The results also demonstrated that most halogenated byproducts could be effectively removed by reverse osmosis treatment processes except NAs, with a lower removal rate of 18%. This study is believed to provide an important theoretical basis for controlling and reducing the ecological risks of halogenated byproducts in textile printing and dyeing wastewater effluents.

Dual approach in textile wastewater treatment: optimisation and comparison of fluidised-bed and conventional Fenton processes

ABSTRACT This study optimises secondary textile dyeing wastewater removal using fluidised-bed Fenton (FBR-Fenton) and standard Fenton processes for chemical oxygen demand (COD) and colour removal efficiency. The Box–Behnken response surface approach optimised pH, iron ion concentration, and hydrogen peroxide concentration. At pH 3.3, [Fe2+] = 2.6 mm, [H2O2] = 6.4 mm in the fluidised bed reactor with 67 g/L quartz sand, with a 50% bed expansion after 40 min, the FBR-Fenton process removed 75.8% COD and 98.0% colour. The standard Fenton method was tuned to pH 3.2, [Fe2+] = 3.1 mm, [H2O2] = 6.6 mm, and COD and colour removal effectiveness of 69.7% and 97.5%, respectively. FBR-Fenton enhanced COD and total iron removal efficiency, reduced chemicals, and reduced sludge by 28.0% compared to conventional Fenton. This study also showed quartz sand reusability in FBR-Fenton treatment cycles. Experimental results matched response surface model predictions, proving regression equation correctness.

Performance of a novel Built-in Static Magnetic Field – Biological Aerated Filter (BSMF–BAF) for treating high-salt textile dyeing wastewater

High-salt textile dyeing wastewater is difficult to treat. Magnetic fields can enhance the biodegradation capacity and extreme environmental adaptabilities of microorganisms. Thus, magnetically enhanced bioreactors are expected to improve the treatment efficiency and stability of high-salt textile dyeing wastewater. Accordingly, a novel Built-in Static Magnetic Field – Biological Aerated Filter (BSMF–BAF) was constructed and investigated for treating actual high-salt textile dyeing wastewater in this study. Two other BAFs packed with traditional and magnetic ceramsite carriers, respectively, were simultaneously operated for comparison. The removal of color, chemical oxygen demand (COD), suspended solid (SS) and acute toxicity were monitored. The activities of key enzymes and microbial community structure were analyzed to reveal possible mechanisms for improving the treatment efficiency of traditional BAF using the BSMF. The results showed that the BSMF–BAF possessed the highest removal efficiencies of color, COD, SS and acute toxicity among the three BAFs. The BSMF induced significant increases in the activities of azoreductase and lignin peroxidase, which were responsible for the degradation of azo compounds in the wastewater and the detoxification of toxic intermediates, respectively. Additionally, the BSMF induced the relative enrichment of potentially effective bacteria and fungi, and it maintained a relatively high abundance of fungi in the microbial community, resulting in a high treatment efficiency.

Enhanced methylene blue degradation by graphene oxide-encapsulated nano zero-valent iron composites: Optimization, mechanistic insights, and environmental implications

Methylene blue (MB) in textile dye wastewater poses a significant environmental challenge due to its high chemical stability and resistance to biodegradation. This study investigates the use of a novel graphene oxide-encapsulated nano zero-valent iron (GO/nZVI) composite for the efficient and sustainable degradation of MB. The GO/nZVI composite was synthesized via hydrothermal co-precipitation and self-assembly methods and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Under optimized conditions, the composite achieved an impressive 99.99 % degradation of MB within 40 min, demonstrating substantial improvements in stability and reusability. The composite retained over 84.5 % of its catalytic activity after five cycles, underscoring its potential for practical wastewater treatment applications. The optimization of reaction conditions through response surface methodology (Box-Behnken design, BBD) facilitated the formation of a core-shell structure, which significantly enhanced electron transfer and radical generation, crucial for MB oxidation. Radical quenching experiments confirmed hydroxyl radicals (·OH) as the primary active species, and gas chromatography-mass spectrometry (GC-MS) analysis elucidated the degradation pathway. This study presents a scalable and environmentally friendly solution for the treatment of recalcitrant organic pollutants, marking a significant advancement in water purification technologies.

