Untitled

Fournier, Diane; Lemieux, R�al; Couillard, Denis

doi:10.1023/a:1005370828275

Cited by 7 publications

(3 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This indicated that these inhibitory compounds were small molecules with molecular weight e 1000. Similar inhibitory effects were also observed by Fournier et al (20) and Cho et al (21) and were generally attributed to soluble organic matter present in sewage sludge, but the compounds responsible for this inhibition are still unknown. Hence, it is essential to identify the potential inhibitory substances present in sludge N and to monitor their dynamics during the anaerobic digestion of sewage sludge since identifying and controlling the potential inhibitory substances may pave the way for further improving the performance of these sludge bioleaching systems.…”

Section: Ferrous Iron Oxidation By a Ferrooxidans Anyl-1 In Sludgesupporting

confidence: 80%

“…In the present study there is no evidence for the presence of any other inhibitory substances in sludge N since artificial addition of similar amounts of organic acids into sludge N with the liquid fraction replaced by the filtrate of sludge S showed similar inhibitory effects on iron oxidation and metal solubilization (Figure 6). The presence of organic acids can also explain the low metal solubilization efficiencies reported by Fournier et al (20) and Cho et al (21) since autoclave-sterilized sewage sludge had been used in these two bioleaching systems, which might lead to an increased soluble fraction of organic matter (26). However, inhibitory substance(s) other than organic acids could not be ruled out.…”

Section: Identification Of Inhibitory Substance(s) In Sludge Nmentioning

confidence: 99%

“…Sludge is rich in organic compounds, which may affect the growth of bioleaching bacteria and thus metal solubilization efficiencies. Significant inhibitory effects of anaerobically digested sludge or sludge extract on iron oxidation and metal solubilization have been reported and attributed generally to soluble organic matters present in sewage sludge (20,21). Unfortunately, no specific inhibitory compounds have been identified in these bioleaching systems.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Identification of Inhibitory Substances Affecting Bioleaching of Heavy Metals from Anaerobically Digested Sewage Sludge

Wong

2004

Environ. Sci. Technol.

View full text Add to dashboard Cite

Significant inhibitory effects of the filtrate medium of anaerobically digested sewage sludge on iron oxidation by Acidithiobacillus ferrooxidans ANYL-1 were observed in our preliminary experiments, indicating the presence of inhibitory substances in anaerobically digested sewage sludge. The objectives of the present study were to identify the possible inhibitory substances and to evaluate their impacts on metal solubilization during bioleaching of sewage sludge. The results showed that the concentrations of total reducing sugars, all tested metal ions, and anions were too low to suppress iron oxidation, and only organic acids, especially acetic and propionic acids, were found at concentrations higher than their inhibitory levels. The presence of 10.8 mM acetic acid and 9.88 mM propionic acid in sewage sludge (sludge N) led to long lag periods of 6 and 7 days for solubilization of Cu and Cr, respectively, as compared to a lag period of only 1 day in the control and another sludge (sludge S) with a low level of organic acids. Meanwhile the leaching time for maximum solubilization of Zn also extended to 6 days in the presence of organic acids as compared to 3 days in the control. Acetic and propionic acids posed an unfavorable bioleaching condition for anaerobically digested sewage sludge; therefore, further studies are required to explore the means to remove the inhibitory effects to improve the heavy metal bioleaching efficiency.

show abstract

Section: Ferrous Iron Oxidation By a Ferrooxidans Anyl-1 In Sludgesupporting

confidence: 80%

Section: Identification Of Inhibitory Substance(s) In Sludge Nmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Identification of Inhibitory Substances Affecting Bioleaching of Heavy Metals from Anaerobically Digested Sewage Sludge

Wong

2004

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

Identification of Procaryotes

Krieg¹

2015

Bergey's Manual of Systematics of Archaea and Bacteria

View full text Add to dashboard Cite

An identification scheme for a group of organisms can be devised only after that group has first been classified (i.e., recognized as being different from other organisms). Identification of that group is based on one or more characteristics, or on a pattern of characteristics, which all the members of the group have and which other groups do not have. The particular pattern of characteristics used for identifying a bacterial group should not be found in any other bacterial group. The identifying characteristics may be phenotypic, such as cell shape and Gram reaction or the ability to ferment certain sugars, or they may be genotypic, such as a particular nucleotide sequence. There should be universal systems for identifying a pure culture. Phenotypic characteristics chosen for an identification scheme should be easily determinable by most microbiology laboratories. Identification should rely on relatively few characteristics compared to classification schemes. Determination of the characteristics chosen for an identification scheme should be relatively inexpensive. The identification scheme should give results rapidly.

show abstract

Bioleaching of sulfidic tailing samples with a novel, vacuum‐positive pressure driven bioreactor

Rzhepishevska

Lindström

Tuovinen

et al. 2005

Biotech & Bioengineering

View full text Add to dashboard Cite

This study presents a design for a novel bioreactor that uses alternating vacuum and positive pressure cycles to transfer acidic leach solution in and out of contact with finely ground sulfidic mine tailings. These tailings constitute an environmental problem that needs experimental data to support the development of management and control strategies. A conventional stirred tank bioreactor was used as a reference system. Both bioreactors were inoculated with mixed cultures of acidophilic iron and sulfur oxidizers. The rate of the bioleaching of tailings was 0.50 +/- 0.14 g Fe/L . day in the stirred tank bioreactor and 0.17 +/- 0.05 g Fe/L . day in the novel bioreactor. Microbial populations were identified in the two-bioreactor systems by analysis of 16S rRNA genes involving amplification, denaturing gradient gel electrophoresis (DGGE), cloning, and sequencing. The inoculum contained sulfur-oxidizing Acidithiobacillus caldus and Acidithiobacillus thiooxidans, iron oxidizers from the genera Leptospirillum and Ferroplasma, and a chemoorganotrophic Alicyclobacillus sp. During bioleaching of the tailings, the microbial populations in both bioreactors were similar to the inoculum culture, except that At. thiooxidans outgrew At. caldus. Sequences consistent with a Sulfobacillus sp. were amplified from both bioreactor samples although this bacterium was initially below the level of detection in the inoculum. After prolonged operation, Ferroplasma acidiphilum and an uncultured bacterium related to the CFB group were also detected in the novel bioreactor, whereas Sulfobacillus sp. was no longer detected. The novel bioreactor has potential uses in other areas of environmental biotechnology that involves periodic contact of liquids with solid substrates.

show abstract

Untitled

Cited by 7 publications

References 8 publications

Identification of Inhibitory Substances Affecting Bioleaching of Heavy Metals from Anaerobically Digested Sewage Sludge

Identification of Inhibitory Substances Affecting Bioleaching of Heavy Metals from Anaerobically Digested Sewage Sludge

Identification of Procaryotes

Bioleaching of sulfidic tailing samples with a novel, vacuum‐positive pressure driven bioreactor

Contact Info

Product

Resources

About