Chloride or sulfate? Consequences for ozonation of textile wastewater

JOURNAL OF ENVIRONMENTAL MANAGEMENT

卷:247

Article

Oktem, Yalcin Askin¹  Yuzer, Burak¹  Aydin, Muhammed Iberia¹  Okten, Hatice Eser²  Meric, Sureyya³  Selcuk, Huseyin¹ 

[1] Istanbul Univ Cerrahpasa, Engn Fac, Environm Engn Dept, Istanbul, Turkey

[2] Izmir Inst Technol, Engn Fac, Environm Engn Dept, Izmir, Turkey

[3] Namik Kemal Univ, Engn Fac, Environm Engn Dept, TR-59860 Corlu, Tekirdag, Turkey

关键词: Adsorbable organic halogens;    Ozonation;    Reactive dye;    Treatment;    Textile wastewater;    Toxicity;   

DOI  :  10.1016/j.jenvman.2019.06.114

来源: Elsevier

【 摘 要 】

Ozonation of chloride-rich textile wastewater is a common pretreatment practice in order to increase biodegradability and therefore meet the discharge limits. This study is the first to investigate ozone-chloride/bromide interactions and formation of hazardous adsorbable organic halogens (AOX) in real textile wastewater. Initially effect of ozonation on chloride-rich real textile wastewater samples were investigated for adsorbable organic halogens (AOX) formation, biodegradability and toxicity. After 15 min of ozonation, maximum levels of chlorine/bromine generation (0.3 mg/l) and AOX formation (399 mg/l) were reached. OUR and SOUR levels both increased by approximately 58%. Daphnia magna toxicity peaked at 100% for 10 min ozonated sample. Considering adverse effects of ozonation on chloride-rich textile industry effluents, we proposed replacement of NaCl with Na2SO4. Comparative ozonation experiments were carried out for both chloride and sulfate containing synthetic dyeing wastewater samples. Results showed that use of sulfate in reactive dyeing increased biodegradability and decreased acute toxicity. Although sulfate is preferred over chloride for more effective dyeing performance, the switch has been hampered due to sodium sulfate's higher unit cost. However, consideration of indirect costs such as contributions to biodegradability, toxicity, water and salt recovery shall facilitate textile industry's switch from chloride to sulfate.

【 授权许可】

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