Unleashing the potential of electrooxidation and PVDF/TiO2 photocatalysis for textile dye wastewater treatment

Unleashing the potential of electrooxidation and PVDF/TiO2 photocatalysis for textile dye wastewater treatment

Textile dyeing wastewater negatively influences the hematological profile and reproductive health of male Swiss albino mice

Objective: To determine the effects of textile dyeing industrial wastewater on the hematological parameters and reproductive health including histoarchitecture of male gonad (testes) of mice. Methods: Twenty-four Swiss albino mice at 4-weeks old were divided into four groups (n=6 per group). Mice of group 1 supplied with normal drinking water were served as the control group. Mice of group 2, 3 and 4 were supplied normal drinking water mixed with textile dyeing wastewater at 5%, 10% and 20% concentration, respectively. After completing 24 weeks of treatment, different hematological profile, weight of testes, gonadosomatic index (GSI), sperm concentration and morphology were measured. Moreover, histopathological changes in testes were examined. Results: Hematocrit value and hemoglobin concentrations were decreased in all groups of wastewater-treated mice compared to the control group. Likewise, weight of testes, GSI and sperm concentration were decreased significantly in wastewater-treated mice in comparison to the control group. The percentage of morphologically healthy epididymal sperm was significantly reduced in wastewater-treated mice. Histopathological examination revealed degenerative changes in seminiferous tubules, a smaller number of spermatogenic cells, elongation of seminiferous tubules and degenerative changes of seminiferous tubules in wastewater- treated mice. Conclusions: Textile dyeing wastewater has harmful effects on hematological profile and reproductive health of male mice.

Narrowing Band Gap of Zno Codoping (Al+Mn) as a Photocatalyst Candidate for Degraded Textile Dye Wastewater

Photocatalyst degradation is one method to reduce industrial textile dye pollution in water. In this study, ZnO material has been synthesized by codoping Al and Mn by chemical coprecipitation method to determine the structural properties and optical properties of the material. From this research, it was found that the structure of ZnO after codoping Al and Mn did not change the hexagonal wurtzite phase but changes in other lattice parameters. The addition of Mn and Al codoping is reported to affect the intensity of XRD peaks, especially on the 101 lattice. The higher the scattering peak, the more angular the shift, indicating the magnitude of oxygen vacancies. The reflectance confirms this result that increasing Mn concentration decreases the energy gap to 3.258 eV. From these structural properties and energy gap values, ZnO codoping Al and Mn materials can be included in candidate materials that can be used as photodegradation agents for textile dyes.

Investigating the efficiency of electrocoagulation using similar/dissimilar electrodes for the detoxification of Coralene Rubine dye: a cost effective approach.

Efficient treatment of textile dyeing wastewater can be achieved through electrocoagulation (EC) with minimal sludge production; however, the selection of the appropriate electrode is essential in lowering overall costs. Also, the reuse of the treated aqueous azo dye solution from this process has not been explored in detail. With these objectives, this study aims to treat synthetic azo dye solutions and achieve high colour removal efficiency (CRE%) using similar (Ti-Ti) and dissimilar (Ti-Cu) metal electrodes through EC with an attempt to reduce the cost. The aqueous Coralene Rubine GFL azo dye was used to examine the efficiency and cost of the EC process. X-Ray Photoelectron Spectroscopy was used to study the EC mechanism, while High Performance Liquid Chromatography was used to analyse the degradation of the dye and the formation of intermediate compounds. The concentration of metal ions in the treated dye solution was quantified using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), with Ti-Ti treated solution having 14.20mg/L concentration of Ti and Ti-Cu treated solution having 0.078mg/L of Ti and 0.001mg/L of Cu, respectively. Colour removal efficiency of 99.49% was obtained for both electrode sets, with a lower operating time and voltage for dissimilar metal combination. Ecotoxicity studies showed negligible toxicity of Ti-Cu treated dye samples compared to untreated solutions. Survival rate, protein estimation, and catalase activity was used to validate the treatment method's efficacy. The study found that the dissimilar electrode material exhibited reduced toxicity due to the presence of heavy metals below the permissible limit.

Sustainable green synthesis and characterization of nanocomposites for synergistic photocatalytic degradation of Reactive Orange 16 in textile wastewater using CuO@A-TiO2/Ro-TiO2

This paper explores the photocatalytic degradation of Reactive Orange 16 (RO16) dye in textile wastewater employing a novel CuO@A-TiO2/Ro-TiO2 nanocomposite. The nanocomposite was synthesized via a hydrothermal technique, resulting in a monoclinic phase of leaf-shaped CuO loaded on a hexagonal wurtzite structure of rod-shaped ZnO, as confirmed by FE-SEM and XRD analyses. Optical experiments revealed band gap energies of 1.99 eV for CuO, 2.19 eV for ZnO, and 3.34 eV for the CuO@A-TiO2/Ro-TiO2 nanocomposite. Photocatalytic degradation experiments showcased complete elimination of a 100 mg/L RO16 solution (150 mL) after 120 min of UV light illumination and 100 min of sunlight illumination, emphasizing the nanocomposite's efficiency under both light sources. The study further delves into the application of the CuO@A-TiO2/Ro-TiO2 nanocomposite for the degradation of actual textile wastewater samples under sunlight irradiation. The results underscore the nanocomposite's remarkable efficacy in treating RO16 in textile wastewater, positioning it as a promising candidate for sustainable and efficient wastewater treatment applications. This research contributes valuable insights into the development of advanced photocatalytic materials for textile dye degradation in wastewater treatment.

