Article

Textile Industry Wastewater Treatment

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Abstract

Effective water and waste management strategies enable us to decrease water consumption and pollution load of wastewaters. Typical examples of low-waste technologies are lanolin recovery in wool scouring, hydroxide recovery in cotton mercerizing, recovery of synthetic sizes and reuse of dye baths. Wastewaters are treated by a sequence of physical-chemical and biological processes. Traditionally, coagulation/flocculation (C/F) has been favored as the first treatment step followed by biological treatment as the second step. More recently a reverse sequence of treatment has been utilized in several cases with success. Novel technologies have been developed such as catalytic oxidation, decoloration by ozone, adsorption/desorption. Their practical use is, however, still rare. Joint treatment with municipal wastewaters has been favored wherever possible.

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... Discharging of water pollutants like synthetic dyes from textile process, even in small concentration, poses a great threat to the aquatic living organisms, resulting in significant disturbance in the ecological system of the receiving water, beyond their undesirable aspects [1,2]. However, wastewater containing colored compounds from textile operations is very hard to treat by conventional activated sludge systems owing to the non-biodegradable nature of the dyes. ...
... M), catalyst loading (0-0.05 g), initial pH of solution (2)(3)(4)(5)(6)(7)(8)(9)(10), and initial dye concentration (50-500 mg/l) on the decolorization process was studied. Morphology, crystallinity and textural characteristics of the modified MWCNT before and after deposition of MnO 2 were examined by SEM, XRD, EDX, FTIR and N 2 adsorption at 77 K, respectively. ...
... Effect of initial pH on degradation of RB19 by 0.5MnO 2 ...
... Worldwide, different industries produce a large quantity of wastewater that is highly colored and contains high levels of organic matter [1]. The use of large quantities of dyestuffs during the dyeing stages of leather manufacturing processes is a cause of such pollution that causes major aesthetic and environmental problems [2,3]. ...
... The most important EAOP is electrochemical oxidation (EOx), where organics are oxidized via Å OH produced from water discharge at the surface [9][10][11]13]. The anodes (with a high O 2overpotential) principally used for this electrochemical approach are PbO 2 , SnO 2 and, more recently, boron doped diamond electrodes (BDD) [9][10][11], according reaction (1). BDDs are considered the best anodes for EOx due to their wide electrochemical window, low adsorption ability, large chemical stability and higher O 2 -overpotential than other electrodes [13]. ...
... Hence, most of the wastewater from the textile industry is currently mixed and discharged to municipal wastewater treatment plants with little or even no pre-treatment (Libra and Sosath, 2003 ). In fact, when centralized treatment is performed , the joint treatment with municipal wastewater is considered to be the optimum alternative, as it can help to solve many difficulties such as the extreme fluctuations in flow and wastewater composition (Grau, 1991). Moreover, the municipal contribution supplies nitrogen and phosphorus (necessary for the biological process) and increases the biodegradable fraction of the wastewater (Grau, 1991). ...
... In fact, when centralized treatment is performed , the joint treatment with municipal wastewater is considered to be the optimum alternative, as it can help to solve many difficulties such as the extreme fluctuations in flow and wastewater composition (Grau, 1991). Moreover, the municipal contribution supplies nitrogen and phosphorus (necessary for the biological process) and increases the biodegradable fraction of the wastewater (Grau, 1991). The domestic component is expected to provide some buffering in terms of the characteristics of the combined flow and, therefore, to enable an easier treatment of combined wastewater compared to individual treatment of industrial effluents on their own (Ng, 2006). ...
Article
Textile effluents are characterised by high content of recalcitrant compounds and are often discharged (together with municipal wastewater to increase their treatability) into centralized wastewater treatment plants with a complex treatment scheme. This paper reports the results achieved adopting a granular sludge system (sequencing batch biofilter granular reactor – SBBGR) to treat mixed municipal-textile wastewater. Thanks to high average removals in SBBGR (82.1% chemical oxygen demand, 94.7% total suspended solids, 87.5% total Kjeldahl nitrogen, 77.1% surfactants), the Italian limits for discharge into a water receiver can be complied with the biological stage alone. The comparison with the performance of the centralized plant treating the same wastewater has showed that SBBGR system is able to produce an effluent of comparable quality with a simpler treatment scheme, a much lower hydraulic residence time (11 h against 30 h) and a lower sludge production.
