Remediation of Soils Contaminated with Tetraethyl Lead by Electric Fields

1998 ◽  
Vol 1615 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Akram N. Alshawabkeh ◽  
Elif Ozsu-Acar ◽  
Robert J. Gale ◽  
Susheel K. Puppal
Keyword(s):  
Electric Fields ◽  
Dry Weight ◽  
Buffering Capacity ◽  
Lead Extraction ◽  
Tetraethyl Lead ◽  
Soluble Ions ◽  
High Calcium ◽  
Octane Rating ◽  
High Concentrations ◽  
Soil Buffering

Four tests were conducted to investigate potential uses of electric fields for remediation of high buffering capacity soils contaminated with high lead concentrations (11 percent by dry weight). The soil samples were collected from a site in Louisiana where tetraethyl lead was used extensively for increasing the octane rating of leaded gasoline. Calcium was present at relatively high concentrations (9 percent by dry weight). Initial soil pH was basic (about 8.5). Two enhancement procedures were used: acetic acid for neutralizing the cathode and membranes to prevent migration of hydroxyl ions from the cathode. Current densities applied were in the order of 5 A/m2 to 10 A/m2. Tests were processed for up to 3,220 hours. Lead extraction rates were significantly affected by high calcium concentration. Energy expenditure was very high (up to 20 667 kWh/m3 in the unenhanced test). The study showed that the soil buffering capacity significantly affected energy requirements, cost-effectiveness, and success of the process. Efficient extraction of lead in soils will be controlled by the presence of high concentrations of soluble ions (such as calcium) in the soil.

Potential Contribution of Nutrients and Polycyclic Aromatic Hydrocarbons from the Creeks of Cootes Paradise Marsh

1996 ◽  
Vol 31 (3) ◽  
pp. 485-504 ◽  
Author(s):  
Patricia Chow-Fraser ◽  
Barb Crosbie ◽  
Douglas Bryant ◽  
Brian McCarry
Keyword(s):  
Aromatic Hydrocarbons ◽  
Laboratory Experiments ◽  
Dry Weight ◽  
Common Source ◽  
Potential Contribution ◽  
Nitrogen And Phosphorus ◽  
Engine Combustion ◽  
Polycyclic Aromatic ◽  
High Concentrations ◽  
Derivatives Of

Abstract During the summer of 1994, we compared the physical and nutrient characteristics of the three main tributaries of Cootes Paradise: Spencer, Chedoke and Borer’s creeks. On all sampling occasions, concentrations of CHL α and nutrients were always lowest in Borer’s Creek and highest in Chedoke Creek. There were generally 10-fold higher CHL α concentrations and 2 to 10 times higher levels of nitrogen and phosphorus in Chedoke Creek compared with Spencer Creek. Despite this, the light environment did not differ significantly between Spencer and Chedoke creeks because the low algal biomass in Spencer Creek was balanced by a relatively high loading of inorganic sediments from the watershed. Laboratory experiments indicated that sediments from Chedoke Creek released up to 10 µg/g of soluble phosphorus per gram (dry weight) of sediment, compared with only 2 µg/g from Spencer Creek. By contrast, sediment samples from Spencer Creek contained levels of polycyclic aromatic hydrocarbon that were as high as or higher than those from Chedoke Creek, and much higher than those found in Borer’s Creek. The distribution of normalized PAH concentrations suggests a common source of PAHs in all three tributaries, most likely automobile exhaust, since there were high concentrations of fluoranthene and pyrene, both of which are derivatives of engine combustion.

MO843PREVALENCE AND MANAGEMENT OF HYPERTENSION IN HEMODIALYSIS PATIENTS

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Ali AlSahow ◽  
Anas Alyousef ◽  
Bassam Alhelal ◽  
Heba AlRajab ◽  
Yousif Bahbahani ◽  
...  
Keyword(s):  
Weight Gain ◽  
Fluid Intake ◽  
Salt Intake ◽  
Statistical Significance ◽  
Dry Weight ◽  
Weekly Schedule ◽  
Interdialytic Weight Gain ◽  
High Salt Intake ◽  
Number Of Patients ◽  
High Calcium

