Treatment Of Textile Effluent Research Articles

Advanced sulfonated polyester nanofiltration membranes for superior dye separation, desalination, and chlorine resistance

This study introduces an innovative thin-film composite (TFC) nanofiltration membrane made from sulfonated polyvinyl alcohol (SPVA)-based polyester, specifically engineered for effective wastewater treatment. This novel membrane is developed through interfacial polymerization on a polysulfone substrate, demonstrating exceptional water permeability and filtration efficiency. It is particularly effective in separating dyes and salts due to its superior hydrophilicity, optimized surface charge, and precisely tailored morphology. Critical fabrication parameters were finely tuned, utilizing a 2 wt% SPVA solution and a 0.35 wt% trimesoyl chloride (TMC) in the organic phase, with both immersion and polymerization times set at 2 min. The performance metrics are outstanding, featuring a water permeance of 97 L m−2 h−1·bar−1, high dye rejection rates (99.51 % for Congo Red and 99.55 % for Brilliant Blue), and significant salt permeability (30.35 % for Na2SO4 and 29.93 % for MgSO4). The membrane also exhibits excellent antifouling properties, robust chlorine resistance (up to 48,000 ppm h), and sustained operational stability, underscoring its industrial viability for dye and textile effluent treatment. The TFC-SPVA membrane addresses critical environmental challenges in wastewater management, marking a significant advancement in membrane technology.

Assessment of textile effluent treatment by immobilized Trametes pubescens MB 89 for plant growth promotion.

Industrialization and the ever-increasing world population have diminished high-quality water resources for sustainable agriculture. It is imperative to effectively treat industrial effluent to render the treated water available for crop cultivation. This study aimed to assess the effectiveness of textile effluent treated with Trametes pubescens MB 89 in supporting maize cultivation. The fungal treatment reduced the amounts of Co, Pb and As in the textile effluent. The biological oxygen demand, total dissolved solids and total suspended solids were within the permissible limits in the treated effluent. The data indicated that the irrigation of maize with fungal-treated textile effluent improved the growth parameters of the plant including root, shoot length, leaf area and chlorophyll content. Moreover, better antioxidant activity, total phenol content and protein content in roots, stems and leaves of maize plants were obtained. Photosynthetic parameters (potential quantum yield, electron transport rate and fluorescence yield of non-photochemical losses other than heat) were also improved in the plants irrigated with treated effluent as compared to the control groups. In conclusion, the treatment of textile effluent with the immobilized T. pubescens presents a sustainable solution to minimize chemical pollution and effectively utilize water resources.

Microfiber prevalence and removal efficiency of textile effluent treatment plants in Bangladesh

Bangladesh is one of the hubs of the textile industry in the world; consequently, microfibers are an emerging threat to the aquatic ecosystem. Traditional effluent treatment plants (ETPs) might not be capable of removing most emerging pollutants like surfactants, dyes, and additives, including microfibers, and the textile industry may be a major source of microfiber pollution through products and ETPs. This study investigated the eleven woven, knit, and denim industries' ETP microfiber abundance and removal efficiency. The average (range) of microfibers found in influent, effluent, and sludge samples was 615.45 ± 377.52 particles/L (170−1460), 212.72 ± 80.14 particles/L (130−380), and 10545.45 ± 7989.54 particles/kg (4400−31000), respectively. The abundant shape was fiber, and most microfibres had sizes between 0 and 100 μm. Eight distinct colors of microfibers were found in the samples; black was the most abundant color among all the samples, followed by brown and blue. The studied ETPs showed a 23.52 % to 82.19 % microfiber removal rate, which is not satisfactory for minimizing pollution. The Fourier transform infrared (FTIR) analysis revealed that the main polymers in the samples were nylon, ethylene-vinyl acetate (EVA), polyethylene terephthalate (PETE), acrylonitrile butadiene styrene (ABS), cellulose acetate (CA), low-density polyethylene (LDPE or linear LDPE), and high-density polyethylene (HDPE). The contamination factor (CF) and pollution load index (PLI), which assess ecological risks, showed that samples were moderately to very highly contaminated by microfiber and could pose a threat to the aquatic ecosystem. The findings would help identify transformative challenges required for minimizing microfiber pollution from industrial sectors and improving ETP systems.