... Five waste water samples of major textile industrial area of Bhilwara were collected from different locations in clean polyethylene bottles. The following parameters of samples were analysed: pH, EC (electrical conductivity), turbidity, TSS (total suspended solids), TDS (total dissolved solid), BOD (biological oxygen demand) and COD (chemical oxygen demand) to determine characteristics of waste water [9,10]. ...
Article
Full-text available
During the last decade, Bhilwara has developed into a leading place in the textile industry in India. The water used in textile industry is almost entirely discharged as waste. The effluents are very complex, containing salt, surfactants, ionic metals and their metal complexes, toxic organic chemicals, biocides, and toxic anions, which are harmful to both flora and fauna existing on our planet. Degradation of these non-biodegradable organic compounds is not possible by conventional treatment processes. The analysis of waste water with different quality parameters and photocatalytic bleaching was examined by using UV light in photochemical reactor with SnO2 catalyst.
... To solve the problems related to textile effluents, several studies have focused on the origin of pollution (integrated approach) [8][9][10][11] and at the treatment of the final effluents (end-of-pipe approach) [9,[13][14][15]. ...
Conference Paper
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Treatment of colored wastewater from the textile industry is essential to minimize damage to the environment. Various methods based on the adsorbents, biological degradation, coagulation-flocculation, oxidation of Fenton, membrane separation, oxidation with ozone, were used to remove dyes from aqueous solutions. In the present work, according to the phase inversion technique, we have developed polymer inclusion membranes (PIMs) based on polymer supports polyvinylidene fluoride (PVDF) and polyvinyl pyrrolidone (PVP), with chitin as extractive agent (EA). These PIMs have been used to study the facilitated extraction and recovery of the Methylene Blue (MB) and Blue P3R dyes from simulated aqueous textile solutions. FT-IR spectra and SEM micrographs of these membranes were recorded to explore composition, structure and morphology of the elaborated PIMs. The adoption of the kinetic and thermodynamic models based on the Fick's laws, and the saturation law of the EA by the substrate (dyes) were tested to explain the performance of each membrane and the mechanism of the studied process for the recovery of dyes from water. The overall data indicate that the used extractive agent is effective for this oriented process, and the adopted membranes can remove about 87% of dyes from wastewater, without applying any external pressure on the polluted aqueous medium.
... Further the transition metal vanadates are used in catalysis, batteries and implantable cardiac defibrillators (ICDs) [2][3][4] . Dyes of different structure with organic properties including methyl red dye use in many industries pollute the whole aqua system in earth 5 . The different dyes were used in different textile industries introduce various colour dye to water which can create environmental pollution [6][7][8][9][10] . ...
Article
The nanostructures with different morphology have enormous applications in science and technology field, due to its vast advantages over normal materials. Here in, the research work has been carried out for the synthesis of novel nanostructures via hydrothermal method. The selection of nanomaterials was started with focus on the transition metal vanadates with high photocatalytic activity. The present work was carried out for the synthesis of copper metavanadates (CuV2O6) with different morphology like spherical and leaf like nanoparticle by hydrothermal method. The crystalinity and morphological properties were analyzed by using advanced instruments XRD and SEM respectively. Further, the photocatalytic properties of synthesized nanoparticle was investigated by made treatment with synthetic wastewater which contains the methyl red dye and heavymetals in it. The treatment was carried out for the different concentration of catalyst, methyl red dye, and heavymetals. However the effect of concentration of catalyst, pH, Dye concentration and heavymetal concentration was also investigated and founded the optimum concentration for the dye degradation and heavy metal removal simultaneously. This copper metavanadate with different morphology has high photocatalytic performance and the results were obtained with high efficiency. © 2018 Oriental Scientific Publishing Company. All Rights Reserved.
... 1,2 Nowadays, organic dyes used in textile and food industries are the major sources of environmental contamination due to their nonbiodegradability, high toxicity, and carcinogenic effects. 3,4 Additionally, wastewater treatment of pollutants produced from dye processing industries demonstrates a major challenge to attain desired effluent discharge standards, followed by appropriate recycle and reuse of those products in manufacturing processes. Therefore, the degradation of these refractory pollutants has drawn adequate interest and become the need of the hour in the ongoing effort to diminish their environmental impact. ...
