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25Section 3. Inorganic chemistry
Amirova Nodira, PhD of department of "Chemical technology", Tashkent Institute of Textile and Light Industry, Uzbekistan
E-mail: [email protected]
Environmental issues in dyeing textile materials
Abstract: In the modern world currently, according to the researchers, increases the risk of harm to human health in the operation of textile product. In the finishing of textile materials are used different materials, i. e. a wide class of synthetic dyes and harmful chemicals, which leads to an increase of ecological crisis, and thus reduce reliability of the human immune system, causing allergies. Given all this, the production of textile products should be replaced where possible chemical textile natural materials, natural synthetic dyes, artificial fibers, natural etc. the Most promising routes is the development of waste-free production technologies with the aim of obtaining ecological products.
Keywords: Dyeing textile materials, dyeing of silk, waste, knitted fabrics, cation, reactor, proetching.
Introduction. The last 10-15 years the world has increased the interest in natural dyes, especially vegetable origin. Many of these dyes can be obtained from the available cheap raw materials and waste production. The manufacture and use of these dyes is economical and environmentally friendly, they provide a sufficient range of colors and shades.
Object research. Many synthetic dyes are environmentally adversely affects the person and in this regard, scientists from different countries make attempts to return to the coloring of textile materials historically traditional natural dyes.
Considering that Uzbekistan buys synthetic dyes for hard currency, and in the flora it grows more than 300 species of dye plants [1], the study of the possibility of coloring of silk in rich and durable color natural waste is of great practical interest in the creation of effective processes of dyeing in the case of small and private enterprises.
The natural conditions for workers in the production of comfortable clothes to wear and do not have a negative impact on the biochemical processes of sewage treatment.
But they are not without drawbacks: the limited color tones, the use of heavy salts as stains.
Natural dyes are diverse in composition and chemical structure, for example, yellow dyes are compounds of carotenoids and flavonoids, the an-thocyanins red, blue, blue, purple and green, tanney, indigoid, anthraquinones etc., being.
Proetching dyes are fixed on natural fibers due to the coordination bonds through the metal d-orbital which free. Decoctions of the same dye plants with different metal salts can be obtained in various colors and color tones. Coloring natural dyes have a high strength-to-action to wet treatments and light, rich in colors, soft and muted shades.
Analysis. Previously, we studied the dyeing process of silk fabrics with the extract and decoction of pomegranate peels, decoction of leaves and pericarp of walnut, onion skin, leaves and fruits of elderberry and black using the following metal salts: Fe 3+, Fe 2+, Cu 2+, Ni 2+, Cr 3+, Cr 6+, Cu 2+, Sn 2+, Al 3+ with different anions. A study was conducted on factors such as pH of environment, concentration of colorant, electrolyte and salts of heavy metals, temperature and time of dyeing, the nature of the metal anion salts [2; 3].
The advantage of the recommended technology of dyeing of natural dyes is to reduce the consumption of metals used as mordants, as well as waste disposal production of fruits and vegetables.
On the basis of systematic studies we have shown [2; 3] the possibility of reducing the concentration of stain in 3-6 times, instead of the traditional concentration of7-14% by weight ofsilk to 2.5 (5,0). In addition,
Table 1. - The process conditions waste plant (M=25, pH = 4
in order to reduce the number of metal salts, in waste water the recommended 2-fold reuse of the waste pro-etching solution after concentration by evaporation.
On the basis of the results obtained the recommended composition, modes and technology of dyeing.
The process conditions of dyeing waste dyeing in a decoction of the plant is presented in table. 1.
and recipe of dyeing of silk in broth -5, silk 100 kg, V p = 2500 l)
Name operations Name chem. materials Concentration trace, % by weight of silk Mode
Temperature, °C Time, min
Proetching
Treatment is held in Bay solution stain, heated and processing of silk metal Salt. CH3COOH (30%) 1,5-(5,0)* 4,0 50 50
Drain solution** 2-3
Dyeing
Bay solution and dyeing Neutral decoction of the natural dye CH3 COOH (30%-Hoe) 3-10 4,0 95 60
Drain solution 2-3
1st-rinsing Water 60 10
2nd-flushing and osivka Acetic acid 98% 0,5 25 10
Drying 105 10-15
* stain concentration of 5% by weight of the silk is used only for black color, sulfate, Fe 3+;
* used solutions of metal salts after the concentration are reused for the next batch of silk, so collecting them in a heated tank for evaporation.
To prepare the broth from waste plants equipped with an anchor stirrer, but it is possible use recommended to use small reactors with a volume of propeller mixers (4). Heating of the solution in of 50, 100, 160, and 250. The reactors with the the reactor is carried out by passing steam through pipe for displacement of solution with compressed the steam jacket with a drain through the nipple on air and the lower the descent, designed to work the bottom of the steam jackets (Figure 1). under the pressure of 0.3-0.4 MPa. The reactor is
1. Reactor to prepare the broth from waste plants;
2. Storage tank;
3. Jet dyeing line;
4. Tanks for the collection and evaporation of waste solution stain.
4
T
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Figure 1. Technological scheme of installation for dyeing fabrics (or knitted fabrics) of natural dyes with re-use of stain solution
Themselves natural dyes as opposed to synthetic do not have a negative impact on the biochemical processes of sewage purification, but purification is necessary first to extract the heavy metal salts because these salts can lead to the death of microorganisms.
