is generally difficult to achieve the desired treatment effect, mixed treatment method is significantly stronger than the single treatment method. Physical treatment methods, including adsorption, membrane separation technology, electronic decolorization technology, extraction technology, magnetic separation method. The most widely used in the physical treatment method is the adsorption method, which is suitable for the deep treatment of low concentration printing and dyeing wastewater. The cost is low and the decolorization effect is good, which is suitable for the treatment of small and medium-sized dyeing and printing plant wastewater. Membrane separation is one of the most commonly used methods for treating printing and dyeing wastewater. It means that in the wastewater treatment, molecules of different particle sizes pass through the semipermeable membrane, so as to achieve selective separation. Membrane separation technology is purely physical process, the membrane does not change phase, without adding catalyst, running low cost. However, the one-time cost of the film is high and the pollution is serious. Different pretreatment methods are selected according to the type of the waste water. Properly remove the suspended solids at the pretreatment time to increase the service life of the membrane, but increase the cost. The extraction method mainly uses the organic matter in water and in the organic solvent solubility difference, then the extractant and the pollutant separation, may use the extraction agent, the pollutant can also be further processed after turning waste into treasure. Liquid film technology is one of the rapid development methods in recent years, and can extract dye material in dye-containing wastewater. Magnetic separation technology is a new type of water treatment technology
Mixed bacteria consortium refer to a micro-ecological system in which two or more microorganisms reach the advantage of its largest group of the combined effects through common culture, interaction and mutual influence. The organic matter in dyeing wastewater may be degradated more thoroughly and completely due to the co-metabolism between a variety of bacteria. So the decoloration rate and the degradation effects of mixed bac- teria consortium are all better than single bacteria. There have been many scholars engaging in screening and domesticating mixed bacteria consortium so far (Safia et al., 2007; Saratale et al., 2009). Taruna et al. (2008) screened a bacteria consortium TJ-1 which possesses the degradation capacity of acid orange 7 and a lot of azo dyes wastewater. The decolorization rate of TJ-1 is higher than single bacteria which prove that there are inte- ractions among the bacteria. After treating AO7 solution 16 h at the concentration of 200 mg/L, the decoloriza- tion rate had reached 90% which showed perfect effects.
The continuous combined process for washing and dyeing wastewater consists of coagulation and settling reac- tor and photocatalytic system. A flow diagram of the continuous washing and dyeing wastewater treatment sys- tem used in this study is shown in Figure 1. Flocculation pretreatment was carried out in an up-flow inner cir- culation coagulation and settling reactor. The washing and dyeing wastewater with a certain velocity into the flocculation sedimentation tank, while adding nano flocculant, the waste water and the nano flocculant mixed rapidly within the reactor settlement, removing most of the chroma and COD, and then the sludge discharged from the bottom. The supernatant from the upper overflow weir inflow photocatalytic reactor, after photocataly- tic degradation in the sunlight further the removal of COD, to achieve the reuse standard.
electrode, the enhancement of rare earth doped for dye degradation was explored. The effects of operational factors in electrochemical oxidation were detailed studied. Based on the intermediates detected by IC and HPLC, the possible degradation mechanism was discussed. This paper can provide basic data for dyeing wastewater pollution control.
Nanophotocatalytic ozonation (PCO) of textile dyeing wastewater with Cu-ZnO nanocatalyst was studied in a laboratory scale recirculating photocatalytic ozonation batch reactor. A bench scale reactor was fabricated to suit the integration of ozonation and nano photocatalytic treatment. After optimizing the reaction parameters such as Ozone dosage, Catalyst dosage, pH for nano PCO with Copper doped zinc oxide (Cu-ZnO) nanocatalyst and Amaranth dye as a model pollutant, the efficiency of the PCO reactor was investigated with respect to ozone dosage (0.24g/h-0.57g/h), liquid volume (1000 mL-5000 mL), recycle rate (6 L/h- 39L/h). Based on the optimized parameters, the mineralization of the Amaranth dye resulted in 85.6% removal. Ozone dose was found to have a significant impact on the process efficiency. Wastewater from textile dyeing industry showed 95% degradation measured by Chemical Oxygen Demand removal and 80% mineralization by reduction of Total Organic Carbon. Biodegradability of the treated wastewater increased to 0.42 implying that the further treatment could be progressed by biological method. This study on recirculating batch reactor shows that this treatment could be scaled up for industrial sector.
the following dimensions: 0.2×8×12 cm 3 . These were 2 cm apart and had a monopolar electrode configuration inside the reactor. A HUA ELECTRONICS converter (model DC POWER SUPPLY HY3003-F), capable of adjusting the voltage from zero to 40 V was used to apply the desired voltage to the electrocoagulation reactor. A magnetic stirrer (model RCT Basic made by the German company, IKA) was employed to mix the wastewater. Also the utilized products in this experiment were originated from the German company, Merck. They included 1N sulfuric acid and sodium hydroxide for adjusting the pH as well as hydrochloric acid for washing the blades. Figure 1 shows the schema of the used reactor.
