Effect of Additives on Ozone-Based Decomposition of Reactive Black 5 and Direct Red 28 Dyes

Article (PDF Available)inWater Environment Research 85(4):291-300 · April 2013with55 Reads
DOI: 10.2175/106143013X13596524515988 · Source: PubMed
  • 10.31 · Autonomous University of Chihuahua
  • 30.05 · Instituto Politécnico Nacional
  • 33.83 · National Polytechnic Institute, Professional Interdisciplinary Unit of Biotechnology
Abstract
In this research, ozonation of Reactive Black 5 (RB5) and Direct Red 28 (DR28) under the presence of Na2SO4 and Na2CO3 used as textile additives was investigated. The effect of these salts on discoloration, degradation dynamics, and the composition of the final compounds were studied. Different systems were evaluated; such as RB5-Na2SO4 (100 g/L), RB5-Na2CO3 (30 g/L), RB5-Na2SO4/Na2CO3 (100 g/ L/30 g/L), and DR28-Na2SO4 (10 g/L, 40 g/L, and 80 g/L) with dye concentrations of 50, 150, and 250 mg/L without pH adjustment. Discoloration of RB5 and DR28 with and without additives was determined by visible and UV (UV-Vis) spectroscopy. Decomposition of the dyes and the dynamics of intermediates and final byproducts were followed by high performance liquid chromatography. The presence of additives accelerated discoloration and decomposition for both dyes (more than 50%). The accumulation of oxalic and formic acids was observed. Possible mechanism schemes of ozonation for both dyes are proposed.

Full-text (PDF)

Available from: Poznyak Tatyana, Feb 17, 2015
  • [Show abstract] [Hide abstract] ABSTRACT: Effluents from dyeing processes of woollen textile finishing industries are highly polluted with recalcitrant compounds compared to effluents from rinsing and finishing processes. Oxidation of woollen textile dyeing effluent consisting of wastewater generated from spent dye baths and first and second rinses (remaining composite wastewater) were investigated. Ozone oxidation (CO3=18.5 mg/l; input rate) was applied on remaining composite wastewater, before and after the biological treatment, for various time intervals. Treatment efficiency was monitored by decolorization and by COD removal rates. Additionally, toxicity tests (bioluminescence test) were carried out to determine the effect of oxidation process. The results indicated that 40 min ozonation of biologically treated wastewater yielded almost colorless effluent with a decolorization efficiency of around 98–99% and with a corresponding ozone absorption rate of 58.0 mg/l. Biological treatment followed by 10 min ozone oxidation reduced the overall toxicity significantly (92%). However, ozonation was found to have only slight effect on COD removal.
    Article · Aug 2003
  • [Show abstract] [Hide abstract] ABSTRACT: Color removal by MgCl(2) when treating synthetic waste containing pure dyes was studied. The color removal efficiency of MgCl(2)/Ca(OH)(2) was compared with that of Al(2)(SO(4))(3), polyaluminum chloride (PAC) and FeSO(4)/Ca(OH)(2). The mechanism of color removal by MgCl(2) was also investigated. The experimental results show that the color removal efficiency of MgCl(2) is related to the type of dye and depends on the pH of the waste and the dosage of the coagulants used. Treatment of waste containing reactive dye or dispersed dye with MgCl(2) yielded an optimum color removal ratio when the pH of the solution was equal to or above 12.0. For both the reactive and dispersed dye waste, MgCl(2)/Ca(OH)(2) was shown to be superior to MgCl(2)/NaOH, Al(2)(SO(4))(3), PAC and FeSO(4)/Ca(OH)(2) for color removal. A magnesium hydroxide precipitate formed at pH values greater than 12.0, which provided a large adsorptive surface area and a positive electrostatic surface charge, enabling it to remove the dyes through charge neutralization and an adsorptive coagulating mechanism. So, the MgCl(2)/Ca(OH)(2) system is a viable alternative to some of the more conventional forms of chemical treatment, especially for treating actual textile waste with high natural pH.
    Article · Feb 2007
  • [Show abstract] [Hide abstract] ABSTRACT: The low biodegradability of many dyes and textile chemicals indicates that biological treatment is not always successful in the treatment of cotton textile wastewater, in terms of color removal. In this study, a specific organic flocculant (Marwichem DEC), powdered activated carbon (PAC), bentonite, activated clay and commercial synthetic inorganic clay (Macrosorb) were directly added into the activated sludge laboratory pilot plant model. Before dosage, the optimum sludge retention time and hydraulic retention time were determined as 30 days and 1.6 days, respectively. The Monod kinetic constants were determined as Y = 0.76 kg MLSS/kg COD, Kd = 0.026 l/day, K(S) = 113.3 mg/L, k = 0.42 l/day and mu(max) = 0.32 kg MLSS/kg COD day. Under these conditions the average COD removal was 94% and color removal was 36%. The addition of these materials did not change COD removal significantly. The most effective materials were found to be DEC and PAC for color removal. While the color removal efficiency for 120 mg/L DEC addition was 78%, it was 65% for 100 mg/L, 77% for 200 mg/L and 86% for 400 mg/L PAC addition. The advantage of DEC compared to PAC was the lower sludge production. Statistical analyses using multiple linear regression indicate that there is no relationship between the effluent color with the influent color and total suspended solids (TSS) for DEC and PAC addition. On the other hand, when only bentonite, activated clay and Macrosorb were added, the effluent color was primarily dependent on the influent color and the TSS concentration had little effect. When the data is examined by using Kruskal-Wallis H and Mann-Whitney U tests and it was found that there was a significant difference between the color data groups.
    Full-text · Article · Jul 2002
Show more