Indigo Carmine Research Articles

Hydrothermal Synthesis and Catalytic Activity of a Nanosized Fe2V4O13 Material in Heterogeneous Fenton-like Reaction for Degradation of Organic Compounds

In this research, the nanosized Fe2V4O13 complex oxide material was synthesized by the hydrothermal method. Its structure, morphology characterization, and other properties were determined using X-ray, SEM, EDX, and DTA-TG methods. The catalytic activity of the material was evaluated in terms of the decolorization and the degradation of the Indigo carmine dye. The optimal condition for the degradation and the reusability of the catalyst were determined. The results showed that the heterogeneous Fenton-like catalyst is a promise for wastewater treatment.

Archetypes of community-based pond aquaculture in Indonesia: applying the social-ecological systems framework to examine sustainability tradeoffs

We analyze archetypes of farmer groups conducting pond aquaculture across the province of Nusa Tenggara Barat, Indonesia using Ostrom’s social-ecological systems framework. Pond aquaculture farmers share coastal irrigation infrastructure as common property, among other resources, and are encouraged by the government to organize into groups with varying sets of evolved rules, norms, social practices and environmental conditions shaping what they produce, how and how much. Yet little is known about the diversity of these pond aquaculture communities, or what factors—both social and ecological—shape production trends and sustainability outcomes. We designed a standardized survey to collect data on 26 indicators from 85 diverse community-based fish farmer groups across the province. Data included indicators on ownership, rules, history, production trends, demographics, government involvement, livelihood dependence, environmental characteristics and risks. Clustering analysis was applied to identify five unique archetypes of pond aquaculture communities, each distinguished by a different set of development challenges and opportunities. Our findings highlight the need to move beyond a ‘one-size-fits-all’ policy approach. We suggest moving towards a locally adapted capacity building strategy that can recognize contextual needs so that policy programs can better target and differentiate between farmer groups that face similar challenges. We further discuss how empowering collective action among the farmers can reduce risks associated with producing blue food for local consumption and regional markets.

Elimination of indigo carmine in water by Pinus patula biochar: Adsorption process optimization, kinetics and isotherms

The textile industry causes major pollution to water bodies due to the discharge of dye-containing wastewater, such as indigo carmine (IC). Biochar has been used to treat organic pollutants like dyes because of its pore structure and surface area, as well as the functional groups contained, low cost, and sustainability of this material. In this study, biochar derived from Pinus patula wood pellets was used to assess its efficiency in the elimination of IC in water. Under optimal conditions of pH, biochar dose, and particle size (3, 13.5 g/L, and 300–450 µm, respectively), a 99% removal of a 25 mg/L solution of IC was achieved. Furthermore, studies on dissolved organic carbon (DOC) revealed that Pinus patula biochar contributed to a 73.8% reduction in the organic matter present in water. The IC adsorptive process was described by the pseudo-second order kinetic and the Freundlich isotherm models. Chemical and physical adsorption mechanisms were associated with the uptake of IC by Pinus patula biochar. Hydrogen bonding, electrostatic attraction, π-π interactions, and pore-filling were regarded as the possible mechanisms involved in the adsorption system. Pinus patula wood pellets biochar was shown to be an efficient adsorbent to remove dyes from water.

The compostability of denim fabrics dyed with various indigos

Denim fabric samples representing current indigo dye sources and fabric structures were biodegraded in feedstock including food waste, manure, and animal bedding, which are typically composted at the Cornell Farm Services Composting Facility and processed under laboratory conditions for 77 days. Indigo types including dry denim, pre-reduced, and natural did not inhibit degradation as compared to undyed 100% cotton fabric. Additionally, fabrics tested as received from the mill and those tested post scouring degraded effectively. As expected, denim containing 24% polyester and 2% spandex retained overall fabric structure despite degradation of the cotton portion of the yarns.