To avoid disturbance of ecological process maxi-
mum allowable concentrations (Macs) of chemicals in the wastewater [4], reducing the concentration of salts ofheavy metals from 14 to 2.5% by weight of silk, reuse local solution and ion-exchange wastewater treatment makes it possible to reduce the quantity ofheavy metals in the residual solution 6-10 times (tab. 2).
Table 2.
The metal Concentration of metal Residual quantity in a solution In enterprise sewage mg/l MAC mg/l [5]
in solution on silk
mg/g mg/l mg/g mg/l mg/g mg/l
Fe 3+ 9,96 199,2 5,4 108,0 4,56 91,2 4,56 2-20
Cr 3+ 5,7 114,0 4,0 80,0 1,70 34,0 1,15 0,5-5
Al 3+ 2,0 40,0 0,34 6,8 1,66 33,2 1,5 1-10
Concentration of the Residual amount of metal In the wastewater enterprise, MAC mg/l in solution.
The residual solution after the re-use ofwastewa-ter is diluted by oxen of the process of dyeing broth and 2 leaching, as a result, the salt concentration of Fe is diluted to 24 mg/l Cr6+ up to 37 mg/l Al3+ to 22 mg/l. considering that in a small business natural used along with other classes of dyes, the wastewater of these processes dilutes the metal-containing waste solutions to EQS.
Despite this, it is possible to envisage local treatment of waste water from heavy metal salts.
Natural feasible methods of sewage purification from salts of heavy metals is the method of ion volume, which is returned to the production of de-materialized water, and the sorbed impurities are extracted from ion-exchange resins during their regeneration [4].
Ion exchange is a process of interaction of the solution with the solid phase having the properties of exchanging ions, contained therein, to other ions present in solution.
A characteristic feature of ion exchange resins is their reversibility, i. e. the possibility of carrying out the reaction in the reverse direction and is the Foundation of their regeneration.
If the cation exchange resin is in the H or Na form, the exchange cations will occur according to the reactions:
Me + H [K] ^Me [K] + H; Me + Na [K] ^Me [K] + Na
where Me+ is a cation, is in bridging the water, [K] is the complex cation [2; 3].
Regeneration of the cation exchange resin is carried out by acid washing (with N-cation exchange resin) or a solution of sodium chloride (with Na — cation exchange resin):
2Me [K] + H2SO4 ^2H [K] +Me2SO4H;
2Me [K] +NaCl ^Na [K]+MeCl The resulting salt solutions after determining their concentration can be used back to dyeing.
Physico-mechanical test showed that dyeing silk fabrics with natural dyes has a positive effect on the strength characteristics. In comparison with the original tensile strength of the dyed fabric is improved by 7.85 and of 12.08% in the warp direction and the basis, respectively, which can be seen from Fig. 2 (a, b).
As a result of implementing our recommendations achieved social and environmental benefits through the production of strongly colored organic and exclusive textile products.
There is an opportunity of realization of finished products at the contract, a higher price that creates additional profits.
Given the points above, development of technology of dyeing of natural textiles, especially designed for children, natural dyes is a key issue.
Therefore, all indicators ofdevelopment oftechnol-ogy ofdyeing textile materials ofnatural dyeing decoctions is, in the language ofenvironmentalists, «green» production, does not affect the environment, but on the contrary only contribute to its preservation.
a)
b)
Fig. 2. Curves of tensile strength in the warp direction and based on the original (a) and painted with natural dyes samples (b) measured on the device Autograf AG-1. 1 — duck 2 — basis.
Conclusion: 2. The calculation of the concentration of salts
1. Considered are the issues of wastewater of heavy metals (for example, 3-stains: Fe 3+, Al 3+
treatment in dyeingwith natural dyes. Recommended and Cr 3+) in wastewater based on the analysis of
local cation method for purifying waste water from sorbed metal silk using the mass spectrometer
salts of metals and indicated the possibility of reuse with inductively bound plasma. It is shown that
of these metals, obtained during the regeneration of as a result of dilution by sewage enterprises
the cation exchanger. the concentration of metals is within the MAC
(maximum allowable concentration).
References:
1. Abramova A. A., Amirova N., Abdukarimova M. Z. "4eBpoHHgH y36eKHCTOH 6yam6oH ycHMAHKAapu.
2. Amirova N. Development of efficient processes for the production of saturated and strong colors on natural silk. Ed Diss PhD, Tashkent, 2010, P. 25.
3. Yakovlev S. V., Karelin Y. A., Affectionate Yu. M., Voronovn Yu. V. Industrial wastewater treatment. - M: Stroyizdat, 1985. - 335 p.
4. www.hydropark.ru/www.equipmention_exchange.htm
