scholarly journals Remediation of Artificially Hydrocarbon Polluted Vadose Zone Soil in Glass Column through Percolation with Solution of Nutrient, Nutrient-Surfactant or Surfactant

2020 ◽  
Vol 24 (6) ◽  
pp. 997-1008
Author(s):  
P.L. Peekate ◽  
J.L. Konne ◽  
T.K.S. Abam
Keyword(s):  
Vadose Zone ◽  
Petroleum Hydrocarbons ◽  
Anaerobic Bacteria ◽  
Surfactant Solution ◽  
Soil Layers ◽  
Start Up ◽  
Glass Column ◽  
Glass Columns ◽  
Microbial Groups ◽  
Hydrocarbon Utilizing Bacteria

Remediation of hydrocarbon polluted vadose zone (HPVZ) through percolation with solution of nutrient, nutrient-surfactant, or surfactant in glass columns was investigated in this study using standard methods. Percolated liquids from the columns and soils retrieved at the end of the  experiment were analyzed for nitrate, phosphate, sulphate, total-petroleum hydrocarbon, and selected microbial groups. Results obtained showed that there were nitrate, phosphate, and sulphate in the percolated liquids. Cumulative hydrocarbon in the percolated liquids was 5.35 – 7.59 % of cumulative hydrocarbon start-up concentration in the columns. Cumulative hydrocarbon attenuation across soil layers in column flooded with solution of nutrients (column NT), nutrient-surfactant (column NTS), and surfactant (column SF) were 89.29, 95.27, and 66.92 % respectively. There was more phosphate reduction in column NTS, and more sulphate reduction in column NT. Hydrocarbon-utilizing fungi in columns NT and NTSincreased from 3.5 Log10 CFU.g-1 to between 4.0 – 5.0 Log10 CFU.g-1, whereas a decrease was observed for column SF. Hydrocarbon-utilizing bacteria in all the columns increased from between 1.0 – 2.5 Log10 CFU.g-1 to between 2.0 - 3.5 Log10 CFU.g-1. Emergence of hydrocarbon utilization among anaerobic bacteria population was also observed in all the columns. It is concludedthat percolation with nutrient-surfactant  solution will be more effective in remediation of HPVZ, and that consequential migration of nutrients alongside hydrocarbons into groundwater canaid in enhancing biodegradation of the infiltrated hydrocarbons. Keywords: Biodegradation; petroleum hydrocarbons; vadose zone; inorganic nutrients; surfactant

The potential of anaerobic bacteria to degrade chlorinated compounds

2001 ◽  
Vol 44 (8) ◽  
pp. 49-56 ◽  
Author(s):  
M.H.A. van Eekert ◽  
G. Schraa
Keyword(s):  
Anaerobic Bacteria ◽  
Granular Sludge ◽  
Chlorinated Ethenes ◽  
Contaminated Sites ◽  
Contaminated Site ◽  
Anaerobic Conditions ◽  
Chlorinated Aromatics ◽  
Start Up ◽  
Acetogenic Bacteria ◽  
Uasb Reactors

Chlorinated ethenes and chlorinated aromatics are often found as pollutants in sediments, groundwater, and wastewater. These compounds were long considered to be recalcitrant under anaerobic conditions. In the past years however, dechlorination of these compounds has been found to occur under anaerobic conditions at contaminated sites and in wastewater treatment systems. This dechlorination is mainly attributed to halo-respiring bacteria, which are able to couple this dechlorination to energy conservation via electron transport coupled phosphorylation. The dechlorinating activities of the halo-respiring bacteria seem to be confined to the dechlorination of chloroethenes and chlorinated aromatic compounds. In addition, methanogenic and acetogenic bacteria are also able to reduce the chlorinated ethenes via a-specific cometabolic pathways. Although these latter reactions may not be important in the remediation of contaminated sites, they may be of substantial influence in the start-up of remediation processes and in the application of granular sludge from UASB reactors. Specific halo-respiring bacteria may be used to increase the dechlorination activities via bioaugmentation in the case that the appropriate microorganisms are not present at the contaminated site or in the sludge.

scholarly journals Modelling the Effect of Efficiency Measures and Increased Irrigation Development on Groundwater Recharge through a Deep Vadose Zone