Degradation of textile polyazodyes by Polyporus ciliatus laccase produced in peanut shell solid medium: purification and characterization

This study describes decolorization of reactive sulfonated azoic dye Direct Blue 71, one of the recalcitrant and highly used industrial dyes, by Polyporus ciliatus derived laccase. Agro-industrial wastes are increasingly used as substrates for laccase production from white rot fungi through solid-state fermentation (SSF). Peanut shell (PS) is an attractive substrate for laccase production, and SSF is an adequate strategy for that purpose. It has been employed as a novel support-substrate for laccase production by Polyporus ciliatus under solid-state fermentation. The highest laccase yield of 1260 U/ml was attained using PS after 13 days of incubation at 30°C. The purified laccase (55 kDa) showed maximum activity at pH 3 and 60°C. The extracellular laccase enzyme was purified 67.6-fold to a specific activity of 1466 U/mg by a Mono-Q anion-exchange column. The purified enzyme Km value was found to be 24 µM, while the Vmax value was observed to be 0.96 µM s-1 with ABTS as a substrate. It had high thermotolerance and pH stability and was resistant to several metal ions including copper, cadmium, and iron. P. ciliatus pure laccase showed high potential for the decolorization and detoxification of the reactive sulfonated azoic dye Direct Blue 71, which suggested that this enzyme could be used for textile effluent treatment.

Statistical Optimization and Kinetic Studies of Water Hyacinth Stem–Based Activated Carbon Adsorbent for Synthetic Textile Dye Effluent Treatment

Statistical Optimization and Kinetic Studies of Water Hyacinth Stem–Based Activated Carbon Adsorbent for Synthetic Textile Dye Effluent Treatment

Treatment of real textile effluent containing indigo blue dye by hybrid system combining adsorption and membrane processes

The rapid expansion of the textile industry in Tunisia has resulted in ever-increasing discharges of wastewater, making it necessary to set up treatment systems allowing i) its discharge into the environment or ii) to recycle the water in the textile plant. In this study, several unitary operations were tested in order to improve the treated water quality. Thus, the following unit operations were applied: adsorption using Natural Clay (NC) and Powdered Activated Carbon (PAC), ultrafiltration (UF) and nanofiltration (NF) individually or in synergy: UF, nanofiltration, PAC-UF, NC-UF, UF-NF et Adsorption-UF/NF. The experiments were carried out on real textile effluent containing Indigo blue dye. A threshold concentration was observed above which performance no longer increases. NF alone showed better reduction of COD (67%), color (78%), and turbidity (98%) than UF alone (26%, 48%, 95%, respectively). The coupling UF–NF showed a clear improvement in water quality in terms of color (99%) and COD (98%) with an improvement in the NF flux from 67.81 L/h.m2 to 90.62 L/h.m2. No fouling was observed for NF while it is significant during UF. The used of adsorption as pretreatment to filtration leads to an enhancement of the treatment performances with a removal of 99.9%, 99.5% and 79.5% respectively for turbidity, color and COD for NC-UF and a removal of 100%, 99.4% and 79.6% respectively for turbidity, color and COD for PAC-UF. Moreover, the addition of adsorbent controls the fouling and a constant and high flux is quickly attained and remains stable over time. The use of natural clay as adsorbent represents an economically profitable solution since it can be obtained locally and the clay used can be reused in the ceramic industry as an additive for road surfacing without the need for regeneration.

Decolorization and Detoxification of Industrial Wastewater Containing Indigo Carmine by Aspergillus niger AN400 in Sequential Reactors

Effluents from the textile industry are an active problem in the sector and one of the world’s main environmental problems. The conventional treatments applied are not always efficient in terms of compliance with legislation, and, in many cases, the efficiency of treatment is guaranteed by the enormous energy expenditure involved, camouflaging the momentary problem and not effectively treating it. In this work, batch reactors with immobilized biomass of Aspergillus niger AN400 were arranged in series for the treatment of real textile wastewater containing approximately 20 mg/L of indigo carmine. Sucrose was added as a co-substrate in concentrations of 1 g/L and 0.5 g/L, in the first and second reactors, respectively, over 19 cycles of 48 h. The highest decolorization rate in the system was (93 ± 4) %, with the largest amount removed in the first reactor (90 ± 6) %, occurring mainly by biological means. The production of aromatic by-products from the initial degradation of the dye molecule was reflected in the lower removal efficiency of dissolved organic matter: 52% in the first reactor, and 25% in the second reactor. The number of colonies of fungi was higher than that of bacteria, 2.24:1 and 2.44:1 in the first and second reactors, respectively. The treated effluent in the system showed less toxicity than the raw effluent, and this demonstrates the potential of this technology in the treatment of textile effluents containing indigo carmine.

