Tekstil atıksularından renk giderimi

Kırdar, Esra
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Süreli Yayın ISSN
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Fen Bilimleri Enstitüsü
Artan çevre kirliliğine ve azalan su kaynaklarına çözüm bulabilmek amacıyla endüstriyel atıksuların arıtılma zorunluluğu doğmuştur. Atıksu kirliliği kontrol parametrelerinden olan renk Resmi Gazetelerde yayınlanan su kirliliği kontrol yönetmeliğinde bulunmamasına rağmen estetik açıdan istenmez. Ayrıca koyu renkli sular güneş ışınlarının geçişini engelleyerek sudaki çözünmüş oksijen miktarımda düşürdüğünden atıksuların renginin giderilerek deşarj edilmesi gereklidir. Bu sebeple ger çekleştirilen bu çalışmada tekstil endüstrisi atıksuyu renginin giderilmesi amaçlanmıştır. Renk giderimi ad- sarban olarak pirinç kabukları kullanılarak adsorbsiyon yöntemi ile gerçekleştirilmiştir. Atıksu rengi spektro- fotometrik yöntemle tesbit edilmiş ve renk giderimi et kinliği üzerine adsorban tane boyutunun, katı/sıvı değerinin, sıcaklığın ve pH'ın etkisi incelenmiştir. Denemeler sırasında adsorbsiyon süresi 2 saat ve karıştırma hızı 130 devir/dak olarak sabit tutulmuştur.
Today, tha high papulation increasmsnt and indust rialization in the world bring an aver uaste water capacity problems, which is more assimilated than programmed and planned by the scientists. The dirtiness occured in discharged areas of these wastes demages the ecological equilibrium and uses up the alternatives in treatment. The wastes occured from textile, chemical, food, paper, leather industries. Industries established in or near the cities have became the mast important polluants of the rivers, lakes and seas etc. The action to prevent this pollution brings a concept to these wastes before dis charging. There are several methods in treatment of the indust rial waste waters. The source of the waste and polluant characteristics are the major factors in determining the right treatment method. Also, there may be some other waste treatment methods depending on the size and charac teristics of the waste, but in general treatment methods can be classified into 3 sections like mechanical, chemical and biological. In Turkey, the textile industry is well developed up today. Same textile industrial wastes, such as textile dyes present in significant concentrations in many waters, have been neglected to a large extent because the dyes are often composed of mixtures of compounds having unknown Shemical structures. Environmental pollu tion by dyes results from wastes from the manufacturing industry and from users as textile plants. Colour has been viewed by many as a parameter that would have little impact on the biota of a receiving stream or a sewage treatment plant. However, the dis charge af highly coloured waste is not only aesthetically VI unacceptable, but also impedes light penetration, there_ by impaining or inhibiting biological processes uiithin a stream. The removal of dyes from an industrial effluent is becoming a major problem as government legislation becomes more stringent. Biological treatment process such as aerated Itgoons and conventional activated sludge processes are frequently used to treat textile effluents. These processes are efficient in the removal of suspended solids (SS) and chemical oxygen demand (COD), but largely ineffective in removing colour from wastewater. In Turkey, the standarts of discharging to the environment of the textile factories are legalized and issued in the Turkish Republic Official Newspaper. This regulation involves the parameters such as pH, Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD) etc. Although Colour does not take place amoung these parameters, it is a significant parameter in determining of the waste water, because dark coloured waters prevent the transition of the sun lights and reduces the amount of dissolved oxygen in water. So, it is not convinient to discharge of the waste-waters in coloured. For this reason, we have studied on colour removal from textile industries wastewaters and supplied a sample from one of the well known textile wool-fieber plant which is located in Istanbul. In this plant, the wastewater coming from dye-house transfers to the treatment unit according to the flow-chart showned in Figure 1. Following these steps, the chemical oxygen demand of the wastewater can be decreased to BOO mg/liter levels from 10.000 mg/liter, but the colour of the waste ia yellow-darkbrown which is not a suitable colour for discharging to the city waste channels. In fact^, the portion of the dye-waste in the whole wastewater is much more coloured, but less polluted. On the other hand, the cleanser water is much more polluted, but less coloured. In this study, the partially treated, coloured waste_ water is being used. The waste characteristic which isused during the experiments are show in Table 1. TABLE: 1. The Wastewater Characteristics of the Wool Textile Plant. PARAMETER 1 st. WASTEWATER 2nd WASTEWATER Suspended solid(mg/l) 550 400 COD (mg/1) 3500 1655 Oil + gress (mg/1) 430 150 pH B. 5-9.0 8. 