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 936 ◽  
Author(s):  
Glen R. Walker ◽  
Dougal Currie ◽  
Tony Smith
Keyword(s):  
Numerical Model ◽  
Vadose Zone ◽  
Time Delays ◽  
Total Change ◽  
Initial Development ◽  
Irrigation Development ◽  
Soil Layers ◽  
Efficiency Measures ◽  
Water Tables ◽  
Individual Actions

Water use measures are being implemented in irrigation areas to make better use of limited water resources and reduce adverse environmental impacts. A semi-analytical model is developed and tested with a numerical model to estimate changes in timing and magnitude of recharge from such measures in irrigation areas to support management of impacts, especially for areas with deep vadose zones and perched water tables. Low hydraulic conductivity of soil layers will lengthen time delays between actions and changes to recharge in addition to limiting the maximum recharge. Despite variations in detailed processes, the recharge outputs from models are surprisingly similar, irrespective of whether lateral effects are major. Superposition may be used to simplify the modelling of the total change in recharge from successive actions, including the initial development. Further simplification is possible, using an exponential conceptual model to approximate recharge responses to individual actions.

scholarly journals Parameter Biokinetika dari Degradasi Limbah Kol dan Tomat Menggunakan Sistem Bioreaktor Anaerobik

2021 ◽  
Vol 10 (2) ◽  
pp. 82-89
Author(s):  
Maya Sarah ◽  
Erni Misran ◽  
Seri Maulina ◽  
Ika Pertiwi ◽  
Nahlionny Ritman ◽  
...  
Keyword(s):  
Alternative Energy ◽  
Fossil Fuels ◽  
Biogas Production ◽  
Anaerobic Bacteria ◽  
Maximum Growth ◽  
Feed Concentration ◽  
Free Oxygen ◽  
Alternative Energy Sources ◽  
Tomato Waste ◽  
Start Up

The world's energy supply is very dependent on non-renewable energy in the form of fossil fuels. This causes fossil fuels depletion and the need for alternative energy sources such as biogas. Biogas is produced from the fermentation process of organic matter with the help of anaerobic bacteria in free oxygen absence. This study aims to produce biogas from cabbage and tomato waste separately. Biogas production was carried out by varying feed concentrations of 100 g/L, 200 g/L, and 300 g/L for cabbage waste and 81.6 g/L; 215 g/L; and 237 g/L for tomato waste. This study consisted of 10 days seeding and acclimatization process, followed by a start-up stage using insulated anaerobic bioreactors. The largest methane from cabbage and tomato waste was 60% at a feed concentration of 200 g/L and 50% at a feed concentration of 237 g/L, respectively. The maximum growth rates (µm) for biogas from cabbage and tomato waste were 0.122 day-1 and 0.121 day-1, respectively.

scholarly journals Responses of Soil Microbial Communities to Robinia Pseudoacacia Plantations of Different Ages in A Loess Area

2017 ◽  
Author(s):  
Bingxue Zhang ◽  
Rumeng Zhao ◽  
Boyuan Bi ◽  
Fengpeng Han
Keyword(s):  
Soil Depth ◽  
Robinia Pseudoacacia ◽  
Principal Component ◽  
Stand Age ◽  
Soil Layers ◽  
Loess Area ◽  
Soil Microbial ◽  
Different Ages ◽  
Microbial Groups ◽  
The Individual