Catalytic thermal treatment (catalytic thermolysis) of textile dyeing effluent

During the production of textiles a large amount of wastewater is generated that contains high organics load and color appearance. If it is directly (untreated) discharged into any water-receiving body then it gets fully contaminated, hence its proper treatment is required. The present study deals with the treatment of textile dyeing effluent (TDE) using catalytic thermolysis (CT) for the reduction of color and COD reduction with the help of CuO as a catalyst. The catalyst (CuO) was prepared successfully on the laboratory scale. The CuO preparation is done by alkali precipitation of copper sulfate followed by drying and calcination. Catalyst is characterized in detail including X-ray diffraction, SEM, and TEM analysis. CT treatment of TDE was carried out in a 0.5 dm3 thermolysis batch reactor using CuO as a catalyst at different pH (2.4–10.4), temperatures (70 °C–115 °C), and catalyst loadings (1.5–5.5 g/dm3). The maximum 72 % COD reduction was achieved at the optimum condition of 70 °C temperature, catalyst loading of 1.5 g/dm3, and 4.4 pH. The residues obtained after CT were characterized by TGA, TDA, and TG. In addition, settling characteristics were also observed for CT-treated sludge at different temperatures. CT is a novel treatment technique to treat highly polluted wastewater. During the CT treatment, the addition of chemicals is not required and it has good removal efficiency. Further CT-treated sludge has good heating value hence it can be used as an industrial fuel. In other words, no secondary pollutants are generated during the CT process.

Effectiveness of Canna indica leaves and stalk biochar in the treatment of textile effluent

Textile effluents often include water polluted with heavy metals, organic and inorganic contaminants, and different colors. It is not practical to remove these pollutants from the water. A variety of methods, including ozone, adsorption, membrane separation, biosorption, biodegradation, electrochemical degradation, and UV radiation, might be used in the water treatment procedure. Biochar made from Canna indica leaves and stems was used to remediate textile industry wastewater, which included color and chemical oxygen demand (COD). By using an absorption technique, the biochar was created by roasting the material at 500 °C, which removed the color and COD from the wastewater. The batches were subjected to many variations in temperature, concentration, and dose of biochar throughout the testing phase. Canna leaves have been shown to be effective in reducing COD at doses between one and 1.5 gm. COD levels were reduced by 83%, and color was reduced by around 94%. On the other hand, while keeping a constant dose, it was shown that canna stalks showed noteworthy effectiveness in lowering COD levels, with a range of 33%–48%. When it comes to eliminating color and COD, the leaves of the canna plant show more specificity than those of other plant species. The Jovanovich isotherm showed a good association with the biochar made from Canna indica leaves, according to the examination of the isotherm computation.

Multitasking needle-shaped copper oxide nanorods decorated cystine modified polymer/graphene oxide nanocomposite for 4-nitrophenol reduction, dye degradation, and textile effluent treatment

Nitroaromatic chemicals, including 4-nitrophenol (4-NP) and dyes, pose substantial risks to human health and the environment. Various catalysts that facilitate the reduction of 4-NP to 4-aminophenol (4-AP) have been documented to reduce its toxicity. Herein, we developed a novel nanocomposite consisting of needle-like copper oxide nanorods immobilized with L-cystine functionalized polyglycidyl methacrylate integrated graphene oxide (Cys-PGMA@GO-CuO) nanocomposite. The formation of this nanocomposite was comprehensively characterized using various analytical techniques. X-ray diffraction revealed a semi-crystalline nature for pure PGMA/GO with a prominent peak at 2θ = 19.25°. The introduction of inherently crystalline CuO nanoparticles in Cys-PGMA@GO-CuO rendered the entire composite completely crystalline. Further, the photocatalytic efficiency of the Cys-PGMA@GO-CuO nanocomposite was evaluated through advanced oxidation processes (AOP) for treating various toxic pollutants in wastewater remediation. The nanocomposite efficiently degraded dyes like methyl orange (99.8%) and methylene blue (99.9%) in just 50 mins and reduced toxic 4-NP to 4-AP within 40 mins. We further investigated the optimal degradation conditions based on [oxidant], [dye], and the presence of scavengers to understand the rate of degradation. Notably, the composite exhibited remarkable recyclability and stability. The performance of Cys-PGMA@GO-CuO was further evaluated using real wastewater samples, achieving a remarkable decolorization of 99.5% in textile dyeing wastewater and 97.1% in methylene blue-contaminated tap water. These results demonstrate the promising potential of this nanocomposite as an economically viable alternative approach for removing various organic pollutants from wastewater. Additionally, its successful application in real water sample analysis suggests its significant potential for practical implementation in water treatment processes.

