Tertiary treatability of molasses secondary effluents for color and organics: performance and limits of ozonation and adsorption

Autor: M. Lucero-Chávez, Mario Esparza-Soto, Khalidou M. Bâ, Cheikh Fall, M. T. Olguín-Gutierrez, L. M. Barrón-Hernández
Rok vydání: 2020
Předmět:
Zdroj: International Journal of Environmental Science and Technology. 17:3651-3662
ISSN: 1735-2630
1735-1472
Popis: Molasses wastewaters (MWWs) such as baker’s yeast and distilleries effluents are usually pretreated by anaerobic, followed by aerobic biodegradation. This removes almost all the BOD, enough for meeting the current discharge standards in many low- and middle-income countries. However, as shown in the present work, the biotreated effluent still contains high levels of recalcitrant COD, color (melanoidins) and inorganic salts that end up in rivers (approx. 1000 mg/L COD, 2850 Pt–Co color units, 5000 mg/L TDS and 5400 μS/cm conductivity). To address this global problematics, and given the lack of proven cost-effective advanced treatment trains for MWW, this study assessed the performance and limits of ozonation and activated carbon (AC) adsorption (contrasting with O3 applications on raw MWW). The applied versus the reacted O3 doses were quantified, allowing also to estimate the ozone uptake rate as a new tool for characterizing the reactivity of the wastewaters. The effects of the treatments on different key parameters were studied: COD, color, aromaticity (UV254 nm), toxicity (Microtox) and biodegradability (by respirometry). O3 reduced the color (> 95%), but causing low COD mineralization (
Databáze: OpenAIRE
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