Abstract Background and Aims Hypertension (HTN) is common in hemodialysis (HD) patients & diagnosed by pre-dialysis BP >140/90 mmHg. Causes include high salt intake, volume overload, & loss of residual kidney function. Therapy includes achieving correct dry weight with each session, restricting interdialytic sodium & fluid intake & medications. We review its prevalence, factors associated with it & its management in our patients. Method Demographics, HD prescription & medications data collected for patients from 5 dialysis centers. Results A total of 1585 files reviewed. Males were 51.8% & mean age was 59. Mean age significantly higher for females (61 vs 57). ESKD cause was DM in 51% & HTN in 35%. However, of files reviewed, adequate data on comorbidities in 1390 patients (table 1), 69% had DM, 92% had HTN, 47% had CVD & 31% had BMI > 25 (which was significantly more frequent in females). HTN was more likely in older patients, diabetics & females with odds of HTN in females nearly twice the odds of HTN in males & odds of HTN with DM is 2.27 times odds of HTN without DM & one-year increase in age would increase odds of HTN by nearly 4%. Mean pre-HD BP for those with HTN was 143/76 mmHg & for those without HTN was 136/75 mmHg. HD frequency was thrice weekly in 94% & HD duration was > 3.5 hours in only 77% of patients. HDF used in 81.5%. Mean interdialytic weight gain (IDWG) was 2.8 kg, with no difference according to gender or presence of DM or HTN (Table 2). Higher IDWG associated with age < 65, Calcium bath of 1.75 & Sodium bath > 138 with 0.638 kg higher IDWG with calcium of 1.75 compared to calcium of 1.25. Higher IDWG was associated with higher BP. Mean volume of fluid removed per session was 2.74, which was less than mean IDWG, with no difference according to gender or DM, however, it was higher in the higher dialysate sodium group, & lower in the shorter session group (with trend towards statistical significance). CCB used to treat HTN in 62% followed by βB in 52%. Number of patients with HTN on 1 drug 21%, 2 drugs 27%, 3 drugs 23%, ≥ 4 drugs 20% & 9% missing data. Number of antihypertensives did not correlate with IDWG. Conclusion Interdialytic weight gain in our HD patients is excessive & contributing to HTN. Patients must restrict salt & fluid intake & dialysis centers must regularly & frequently assess dry weight, ensure thrice weekly schedule & 4 hours per session are met, so excess fluid is completely removed. Also, high sodium & high calcium baths need to be avoided.

scholarly journals Temporal and spatial variation on heavy metal concentrations in the oyster Ostrea equestris on the northern coast of Rio de Janeiro State, Brazil

2005 ◽  
Vol 65 (1) ◽  
pp. 67-76 ◽  
Author(s):  
A. G Ferreira ◽  
A. L. S. Machado ◽  
I. R. Zalmon
Keyword(s):  
Heavy Metal ◽  
Spatial Variation ◽  
Rio De Janeiro ◽  
Dry Weight ◽  
Temporal Variations ◽  
Average Concentration ◽  
Northern Coast ◽  
High Concentrations ◽  
Janeiro State ◽  
Ostrea Equestris

Heavy metal (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) concentrations were determined by ICP-AES in Ostrea equestris from three beaches (Barra do Furado, Buena, and Ponta do Retiro) on the northern coast of Rio de Janeiro State. The average concentration was 0.8 ± 0.18, 0.4 ± 0.21, 58 ± 25.6, 249 ± 52.3, 11 ± 1.31, 0.55 ± 0.16, 0.13 ± 0.11, and 1131 ± 321 µg.g-1 dry weight for Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn respectively. Significant spatial variation (p < 0.05) between the samples areas occurred for Cr, Pb, and Zn with higher values in Barra do Furado; and for Cu in Ponta do Retiro. Significant temporal variations (p < 0.05) were observed for all metals except Cu. Temporal variability may be related to changes in the inputs of metals associated with suspended particles. Concentrations were similar to those found in areas under low pollution impact, except for Zn, the high concentrations of which probably reflect the physiological characteristics of these organisms.

Responses of soil buffering capacity to acid treatment in three typical subtropical forests

2016 ◽  
Vol 563-564 ◽  
pp. 1068-1077 ◽  
Author(s):  
Jun Jiang ◽  
Ying-Ping Wang ◽  
Mengxiao Yu ◽  
Kun Li ◽  
Yijing Shao ◽  
...  
Keyword(s):  
Acid Treatment ◽  
Buffering Capacity ◽  
Subtropical Forests ◽  
Soil Buffering

scholarly journals PP2A Methylation is Necessary for Broad Stress Tolerance

2021 ◽  
Author(s):  
Maria T. Creighton ◽  
Dugassa Nemie-Feyissa ◽  
Nabeela Zaman ◽  
Sverre S. Johansen ◽  
Hege Dysjaland ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Tolerance ◽  
Dry Weight ◽  
Sodium Concentration ◽  
Post Translational Modification ◽  
Iron Starvation ◽  
Methyl Transferase ◽  
High Concentrations ◽  
Fe Homeostasis ◽  
Rock Wool