Nanocomposite ceramic membranes as novel tools for remediation of textile dye waste water – A review of current applications, machine learning based modeling and future perspectives

Textile effluent treatment has gained significant attention due to the carcinogenic effects of the dye pollutants present and their enhanced resistance to degradation. Porous ceramic membranes have gained growing interest for dye remediation due to various unique characteristics, including resistance to fungal invasion, adverse chemical conditions, and high temperature. The current study explores applications of ceramic membrane technology, including membranes like MF, UF, and NF, for dye remediation from textile effluent. The best-performing nanocomposite membranes for eliminating azo dyes from textile effluent and efficiencies achieved are reported as Clay-alumina (99%), yttria-stabilized-zirconia (99%), nano TiO2-bentonite UF (95%), and tight TiO2 UF (100%). Ceramic nanocomposites with TiO2 and Al2O3 active layer NF (99%), Ceramic Hybrid hollow fiber LNF (99.3%). Loose nanofiltration (LNF) ceramic membranes have demonstrated outstanding targeted separation performance for the separation of dyes, making them affirm the effective recoveries and recurrent use of high-value-added constituents amongst all the membrane approaches examined. The potential of ceramic membranes for future research and development, including membrane production and mechanism, are discussed. In addition, the implementation of AI-based methods and Machine learning (ML) algorithms are discussed in relation to predicting membrane filtration performance and fouling tendencies and dye removal processes, maximizing opportunities in this field.

Revealing the interface chemistry of polyaniline grafted biomass via statistical modeling of multi-component dye systems: optimization, kinetics, thermodynamics, and adsorption mechanism.

The growing need to examine the adsorption capabilities of innovative materials in real-world water samples has encouraged a shift from single to multicomponent adsorption systems. In this study, a novel composite, PANI-g-SM was synthesized by covalently grafting a lignocellulosic biomass, Saccharum munja (SM) with polyaniline (PANI). The as-synthesized composite was investigated for the simultaneous adsorption of cationic (Methylene Blue (MB); Crystal Violet (CV)) and anionic dyes (Reactive Red 35 (RR); Fast Green FCF (FG)) from four single components and two binary systems, MB + RR and CV + FG. Further, the effect and interaction of pH (2-11), dosage (0.01-0.04g/10mL), and initial concentration (0.0313 to 0.1563mmol/L) on the elimination of dyes by PANI-g-SM were studied through a novel design of Box-Behnken of Response Surface Methodology (RSM) technique which was found to be highly useful for revealing the chemistry of interfaces in multi-component systems. The extended Langmuir model for the binary system indicated the presence of synergism, as result the maximum monolayer adsorption capacity increased by 44.44%, 645.83%, 67.88%, and 441.07% for MB, RR, CV, and FG dye, respectively. Further, the adsorption process mainly followed a pseudo-second-order kinetic model, and the thermodynamic studies revealed the exothermic nature of adsorption for RR and FG dye while endothermic for MB and CV dye, respectively with varying from - 1.68 to - 6.12kJ/mol indicating the spontaneity of the process. Importantly, the efficacy of the composite was evaluated for the treatment of textile industry effluent highlighting its potential as an adsorbent for wastewater treatment.