Article
We have demonstrated a novel solution chemistry route for the synthesis of nanoscale hierarchical flower-like MnO2 through a light-assisted decomposition of a manganese precursor over the surface of a clay nanotube. By tuning the reaction conditions, we have successfully synthesized δ-MnO2 flowery nanostructures comprising assemblies of intersected nanosheets and subsequently studied their photocatalytic activity for the degradation of organic dyes under natural sunlight irradiations. The crystallographic phase dependent photocatalytic activity of MnO2 nanocomposites has also been carried out toward the photodegradation of dyes, indicating δ-MnO2 nanostructures possess higher catalytic efficiency compared to α-MnO2. The underlying mechanism demonstrates the formation of reactive oxygen species, which in turn facilitate the degradation of dyes and also substantiates that there is no need of any supplementary oxygen sources during photodegradation. The outstanding performance of the hierarchical δ-MnO2 nanocomposites, together with the convenient fabrication method, represents an alternative and environmentally benign route to develop heterogeneous photocatalyst for the degradation of refractory pollutants. Thus, these new insights will shed light in the practical applications of heterogeneous catalysts for environmental remediation through wastewater treatment in a greener approach.
... Although a variety of wastewater treatment processes have been studied for their ability to remove nonylphenolic compounds from wastewater, such as ozonation[83], in particular for the treatment of textile wastewaters[84], it seems that conventional processes still dominate in practice. Primary coagulation/flocculation followed by a secondary anaerobic/anoxic/aerobic activated sludge has been shown to be popularly applied in the textile industry[85], particularly in Vietnam[3,71]. The removal of nonylphenolic compounds depends on the nature of the processes[72], and factors such as the population served by the sewage system[86], wastewater compositions[81,87], hydraulic retention time (HRT)[88], biomass concentration (expressed as MLSS), solids retention time (SRT), pH and temperature[81].Table 1demonstrates the removal efficacies of NPEOs and NP by some commonly used wastewater treatment processes. ...
Article
Full-text available
The textile industry is a significant source of nonyphenol and their ethoxylates, which are suggested to be responsible for endocrine disruption in wildlife and humans. This study is a comparison of two conventional wastewater treatment processes in a cotton and a synthetic fiber factory in Vietnam, with regard to the distribution and removal of nonyphenol ethoxylates and nonyphenol throughout each process. Diverse trends in the distribution of nonyphenol ethoxylates in wastewater from factories, distinguished by their raw materials, could be revealed. Primary coagulation might not perfectly facilitate nitrification in the secondary activated sludge process regarding pH. Nevertheless, satisfactory removals were achieved during coagulation and activated sludge processes in both systems. The roles of long hydraulic retention times (21 and 16 h, respectively), low organic loadings (0.1 and 0.2 gCOD/gMLVSS.day, respectively), extended solids retention times (61 and 66 days, respectively), and mixed liquor suspended solids of greater than 2000 mg/L have been demonstrated. The findings provide evidence and a better understanding of nonyphenol ethoxylate and nonyphenol removal efficacy as well as influencing factors in Vietnamese textile wastewater treatment. The results are beneficial for the textile industry in Vietnam regarding investment decisions for wastewater treatment.
... During the dyeing process, about 15% of the total world production of dyes is lost and released in the textile effluents [1]. Discharging of the untreated textile effluents into water is one of the major sources of water contamination [2]. The presence of dyes in water reduces light penetration and hinders photosynthesis in aquatic plants [3]. ...
Article
Full-text available
Mn3O4 nanoparticles were synthesized from one-step reduction of KMnO4 with glycerol at 80 °C. The structural and surface morphological characterizations were carried out using FT-IR, XRD, and FESEM analyses. The elemental composition was evidenced from EDX analysis. XRD analysis showed the tetragonal crystal geometry of Mn3O4 nanoparticles with an average crystallite size of ∼20 nm. The surface morphology of the Mn3O4 nanoparticles was found to be spherical from the FESEM image. The Mn3O4 nanoparticles were then tested as a potential oxidant for the decolorization of methylene blue (MB) and found to be capable of N-demethylation of MB forming thionine as the final product, and removing 80% of the dye in approximately 1 h. The decolorization of MB by Mn3O4 occurred through a surface mechanism, i.e., formation of surface precursor complex between MB and surface-bound Mn (II, III), where, electron transfer occurs within the surface complex. The effect of suspension pH (3–4 < pHpzc; 5–10 > pHpzc) on MB decolorization was assessed. Suspension pH exerted double-edged effects on MB decolorization by influencing the formation of surface precursor complex, and reducing potential of the system.