Abstract Background: LEUCINE CARBOXYL METHYL TRANSFERASE 1 (LCMT1) transfers a methyl group from the methyl donor S-adenosylmethionine (SAM) to the catalytic subunit of PROTEIN PHOSPHATASE 2A (PP2A). This post-translational modification of PP2A is manifested throughout eukaryotes from yeast to plants and animals. Although highly conserved, the importance of the methylation is poorly understood. Since Arabidopsis plants with knocked out LCMT1 grow and develop fairly normally, we decided to search for conditions that may reveal the benefits of this regulation. We compared the effects of various stressful conditions on Arabidopsis wild type (WT) and a lcmt1 mutant possessing only non-methylated PP2A. Results: Seedlings were grown in Petri dishes for 5-12 days, or in rock wool and soil for up to 7 weeks. A significant increase in sodium concentration was found for lcmt1 relative to WT, but this was not linked with stressful conditions. Plants were exposed to variable levels of the chelator EDTA, iron, zinc, aluminium, heat, and hydrogen peroxide. The lcmt1 mutant was clearly more sensitive than WT to all the various stresses, as demonstrated by effects on seedling root growth and on shoots of rosette stage plants on rock wool. When omitting EDTA, expression of genes known as signature genes for iron deficiency, FIT1, bHLH100, IMA1, IRT1 was strongly enhanced in lcmt1. Although an iron starvation response was induced, Fe homeostasis was apparently maintained by slowed growth in lcmt1 and the Fe level related to tissue dry weight was not changed. Among genes induced in lcmt1 were also the Zn induced gene ZIF1, and heat shock protein HSP90-1. Concentrations of non-iron transition metals, Cu, Mn and Zn, increased significantly in response to lack of EDTA for both lcmt1 and WT tissue, and especially the growth of lcmt1 was strongly hampered. Conclusions: Presence of the LCMT1 gene was necessary to cope efficiently with an imbalance in the micronutrients, heat stress, and oxidative stress. Methylation of PP2A appears important to ameliorate the toxic effects of metals present in unfavourable high concentrations as well as heat or oxidative stress. The experiments establish LCMT1 as a key component in broad stress tolerance.

Boron Deficiency in a Southern Pine Nursery

1982 ◽  
Vol 6 (2) ◽  
pp. 108-112 ◽  
Author(s):  
E. L. Stone ◽  
C. A. Hollis ◽  
E. L. Barnard
Keyword(s):  
Pinus Taeda ◽  
Soil Management ◽  
Late Summer ◽  
Dry Weight ◽  
Height Growth ◽  
Boron Deficiency ◽  
First Year ◽  
Normal Height ◽  
High Calcium ◽  
Pinus Taeda L

Abstract Boron deficiency in seedling loblolly (Pinus taeda L.) and slash pine (Pinus elliotti Engelm.) in a northern Florida nursery was diagnosed by: (1) characteristic damage to shoot tips and buds, including necrosis of only part of the terminal; and (2) boron concentrations as low as only 1.9 ppm (dry weight) in affected tissues. Soil and soil-management features associated with deficiency include extremely low silt and clay contents, organic matter levels of 1 percent or less, lack of boron addition, and high calcium irrigation water leading to soil reactions above pH 6 by late summer. Consequences of deficiency were not limited to the nursery. Damaged seedlings that survived outplanting developed into bushy plants incapable of normal height growth in the first year or two.

Inorganic Bromide in Higher Fungi

1984 ◽  
Vol 39 (9-10) ◽  
pp. 863-866 ◽  
Author(s):  
T. Stijve
Keyword(s):  
Trace Element ◽  
Dry Weight ◽  
Mean Value ◽  
Inorganic Salts ◽  
Chromatographic Methods ◽  
The Mean ◽  
High Concentrations

Abstract A total of 138 samples of higher fungi, representing 35 species (15 belonging to the genus Amanita), were analysed for the trace element bromine using spectrophotometric and gas chromatographic methods. High concentrations of bromine, up to 100 mg/kg on dry weight, were encountered in Amanitaceae, especially in members of the subsections Phalloideae and Eu-Amanita, whereas in other fungi the mean value for this element was only 3,3 m g/kg. Some bromine-accumulating Amanitas also contained unusually high chlorine levels. Am axi­mum concentration of 3 percent on dry weight was measured in A. phalloides. It could be demonstrated that most, if not all of bromine and chlorine was present in the fungi as ionisable inorganic salts. Two organochlorine metabolites, previously reported in some mushrooms, were absent in A. phalloides and A. muscaria.