Solar photocatalytic process using biomass-derived boron carbon nitride (BM-BCN) for the treatment of synthetic textile effluent

This research elucidates the process of synthesizing, characterizing, and evaluating the removal efficiency of a pioneering biomass-derived non-metal photocatalyst BM-BCN. Within this framework, an efficient one-step synthesis method is presented for generating BM-BCN. This material is produced by subjecting a blend of boric acid, citron peel powder, and melamine to pyrolysis. The BM-BCN material exhibited an optical band gap of 2.5 eV, closely resembling the property of a visible light-responsive photocatalyst. It is characterized by intricate porous structure, remarkably expansive surface area, and distinct chemical bonds, porous BM-BCN sheets present considerable benefits in terms of their photocatalytic behavior. The synthesized material showed its maximum photocatalytic performance of 98.32% when degrading indigo carmine (IC) dye under acidic pH conditions, employing 300 ppm of catalyst dosage for 10 ppm of dye concentration over a 180-minute exposure to direct sunlight, confirming the pseudo-first-order kinetics model. Additionally, this scientific study details the mechanism of IC photocatalytic decolorization. The porous BM-BCN sheets showed exceptional stability over extended cycling of 92% or higher throughout five successive iterations.

A Sustainable and Regenerative Process for the Treatment of Textile Effluents Using Nonphotocatalytic Water Splitting by Nanoporous Oxygen-Deficient Ferrite.

Water is crucial for life. Being the world's third-largest industry, the textile industry pollutes 93 billion cubic meters of water each year. Only 28% of textile wastewater is treated by lower- to middle-income countries due to the costly treatment methods. The present work demonstrates the utilization of surface oxygen defects and nanopores in Mg0.8Li0.2Fe2O4 (Li-MgF) to treat textile effluents by a highly economical, scalable, and eco-friendly process. Nanoporous, oxygen-deficient Li-MgF splits water by a nonphotocatalytic process at room temperature to produce green electricity as hydroelectric cell. The adsorbent Li-MgF can be easily regenerated by heat treatment. A 70-90% reduction in the UV absorption intensity of adsorbent-treated textile effluents was observed by UV-visible spectroscopy. The oxygen defects on Li-MgF surface and nanopores were confirmed by X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller (BET) measurements, respectively. To analyze the adsorption mechanism, three known organic water-soluble dyes, brilliant green, crystal violet, and congo red, were treated with nanoporous Li-MgF. The dye decolorization efficiency of Li-MgF was recorded to be 99.84, 99.27, and 99.31% at 250 μM concentrations of brilliant green, congo red, and crystal violet, respectively. The results of Fourier transform infrared (FTIR) spectroscopy confirmed the presence of dyes on the material surface attached through hydroxyl groups generated by water splitting on the surface of the material. Total organic carbon analysis confirmed the removal of organic carbon from the dye solutions by 82.8, 77.0, and 46.5% for brilliant green, Congo red, and crystal violet, respectively. Based on the kinetic and isotherm models, the presence of a large number of surface hydroxyl groups on the surface of the material and OH- ions in solutions generated by water splitting was found to be responsible for the complete decolorization of all of the dyes. Adsorption of chemically diverse dyes by the nanoporous, eco-friendly, ferromagnetic, economic, and reusable Li-MgF provides a sustainable and easy way to treat textile industry effluents in large amounts.

Axenic green microalgae for the treatment of textile effluent and the production of biofuel: a promising sustainable approach

An integrated approach to nutrient recycling utilizing microalgae could provide feasible solutions for both environmental control and energy production. In this study, an axenic microalgae strain, Chlorella sorokiniana ASK25 was evaluated for its potential as a biofuel feedstock and textile wastewater (TWW) treatment. The microalgae isolate was grown on TWW supplemented with different proportions of standard BG-11 medium varying from 0 to 100% (v/v). The results showed that TWW supplemented with 20% (v/v) BG11 medium demonstrated promising results in terms of Chlorella sorokiniana ASK25 biomass (3.80 g L−1), lipid production (1.24 g L−1), nutrients (N/P, > 99%) and pollutant removal (chemical oxygen demand (COD), 99.05%). The COD level dropped by 90% after 4 days of cultivation, from 2,593.33 mg L−1 to 215 mg L−1; however, after day 6, the nitrogen (-NO3−1) and total phosphorus (TP) levels were reduced by more than 95%. The biomass-, total lipid- and carbohydrate- production, after 6 days of cultivation were 3.80 g L−1, 1.24 g L−1, and 1.09 g L−1, respectively, which were 2.15-, 2.95- and 3.30-fold higher than Chlorella sorokiniana ASK25 grown in standard BG-11 medium (control). In addition, as per the theoretical mass balances, 1 tonne biomass of Chlorella sorokiniana ASK25 might yield 294.5 kg of biodiesel and 135.7 kg of bioethanol. Palmitic acid, stearic acid, and oleic acid were the dominant fatty acids found in the Chlorella sorokiniana ASK25 lipid. This study illustrates the potential use of TWW as a microalgae feedstock with reduced nutrient supplementation (20% of TWW). Thus, it can be considered a promising feedstock for economical biofuel production.Graphical abstract

