Ozonation of a denim producing textile industry wastewater-process optimization

Moralı, Eyüp Kaan
Denim production is one of the leading sub-sectors of textile industry which basically generates highly colored indigo dyeing effluents. In the present study, ozonation was applied to the indigo-dyeing effluent(COD=820 mg/L;color=5500 Pt-Co), and to the whole effluent from a denim-producing plant before(COD=2750 mg/L;color=3950 Pt-Co) and after(COD=800 mg/L,color=3700 Pt-Co) biological treatment for degradation/detoxification purposes. Ozonation was also tried in the wastewater of the plant(COD=3100 mg/L;color=4500 Pt-Co) that would be produced after some foreseen cleaner production measures; caustic recovery and reusing of dyeing process wastewater. When applied to indigo-dyeing wastewater; ozonation provided 95% color and 61% COD removals at 1320 mg/h ozone dose within 60 minutes The optimum pH was evaluated as 4 when indigo-dyeing wastewater exposed to ozonation at different pHs(1.6-12.3). On the other side, ozonation applied as pre-treatment to the plant effluent provided 86% color and 46% COD removals with 3240 mg/h ozone dose in 70 minutes. Less satisfactory results were obtained when ozonation was tried in the wastewater after measures, with 86% color and 31% COD removals at 3960 mg/h ozone dose in 80 minutes. When applied to the biologically-treated effluent; at 420 mg/h ozone dose and within 40 minutes, ozonation removed 47% of influent COD and 96% of influent color indicating better performance of ozonation in postoxidation. In order to assess possible improvements on ozonation with the addition of H2O2, different concentrations were tried, but no significant improvement was obtained. The improvement in BOD5/COD index was also determined for the ozonetreated plant effluent to measure the effects of ozonation on biodegradability and found out that BOD5/COD ratio has improved to 0.39 from 0.22.


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Denim production, which is one of the leading sub-sectors of textile industry that generates considerable amount of wastewater with high pollution load both from dyeing and finishing processes. This sub-sector is therefore to consider cleaner production opportunities for these processes to reduce its wastewater generation and pollution load. In a denim-producing plant, the wastewater treatability studies have revealed that the most technically applicable cleaner production alternatives are caustic recovery ...
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The products of textile industry are irrevocable part of our lives: clothes, carpets, towels etc. However, textile industry is known to be having impact on the environment, especially for its high levels of water consumption and waste generation. The European Union’s Industrial Emissions Directive (former IPPC Directive) requires industrial establishments to apply best available techniques (BAT) both in the production processes and in the waste treatment and disposal. The European IPPC Bureau (EIPPCB) produ...
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Zaf, Ruken Dilara; Yetiş, Ülkü; Çulfaz Emecen, Pınar Zeynep; Department of Environmental Engineering (2017)
Textile industry produces wastewater that is often very rich in salt and color, containing residues of dyes and other chemicals. Treating this wastewater to exceptionally high quality standards, typically for reuse purposes, necessitates advanced treatment methods among which membrane technology is a leading one. However, membrane fouling which can be caused by dissolved and particulate solids appears as the major limitation with the use of membranes in wastewater reclamation that leads to reduced efficienc...
Catalytic ozonation of an industrial textile wastewater in a heterogeneous continuous reactor
Polat, Didem; Balci, Irem; Ozbelge, Tulay A. (2015-09-01)
Textile wastewaters (WWs) are highly colored and non-biodegradable having variable compositions of colored dyes, surfactants and toxic chemicals. Discharge of these WWs to the environment is very detrimental for ecosystems, therefore new methods have been investigated in order to meet the quality criteria of water and the discharge standards of the partly treated WWs. Recently, catalytic ozonation being one of the advanced oxidation processes (AOPs), is considered as an effective method that can be used in ...
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The objective of this study is to develop a membrane-based generic treatment scheme for wastewaters of indigo dyeing process of denim industry, based on water reuse. For this purpose, firstly the performances of microfiltration (MF), coagulation, and ultrafiltration (UF) processes were evaluated as pretreatment alternatives and the best pretreatment alternatives appeared to be single stage 5 m MF and sequential 5 m MF followed by 100 kDa UF providing high permeation rate and high color retention. These two ...
Citation Formats
E. K. Moralı, “Ozonation of a denim producing textile industry wastewater-process optimization,” M.S. - Master of Science, Middle East Technical University, 2010.