Enhanced photodegradation of textile dye wastewater using silane/polymer doped ZnO nanocomposites and antibacterial activity

Accumulation of textile dye wastewater is major global issue that causes negative impact to the ecosystem. This study focuses on industrial textile dye effluent treatment by photodegradation, and degradation of Malachite green dye under sunlight, visible and UV light. ZnO demonstrated hexagonal wurtzite structure with average crystallite size 38 nm for ZnO/PEG, 21 nm for ZnO/PEG/VTES and 17 nm for ZnO/PEG/VTMS. Field Emission Scanning Electron Microscopy and Energy Dispersive Spectroscopy revealed nanometer sized particles and purity. Bandgap energy and particle size of ZnO/PEG/VTMS is 102 nm and 3.134 eV is lesser than ZnO/PEG (147 nm, 3.181 eV) and ZnO/PEG/VTES (109 nm, 3.151 eV). Photoluminescence analysis revealed reduced recombination rate of ZnO/PEG/VTMS. Antibacterial efficacy of ZnO/PEG/VTMS was tested against Staphylococcus aureus (35 mm) and Escherichia coli (29 mm). Photodegradation of textile dye wastewater by ZnO/PEG/VTMS under visible and UV light exposure revealed an effective way for textile dye effluent treatment, which maintained its efficiency even after five photodegradation cycles.

Electrochemical degradation of small molecule dyes by TiO2-decorated polyacrylonitrile nanofiber membranes with superior properties

To optimize the uniform dispersion of nanoparticles and enhance their catalytic degradation effect on small molecule dyes in textile wastewater, titanium dioxide (TiO2) was deposited on polyacrylonitrile (PAN) fiber membranes using magnetron sputtering technology, and TiO2/PAN nanofiber membrane (NFM) with low content and high catalytic efficiency was successfully prepared. Through membrane separation coupling electrocatalysis, the composite membranes exhibited outstanding performance in removing Congo red (CR), Sunset yellow (SY), Methyl orange (MO), and Methylene blue (MB) dyes, with removal rates of 99.5%, 98.8%, 98.5%, and 87.2% respectively. Even after continuous catalysis for 10 h, the composite membranes maintained a high dye removal rate, demonstrating their remarkable stability and water treatment capabilities. Furthermore, TiO2/PAN NFMs displayed high pure water permeance, dye permeance, and mechanical strength. Specifically, M20 (magnetron sputtering time of 20 min) showed water permeance and dye (SY) permeance values of 1944 L·m−2·h−1·bar−1 and 816 L·m−2·h−1·bar−1, respectively, and indicate superior mechanical and electrochemical properties. During the electrocatalytic process, TiO2/PAN NFMs generated reactive oxygen species (ROS) on the surface, imparting a self-cleaning property that extended the service life of the membranes and offered an effective solution for textile wastewater treatment.

Electrocoagulation treatment for Remazol Brilliant Blue R (Reactive Blue 19) removal of textile dye simulated wastewater using iron-aluminum electrodes

Abstract The presence of non-biodegradable dyes, such as Remazol Brilliant Blue R (Reactive Blue 19), in wastewater poses a significant environmental challenge. This study investigates the application of electrocoagulation using iron-aluminum (Fe-Al) electrodes to efficiently remove Reactive Blue 19 dye from simulated textile dye wastewater. It considers various parameters such as electrode material, current, stirring speed, as well as the influence of sodium chloride acting as a supporting electrolyte to enhance conductivity. Additionally, it evaluates the economic feasibility through electrode consumption analysis. The experimental setup involved a designed reactor with aluminum and iron electrodes arranged at bipolar parallel connection, along with a 30-minute electrocoagulation process conducted at ambient temperature and subsequent filtration of the treated wastewater for UV-VIS analysis. The optimal parameter combination obtained consists of Fe-Al electrode material, a 3 A current, and a 200-rpm stirring speed, achieving 96.87% dye removal. Furthermore, extending the operating time to 60 minutes improved the removal by 99.15%. Under these optimal conditions, the energy consumption measured was 36 kWh/m3. The high dye removal rate obtained shows the effectiveness of this electrocoagulation process in treating Reactive Blue 19 simulated wastewater. A t-test, employed as a hypothesis testing technique with a significance level of 0.05, confirmed the optimal levels of the factors and interactions within the treatment process. A remarkable coefficient of determination of 0.9794 in the dye removal sensitivity analysis signifies a strong goodness of fit, indicating that these three (3) parameters collectively explain how they affect the outcome while accounting for dye removal efficiency variation. These results showed that electrocoagulation is a promising technology for treatment of Reactive Blue 19 dye wastewater.