5-9. Vll Wastewater ^ Washing CGD = 1D.G00-12.D00 : Equalization Tank H2SD^ ».j Washing Tank Prereaction Tank Dye house water C0D=2500 pH=7.8-8.D Acidic Wapet Phase Stirring pH= pH=^-4.5 Ca(DH) 2 Stirring ~~^ pH=1Q.5-11.00i FeSD k _j Stirring pH=8-9 Precipitate Tank Precipitate Wastewater pH=CDD > Golour : Dark-brouin-Yellaw FIGURE: 1. Wastewater Treatment Flow-Chart in Textile Plant. vixi The assortment and different characteristics of the fibers used in textile industry effects the wastewater composition which is determined in the experiments. The adsorbtion method is being carried out in the experiments due to the excessive colour of the waste. The results of the experiments are obtained by using the spectrophotometry method. Which can specify the wave length, luminance and pollaunts. As an adsorban, rice hulls are being used obtained from Trakya Area, Turkey. The reason of proceeding the experiments with rice hulls is the low cost and easy presence. As steps of the experiments, the rice hulls are grinded to D. 106-0. 180, 0.180-0.425, 0.425-1mm levels. During the experiments, the effects of the below written parameters on colour removal from the wastewater are being searched. - Solid/liquid ratio (Adsorban material amount (mg) sample (ml) - Adsorban material size - pH and - Temparature In the experiments, following parameters are hold as constant. - Stirring speed, as 130 cycle/min - Duration, as 2 hours - Volume of the wastewater sample, as 150 ml The result of the determined colour codes used in the experiments are shown in Table 2. TABLE: 2. The Colour Values of Wastewater PARAMETER 1st WASTEWATER 2nd WASTEWATER - Dirty - Colour - Luminance (% IX + Experiments done with the 1 at wastewater are concluded with workable results as stated below. -Solid/liquid = 1/20D -Adsarban size = 0.425-1 mm After treatment, the wastewater values are obtained as follows. - Dirty = 9 % - Luminance = 71 % Here, the dominant colour did not change, but the colour quality has lightened. In the first wastewater experiments, the colour removal efficiency is obtained as 78. 6 %. + Experiments done with the 2 nd wastewater are concluded with workable results in 5 separete groups. In the 1 st and 2 nd group of experiments are resulted as follows. - Solid/liquid : 1/1 DDD - Adsarban size : 0.18-0. 425mm After treatment, the wastewater values are obtained as fallows. - Dirty : 1.3 % - LUminance: 95.8% Here, the dominant colour did not change, but the colour quality has lightened. In the second wastewater experiments, the colour removal efficiency is obtained as 95.6 %. In the 3 rd group of experiments, the effect of temperature an colour removal is being investigated and found aut ta proceed the experiments in the raam temperature (~25aC). In the k th group of experiments, the effect of pH an colour removal is being investigated and found out to proceed the experiments with the original pH value (pH=9). In the 5th group of experiments, the regeneration of rice hulls after treatment by washing water and acidic water are being investigated and found out to proceed the experiments with water. After the comporision of color removal experiments done by 1 st and 2 nd wastewaters, the finat values for the 2 nd wastewater are being observed as the best. This is because of higher oil content of the 1 st waste water. You may find below the experimental results done by the 2 nd wastewater. TABLE: 3. Colour Removal Results Due to the high consumption of rice in Turkey, the rice hulls have also an increasing potential. This situation enhances the importance of the subject. As an alternative to rice hulls; saw dusts, maize stalks, vermiculites and peatmosses etc. can be used.
Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 1995
Anahtar kelimeler
Arıtma, Endüstriyel atık su, Renk kirliliği, Renk maddeleri, Treatment, Industrial waste water, Color contamination, Color matters