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This standard method is recognized by U.S. EPA, which is labeled Method 5210B in the Standard Methods for the Examination of Water and Wastewater. In order to obtain BOD5, dissolved oxygen (DO) concentrations in a sample must be measured before and after the incubation period, and appropriately adjusted by the sample corresponding dilution factor. This analysis is performed using 300 ml incubation bottles in which buffered dilution water is dosed with seed microorganisms and stored for 5 days in the dark room at 20 °C to prevent DO production via photosynthesis. In addition to the various dilutions of BOD samples, this procedure requires dilution water blanks, glucose glutamic acid (GGA) controls, and seed controls. The dilution water blank is used to confirm the quality of the dilution water that is used to dilute the other samples. This is necessary because impurities in the dilution water may cause significant alterations in the results. The GGA control is a standardized solution to determine the quality of the seed, where its recommended BOD5 concentration is 198 mg/l ± 30.5 mg/l. For measurement of carbonaceous BOD (cBOD), a nitrification inhibitor is added after the dilution water has been added to the sample. The inhibitor hinders the oxidation of ammonia nitrogen, which supplies the nitrogenous BOD (nBOD). When performing the BOD5 test, it is conventional practice to measure only cBOD because nitrogenous demand does not reflect the oxygen demand from organic matter. This is because nBOD is generated by the breakdown of proteins, whereas cBOD is produced by the breakdown of organic molecules.
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This investigation were carried out to satisfy the color fastness properties and limited color variety which are presumed as key constrains in application of natural dyes on tex- tile coloration. Here, cotton fabric was pre-mordanted with metallic salts to improve dye (BFS) fiber binding through fiber-metal-dye interaction via coordination bond. The color differences were represented by ΔH*, ΔC* and ΔL* respectively. Except light fastness all other color fastness properties were gratified greatly. But color variety was not attained in higher extent. For environmental hazard analysis, the metals loading were calculated from residual mordanting bath and dyeing wastewater respectively. The amounts of residual metal ions in mordant bath were beyond the acceptable limit of environmental standards. Though in dyeing wastewater iron and copper existed within the acceptable range but unfortunately the substantial amount of SO 4 2− incurred from these metal salts
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Dyes are one of the most demanding compounds in many industries such as rubber, paper, plastic, cosmetic, etc. However the biggest consumer of dyes are textile industries. It is estimated that about 10,000 of different commercial dyes and pigments exist and over 7 × 10 5 tonnes are produced annually world wide (Pearce et al., 2003 and Yu et al., 2010). Among them azo dyes are the largest group of synthetic dyes (60–70%). A small amount of azo dye in water (10–50 mg/L) is highly visible (Carliell et al., 1995). With enormous demand and consumption of dyes, treatment of textile dyeing wastewater is a big issue.
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The requirement of today industry is the production of desired product with less energy consumption. In textile industry, dyeing and finishing sectors consume the highest amounts of water and energy. Viscos yarns, which are one of the man-made fibers, have great effect of textile industry and it is widely used in clothing sector. On the other hand, in order to achieve a new method of dyeing, a new medium that could play an effective role as a cofactor in absorbing dye particles is needed. Treated clay nanoparticles are between among the mediums that poses such ability. Since, dyeing viscose fabrics have major constraints, improving the tonality of viscose fabrics which are treated with clay nanoparticles in order to be used in shawl production had been studied in the current study. For this purpose, viscose fabrics, which were washed with different values of clay nanoparticles’ concentration, have been treated. Thereafter, the treated viscose fabrics were dyed under the direct reactive, sulfur and dispersants dying process. Meantime, designing the dyed fabrics for being used in shawl production was also studied. Findings of the study shows that the viscose fabrics which were treated with values more than 0/5 (o.w.b) of clay nanoparticles can improve the tonality of treated fabrics and as a consequence prevents its wastage during the Dyeing wastewater treatment.
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Eugenija Zuskin et al. studied pulmonary function among dyeing workers. They used a questionnaire and across-shift changes in spirometric parameters for evaluation. Their results showed that the prevalence of acute and chronic respiratory symptoms in dyeing workers was higher than control group. All spirometric parameters decreased after work shift in male workers and significant decrease was seen in forced expiratory flow (FEF)25–75% and FEF50% and FEF25% in female workers (15).
The effect of temperature is to activate the molecular vibration in the dyes until they exceed the critical energy value necessary for the transfer of dye from the solution to the fiber. The number of molecules which will be able to be reach will be governed by their concentrations. So, the increase in temperature may improve the dye bath exhaustion, but to a limited extent. However higher temperature (95C) are generally recommended for dyeing of fiber to obtain better penetration and high affinity as shown in Table 3.
