scholarly journals Denitrification of nitrate-contaminated groundwater using biodegradable snack ware as carbon source under low-temperature condition

2011 ◽  
Vol 9 (1) ◽  
pp. 113-118 ◽  
Author(s):  
X. M. Wang ◽  
J. L. Wang
Keyword(s):  
Low Temperature ◽  
Carbon Source ◽  
Contaminated Groundwater

scholarly journals Isolation and Characterization of a Biosurfactant Producing Strain Planococcus sp. XW-1 from the Cold Marine Environment

2022 ◽  
Vol 19 (2) ◽  
pp. 782
Author(s):  
Ping Guo ◽  
Weiwei Xu ◽  
Shi Tang ◽  
Binxia Cao ◽  
Danna Wei ◽  
...  
Keyword(s):  
Low Temperature ◽  
Carbon Source ◽  
Crude Oil ◽  
Surface Activity ◽  
Yellow Sea ◽  
High Surface ◽  
Sole Source ◽  
The Yellow Sea ◽  
Isolation And Characterization ◽  
First Time

One cold-adapted strain, named Planococcus sp. XW-1, was isolated from the Yellow Sea. The strain can produce biosurfactant with petroleum as sole source of carbon at low temperature (4 °C). The biosurfactant was identified as glycolipid-type biosurfactant species by thin-layer chromatography (TLC) and Fourier transform infrared spectroscopy (FTIR). It reduced the surface tension of water to 26.8 mN/m with a critical micelle concentration measurement of 60 mg/L. The produced biosurfactant possesses high surface activity at wide ranges of temperature (−18–105 °C), pH values (2–12), and salt concentrations (1–18%). The biosurfactant exhibited higher surface activity and higher growth rate of cells with hexadecane and diesel as carbon source. The strain Planococcus sp. XW-1 was also effective in degrading crude oil, after 21 days of growth at 4 °C in medium with 1% crude oil and 1% (v/v) bacteria broth, 54% of crude oil was degraded. The results suggest that Planococcus sp. XW-1 is a promising candidate for use in the bioremediation of petroleum-contaminated seawater in the Yellow Sea during winter. This study reported for the first time that Planococcus isolated from the Yellow Sea can produce biosurfactant using petroleum as the sole carbon source at low temperature (4 °C), showing its ecological role in the remediation of marine petroleum pollution.

Reduction of bromate in groundwater with an ex situ suspended growth bioreactor

2005 ◽  
Vol 52 (9) ◽  
pp. 265-273 ◽  
Author(s):  
R. Butler ◽  
A.R. Godley ◽  
R. Lake ◽  
L. Lytton ◽  
E. Cartmell
Keyword(s):  
Carbon Source ◽  
Residence Time ◽  
High Rate ◽  
Ex Situ ◽  
Microbial Populations ◽  
Contaminated Groundwater ◽  
Bacterial Strains ◽  
Glucose Addition ◽  
Suspended Growth ◽  
Bromate Reduction

A potential remediation technique for groundwater contaminated by bromate has been investigated, utilising biological bromate reduction to bromide by augmentation of indigenous microbial populations. This technique, involving addition of a carbon source to contaminated groundwater, is being developed as an ex-situ methodology analogous to commercial denitrification systems, but may also havein-situ applications. Trials have focussed on a laboratory-scale anaerobic suspended growth chemostat system, investigating glucose addition to real groundwater supplies. Steady states for a range of glucose and bromate concentrations demonstrated bromate reduction up to 700μgl−1 (50% of 1400μgl−1 influent) with glucose excess (above 52mgl−1), but specific reduction rates (up to 2.83μmol Br.g dry wt−1hr−1 for 1400μgl−1 bromate influent) were low compared to denitrification (up to 305μmol Ng dry wt−1hr−1). More recent enrichment trials have demonstrated reduction of 32mgl−1 bromate within a 40 hour residence time with specific reduction rates of up to 160.48μmol Br.g dry wt−1hr−1, suggesting the presence of high rate bromate reducing bacterial strains.

Enhanced Heterotrophic Denitrification for the Treatment of Nitrate Contaminated Groundwater by Wheat Straw

2013 ◽  
Vol 316-317 ◽  
pp. 625-628
Author(s):  
Jian Mei Zhang ◽  
Chuan Ping Feng ◽  
Si Qi Hong ◽  
Hui Ling Hao
Keyword(s):  
Carbon Source ◽  
Wheat Straw ◽  
Carbon Sources ◽  
Complete Removal ◽  
Contaminated Groundwater ◽  
Column Experiments ◽  
Inlet Concentration ◽  
Reducing Conditions ◽  
Organic Carbon Sources ◽  
Heterotrophic Denitrification

The method of the heterotrophic denitrification remediation of nitrate-polluted groundwater involves the study of organic carbon sources as electron donor. The aim of the present study was to evaluate wheat straw for its ability to enhance denitrification in column experiments. The inlet concentration was 50.0 mgNO3--N/L and the column operated at the flow rate of 2.0 ml/min. The result showed that in the presence of wheat straw, highly reducing conditions were generated and complete removal of nitrate (>95%) was achieved, with less accumulation of nitrite. Consequently, wheat straw is an attractive carbon source for groundwater denitrification.