Alginate-laccase beads in the decolourization of indigo carmine

The aim of the study was to assess the feasibility of utilizing sodium alginate biopolymer as animmobilization carrier for laccase in the removal of indigo carmine (IC), an anionic dye. The main goal of this work was to optimize the decolourization process by selecting the appropriate immobilized enzyme dose per 1 mg of dye, as well as the process temperature. The effective immobilization of laccase using sodium alginate as a carrier was confirmed by Raman spectroscopy. An analysis of the size and geometric parameters of the alginate beads was also carried out. Tests of IC decolourization using alginate-laccase beads were conducted. Applying the most effective dose of the enzyme (320 mg of enzyme/1 mg of IC) made it possible to remove 92.5% of the dye over 40 days. The optimal temperature for the IC decolourization process, using laccase immobilized on sodium alginate, was established at 30-40ºC. The obtained results indicate that laccase from Trametes versicolor immobilized on sodium alginate was capable of decolourizing the tested dye primarily based on mechanism of biocatalysis.

Analysis of the feasibility of using biopolymers of different viscosities as immobilization carriers for laccase in synthetic dye removal

The main aim of the study was to assess the feasibility of using biopolymers of different viscosities (high, medium and low viscosity) as immobilization carriers for laccase in synthetic dye removal. The following dye solutions were decolorized: indigo carmine (IC, anionic dye), methylene blue (MB, cationic dye), and their mixture in a molar mass ratio MB/IC=0.69, using biopolymers of different viscosities as laccase immobilization carriers. Toxicity tests were also carried out to assess the toxicity of the post-decolorization samples. Decolorization tests showed that the main decolorization mechanism depends on the dye class. The removal of IC (max. total removal efficiency 72.15%) was mainly by biocatalysis. The mechanism of the MB decolorization process was mainly by sorption on alginate beads, and the efficiency of enzymatic removal was low. However, the highest efficiency of MB decolorization (45.80%) was obtained for beads prepared using the high viscosity alginate when decolorization occurred by both sorption and biocatalysis. The results of mixture decolorization tests differ from the results obtained for single dyes.The results showed differences in the efficiency of the dye sorption process depending on the alginate used for immobilization. Moreover, the varying mechanisms of dye removal from the dye mixture were confirmed by toxicity tests. The occurrence of both biocatalysis and sorption promotes reduced toxicity

Conductometric and spectral analyses of dye-surfactant interactions between indigo carmine and N-alkyltrimethylammonium chloride

The electrical conductivity technique was used to investigate the critical micelle concentration (CMC) of cationic surfactants N-alkyltrimethylammonium chloride (CnTAC; n = 12, 14, 16, and 18). Meanwhile, the interaction between CnTAC and indigo carmine (IC, an anionic dye) was studied using spectrophotometry. Employing the Benesi-Hildebrand and Scott equations, the binding constant (Kb) of IC to the cationic micelles was determined. Calculation of the Gibbs free energy (ΔG) revealed the tendency of IC to bind to micelles. The association between IC and CnTAC clearly depends on the CnTAC concentration: a lower surfactant concentration disrupts the IC-CnTAC complex and decreases IC adsorption, while a higher surfactant concentration has the opposite effect. The alkyl chain length of CnTAC was also found to affect the CMC, Kb, and thermodynamic parameters. A longer alkyl chain reduces the CMC and ΔG and increases Kb, leading to increased solubilization and high spontaneity of the dye. The binding of IC to micelles is ranked as C12TAC < C14TAC < C16TAC < C18TAC.