... En çok su kullanan endüstriyel sektörler arasında yer alan tekstil atıksuları miktar ve bileşim yönünden çok değişken olup, kompleks bir yapıya sahiptirler (Grau, 1991;Germirli 1990a; Germirli ve diğ., 1990b). ...
... Dyes used in the textile industry are major water pollutants with upsetting environmental impacts. 1 The textile manufacturing process involves the preparation and utility of various dyes, and partly introduces these dyestuffs into aquatic systems and thus leads to environmental pollution and health hazards. [2][3][4][5][6] Methyl red dye has been extensively used in textile, leather and paper industries and the efficient removal of methyl red dye has become a challenging task for environmental chemists. ...
Article
Carbon nanotubes (CNTs), due to their van der Waals forces and π-π interaction have great potential as a strong material resource for the environment water purification. Herein, we reported the purification of industrial effluent using polyvinyl alcohol (PVA) and multiwall carbon nanotubes (MWCNTs) composite material. It is demonstrated that the removal of methyl red dye and heavy metals can be driven simultaneously by efficient composite material. The methyl red dye present in aqueous solution of effluent made hydrogen bond with PVA polymers and adsorbed, simultaneously the heavy metals also adsorbed on the cylindrical hallow structure of MWCNTs and removed. The environmental friendly removal of dye and heavy metals was confirmed by advanced analytical techniques such as scanning electron microscopy, chemical oxygen demand, X-ray diffraction and UV-visible spectrophotometer.
... More recently some authors started to look at the natural flocculating materials for the treatment of various types of wastewater. Among the natural flocculating materials, various polysaccharides are considered as better option for wastewater treatment[8]. We have reported the use of some natural and grafted polysaccharides for the treatment of various types of wastewater[9][10][11]. ...
... Effluents from the dyeing and finishing processes in the textile industry are known to contain strong color, high amounts of surfactants, dissolved solids, fluctuating temperature, high pH and possibly heavy metals (e.g. Cu, Cr, Ni) [3]. Existing physicochemical technologies, such as membrane filtration or activated carbon adsorption, are expensive and commercially unattractive. ...
Article
In this study, the treatment efficiency of different advanced oxidation (Fe+2/H2O2, Fe+3/H2O 2, O3) and chemical coagulation processes were investigated. Wastewater samples were taken from two different textile industries. Optimum efficiencies in color and COD removal were determined based on the applications of different chemical species and pH. 150 mg/L FeSO 4 at pH 12 has provided the maximum color and COD removal efficiency in chemical coagulation experiments for textile industry 1. For textile industry 2, maximum color and COD removal efficiencies were obtained with Fe +2/H2O2 (Fenton) process at pH 3 (FeSO 4 200 mg/L and H2O2 200 mg/L dosages). The operating costs of all proposed treatment systems were also evaluated in this study.
... Boyama, diðer tekstil prosesleri olan hazýrlama, yýkama ve aprelemeye nazaran oldukça fazla miktarda su ve kimyasal madde tüketen bir prosestir. Boyama iþleminden gelen atýksularýn içerisinde önemli miktarda boya banyo kalýntýlarý ve fiske olmamýþ boyarmaddeler bulunmaktadýr (Grau 1991). Boyama sýrasýnda kullanýlan birçok kimyasal madde, kalýcý ve biyolojik olarak ayrýþmasýnýn zor olmasý nedeniyle biyolojik ve fizikokimyasal (adsorpsiyon, koagülasyon ve çöktürme) arýtma proseslerine karþý dirençli olup bu tip arýtma yöntemleri ile giderilememektedir (Pagga ve Brown 1986, Ýnce ve Gönenç 1987. ...