Screening of Azo-Dye-Degrading Bacteria from Textile Industry Wastewater-Activated Sludge

This study investigates the biodegradation of Reactive Red 141 (RR 141), an azo dye prevalent in the textile industry, by bacteria isolated from activated sludge in a textile effluent treatment plant. RR 141, characterized by nitrogen–nitrogen double bonds (-N=N-), contributes to environmental issues when improperly disposed of in textile effluents, leading to reduced oxygen levels in water bodies, diminished sunlight penetration, and the formation of potentially carcinogenic and mutagenic aromatic amines. This research focuses on identifying bacteria from activated sludge with the potential to decolorize RR 141. Microbiological identification employs MALDI-TOF-MS, known for its precision and rapid identification of environmental bacteria, enhancing treatment efficiency. Results highlight Bacillus thuringiensis and Kosakonia radicincitans as the most promising strains for RR 141 decolorization. Analysis of micro-organisms in activated sludge and database exploration suggests a correlation between these strains and the decolorization process. It is worth noting that this is the first report on the potential use of K. radicincitans for azo dye decolorization. Three distinct culture media—BHI, MSG, and MS—were assessed to investigate their impact on RR 141 decolorization. Notably, BHI and MSG media, incorporating a carbon source, facilitated the bacterial growth of both tested species (B. thuringiensis and K. radicincitans), a phenomenon absent in the MS medium. This observation suggests that the bacteria exhibit limited capability to utilize RR 141 dye as a carbon source, pointing towards the influence of the culture medium on the discoloration process. The study evaluates performance kinetics, decolorization capacity through UV-VIS spectrophotometry, potential degradation pathways via HPLC-MS analysis, phytotoxicity, and enzymatic activity identification. B. thuringiensis and K. radicincitans exhibit potential in decolorizing RR141, with 38% and 26% removal individually in 120 h. As a consortium, they achieved 36% removal in 12 h, primarily through biosorption rather than biodegradation, as indicated by HPLC-MS analyses. In conclusion, the research emphasizes the importance of exploring bacteria from activated sludge to optimize azo dye degradation in textile effluents. B. thuringiensis and K. radicincitans emerge as promising candidates for bioremediation, and the application of MALDI-TOF-MS proves invaluable for rapid and precise bacteria identification.

Characterization of textile effluent treatment plant sludge and its industrial application in fired clay bricks with health risk assessment

The textile industry in Bangladesh faces environmental and health challenges due to the disposal of solid waste from Effluent Treatment Plants (ETPs). To address this issue, a study was conducted using soil from a brick industry near Dhaka, amending it with varying amounts of dry sludge to create clay bricks. The original soil had a loam texture and medium plasticity. The research found that adding 9 wt% of sludge resulted in Grade A commercial bricks with a compressive strength of 15.33 MPa and water absorption of 13.33 wt%, meeting BDS 208 standards. However, these sludge-incorporated bricks experienced more shrinkage during the burning process due to organic content, requiring additional soil to maintain conventional dimensions. Also, to assess the health hazards of these sludge-incorporated bricks, a leaching test was performed, revealing that no toxic heavy metals (Pb, Cd, Cr, Cu, Ni, and Zn) in the leachate exceeded the limits set by the United States Environmental Protection Agency (USEPA). The study indicates that textile ETP sludge can serve as a sustainable raw material for bricks, potentially reducing the environmental burden caused by textile sludge disposal by 28.75%. This innovative approach offers a promising solution to both environmental and health concerns associated with textile waste in Bangladesh's industrial sector.

Microalgae-Based Remediation of Real Textile Wastewater: Assessing Pollutant Removal and Biomass Valorisation.