Phospholipid fatty acids (PLFAs) can be used as biomarkers for qualitative and quantitative analyses of soil microbial community diversity. In this study, we collected soil samples at 10-cm intervals to a depth of 1 m from Robinia pseudoacacia plantations of four different ages (10, 15, 25 and 40 years) in a loess area and analysed the soil microbial community structure by PLFA analysis. A total of 97 PLFAs were detected in soils of R. pseudoacacia plantations of different ages. The individual PLFA contents gradually decreased in the 0- to 40-cm soil layers, with little variation in the 40- to 100-cm soil layers. The individual PLFAs were similarly distributed in the soils of R. pseudoacacia plantations of different ages, and there was a clear variation with stand age and soil depth. The individual PLFA contents in the 0- to 20-cm soil layers were highest for the 25-year-old plantation, while those in the 20- to 40-cm soil layers were relatively high for the 25- and 40-year-old plantations; the 16:0 content was the highest among individual PLFAs. The total PLFA content and the PLFA contents of different microbial groups [bacteria, fungi, Gram-positive bacteria (G+), Gram-negative bacteria (G-) and actinomycetes] initially increased before decreasing in the soils of R. pseudoacacia plantations with increasing stand age, whereas these contents gradually decreased with increasing soil depth; the highest PLFA contents was found in the 25-year-old plantation. The total PLFA content and the contents of fungal, G- and actinomycete PLFAs in the soils of R. pseudoacacia plantations differed significantly among stands of different ages in the 0- to 10-cm, 10- to 20-cm and 30- to 40-cm soil layers, while no significant differences were found in the 20- to 30-cm soil layers; the G+ and bacterial PLFAs contents in each of the 0- to 40-cm soil layers were significantly different. The PLFA ratios between different microbial groups differed among the stands of different ages. The fungi/bacteria ratio showed a “decrease-increase-decrease” trend with stand age, while the G+/G- ratio showed an “increase-decrease” trend. The saturated/monounsaturated PLFA ratio initially decreased before plateauing, while the opposite trend was observed for the cyclopropyl/precursor ratio. The PLFA contents of different microbial groups were ranked as follows: bacteria > G- > G+ > actinomycetes > fungi. In the principle component analysis, 18:1ω9c, 10Me18:0, i17:0, a17:0, 18:1ω7c, 18:1ω5c and 18:0 made the greatest contribution to principal component 1, and a14:0, i14:0 3OH, i14:0, i14:1ω7c and 14:0 made the greatest contribution to principal component 2. In conclusion, soil nutrient status and other soil eco-environmental stress factors should be considered in 10- to 25-year-old (particularly ~15-year-old) plots for the management of R. pseudoacacia plantations to prevent forest soil degradation and improve forest stand quality, thereby achieving better soil and water conservation and environmental improvement in R. pseudoacacia plantations.

Microbial degradation of petroleum hydrocarbons in estuarine sediment of Tama River in Tokyo urban aera

1997 ◽  
Vol 35 (8) ◽  
pp. 69-76 ◽  
Author(s):  
Akiko Yamane ◽  
Koji Sakakibara ◽  
Masaaki Hosomi ◽  
Akihiko Murakami
Keyword(s):  
Petroleum Hydrocarbons ◽  
Heterotrophic Bacteria ◽  
Anaerobic Biodegradation ◽  
Estuarine Sediment ◽  
Aerobic Biodegradation ◽  
Aerobic Degradation ◽  
Sediment Slurry ◽  
Normal Water ◽  
Hydrocarbon Utilizing Bacteria ◽  
Aerobic And Anaerobic

Aerobic and anaerobic biodegradation rates of petroleum hydrocarbons, i.e., hexadecane (HEX), phenanthrene (PHE), and anthracene (ANT), were determined in estuarine sediment of the Tama River in urban Tokyo, followed by estimating their respective degradation potential. While in a sediment slurry, the aerobic biodegradation rates of these petroleum hydrocarbons ranged from 40 to 70 μg·g−1 dry sediment· day−1. The anaerobic biodegradation rate of HEX was found to be 5 - 8 μg·g−1 dry sediment· day−1, whereas that of PHE and ANT could not be detected following a 2-month incubation. Aerobic degradation of HEX was not affected by coexistence with either PHE or ANT, nor by the salinity level. The number of HEX-, PHE-, or ANT-utilizing bacteria ranged from 5 - 10% of the total number of aerobic heterotrophic bacteria. We calculated their biodegradation potentials using the biomass of naturally existing petroleum hydrocarbon-utilizing bacteria present in the sampled sediment, with results for HEX, PHE, and ANT being 1.0 − 3.5, 4.2 × 10−2, and 1.2 × 10−2 − 9.4 × 10−1 μg·g−1 dry sediment· day−1, respectively. In the aerobic tidal sediment of the Tama River, the purification potentials of HEX, PHE, and ANT were assessed to be approximately equal to their accumulation potentials occurring at the normal water level.

scholarly journals Comparison between Cultured Small-Intestinal and Fecal Microbiotas in Beagle Dogs