Enhancing the Concentration Capability of Nonsupported Electrically Driven Liquid-Phase Microextraction through Programmable Flow Using an All-In-One 3D-Printed Optosensor: A Proof of Concept.

A versatile millifluidic 3D-printed inverted Y-shaped unit (3D-YSU) was prototyped to ameliorate the concentration capability of nonsupported microelectromembrane extraction (μ-EME), exploiting optosensing detection for real-time monitoring of the enriched acceptor phase (AP). Continuous forward-flow and stop-and-go flow modes of the donor phase (DP) were implemented via an automatic programmable-flow system to disrupt the electrical double layer generated at the DP/organic phase (OP) interface while replenishing the potentially depleted layers of analyte in DP. To further improve the enrichment factor (EF), the organic holding section of the OP/AP channel was bifurcated to increase the interfacial contact area between the DP and the OP. Exploiting the synergistic assets of (i) the continuous forward-flow of DP (1050 μL), (ii) the unique 3D-printed cone-shaped pentagon cross-sectional geometry of the OP/AP channel, (iii) the bifurcation of the OP that creates an inverted Y-shape configuration, and (iv) the in situ optosensing of the AP, a ca. 24 EF was obtained for a 20 min extraction using methylene blue (MB) as a model analyte. The 3D-YSU was leveraged for the unsupervised μ-EME and the determination of MB in textile dye and urban wastewater samples, with relative recoveries ≥88%. This is the first work toward analyte preconcentration in μ-EME with in situ optosensing of the resulting extracts using 3D-printed millifluidic platforms.

Optimization of anionic dye removal using cross-linked chitosan composite as eco-friendly bio-adsorbent

The environmental impact of wastewater discharged from the textile dyeing industry has a significant challenge and influence on aquatic ecosystems and human health if not properly managed. This study aimed to develop a novel cross-linked chitosan composite, denoted as chitosan/fly ash/polyvinyl alcohol (Ch/FA/PVA), as a bio-adsorbent for removing Congo Red (CR) textile dye from industrial wastewater. The synthesis involved the incorporation of FA into the chitosan matrix at various ratios to optimize the process. A specifically tailored composite, Ch/FA0.75/PVA, exhibited superior performance with a remarkable 99.7% CR removal under optimum conditions: adsorbent dose (0.9 g/l), contact time (50 min), and dye concentration (40 mg/l). The characterization of Ch/FA0.75/PVA through SEM–EDX, BET, FTIR, and pHzpc confirmed its suitability for adsorption. Employing Box–Behnken design and analysis of variance (ANOVA) facilitated the optimization of key adsorption variables. The Freundlich model described the adsorption equilibrium, indicating a maximum adsorption capacity of 263.15 mg/g for CR dye. The pseudo-second-order model demonstrated favorable kinetics. The study was scaled up to the practical application of Ch/FA0.75/PVA in a pilot plant for industrial wastewater treatment, revealing substantial removal percentages for dye, color, COD, BOD5 and TDS. This comprehensive approach highlights the promising efficacy of Ch/FA0.75/PVA in addressing environmental concerns associated with textile dye wastewater.

Bioaugmented biological contact oxidation reactor for treating simulated textile dyeing wastewater

In this study, modified polyamide fibers were used as biocarriers to enrich dense biofilms in a multi-stage biological contact oxidation reactor (MBCOR) in which partitioned wastewater treatment zone (WTZ) and bioaugmentation zone (BAZ) were established to enhance the removal of methyl orange (MO) and its metabolites while minimizing sludge yields. WTZ exhibited high biomass loading capacity (5.75 ± 0.31 g/g filler), achieving MO removal rate ranging from 68 % to 86 % under different aeration condition within 8 h in which the most dominant genus Chlorobium played an important role. In the BAZ, Pseudoxanthomonas was the dominant genus while carbon starvation stimulated the enrichment of chemoheterotrophy and aerobic_chemoheterotrophy genes thereby enhanced the microbial utilization of cell-released substrates, MO as well as its metabolic intermediates. These results revealed the mechanism bioaugmentation on MBCOR in effectively eliminating both MO and its metabolites.