The textile industry generates highly contaminated wastewater. It severely threatens local ecosystems without proper treatment, significantly diminishing biodiversity near the discharge point. With rapid growth rates, microalgae offer an effective solution to mitigate the environmental impact of textile wastewater, and the generated biomass can be valorised. This study sets out to achieve two primary objectives: (i) to assess the removal of pollutants by Chlorella vulgaris from two distinct real textile wastewaters (without dilution) and (ii) to evaluate microalgal biomass composition for further valorisation (in a circular economy approach). Microalgae grew successfully with growth rates ranging from 0.234 ± 0.005 to 0.290 ± 0.003 d-1 and average productivities ranging from 78 ± 3 to 112.39 ± 0.07 mgDW L-1 d-1. All cultures demonstrated a significant reduction in nutrient concentrations for values below the legal limits for discharge, except for COD in effluent 2. Furthermore, the pigment concentration in the culture increased during textile effluent treatment, presenting a distinct advantage over conventional ones due to the economic value of produced biomass and pigments. This study underscores the promise of microalgae in textile wastewater treatment and provides valuable insights into their role in addressing the environmental challenges the textile industry poses.

Biochar from Manihot esculenta stalk as potential adsorbent for removal of reactive yellow dye

Textile effluent treatment is crucial for a cleaner and safer community. The purpose of this study is to utilize biochar prepared from Manihot esculenta stalk to remove reactive yellow dye through Pyrolysis at 350 °C for 210 min. The effect of quantity of adsorbent, pH values of the adsorbate solution experimented, contact time required, starting dye concentration, current temperature of the solution, speed of agitation, as well as size of the particle on reactive yellow dye removal was examined using biochar through batch trials. At an equilibrium period of 25 min, pH of 7, bio-char dosage of 2 g, temperature of 25 °C, agitation speed of 150 rpm, as well as particle size of 231 µm, 86% of the dye could be removed with highest adsorption capacity of 53.47 mg/g. Pseudo-first order type kinetics in addition to the Langmuir isotherm model were set up to finest fit the adsorption model of reactive yellow dye onto biochar from M. esculenta stalk. The process is chemisorption, exothermic, feasible, and spontaneous, as it is predicted by the thermodynamically negative enthalpy as well as entropy of adsorption values. The spent M. esculenta stalk biochar was reused for six cycles of adsorption at same optimal process conditions and adsorption capacity was found to be insignificant up to fourth cycle. Also, M. esculenta biochar was characterized through scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX) and Fourier Transform Infrared Spectroscopy (FTIR) for morphology, elemental composition, and functional groups respectively. So, the M. esculenta stalk biochar could be an active adsorbent for elimination of reactive dye from the solution of dye.

Biodegradation of crystal violet by newly isolated bacteria.

Confronting the environmental threat posed by textile dyes, this study highlights bioremediation as a pivotal solution to mitigate the impacts of Crystal Violet, a widely-utilized triphenylmethane dye known for its mutagenic and mitotic toxicity. We isolated and identified several bacterial strains capable of degrading Crystal Violet under various environmental conditions. Newly identified strains, including Mycolicibacterium nivoides, Chryseobacterium sp., Agrobacterium rhizogenes, Pseudomonas crudilactis, and Pseudomonas koreensis demonstrated significant decolorization activity of Crystal Violet, complementing the already known capabilities of Stenotrophomonas maltophilia. Initial experiments using crude extracts confirmed their degradation potential, followed by detailed studies that investigated the impact of different pH levels and temperatures on some strains' degradation efficiency. Depending on the bacteria, the degree of activity change according to pH and temperature was different. At 37 °C, Chryseobacterium sp. and Stenotrophomonas maltophilia exhibited higher degradation activity compared to 25 °C, while Pseudomonas crudilactis and Mycolicibacterium nivoides did not exhibit a statistically significant difference between the two temperatures. Mycolicibacterium nivoides performed optimally at pH 8, while Pseudomonas crudilactis showed high activity at pH 5. Stenotrophomonas maltophilia's activity remained consistent across the pH range. These findings not only underscore the effectiveness of these bacteria as agents for Crystal Violet degradation but also pave the way for their application in large-scale bioremediation processes for the treatment of textile effluents, marking them as vital to environmental sustainability efforts.