Synergistic effects of micronanobubbles and AC/Ag–TiO2 nanocomposites in photocatalytic process

The AC/Ag–TiO2 nanocomposites were prepared by sol-gel method using different concentrations of Ag. Comprehensive characterization of the crystalline structure, surface morphology, elemental composition, and optical properties of the AC/Ag–TiO2 photocatalysts was carried out using XRD, FTIR, SEM, EDX, TEM, and UV–vis DRS techniques. Consequently, a detailed investigation into the photocatalytic degradation of Indigo Carmine (IC) and Reactive Black 5 (RB5) dyes was conducted, thoroughly examining the involved photocatalytic mechanisms. The study revealed promising outcomes, particularly with the hybrid photocatalyst AC/0.5%Ag–TiO2, showcasing enhanced characteristics in both photooxidation and absorption processes, thereby boosting overall efficacy for IC (70.15%) and RB5 (69.9%). Remarkably, the introduction of small air bubbles significantly improved the removal efficiency of IC and RB5 dyes, achieving removal levels of 93.66% and 88.66%, respectively. The utilization of these micro-nanobubble systems (MNBs) resulted in notably higher first-order reaction constants compared to scenarios without MNBs, indicating the pivotal role of the photocatalyst in dye removal processes. Additionally, the photocatalyst showed unmatched efficacy in eliminating the pesticide carbaryl, attaining 100% removal with and without the presence of MNBs. Moreover, the AC/Ag–TiO2 photocatalyst exhibited significant inhibition of both gram-positive and gram-negative pathogenic bacteria, showcasing its capability to curb their growth even without MNB aeration. This underscores its potential for applications in environmental remediation and microbial control.

Study of PEG-b-PLA/Eudragit S100 Blends on the Nanoencapsulation of Indigo Carmine Dye and Application in Controlled Release.

A nanocapsule shell of poly(ethylene glycol)-block-poly(d,l-lactic acid) (PEG-b-PLA) mixed with anionic Eudragit S100 (90/10% w/w) was previously used to entrap and define the self-assembly of indigo carmine (IC) within the hydrophilic cavity core. In the present work, binary blends were prepared by solution mixing at different PEG-b-PLA/Eudragit S100 ratios (namely, 100/0, 90/10, 75/25, and 50/50% w/w) to elucidate the role of the capsule shell in tuning the encapsulation of the anionic dye (i.e., IC). The results showed that the higher content of Eudragit S100 in the blend decreases the miscibility of the two polymers due to weak intermolecular interactions between PEG-b-PLA and Eudragit S100. Moreover, with an increase in the amount of Eudragit S100, a higher thermal stability was observed related to the mobility restriction of PEG-b-PLA chains imposed by Eudragit S100. Formulations containing 10 and 25% Eudragit S100 exhibited an optimal interplay of properties between the negative surface charge and the miscibility of the polymer blend. Therefore, the anionic character of the encapsulating agent provides sufficient accumulation of IC molecules in the nanocapsule core, leading to dye aggregates following the self-assembly. At the same time, the blending of the two polymers tunes the IC release properties in the initial stage, achieving slow and controlled release. These findings give important insights into the rational design of polymeric nanosystems containing organic dyes for biomedical applications.

Development and validation of YARN: A novel SE-400 MPS kit for East Asian paternal lineage analysis

Y-chromosomal short tandem repeat polymorphisms (Y-STRs) and Y-chromosomal single nucleotide polymorphisms (Y-SNPs) are valuable genetic markers used in paternal lineage identification and population genetics. Currently, there is a lack of an effective panel that integrates Y-STRs and Y-SNPs for studying paternal lineages, particularly in East Asian populations. Hence, we developed a novel Y-chromosomal targeted panel called YARN (Y-chromosome Ancestry and Region Network) based on multiplex PCR and a single-end 400 massive parallel sequencing (MPS) strategy, consisting of 44 patrilineage Y-STRs and 260 evolutionary Y-SNPs. A total of 386 reactions were validated for the effectiveness and applicability of YARN according to SWGDAM validation guidelines, including sensitivity (with a minimum input gDNA of 0.125 ng), mixture identification (ranging from 1:1–1:10), PCR inhibitor testing (using substances such as 50 μM hematin, 100 μM hemoglobin, 100 μM humic acid, and 2.5 mM indigo dye), species specificity (successfully distinguishing humans from other animals), repeatability study (achieved 100% accuracy), and concordance study (with 99.91% accuracy for 1121 Y-STR alleles). Furthermore, we conducted a pilot study using YARN in a cohort of 484 Han Chinese males from Huaiji County, Zhaoqing City, Guangdong, China (GDZQHJ cohort). In this cohort, we identified 52 different Y-haplogroups and 73 different surnames. We found weak to moderate correlations between the Y-haplogroups, Chinese surnames, and geographical locations of the GDZQHJ cohort (with λ values ranging from 0.050 to 0.340). However, when we combined two different categories into a new independent variable, we observed stronger correlations (with λ values ranging from 0.617 to 0.754). Overall, the YARN panel, which combines Y-STR and Y-SNP genetic markers, meets forensic DNA quality assurance guidelines and holds potential for East Asian geographical origin inference and paternal lineage analysis.