2005 ◽  
Vol 71 (8) ◽  
pp. 4169-4175 ◽  
Author(s):  
Silja Mentula ◽  
Jaana Harmoinen ◽  
Matti Heikkilä ◽  
Elias Westermarck ◽  
Merja Rautio ◽  
...  
Keyword(s):  
Small Intestine ◽  
Bacterial Species ◽  
Anaerobic Bacteria ◽  
Beagle Dogs ◽  
Fecal Samples ◽  
Qualitative And Quantitative ◽  
Small Intestinal ◽  
The Stability ◽  
Microbial Groups ◽  
Bacterial Groups

ABSTRACT The microbiota of the small intestine is poorly known because of difficulties in sampling. In this study, we examined whether the organisms cultured from the jejunum and feces resemble each other. Small-intestinal fluid samples were collected from 22 beagle dogs with a permanent jejunal fistula in parallel with fecal samples. In addition, corresponding samples from seven of the dogs were collected during a 4-week period (days 4, 10, 14, and 28) to examine the stability of the microbiota. In the jejunal samples, aerobic/facultative and anaerobic bacteria were equally represented, whereas anaerobes dominated in the fecal samples. Despite lower numbers of bacteria in the jejunum (range, 102 to 106 CFU/g) than in feces (range, 108 to 1011 CFU/g), some microbial groups were more prevalent in the small intestine: staphylococci, 64% versus 36%; nonfermentative gram-negative rods, 27% versus 9%; and yeasts, 27% versus 5%, respectively. In contrast, part of the fecal dominant microbiota (bile-resistant Bacteroides spp., Clostridium hiranonis-like organisms, and lactobacilli) was practically absent in the jejunum. Many species were seldom isolated simultaneously from both sample types, regardless of their overall prevalence. In conclusion, the small intestine contains a few bacterial species at a time with vastly fluctuating counts, opposite to the results obtained for the colon, where the major bacterial groups remain relatively constant over time. Qualitative and quantitative differences between the corresponding jejunal and fecal samples indicate the inability of fecal samples to represent the microbiotas present in the upper gut.

Impact of Sustainable Urban Drainage Systems (SUDS) on Vadose Zone Water

2020 ◽  
Author(s):  
Arne Reck ◽  
Eva Paton ◽  
Björn Kluge
Keyword(s):  
Trace Metal ◽  
Vadose Zone ◽  
Natural Water ◽  
Water Cycle ◽  
Stormwater Runoff ◽  
Urban Drainage ◽  
Soil Layers ◽  
Term Operation ◽  
Metal Contents

<p>Sustainable Urban Drainage System (SUDS), like bioretention for stormwater runoff infiltration, offer several advantages compared to the traditional centralised sewage drainage. Such approaches maintain the natural water cycle in the urban critical zone and help to mitigate climatic extremes impact on urban areas by retarding, storing and evaporating stormwater runoff. Although SUDS are established since longer time (>25 years for example in Germany) we lack systematic investigations on the hydrological functionality and pollutant retention performance of these systems after long-term operation. We employed laboratory and field experiments coupled with numerical simulations to investigate three long-term operated bioretention systems in Germany with following objectives: (i) a detailed mapping of spatial contamination patterns; (ii) a soil hydrological and -chemical substrate characterisation; (iii) an event-based influent and effluent trace metal concentrations monitoring covering 36 months in total; and (iv) a soil water balance simulation using HYDRUS-1D. Regarding the pollution patterns, we found significantly enhanced trace metal contents in the soil substrate mainly as a function of the drainage area type and kind of inflow regime. Nonetheless, average free metal ion concentrations in the soil seepage water extracted below the upper soil layers (30-45 cm) fall below German trigger values considering the soil-groundwater pathway at all three investigated sites. Compared to influent concentrations, average load reduction of the major pollutants Cu and Zn was 55-95 % within the upper soil layers. With regard to infiltrated runoff volumes, simulated water balances revealed hydraulic load reductions of 10-40 % by evapotranspiration. Our current findings demonstrate no risk of groundwater degradation suggesting bioretention as a powerful tool in terms of maintaining the natural water cycle in the urban vadose zone even after long-term operation. Debatable might be the handling of soil substrates modified by stormwater infiltration showing enhanced trace metal contents and a certain amount of technogenic sediments like tyre wear. On the one hand, a big metal pool is specifically bound meaning it can easily turn into free ions during changing conditions like the application of de-icing agents. On the other hand, these substrates perfectly fulfil pollutant retention and water conductivity requirements as mandatory for an effective stormwater treatment using SUDS approaches.</p>

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