The pH of K-deficient muscle

1959 ◽  
Vol 196 (4) ◽  
pp. 811-818 ◽  
Author(s):  
Robert E. Eckel ◽  
Andrew W. Botschner ◽  
Don H. Wood
Keyword(s):  
Indirect Method ◽  
Direct Method ◽  
Dry Weight ◽  
Buffering Capacity ◽  
Muscle Proteins ◽  
Acid Base Balance ◽  
Acid Base ◽  
Weak Bases ◽  
Base Balance ◽  
K Deficiency

The acid-base balance of muscle from control and K-deficient rats was studied. From the measured buffering capacity, 8–11 mEq excess of anions or deficit of cations would be required to acidify 100 gm fat-free dry weight of muscle, 0.5 pH units. No evidence of increased organic acids, increased anionic equivalence of muscle proteins, or of decreased concentrations of weak bases which are potential cations in cell acidosis was found. This evidence, supplemented with data in the literature, fails to account for the cell acidosis reported in the literature. Reliability of the ‘chloride space’ as a measure of the extracellular phase of muscle in K deficiency has been confirmed by showing its agreement with the ‘raffinose space.’ The cell pH has then been calculated from the distribution of CO2 in muscle (indirect method) and from the pH of muscle homogenates (direct method) in control and K-deficient animals. Control and K-deficient muscle pH's are, respectively, 6.89 and 6.83 by the direct method, and 7.11 and 7.05 by the indirect method.

Relationships between organic matter composition and methyl mercury content of offshore and carbon-rich littoral sediments in an oligotrophic lake

2003 ◽  
Vol 60 (7) ◽  
pp. 888-896 ◽  
Author(s):  
Martin Kainz ◽  
Marc Lucotte ◽  
Christopher C Parrish
Keyword(s):  
Organic Matter ◽  
Methyl Mercury ◽  
Lacustrine Sediments ◽  
Desulfovibrio Desulfuricans ◽  
Dry Weight ◽  
Mercury Content ◽  
Sulfate Reducing ◽  
Littoral Sediments ◽  
High Concentrations ◽  
Offshore Sediments

Relationships between organic matter (OM) compounds and methyl mercury concentrations ([MeHg]) have been examined in littoral and offshore sediments of Lake Lusignan (Québec). The highest [MeHg] were generally found at the sediment–water interface with exceptionally high concentrations at littoral sites (5.8 ± 1.3 ng·g dry weight–1), which were four times more elevated than at offshore sites (1.6 ± 0.77 ng·g dry weight–1). Source-specific fatty acid (FA) biomarkers identified that littoral sediments contained more than twice as much terrestrial and bacterial OM compounds than offshore sediments, whereas the amount of labile algal OM was three times higher at littoral sites. Results indicate that [MeHg] were higher in the presence of labile OM substrates, and the amount of terrestrial OM compounds could not predict [MeHg]. Correlations between [MeHg] and FA of Desulfovibrio desulfuricans (a sulfate-reducing bacterium producing MeHg) could significantly account for 36% of [MeHg] at offshore sites; however, no significant relationships were found at littoral sites. This study illustrates that the microbial dynamics involved in producing and degrading MeHg in lacustrine sediments are complex and cannot be predicted solely by the quantification of FA biomarkers in D. desulfuricans or by biomarkers in the OM itself.

Burning Nettle, Common Purslane, and Rye Response to a Clove Oil Herbicide

2006 ◽  
Vol 20 (3) ◽  
pp. 646-650 ◽  
Author(s):  
Nathan S. Boyd ◽  
Eric B. Brennan
Keyword(s):  
Weed Management ◽  
Production Systems ◽  
Dry Weight ◽  
Organic Production ◽  
Management Tool ◽  
Vegetable Production ◽  
Clove Oil ◽  
Organic Farms ◽  
High Concentrations ◽  
Common Purslane

Weed management is often difficult and expensive in organic production systems. Clove oil is an essential oil that functions as a contact herbicide and may provide an additional weed management tool for use on organic farms. Burning nettle, purslane, and rye responses to 5, 10, 20, 40, and 80% v/v clove oil mixture applied in spray volumes of 281 and 468 L/ha were examined. Log-logistic curves were fitted to the nettle and purslane data to determine the herbicide dose required to reduce plant dry weight 50% (GR50) and 90% (GR90). A three-parameter Gaussian curve was fitted to the rye data. The GR50 and GR90 were largely unaffected by spray volume. Nettle dry weight was reduced by 90% with 12 to 61 L clove oil/ha, whereas 21 to 38 L clove oil/ha were required to reduce purslane biomass to the same level. Rye was not effectively controlled by clove oil. Clove oil controls broadleaf weeds at high concentrations, but its cost makes broadcast applications prohibitive, even in high-value vegetable production systems.

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