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.

Effects of Indigo Carmine on Growth, Cell Division, and Morphology of Allium cepa L. Root Tip.

Indigo carmine has a variety of uses in foods, textiles, medicine, pharmaceuticals, and cosmetics. There are studies reporting the toxic potential of indigo carmine on human health and the environment. In this study, we investigated the cytogenotoxic effects of indigo carmine using apical root cells of Allium cepa. Allium cepa bulbs were subjected to four treatments with indigo carmine (0.0032, 0.0064, 0.0125, and 0.2 mg/mL) and to ultrapure water as a control. After 5 days, root growth, root length, mitotic index, mitotic inhibition, chromosomal anomalies, and cell morphology were analyzed. According to our results, a decrease in root length and mitotic index was observed at all concentrations of indigo carmine. Additionally, several types of chromosomal abnormalities were observed, such as disturbed metaphase, sticky chain metaphase, anaphase bridge, and laggard chromosomes. Moreover, histological observation indicated that indigo carmine induces alterations in various components of root tip tissue, such as deformation and alteration of the cell wall, progressive condensation of chromatin, shrinkage of the nuclei, and an increase in the number of irregularly shaped nuclei and nuclear fragments. Our results indicate that the tested concentrations of indigo carmine may have toxic effects and raise concerns about its intensive use in many fields.

Going Green for Blue - An Indigo Approach

Introduction: Dominating use of chemical processes for reducing indigo at several small-scale production houses formed the ground for initiating this study. Conventional textile processing hubs still use sodium hydrosulphite as a reducing agent irrespective of the source of indigo, whether natural or synthetic ignoring the unfavourable consequences of their disposal and elimination from effluent Method: The paper addresses the critical environmental issues related to the conventional reduction of indigo and studies already undertaken. It examines the indigo dyeing process of cotton using natural, chemical and eco-friendly reducing agents in combination with calcium hydroxide for a comparative study. Identification of natural indigo through High-Performance Liquid Chromatography was undertaken for further experimentation. Under specific parameters, the study examined the effect of Thiourea dioxide and natural reducing agents in indigo dyeing replacing Sodium hydrosulphite. The difference in weight, strength, and colour parameters such as K/S (HUNTERLAB), CIELab values and colourfastness are measured. The experimental results showed weight gain in all fabrics after indigo dyeing. There is a decrease in weft strength only in tamarind, iron, jaggery and dextrose vats. Iron vat showed a higher colour yield out of all reducing agents due to forming metal complexes with the cotton fabric, which influenced colour depth and highest relative colour strength % (114.11) and ΔC (8.48). Result: Thiourea dioxide showed the next highest relative colour strength % (96.59) and lowest ΔH values (8.54) concerning the values of the hydro process. Structural changes of fiber were studied by using SEM (Scanning Electron Microscope) after using different reducing agents, which revealed superior surface topography of samples dyed using thiox. The colour difference showed no significant effect on the colourfastness of alternative reducing agents. Conclusion: Thiox can be a perfect substitution for hydro in indigo dyeing as it was found practical and feasible for implementation even by small-scale units in India.