Article
In this study, COD and colour removal efficiencies of a textile industry wastewaters, which is located in Bursa City were investigated, using different advanced oxidation processes. Coagulation, Fenton, Fenton-like and ozonation processes were applied to the wastewater taken from the equalization tank of the treatment plant of the industry. The results show that, the best results for COD and colour removal were obtained using Fenton processes and ozonation. COD and colour removal efficiencies for Fenton process and ozonation were determined as %52 and %96, %51 and %98, respectively. Operating costs of various advanced oxidation processes were also determined in the study. Considering operation and investment costs, for COD and colour removal from textile industry effluent Fenton process was suitable.
... Dyes are one kind of highly harmful contaminants originating from various industries viz. Paper, textiles, rubber, plastics, cosmetics, leather, food and so on, which pose a worldwide environmental issue due to the inclusion of acids, dissolved solids, toxic compounds, color and possibly harmful heavy metals such as Cr, Ni and Cu [1][2][3][4][5] . Once disposed into the water bodies, dyes not only impart toxicity to the aquatic lives and interfere the balance of water environment, but also cause hazardous influences on human health via damaging vital organs like the brain, kidneys, live and reproductive systems [6][7][8][9] . ...
Article
MCM-41 is demonstrated to be an efficient adsorbent for the removal of two representative cationic dyes, namely Basic Violet 5BN (BV) and Basic Green (BG). Characterization of the adsorbent was studied by FTIR, X-ray diffraction, and Brunauer-Emmett-Teller. And various parameters including the solution pH, adsorbent dosage, contact time, initial cationic dye concentration, and temperature were systematically analyzed. It was found that the adsorption was pH independent and the maximum removal percentage of 86.81% BV occurred at pH 5.0 and 25°C using 0.3-g MCM-41, whereas 94.79% BG under the same experimental conditions. Besides, both the adsorptive removal of BV and BG by MCM-41 increased with the adsorbent dosage and contact time, but decreased with the initial dye concentration and temperature. In single component systems, equilibrium data were well presented by the Langmuir isotherm, suggesting the adsorption to be monolayer. And the E values (<8 kJ/mol) resulted from the D–R isotherm fitting showed the adsorption was physical in nature. The adsorption kinetics fitted better with the Lagergren pseudo-second-order model, and rate-controlling steps were both the external diffusion and intraparticle diffusion. Thermodynamic parameters (ΔG°, ΔH°, and ΔS° < 0) indicated that the adsorption process was feasible, spontaneous, and exothermic. Furthermore, competitive adsorption existed between the mixed dyes, and the removal efficiency and adsorption capacity of the dyes in binary component systems were lower than those in single systems. The adsorption isotherm and kinetic data of the binary component systems could also be well described by the Langmuir and Lagergren pseudo-second-order models. High recovery percentage of BV and BG by 0.1-M NaOH solution allowed excellent desorption and regeneration of the cationic dyes in practical applications.
... Many textile industries use dyes generating a colored wastewater that causes damage to the ecological system. Therefore, treating dye effluents prior to their discharge is essential [1]. Manganese oxides are powerful oxidants due to their relatively high reducing potential (Fig. S1). ...
Article
Degradation of methylene blue (MB) is investigated using Mn3O4 as an oxidant. Discrete Mn3O4 particles and Mn3O4/Fe3O4 nanocomposites are synthesized via coprecipitation by using air as an oxidant in the absence and presence of previously synthesized magnetite nanoparticles, respectively. Characterization results show that superparamagnetic magnetite nanoparticles of 10 nm were synthesized. The Mn3O4 synthesis in the presence of these magnetite nanoparticles favors the formation of a pure, highly ordered Mn3O4/Fe3O4 superparamagnetic nanocomposite, which can be separated by an external magnetic field. This nanocomposite is applied to the oxidative decolorization of methylene blue (MB) and is capable of catalyzing the complete N-demethylation of MB, forming thionine as the final product and removing 93% of the dye in approximately 1 h.
... As from the table 3, sample E1 collected from the CETP, Veerapandi can be easily biodegradable and we suggest that the biological treatment process for purification. According to Grau [27] , coagulation prior to biological treatment might be advantageous for alkaline wastewaters. But for effluent samples from other places E2 to E4 need both physico chemical treatments such as adsorption, ionexchange, membrane technology, Electrocoagulation treatments etc. ...
