Suntud Sirianuntapiboon

Decolorization of molasses wastewater by Lactobacillus plantarum No. PV71-1861.

Lactobacillus plantarum No. PV71-1861, isolated from pickle samples in Thailand, showed the high potential for use in decolorization of molasses wastewater under both anaerobic and facultative (static) conditions. The strain showed the highest melanoidin pigment (MP) decolorization yield of 68.12% with MP solution (color intensity corresponding to an optical density of 3.5 units at 475 nm) containing 2% glucose, 0.4% yeast extract, 0.1% KH(2)PO(4), 0.05% MgSO(4).7H(2)O and initial pH of 6 under static condition at 30 degrees C within 7 days. But, it showed low growth and MP decolorization yields under aerobic conditions. Gel filtration chromatograms of the MP solutions showed that the small molecular weight fraction of MP solution was decolorized by the strain when the large molecular weight fraction still remained in the effluent. For application, the strain could apply to treat anaerobic treated-molasses wastewater (T-MWW) with high removal efficiency. The highest MP removal efficiencies and growth yield of 76.6% and 2.6 mg/mL, respectively, were observed with the T-MWW within 7 days of culture, and the effluent pH of the system was decreased to lower than 4.0 after 2-3 days operation.

Effect of bio-sludge concentration on the efficiency of sequencing batch reactor (SBR) system to treat wastewater containing Pb2+and Ni2+

The removal efficiency of sequencing batch reactor (SBR) system with synthetic industrial estate wastewater (SIEWW) containing Ni(2+) or Pb(2+) was increased with the increase of mixed liquor suspended solids (MLSS). But, the sludge volume index (SVI) of the system was increased up to higher than 100mL/g under MLSS of up to 4000 mg/L. Also, the effluent NO(3)(-) was decreased with the increase of MLSS. The heavy metals (Ni(2+) or Pb(2+)), BOD(5), COD and TKN removal efficiencies of SBR system with SIEWW containing 5mg/L heavy metal (Ni(2+) or Pb(2+)) under MLSS of 3000 mg/L were 83-85%, 96-97%, 95-96% and 83-94%, respectively. The increase of heavy metal (Ni(2+) or Pb(2+)) concentrations of SIEWW from 5 to 50mg/L were not significantly effected to both COD and BOD(5) removal efficiencies (they were reduced by only 4-5%), but they were strongly effected to both TKN and heavy metals removal efficiencies (they were reduced by 15 and 20-30%, respectively). Both Ni(2+) and Pb(2+) could repress the growth of both nitrification and denitrification bacteria. And Ni(2+) was more effective than Pb(2+) to reduce the heavy metals removal efficiency. The SBR system could be applied to treat the industrial estate wastewater (IEWW) containing both Pb(2+) and Ni(2+) even the heavy metals concentrations was up to 5mg/L, but the removal efficiency was quite low and excess bio-sludge did not produce. However, the system efficiency could be increased with the increase of BOD(5) concentration of the wastewater. The Pb(2+), Ni(2+), COD, BOD(5) and TKN removal efficiencies of the system with IEWW containing 500 mg/L BOD(5), 5mg/L Ni(2+) and 5mg/L Pb(2+) under HRT of 3 days were 85.68+/-0.31%, 87.03+/-0.21%, 86.0+/-0.5%, 94.04+/-0.4% and 90.5+/-0.9%, respectively. And the effluent SRT, SS and SVI of the system were 44.7+/-0.6 days, 150+/-6 mg/L and 100mL/g, respectively.

Effects of some operating parameters on the efficiency of a sequencing batch reactor system for treatment of textile wastewater containing acid dyes

Abstract The purpose of this research was to find the optimal treatment conditions of a sequencing batch reactor (SBR) system for treatment of various types of textile wastewater (TWW) and synthetic textile wastewater containing acid red 18 and acid blue 9 dyes. Experiments were carried out under various BOD5:TN ratios of 100:5, 100:10, 100:15, and 100:20, with mixed liquor suspended solids of 3,000 mg/L, and at hydraulic retention times (HRT) of 5, 7.5, and 10 d in order to determine the highest removal efficiency. Also, glucose, starch industrial wastewater (SWW), and noodle industrial wastewater were tested for their suitability as a carbon source. The results showed that mixed acid dyes had no significant effect on heterotrophic bacteria, but strongly repressed denitrifying bacteria activity. The SBR system with two times diluted TWW containing 1,480 mg/L glucose demonstrated high removal efficiencies for color, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), and TN (75.9 ± 2.1, 89 ± 7...

Melanoidin decolorization mechanism and some properties of Issatchenkia orientalis No.SF9-246

-1 in the medium containing MP within 7 days cultivation and the crude protein content of the biomass was 36.38±1.12%. In addition, the strain produced intracellular glutathione S-transferase enzymes types Y-1 and Y-2 (GST Y-1 and GST Y-2) and GST Y-1 production was induced by MP.