Kamphaugite-(Y) from La Cabrera massif, Spain: a low-temperature hydrothermal Y-REE carbonate

2006 ◽  
Vol 70 (4) ◽  
pp. 397-404 ◽  
Author(s):  
J. González del Tánago ◽  
A. La Iglesia ◽  
A. Delgado
Keyword(s):  
Low Temperature ◽  
Carbon Source ◽  
Alkali Feldspar ◽  
Hydrothermal Activity ◽  
Average Composition ◽  
Central System ◽  
Free Surfaces ◽  
Spanish Central System ◽  
Miarolitic Cavities ◽  
Very Low Temperature

AbstractKamphaugite-(Y) occurs as white to cream-coloured spherical to semi-spherical aggregates of radial crystals in the La Cabrera granitic pluton (Spanish Central System). It mainly occurs on the free surfaces of alkali feldspar, quartz, calcite, kainosite-(Y) and laumontite, and inside miarolitic cavities. La Cabrera kamphaugite-(Y) has an average composition of Ca0.94Y0.89REE0.21(CO3)2 [F0.05(OH)0.95]·1.19H2O. Negative δ13CV-PDB values (–14 to –15‰) indicate a meteoric carbon source. Textural relations between kamphaugite-(Y) and coexisting minerals, its relatively high δ18OV-SMOW values (+25 to +26‰), and the occurrence of laumontite inclusions in kamphaugite-(Y), point to a genesis at < 50°C during very low-temperature post-magmatic hydrothermal activity.

Effect of External Carbon Source on Denitrification in Biofilter at Low Temperature

2010 ◽  
Vol 113-116 ◽  
pp. 1358-1362
Author(s):  
Hong Jun Han ◽  
Yu Fei Li ◽  
Hong Bo Hu ◽  
Bing Wang
Keyword(s):  
Low Temperature ◽  
Carbon Source ◽  
Carbon Sources ◽  
Efficiency Enhancement ◽  
Denitrification Potential ◽  
External Carbon Source ◽  
Batch Tests ◽  
Sewage Plant ◽  
The Mean ◽  
Lower Temperature

The aim of this study is to investigate the denitrification efficiency enhancement and to evaluate the denitrification potential at the condition of lower temperature. Three identical biofilter were operated in parallel at batch tests. Results showed that the denitrification potential can be substantially increased by addition of ethanol and hydrolysate of sludge as external carbon sources compared with raw sewage. The mean denitrification rates of ethanol and hydrolysate reached up to 0.058 and 0.08 mgN/(g MLVSS•h), respectively, while that of raw sewage was only 0.041 mgN/(g MLVSS•h). The denitrification potential increased respectively from 0.76 to 1.54 and 5.3 mg NO3-N/L owing to ethanol and hydrolysate addition. By comparison, hydrolysate of sludge was found to be the better carbon source for denitrification considering strengthening denitrification performance and price. This study provides evidence for external carbon sources choice of sewage plant and surplus sludge reutilization.

SiC Epitaxial Growth on Si(100) Substrates Using Carbon Tetrabromide

2010 ◽  
Vol 645-648 ◽  
pp. 139-142 ◽  
Author(s):  
Giovanni Attolini ◽  
Matteo Bosi ◽  
Francesca Rossi ◽  
Bernard Enrico Watts ◽  
Giancarlo Salviati ◽  
...  
Keyword(s):  
Low Temperature ◽  
Carbon Source ◽  
Epitaxial Growth ◽  
Carbon Tetrabromide ◽  
Continuous Layer ◽  
Sic Films

3C-SiC films were grown on Si by VPE using CBr4 as the carbon source, at temperatures ranging between 1100 to 1250°C. XRD, TEM, AFM, and SEM results indicate that the epitaxy proceeds as a 3D growth of uncoalesced islands at low temperature, whereas a continuous layer with hillocks on top is obtained above 1200°C. The shape and faceting of the islands are analyzed by AFM, showing (311) preferred facets.

scholarly journals H-NS Controls pap and daaFimbrial Transcription in Escherichia coli in Response to Multiple Environmental Cues

2000 ◽  
Vol 182 (22) ◽  
pp. 6391-6400 ◽  
Author(s):  
Christine A. White-Ziegler ◽  
Anuradha Villapakkam ◽  
Karla Ronaszeki ◽  
Sarah Young
Keyword(s):  
Escherichia Coli ◽  
Low Temperature ◽  
Carbon Source ◽  
Iron Concentration ◽  
Environmental Cues ◽  
Rich Medium ◽  
High Osmolarity ◽  
E Coli ◽  
Transcriptional Fusions

ABSTRACT A comparative study was completed to determine the influence of various environmental stimuli on the transcription of three different fimbrial operons in Escherichia coli and to determine the role of the histone-like protein H-NS in this environmental regulation. The fimbrial operons studied included the pap operon, which encodes pyelonephritis-associated pili (P pili), the daaoperon, which encodes F1845 fimbriae, and the fan operon, which encodes K99 fimbriae. Using lacZYA transcriptional fusions within each of the fimbrial operons, we tested temperature, osmolarity, carbon source, rich medium, oxygen levels, pH, amino acids, solid medium, and iron concentration for their effects on fimbrial gene expression. Low temperature, high osmolarity, glucose as a carbon source, and rich medium repressed transcription of all three operons. High iron did not alter transcription of any of the operons tested, whereas the remaining stimuli had effects on individual operons. For the pap and daa operons, introduction of thehns651 mutation relieved the repression, either fully or partially, due to low temperature, glucose as a carbon source, rich medium, and high osmolarity. Taken together, these data indicate that there are common environmental cues that regulate fimbrial transcription in E. coli and that H-NS is an important environmental regulator for fimbrial transcription in response to several stimuli.

Sign in / Sign up

Export Citation Format

Share Document