Article
Full-text available
The pollution load of the various textiles industrial effluents vary from time to time depends upon the dyes, impurities on the fabrics and other processing chemicals used for the dyeing. Five sampling points were identified from textile industries of Tirupur city, India (E1 to E5) and the study was carried out on the basis of field analysis and characterization studies. The major pollution indicating parameters like COD, BOD, TDS, SS, alkalinity, pH, total hardness, sulfate and chloride levels were analyzed. The effluent was highly turbid and coloured with average organic and inorganic loading. BOD5/COD ratios ranged from 0.2-0.5 indicates that the effluent contained a large proportion of non-biodegradable organic matter. The effluent also contained high concentration of sulfate, chloride, calcium and magnesium, which are responsible for higher total hardness of effluent. Sample E4 shows high total hardness, alkalinity, pH and conductivity compare to all other effluents is needed much attention to find a suitable technology for the treatment. The effluents from the study area containing pollution indicating parameters considerably higher than the standards stipulated by the governmental authorities. Based on these characteristics, it is suggested that the effluent is not be suitable for discharge directly into aqueous bodies without treatment.
... Acid, basic, reactive and direct dyes are soluble dyes, while dispersed pigments and oxidized dyes are insoluble in water [6]. The wastewaters originated from textile industry include high chemical oxygen demand (COD), high biological oxygen demand (BOD), suspended solids, heat, acidity, alkalinity and chemicals such as salts [7] and various pollutants such as high organic materials and color depending on dyes in various structures and textile auxiliary materials such as surface active materials and polyvinyl alcohol (PVA) utilized in sizing process [8]. These wastewaters, which include azo dyes, may cause toxic effects on living organisms in the environment into which they are discharged [9]. ...
... Textile dyeing is the most chemically intensive process among all textile industry steps, which include textile preparation, dyeing, washing and finishing. Wastewaters resulting from textile dyeing contain significant concentrations of unfixed dyestuff and considerable quantities of auxiliary products (Grau, 1991). Unfortunately, many of the chemicals and dyes used in textile dyeing are recalcitrant; they are often not biodegradable and eventually toxic (Anouzla et al., 2009). ...
Article
New strategies were herein applied for treating a cotton dyeing wastewater: coagulation/flocculation followed by Fenton's oxidation - Approach 1, Fenton process per se - Approach 2, and Fenton followed by coagulation/flocculation - Approach 3, aiming reducing chemicals consumption. Regarding the cost analysis, which is crucial for deciding on the best strategy to implement, it was found that in approach 1 and approach 2 the hydrogen peroxide has a major influence on the total costs as compared to ferrous ion. In approach 3, the total costs are again mostly related to the consumption of reagents in the oxidation stage. The integration of the Fenton's process followed by coagulation/flocculation provided an effluent that meets the discharge limits, with global organic matter removals of 55.6% for COD, 42.7% for BOD5 and 70.4% for DOC, and almost complete colour reduction (99.6%). However, the combined treatment of coagulation/flocculation followed by Fenton's oxidation exhibits also high overall efficiencies (61.7%, 25.8% and 71.2% for COD, BOD5 and DOC removal, respectively, with almost complete decolourisation) but simultaneously smaller operating costs associated with chemicals consumption (0.82 €/m3), putting into evidence the usefulness of the novel strategy implemented: use of the residual dissolved iron employed as coagulant in the first stage as catalyst in the subsequent Fenton's oxidation.
... Many industries use dyes to colour their products. Wastewaters generated from textile industry contain various pollutants including a high content of organic matter and colour depending on forms of dyes, surface active materials and textile additive materials used in the textile dyeing process [1]. Almost 15% from the dyes used in textile industry are lost in dyeing processes and are recovered in the wastewaters [2 -3]. ...