P-N bonds in P-modified biochar/g-C3N4 composite constructed via mechanochemical method to enhance photodegradation of indigo carmine

P-N bonds in P-modified biochar/g-C3N4 composite constructed via mechanochemical method to enhance photodegradation of indigo carmine

Effect of Chemical Modifications on the Adsorptive Ability of Palm Kernel Fiber for Indigo Blue Dye

This research work investigated the potentials of unmodified Palm Kernel Fibers and its modified forms for the adsorption of Indigo blue dye from aqueous solutions using batch adsorption procedures. Characterization of the fibers were done with the scanning electron microscopy (SEM) and FTIR. Adsorption result showed that maximum uptake of 38.3, 31.0, 33.5 and 14.5 mg/g were respectively obtained for Bleached (BPKF), Acetylated (APKF), Mercerized (MPKF) and Unmodified Palm Kernel Fibers (UPKF) adsorbents at an optimum time of 3 hours. The sorption kinetic obeyed pseudo second order with the bleached adsorbent (BPKF) having the best fit, and at a certain time limit, intra-particle diffusion controlled the process. Data collected from effect of initial concentration experiments were better fit to the Freundlich isotherm. The result from the thermodynamics of the process showed an endothermic process. Increasing adsorbent dosages led to corresponding increase in the quantity of the indigo dye adsorbed by the different adsorbents. This work revealed the potentials of modified palm kernel fibers over the unmodified fiber for effective removal of Indigo blue dye from wastewater.

Efficient bioremediation of indigo-dye contaminated textile wastewater using native microorganisms and combined bioaugmentation-biostimulation techniques

In this work, the bioremediation of wastewater from the textile industry with indigo dye content was carried out using combined bioaugmentation, bioventilation, and biostimulation techniques. Initially, the inoculum was prepared by isolating the microorganisms from the textile wastewater in a 2 L bioreactor. Then, the respirometry technique was implemented to determine the affinity of the microorganisms and the substrate by measuring CO2 and allowed the formulation of an empirical mathematical model for the growth kinetics of the microorganism. Finally, the bioremediation was carried out in a 3 L bioreactor obtaining an indigo dye removal efficiency of 20.7 ± 1.2%, 24.0 ± 1.5%, and 29.7 ± 1.1% for equivalent wavelengths of 436 nm, 525 nm, and 620 nm. The chemical oxygen demand showed an average reduction of 88.9 ± 2.5%, going from 470.7 ± 15.6 to 52.3 ± 10.7 ppm after 30 days under constant agitation and aeration. A negative generalized exponential model was fitted to assess the affinity of the microorganism with the wastewater as a substrate by evaluating the production of CO2 during the bioremediation. Bioremediation techniques improve water discharge parameters compared to chemical treatments implemented in the industry, reducing the use of substances that can generate secondary pollution. Bioaugmentation, biostimulation, and bioventing of the textile wastewater in this study demonstrate the potential of these combined techniques to serve as an efficient alternative for indigo-contaminated wastewater in the textile industry.

Degradation of indigo carmine dye with peroxydisulphate ion in aqueous sulphuric acid phase: Kinetic study

AbstractThe quest for cleaner environments is a global concern. Hence, the investigation of degradation of the indigo carmine dye (IC) with peroxydisulphate ion in an aqueous sulphuric acid system with a view to understanding its kinetic degradation and mechanism. The degradation depicts first‐order kinetics in [S2O82−] and [IC], and the degradation mole ratio of IC: S2O82− is 1:1. The degradation rate is dependent on the change in ionic strength and medium permittivity of the system. Also, added ions (NH4+ and NO3−) influence the degradation rate of the dye which further supported the outcome of the change in ionic strength. Free radical participation is ruled out. The experimental rate law is given as (Kk3[H+])[IC][S2O82−]. Owing to the absence of detectable intermediates in the degradation process, an outer‐sphere mechanism is proposed. The study is significant in textile industries and medical settings for making environments less toxic with a well‐understood degradation rate pathway.