The self-boosting ultrafast removal of Cr(VI) and organic dye in textile wastewater through sulfite-induced redox processes

The treatment of textile wastewater containing harmful metal ions poses a significant challenge in industrial applications due to its environmental impact. In this study, the use of sulfite for treating simulated dye wastewater containing New Coccine (NC) and Cr(VI) was investigated. The removal of NC was influenced by the redox reaction between Cr(VI) and sulfite, demonstrating a strong self-boosting effect of Cr(VI) on NC removal. Remarkable NC decoloration (95%) and Cr(VI) reduction (90%) were achieved within 1 min, highlighting the effectiveness of the treatment. Quenching experiments and electron paramagnetic resonance (EPR) technology confirmed that singlet oxygen (1O2) was the main oxidative agent for organic dye removal and SO4•−, •OH and Cr(V) were also identified as key contributors to NC degradation. The Cr(VI)/sulfite system exhibited higher efficiency in degrading azo dyes, such as NC and Congo Red (CR), compared to non-azo dyes like Methylene Blue (MB). This superiority may be attributed to the action of Cr(V) on azo groups. Additionally, the COD removal experiments were conducted on the actual dye wastewater, showing the excellent performance of the Cr(VI)/Sulfite system in treating industrial textile wastewater. This approach presents a promising strategy for effective “waste control by waste”, offering great potential for addressing challenges related to dye wastewater treatment and environmental pollution control in practical industrial scenarios.

Heavy Metal Ion Adsorbent in Aqueous Solution: A Review on Chitosan and Chitosan Composites

One prominent contributor to environmental degradation is the presence of heavy metal ions, which are commonly introduced into ecosystems through diverse channels, including mining operations, paint manufacturing, battery production, and agricultural practises. The unprocessed waste from these industries typically undergoes direct discharge into rivers and seas, thereby adversely influencing the potable water supply and marine ecosystem. This results in the accumulation of heavy metals within living organisms and subsequent environmental degradation that poses a significant risk to human health, as their prolonged consumption can harm various organs and the nervous system. Therefore, the United States Environmental Protection Agency (US-EPA) and the World Health Organisation (WHO) have established stringent regulations regarding the allowable levels of heavy metal intake, particularly concerning potable water consumption. The imperative lies in surmounting this challenge by discovering the optimal technique for extracting heavy metals. This paper examines the primary methods of eliminating heavy metal ions using chitosan-based materials. Specifically, the methods under scrutiny include electrocoagulation (E.C.), bioremediation, ion-exchange, membrane filtration (purification), and adsorption. Adsorption, as a highly efficient method, presents itself as a viable strategy for the remediation of dyes in textile wastewater due to its advantageous characteristics. Notably, this approach obviates the need for extensive spatial requirements and exhibits a commendably swift treatment duration. Chitosan exhibits promising adsorptive characteristics owing to its advantageous physical attributes, including crystalline structure, porous nature, and particle dimensions, all of which synergistically enhance the adsorption capacity of chitosan. Research findings indicate that the adsorption characteristics of chitosan are subject to variation contingent upon the distinct heavy metal ions under consideration and the specific experimental parameters employed. Hence, optimising these parameters becomes imperative to attain enhanced chitosan adsorption capabilities for heavy metal ion removal.

Assessment of the efficacy of Azolla pinnata in improving textile dye wastewater quality at varying concentrations

This in-vitro study scrutinized the efficacy of Azolla pinnata in ameliorating the quality of wastewater emanating from textile dyeing. The investigation centered on three discrete textile dye wastewater concentrations (30%, 60%, and 100%) within a mesocosm environment over five days. Physicochemical parameters, including temperature, pH, electrical conductivity (EC), chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total dissolved solids (TDS), total suspended solids (TSS), turbidity, and salinity, were systematically assessed both prior to and subsequent to the introduction of Azolla pinnata. Significantly, throughout the five-day duration of the experiment, periodic observations were conducted at 24-h intervals, and no pH adjustments were executed. The results demonstrated that Azolla pinnata exhibited optimal efficacy in the treatment involving a 30% concentration of wastewater (designated as T1). The improvements in water quality indicators for this specific treatment (T1) were quantified as follows: 36.84% for pH, 66.67% for BOD5, 55.05% for COD, 53.40% for EC, 46.85% for TDS, 58.60% for TSS, 52.21% for salinity and 76.86% for turbidity. The authors suggest that the utilization of Azolla pinnata in a selective treatment approach demonstrates considerable promise and viability for the phytoremediation of wastewater contaminated with textile dyes.