Article
Full-text available
Delivery of textile or chemical wastewaters in river streams or pipeworks without an adequate treatment determines undesired consequences. Moreover, most dyes used nowadays are refractory compounds. Conventional biological treatments are not effective for most of synthetic dyes especially due to their polyaromatic structure. That is why advanced oxidation processes (e.g., H2O2/Fe2+) for decomposition of nonbiodegradable organic contaminants into industrial effluents are attractive alternatives to conventional treatment. The paper proposes the study of homogenous oxidation (Fenton reagent) with hydrogen peroxide applied for some wastewaters containing Methylene Blue dye in different operational conditions in order to get the maximum decolourization removal using the empirical Box method. All kinetic experiments were performed on wastewater samples of 100 mL (100 mg dye/L) under continuing agitation, at a temperature of 17 °C, pH of 6.5 and different concentrations (or volumes) of H2O2 and FeSO4 solutions.
... Reactive dyes are the most commonly applied among more than 10,000 dyes used in textile processing industries(Van der zee, F.P et al 2001). Reactive dyes are particularly problematic in dye wastewaters as many of these are resistant to biodegradation processes (Grau, P ,1991 However, no effort is made to optimize coagulation highly depends on the extent to which the soluble colour contributing COD can be coagulated and flocculated in addition their floc formation and settling abilities. The present investigation describe the chemical coagulation of four selective reactive dyes generally used for cotton yarn dyeing using polyaluminium chloride (AlCl 3 6H 2 O). ...
Article
Poly Aluminium Chloride (AlCl3 6H2O) was used as a coagulant for the removal of Chemical oxygen demand (COD) of selective reactive dyes at different doses. The results indicate that the removal of COD of RB 41, RB 209, RB204 and RB 184 were 68, 40, 36 and 29 percent respectively at optimum doses. The optimum doses polyaluminium chloride for RB41, RB209, RB 204 and RB 184 were 5.2, 34.3, 20 and 22 mg of PAC per mg. of COD removed respectively.
... Residual and waste water have become a problem of paramount importance in modern societies [1]. Recently, the number of proposals to solve this issue has incremented importantly [2]. ...
... However, bulking of activated sludge occurs frequently if a large proportion of the wastestream consists of desizing waste water. 6 The use of recyclable sizes such as polyvinyl alcohol (PVA) is a viable option for integrated Anaerobic treatment produces a much smaller volume of sludge when compared with aerobic treatment and no aeration is needed, a factor which represents a major cost in aerobic treatment, given the high BOD levels involved. This gives the anaerobic digestion process a potential economic advantage. ...
Article
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... Highly colored effluents with considerable amounts of organic compounds are commonly generated in dyeing textile industries. 1 The presence of these pollutants, namely dyes, in dyeing wastewaters is the cause of such pollution 2,3 and generates a negative impact in receptor water courses, as dyes exhibit toxicity to mammals and aquatic organisms, 3 absorb the sunlight, and hinder the photosynthetic activity of aquatic plants, leading to serious problems in the ecosystem. 4 For minimizing the negative impacts that such effluents impart, it is necessary to apply an efficient treatment in the wastewater before its discharge. ...
Article
The degradation via the photo-Fenton process of dyes and organic compounds present in acrylic, cotton, and polyester dyeing wastewaters was investigated, aiming at reducing the consumption of chemicals, as compared to the dark Fenton process, while simultaneously minimizing the energy costs by using simulated solar radiation. The reduction of the hydrogen peroxide dose is limited by the need of achieving treated effluents complying with discharge limits, but for dark Fenton the operating costs are excessive. The costs associated with the use of artificial radiation in the photo-Fenton process (17.4, 9.6, and 2.9 €/m3 for acrylic, cotton, and polyester effluents, respectively) are also too high. The use of (simulated) solar light allows for obtaining high degrees of removal of color (>98–99%) and significant COD (30.1–72.0%) and DOC (46.2–71.5%) reductions at a total cost reduction of a factor of ca. 3. Treated effluents by the solar photo-Fenton process also meet the discharge standards.
... Thus, several governments have established environmental restrictions with regard to the quality of colored wastewater and have forced dye-using industries to remove dyes from their effluents before discharging them into water bodies. Several dye removal methods such as biological, chemical, and physical processes have been investigated extensively [3,[11][12][13][14][15][16][17]. Adsorption as a physical process can handle large flow rates, producing a highquality effluent that does not result in the formation of harmful substances, during the process. ...