Recycling of natural and waste materials as supports for green silver nanoparticles as efficient catalysts in photodegradation of organic pollutants

The use of a sustainable technology to synthesize green silver nanoparticles (AgNP) from renewable resources is very appealing. Here, a green protocol for the production AgNP/composites is introduced, via in situ reduction of Ag+ ions on sustainable materials (clays and waste materials) using eucalyptus leaves extract (ELE) as a reducing and stabilizing agent, without the addition of any harmful or expensive organic solvent, surfactant or dangerous compounds. The synthesized AgNP/composites were evaluated as photocatalysts to degrade Indigo Carmine (IC) dye as a model pollutant under visible light. Kaolin and pistachio shells showed to be promising supports for green AgNP, with decolorization efficiency of 85.3(±1.8)% and 48.3(±4.1)%, respectively, after 120 min of irradiation. The best catalytic results were obtained with kaolin as support and so the influence of different synthesis parameters of AgNP/kaolin nanocomposite was evaluated. The catalytic results indicated that increasing the amount of AgNO3 and ELE in the nanocomposites, increased their photocatalytic performance. Nanocomposites synthesized at room temperature showed smaller amount of AgNP and higher decolorization efficiency, compared to those biosynthesized at 50 °C. The evaluation of active species responsible for the photodegradation of IC showed that O2•- and H+ radicals are species involved in the reaction. The AgNP/kaolin showed also to be efficient to degrade both atrazine and sulfamethoxazole after 120 min of irradiation.

Analysis of Thoracoscopic Enucleation Combined with Esophagoscopy in the Prone Position for Esophageal Submucosal Tumor.

Background: Esophageal submucosal tumors (SMTs) are rare, occurring in less than 1% of esophageal neoplasms. For surgical treatment of esophageal SMTs, enucleation is usually the procedure of choice for benign tumors. This study aimed at evaluating the surgical technique and outcomes of thoracoscopic enucleation with esophagoscopy for esophageal SMTs. Methods: Patients with esophageal SMTs who underwent thoracoscopic enucleation between 2015 and 2022 were retrospectively investigated. Surgery was performed with the patient in the prone position. First, an esophagoscope was inserted, and a sodium hyaluronate solution with indigo carmine dye was injected into the submucosal layer just below the tumor. Next, under thoracoscopy, the tumor was exposed through a thoracoscopic incision and dissection of the muscularis propria and adventitia was performed at the tumor site. The colored layer resulting from the previously injected dye was identified, and tumor enucleation was performed under guidance of the dye so as not to damage the mucosa or pseudocapsule. Results: In total, 5 surgeries were performed. The mean operative time was 122.6 minutes (range 84-168 minutes), mean blood loss was 21.1 mL (range 0-80 mL), and mean postoperative hospital stay was 8 days (range 7-10 days). There were no postoperative complications. Pathological diagnosis revealed 2 cases of gastrointestinal stromal tumors, 2 cases of schwannoma, and 1 case of leiomyoma. Conclusions: We believe that this technique is a useful and safe method of performing thoracoscopic enucleation of esophageal SMTs because the injected dye provides an indicator of the resection line during enucleation.

Photocatalytic degradation of organic dyes using reduced graphene oxide (rGO)

Photocatalysts have developed into a successful strategy for degrading synthetic and organic toxins, such as chemicals and dyes, in wastewater. In this study, graphene oxide was reduced at different temperatures and used for degrading indigo carmine and neutral red dyes. The wide surface areas, strong adsorption sites, and oxygen functionalities of reduced graphene oxide (rGO) at 250 °C (rGO-250) produced more photocatalytic degradation efficiency and adsorption percentage. The catalyst dosage, initial dye concentration, solution pH and recyclability were all used to optimize the photocatalytic activity of rGO-250. This research presents a capable nano-adsorbent photocatalyst for the efficient degradation of organic dyes. GO and rGOs were also investigated for carbon dioxide (CO2) absorption properties. Results showed that rGO-250 has better CO2 adsorption properties than other rGOs. Overall, it was observed that rGO-250 has better photocatalytic and CO2 adsorption capabilities compared to graphene oxide reduced at different temperatures.