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It was concluded that the mixed dyeing in two dye baths with indigo and madder colorants achieved a more intense and uniform coloration. The results were attributed to the difference in optimal dyeing conditions between the indigo and madder colorants. The pH of the medium was the most important factor that caused this difference. Therefore, indigo required a high alkaline medium to achieve complete solubility in a dye bath. In contrast, the madder colorants had a lower substantivity towards wool fiber in this high alkaline medium.
The catechinone dyes hair orange, reddish orange or deep yellowish brown depending on dyeing conditions such as the oxidation method, dye concentration, temperature, pH and additives  . The colour fastness of the hair dyed by catechinone to washing and light (daylight and ultraviolet light) is high enough as same as that of oxidation hair dyes  . However, the dyeability of catechinone is not high enough for practical use, be- cause the hair dyeing by using it is mild way and the dye colourant molecules do not vigorously penetrate into hair. Therefore, improving its dyeability without using harmful agents is important and requisite for developing the technique.
hot and cold water and then dried in air. The disperse dyeing of the scoured fibres was carried out in a high temperature / high pressure beaker dyeing machine (Rota dyer, India) using a standard method of the dyeing of synthetic fibres. The dyed samples were then subjected to reduction clearing treatment with 2 g/l caustic soda and 2 g/l sodium hydrosulphite for 20 min at 70 0 C, which was
a special dyeing frame of loose fibers was designed. Using the dyeing frame and inner and outer dyeing processes, polyester fibers were dyed with disperse red 153 # maternal dyes at temperatures of 80-140 ℃ , pressures of 17-29MPa and time of 20-80min, respectively. The experimental results revealed that the dyeing performance of fibers was good on the dyeing frame, as well as with a favorably increased temperature, pressure and time. Dyeing temperature had a strong influence on the color yield. The dyeing results were compared with those of polyester fibers dyed with disperse red 153 # dyes. With the special dyeing frame of loose fibers, color fastness to washing and artificial light was generally similar to conventional aqueous medium methods. Keywords: Loose fiber; Dyeing; Polyester; Dyeing frame; Supercritical CO 2
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The alkaline agent selected as fixing agent could enhance dye uptake . Different amount of fixing agent was added, and the results of its effects are presented in Fig. 8. Clearly, dye uptake and K/S value initially increased, and then decreased with increased fixing agent. Dye uptake reached the maximum value at 31.2%, when the fixing agent was increased to 25 g/L. However, the K/S was maximized to 13.00 at 30 g/L. Addition of fixing agent could increase the pH value of dye solution and form more cellulose hydroxy anions, and thus the rate of dye-fixing reaction was acceler- ated. Moreover, the amount of dye fixed on the wood fiber rapidly increased, so the K/S value increased. However, when addition of fixing agent was further increased, the hydrolysis rate was higher than the reaction rate, so the dye uptake and K/S decreased. Therefore, according to the com- prehensive consideration, the better fixing agent was 25 g/L. Through the above analyses, the idealized process by single-factor experiment uses a temperature of 50 °C, a dye concentration of 0.5%, a ultrasonic power of 160 W, a dyeing time of 120 min, a dyeing assistant of 40 g/L, and a fixing agent of 25 g/L.
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In this section, other reactive dyes were used to assess the suitability of cationic modification. The cationic cotton was dyed without the addition of salt and untreated cotton was dyed with conventional method (adding 50g/L NaCl). Table 2 shows that the color yield and the total dye utilization of the cationic cotton with four reactive dyes were all much higher than those of untreated cotton. In comparison with untreated cotton, the cationic cotton displayed excellent color strength using salt-free dyeing. Though S r (λ) of the cationic cotton fabric was slightly higher than that of untreated cotton, the
The untreated and solvent- pretreated 65/35 blended fabric after dyeing were tested for their wash fastness, light fastness and rub fastness using AATCC test methods (AATCC technical manual 2000). The washing fastness, was evaluated by AATCC method 61(2A) using an Atlas-Launder Ometer. Fastness to light was evaluated by AATCC method 16E using an Atlas CI 3000 + Xenon Weatherometer. The fastness to rubbing was also evaluated as per AATCC 116-1995 standards using crock meter.
process modification was carried out by eliminating the curing stage at the experimental process. However, conventionally this process was done in three stages namely pad-dry-cure process which is available in most manufacturing unit. But it is possible to accomplish the whole process in two stages i.e. pad-dry, without compromising the garments fastness and other properties. Hence the later process can be more efficacious than existing one, as one step can be eliminated completely which contributes reducing the process time along with power and cost savings. Experimental result shows that sample developed in pad-dry process possess good properties in comparison with the existing process (pad-dry-cure). Thus the experimental process can be used in a manufacturing unit to perform cold pigment dyeing. The purpose of this study is to establish a norm using experimental processes which will lead to a substantial cost reduction and energy saving in manufacturing unit. Therefore, the processes optimization and modification are the alternative procedures to achieve better cold pigment dyeing (CPD) efficiency and environmentally friendly as the cleaner production concept.