Article
Full-text available
In this paper, the thermodynamic properties of textile dye removal from aqueous solutions using poly(propylene imine) (PPI) dendrimer were studied. Direct Red 80 (DR80) and Acid Green 25 (AG25) were used as model dyes. The surface coverage of dendrimer was obtained to investigate the adsorbent characteristics. The effect of temperature on dye removal has been studied at different dye concentrations. The adsorption isotherms (Langmuir and Freundlich) and kinetics (pseudo-first-order and pseudo-second-order) were studied in various temperatures. Thermodynamic parameters such as free energy of adsorption (∆G), enthalpy (∆H), and entropy (∆S) changes were calculated to predict the nature of the adsorption. It was found that the isotherm data of DR80 and AG25 followed Langmuir model at different temperatures. Adsorption kinetics of dyes was found to conform to pseudo-second-order with a good correlation coefficient. The estimated values for ∆G showed that the adsorption process was spontaneous. Based on the data of the present study, it can be concluded that PPI dendrimer, as an eco-friendly material, is a suitable adsorbent for the elimination of dyes from colored textile wastewater at different temperatures.
... The color impedes light penetration and the dyes and/or their degradation derivatives can prove toxic to aquatic life. 3,4 Reactive dyes are by far the best choice for dyeing cotton and other cellulose fibers. These dyes utilize a chromophore containing a substituent that is capable of directly reacting with the fiber substrate. ...
Article
Full-text available
The present study describes the advanced oxidation (Photo catalytic oxidation) of an anaerobically degraded textile dye bath effluent containing reactive red 2 dye by combined UV and hydrogen peroxide. The reactor used in this study is a batch laboratory-scale photo-reactor equipped with a low-pressure mercury lamp. Different initial dosages of hydrogen peroxide at variable TiO 2 concentrations were used. The degradation of secondary metabolites formed during the anaerobic degradation was measured in terms of Chemical Oxygen Demand (COD) reduction. Within 5 hours of exposure time at 200 rpm stirrer speed with 30 mmolL -1 H 2 O 2 concentration, 350 mg L -1 TiO 2 concentration and pH 3 the COD reduction was appreciable with 97% COD reduction based on the inlet COD to the photocatalytic reactor.
... Dyes from textile industries are major water pollutants with upsetting environmental impacts. 1 Because of their toxicity and ability to reduce the uptake of light; dyes interfere with the photosynthesis of aquatic plants hence having a direct impact in 25 the oxygen content of water sources. 2 Nanostructured materials may offer efficient and innovating solutions to environmental problems. 3,4 Specifically, manganese oxides are of great interest and have demonstrated adsorption and catalytic properties suitable for use in environmental 30 remediation. ...
Article
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We report on the in situ synthesis of nanostructured MnO2 onto natural fique fibers. The fiber surface was rendered positive by exposure to alkaline conditions, and permanganate anions (MnO4!) were embedded onto the resultant alkali cellulose via coulombic interactions. An ultrasound-assisted pro- cedure was used to reduce MnO4! and yield MnO2 nanoparticles (NPs). UV-Vis diffuse reflectance was used to assess the influence of the precursor concentration, loading and reduction times on the synthesis of the nanostructured MnO2. FESEM provided direct evidence that MnO2 NPs and aggregates could be formed on the fiber’s surface. The catalytic activity of the new bionanocomposite was tested for the removal of indigo carmine dye in water samples. The MnO2–fique fiber bionanocomposite was able to remove up to 98% of the colour present in the contaminated water samples in less than 5 minutes. Mass spectrometry was used to determine the degradation route of the dye. Additionally, we found that the bionanocomposite can be reused with no effect on the dye degradation efficiency. The reported pro- cedure provides a new route for the development of biodegradable and easy to synthesize composite materials capable of efficiently degrading pollutants found in industrial effluents.
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In this study, waste tire was used as raw material for the production of activated carbons through pyrolysis. Tire char was first produced by carbonization at 550°C under nitrogen. A two factorial design was used to optimize the production of activated carbon from tire char. The effects of several factors controlling the activation process, such as temperature (850–950 °C), time (2–6 h) and percentage of carbon dioxide (70%–100%) were investigated. The production was described mathematically as a function of these three factors. First order modeling equations were developed for surface area, yield and mesopore volume. It was concluded that the yield, BET surface area and mesopore volume of activated carbon were most sensitive to activation temperature and time while percentage of carbon dioxide in the activation gas was a less significant factor.
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