Effect of HRT on the biological pre-denitrification process for the simultaneous removal of toxic pollutants from cokes wastewater

Kim, Young Beom; Park, Donghee; Jeon, Che Ok; Lee, Dong Hoon; Park, Jong

doi:10.1016/j.biortech.2008.04.050

Cited by 105 publications

(47 citation statements)

References 37 publications

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“…Bacterial thiocyanate degradation has been extensively studied in industrial activated sludge reactors for treatment of wastewaters and especially industrial coke wastewaters. It has been shown that in anaerobic reactors, bacterial degradation of thiocyanate is either slow or does not occur (Shieh and Richards 1988;Chakraborty and Veeramani 2006;Kim et al 2008;Sahariah and Saswati 2011). These results are consistent with the results of our incubation experiments.…”

Section: Sediment Amendment Incubationssupporting

confidence: 93%

Hydrogen Cyanide Accumulation and Transformations in Non-polluted Salt Marsh Sediments

et al. 2012

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While cyanide is known to be produced by many organisms, including plants, bacteria, algae, fungi and some animals, it is generally thought that high levels of cyanide in aquatic systems require anthropogenic sources. Here, we report accumulation of relatively high levels of cyanide in non-polluted salt marsh sediments (up to 230 lmol kg -1 ). Concentrations of free cyanide up to 1.92 lmol L -1 , which are toxic to aquatic life, were detected in the pore-waters. Concentration of total (free and complexed) cyanide in the pore-waters was up to 6.94 lmol L -1 . Free cyanide, which is released to the marsh sediments, is attributed to processes associated with decomposition of cord grass, Spartina alterniflora, roots and possibly from other sources. This cyanide is rapidly complexed with iron and adsorbed on sedimentary organic matter. The ultimate cyanide sink is, however, associated with formation of thiocyanate by reaction with products of sulfide oxidation by Fe(III) minerals, especially polysulfides. The formation of thiocyanate by this pathway detoxifies two poisonous compounds, polysulfides and hydrogen cyanide, preventing release of free hydrogen cyanide from salt marsh sediments into overlying water or air.

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Section: Sediment Amendment Incubationssupporting

confidence: 93%

Hydrogen Cyanide Accumulation and Transformations in Non-polluted Salt Marsh Sediments

et al. 2012

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“…As shown in Fig. 5c, the SNRR increased from 29.3 to 31.2 mg N/(g MLSS h) with the decrease in HRT from 17 to 9 h. Kim et al (2008) found that average specific denitrification rate increased from 15.0 to 48.0 mg N/(g MLSS h) with the decrease in HRT from 24.9 to 7.9 h in the biological pre-denitrification process for the simultaneous removal of toxic pollutants from cokes wastewater.…”

Section: Effect Of Hrt On Microbial Activitymentioning

confidence: 83%

Effect of hydraulic retention time on performance of an anoxic–aerobic sequencing batch reactor treating saline wastewater

Wang

Gao

Ren

et al. 2014

Int. J. Environ. Sci. Technol.

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The effects of hydraulic retention time on the performance and microbial community structure of an anoxic-aerobic sequencing batch reactor treating saline wastewater were investigated. The average removal efficiencies of chemical oxygen demand and ammonia nitrogen decreased from 90 and 85 % to 68 and 71 % with the decrease in hydraulic retention time from 17 to 9 h, respectively. No obvious accumulation of nitrate nitrogen and nitrite nitrogen in the effluent was found. The contents of polysaccharide and protein in extracellular polymeric substances increased with the decrease in hydraulic retention time. The polysaccharide/protein ratio decreased from 1.18 to 1.11 with the decrease in hydraulic retention time from 17 to 9 h. The increase in extracellular polymeric substances with the decrease in hydraulic retention time led to the increase in sludge volume index. The specific ammonium oxidation rate, specific nitrite oxidation rate, specific nitrate reduction rate, and specific oxygen uptake rate increased with the decrease in hydraulic retention time. The diversity indices of microbial community decreased from 2.69 to 2.39 with the decrease in hydraulic retention time from 17 to 9 h. The a-proteobacteria were the dominant groups under hydraulic retention time of 17, 14, 11, and 9 h, which constituted 46, 30, 40, and 40 % of the whole microbial community, respectively.

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“…To create favorable conditions for nitrification and denitrification, continuous operation and a relatively long HRT are required (11). However, HRT is the main operating variable for biological stabilization.…”

Section: Effect Of Hydraulic Retention Timementioning

confidence: 99%

Ammonium Removal by Nitrification and Denitrification in an Integrated Fixed Film Activated Sludge Process

et al. 2014

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Background: When nitrogen-containing compounds are released into the environment, they could create serious problems such as eutrophication of rivers, deterioration of water quality and potential hazard to human or animal health. Biological nitrogen removal is generally preferred over physicochemical methods due to its lower cost, lower chemical/energy requirements, and being environmental friendly. Objectives: The current study aimed to evaluate the performance of a simultaneous nitrification and denitrification in a modified integrated fixed-film activated sludge (IFAS). Materials and Methods:The ammonia and chemical oxygen demand (COD) (Ammonia 25, 40, 80, 120 and 160 mg/L and COD = 500 mg/L) removal were studied by the proposed system. Two reactors in bench scale with the capacity of 13 liters were considered. Effective parameters such as hydraulic retention time, COD consumption, and the effect of loading ammonia were evaluated. Results: Employing the BET, surface area (S a ), total pore volume (V p ), and average size of the nanostructure were 0.4026 m 2 /g, 3.808903 cm 3 /g and 44.7 nm, respectively. Results indicated that the desirable hydraulic retention time for nitrification occurred at 12. Due to higher COD consumption, there was no significant difference between the conventional IFAS and modified IFAS units. Based on the nitrification and denitrification results, the best condition for nitrifying/denitrifying performance was obtained by modified IFAS. Conclusions: Based on nitrification and denitrification data, the best condition for nitrifying/ denitrifying performance was obtained by modified-IFAS. Hence, the modification can be used to obtain the best activities of microbial and nitrogen removal improvement.

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Effect of HRT on the biological pre-denitrification process for the simultaneous removal of toxic pollutants from cokes wastewater

Cited by 105 publications

References 37 publications

Hydrogen Cyanide Accumulation and Transformations in Non-polluted Salt Marsh Sediments

Hydrogen Cyanide Accumulation and Transformations in Non-polluted Salt Marsh Sediments

Effect of hydraulic retention time on performance of an anoxic–aerobic sequencing batch reactor treating saline wastewater

Ammonium Removal by Nitrification and Denitrification in an Integrated Fixed Film Activated Sludge Process

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