H2O2/UV-C Treatment of the Economically Important Naphthalene Sulfonate J-Acid: Process Optimization, Kinetic Evaluation and Activated Sludge Inhibition

2010 ◽  
Vol 13 (1) ◽  
Author(s):  
Idil Arslan-Alaton ◽  
Tuğba Olmez-Hanci ◽  
Zeynep Kartal

AbstractJ-acid (2-amino-5-naphthol-7-sulfonic acid) is an economically important naphthalene sulfonate having a highly polar, aromatic structure that renders it a difficult-to-oxidize, coagulate or adsorb pollutant. In the present study, the treatability of aqueous J-acid employing H2O2/UV-C oxidation and the effect of H

1988 ◽  
Vol 20 (11-12) ◽  
pp. 131-136 ◽  
Author(s):  
A. D. Wong ◽  
C. D. Goldsmith

The effect of discharging specific oil degrading bacteria from a chemostat to a refinery activated sludge process was determined biokinetically. Plant data for the kinetic evaluation of the waste treatment plant was collected before and during treatment. During treatment, the 500 gallon chemostatic growth chamber was operated on an eight hour hydraulic retention time, at a neutral pH, and was fed a mixture of refinery wastewater and simple sugars. The biokinetic constants k (days−1), Ks (mg/L), and K (L/mg-day) were determined before and after treatment by Monod and Lineweaver-Burk plots. Solids discharged and effluent organic concentrations were also evaluated against the mean cell retention time (MCRT). The maximum utilization rate, k, was found to increase from 0.47 to 0.95 days−1 during the operation of the chemostat. Subsequently, Ks increased from 141 to 556 mg/L. Effluent solids were shown to increase slightly with treatment. However, this was acceptable due to the polishing pond and the benefit of increased ability to accept shock loads of oily wastewater. The reason for the increased suspended solids in the effluent was most likely due to the continual addition of bacteria in exponential growth that were capable of responding to excess substrate. The effect of the chemostatic addition of specific microbial inocula to the refinery waste treatment plant has been to improve the overall organic removal capacity along with subsequent gains in plant stability.


2009 ◽  
Vol 59 (5) ◽  
pp. 1003-1009 ◽  
Author(s):  
M. H. So ◽  
J. S. Han ◽  
T. H. Han ◽  
J. W. Seo ◽  
C. G. Kim

The cyclic ether 1,4-dioxane is a synthetic industrial chemical that is used as a solvent in producing paints and lacquers. The EPA and the International Agency for Research on Cancer(IARC) classified 1,4-dioxane as a GROUP B2(probable human) carcinogen. 1,4-dioxane is also produced as a by-product during the manufacture of polyester. In this research, a polyester manufacturing company (i.e. K Co.) in Gumi, Korea was investigated regarding the release of high concentrations of 1,4-dioxane (about 600 mg/L) and whether treatment prior to release should occur to meet with the level of the regulation standard (e.g., 5 mg/L in 2010). A 10 ton/day pilot-scale treatment system using photo-Fenton oxidation was able to remove approximately 90% of 1,4-dioxane under the conditions that concentrations of 2800 ppm H2O2 and 1,400 ppm FeSO4 were maintained along with 10 UV-C lamps (240 μW/cm2) installed and operated continuously during aeration. However, the effluent concentration of 1,4-dioxane was still high at about 60 mg/L where TOC concentration in the effluent had been moreover increased due to decomposed products such as aldehydes and organic acids. Thus, further investigation is needed to see whether the bench scale (reactor volume, 8.9 L) of activated sludge could facilitate the decomposition of 1,4-dioxane and their by-products (i.e., TOC). As a result, 1,4-dioxane in the effluent has been decreased as low as 0.5 mg/L. The optimal conditions for the activated sludge process that were obtained are as follows: DO, 3-3.5 mg/L; HRT, 24 h; SRT 15 d; MLSS, 3,000 mg/L. Consequently, photo-Fenton oxidation coupled with activated sludge can make it possible to efficiently decompose 1,4-dioxane to keep up with that of the regulation standard.


2004 ◽  
Vol 50 (5) ◽  
pp. 203-208 ◽  
Author(s):  
A. Kloepfer ◽  
R. Gnirss ◽  
M. Jekel ◽  
T. Reemtsma

A number of 2-substituted benzothiazoles that are known to be used as fungicides, corrosion inhibitors and vulcanization accelerators in industry have been analyzed in municipal wastewater and the effluents of activated sludge and membrane bioreactor (MBR) treatment over a three month period. All six analytes were regularly detected in the municipal wastewater by liquid chromatography-mass spectrometry and amount to a total concentration of 3.4 μg/L. Of these compounds benzothiazole-2-sulfonic acid (1,700 ng/L), benzothiazole (850 ng/L) and 2-hydroxybenzothiazole (500 ng/L) were most prominent. The source of the benzothiazole emission is yet unknown. Activated sludge treatment did not reduce total benzothiazole concentration significantly. Removals of the individual compounds ranged from 90% for 2-mercaptobenzothiazole and 70% for hydroxybenzothiazole to 40% for benzothiazole. The concentration of benzothiazole-2-sulfonic acid increased by 20%, whereas 2-methylthiobenzothiazole increased by 160% during activated sludge treatment, likely due to the methylation of mercaptobenzothiazole. Total benzothiazole removal in two parallely operated MBRs was significantly better (43%) than in the conventional activated sludge treatment. Namely benzothiazole and benzothiazole-2-sulfonic acid were more effectively removed. This first systematic study on the occurrence of benzothiazoles in municipal wastewater has shown that this is a relevant class of trace contaminants in municipal wastewater which is only incompletely removed in biological wastewater treatment. Emission from sewage treatment is dominated by the most polar benzothiazole-2-sulfonic acid. MBR treatment may reduce but cannot avoid this emission.


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