Aquatic carbon concentrations and fluxes in a degraded blanket peatland with piping and pipe outlet blocking

The paper presents results of studies on the crystallite sizes of oxide layer formed during a long-term operation on 10CrMo9-10 steel at an elevated temperature (T = 545° C, t = 200,000 h). This value was determined by a method based on analysis of the diffraction line profile, according to a Scherrer formula. The oxide layer was studied on a surface and a cross-section at the outer and inner site on the pipe outlet, at the fire and counter-fire wall of the tube. X-ray studies were carried out on the surface of a tube, then the layer’s surface was polished and the diffraction measurements repeated to reveal differences in the originated oxides layer.

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Impact of climate and bulking materials on characteristics of compost from ecological toilets

Journal of Water Sanitation and Hygiene for Development ◽

10.2166/washdev.2012.059 ◽

2012 ◽

Vol 2 (2) ◽

pp. 79-86 ◽

Cited By ~ 3

Author(s):

James W. McKinley ◽

Rebecca E. Parzen ◽

Álvaro Mercado Guzmán

Keyword(s):

Low Carbon ◽

Pathogen Inactivation ◽

High Ph ◽

Moisture Contents ◽

Urine Diversion ◽

Ph Values ◽

Dominant Process ◽

Nitrogen Ratio ◽

Storage Times ◽

Carbon Concentrations

Urine-diversion dehydration toilets (UDDT) are common throughout the developing world, and the toilet product is widely used as compost. There is no comprehensive research to date that characterizes the compost to determine its quality, extent of pathogen inactivation, and the effects of climate and bulking materials on the compost. Compost was collected from 45 UDDT in Bolivia and analyzed for physical, chemical, and biological parameters. Eighty percent and 56% of samples did not meet acceptable compost guidelines for moisture content and pH, respectively, indicating desiccation was the dominant process in UDDT. Bulking materials significantly impacted compost characteristics in terms of pH, carbon, carbon-to-nitrogen ratio, and carbon stability (P < 0.05). Composts with ash exhibited, on average, low carbon concentrations (4.9%) and high pH values (9.7), which can be harmful to plants and composting microorganisms. Composts with sawdust exhibited, on average, high carbon concentrations (40.0%) and carbon-to-nitrogen ratios (31.0). Climate had no significant impact on chemical characteristics, however composts from humid regions had significantly higher moisture contents (34.4%) than those from arid climates (24.8%) (P < 0.05). Viable Ascaris lumbricoides ova were identified in 31% of samples, including samples with high pH, low moisture contents, and long storage times.

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Fate of Toxic Organic Compounds in Activated Sludge and Integrated PAC Systems

Water Science & Technology ◽

10.2166/wst.1987.0227 ◽

1987 ◽

Vol 19 (3-4) ◽

pp. 471-482 ◽

Cited By ~ 19

Author(s):

W. J. Weber ◽

B. E. Jones ◽

L. E. Katz

Keyword(s):

Activated Carbon ◽

Activated Sludge ◽

Organic Compounds ◽

Powdered Activated Carbon ◽

Carbon Adsorption ◽

Powdered Carbon ◽

Benzene Toluene ◽

Adsorptive Properties ◽

Carbon Concentrations ◽

Toxic Organic Compounds

The addition of powdered activated carbon (PAC) to activated sludge treatment systems to enhance removal of specific toxic organic compounds from wastewater was evaluated. Nine organic compounds encompassing a range of solubility, volatility, biodegradability, and adsorptive properties were studied. Kate and equilibrium investigations were conducted to quantify the removal mechanisms of volatilization, biodegradation, biosorption, and carbon adsorption. Results from steady-state bioreactor studies showed that the addition of less than 100 mg/ℓ powdered activated carbon to the influent did not enhance the removal of the biodegradable target compounds investigated: benzene, toluene, ethylbenzene, o-xylene, chlorobenzene, and nitrobenzene. Significantly improved removals of the poorly degradable and non-biodegradable compounds 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, and lindane occurred at influent powdered carbon concentrations in the 12.5 to 25 mg/ℓ range. Influent powdered carbon concentrations of 100 mg/ℓ effected overall removals of greater than 90%. The addition of powdered activated carbon not only reduced effluent concentrations but also reduced the amounts of the volatile compounds stripped to the atmosphere.

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PM2.5 Magnetic Properties in Relation to Urban Combustion Sources in Southern West Africa

Atmosphere ◽

10.3390/atmos12040496 ◽

2021 ◽

Vol 12 (4) ◽

pp. 496

Author(s):

Aruã da Silva Leite ◽

Jean-François Léon ◽

Melina Macouin ◽

Sonia Rousse ◽

Ricardo Ivan Ferreira da Trindade ◽

...

Keyword(s):

Narrow Range ◽

Excellent Correlation ◽

Magnetic Mineralogy ◽

Particulate Emission ◽

Magnetic Parameters ◽

Element Carbon ◽

Physico Chemical ◽

Magnetic Investigation ◽

Combustion Sources ◽

Carbon Concentrations

The physico-chemical characteristics of particulate matter (PM) in African cities remain poorly known due to scarcity of observation networks. Magnetic parameters of PM are robust proxies for the emissions of Fe-bearing particles. This study reports the first magnetic investigation of PM2.5 (PM with aerodynamic size below 2.5 μm) in Africa performed on weekly PM2.5 filters collected in Abidjan (Ivory Coast) and Cotonou (Benin) between 2015 and 2017. The magnetic mineralogy is dominated by magnetite-like low coercivity minerals. Mass normalized SIRM are 1.65 × 10−2 A m2 kg−1 and 2.28 × 10−2 A m2 kg−1 for Abidjan and Cotonou respectively. Hard coercivity material (S-ratio = 0.96 and MDF = 33 mT) is observed during the dry dusty season. Wood burning emits less iron oxides by PM2.5 mass when compared to traffic sources. PM2.5 magnetic granulometry has a narrow range regardless of the site or season. The excellent correlation between the site-averaged element carbon concentrations and SIRM suggests that PM2.5 magnetic parameters are linked to primary particulate emission from combustion sources.

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Traffic Density-Related Black Carbon Distribution: Impact of Wind in a Basin Town

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18126490 ◽

2021 ◽

Vol 18 (12) ◽

pp. 6490

Author(s):

Borut Jereb ◽

Brigita Gajšek ◽

Gregor Šipek ◽

Špela Kovše ◽

Matevz Obrecht

Keyword(s):

Black Carbon ◽

Carbon Concentration ◽

Ground Level ◽

Traffic Density ◽

Carbon Distribution ◽

Wind Speeds ◽

Black Carbon Concentration ◽

Low Wind Speeds ◽

Temperature Inversions ◽

Carbon Concentrations

Black carbon is one of the riskiest particle matter pollutants that is harmful to human health. Although it has been increasingly investigated, factors that depend on black carbon distribution and concentration are still insufficiently researched. Variables, such as traffic density, wind speeds, and ground levels can lead to substantial variations of black carbon concentrations and potential exposure, which is even riskier for people living in less-airy sites. Therefore, this paper “fills the gaps” by studying black carbon distribution variations, concentrations, and oscillations, with special emphasis on traffic density and road segments, at multiple locations, in a small city located in a basin, with frequent temperature inversions and infrequent low wind speeds. As wind speed has a significant impact on black carbon concentration trends, it is critical to present how low wind speeds influence black carbon dispersion in a basin city, and how black carbon is dependent on traffic density. Our results revealed that when the wind reached speeds of 1 ms−1, black carbon concentrations actually increased. In lengthy wind periods, when wind speeds reached 2 or 3 ms−1, black carbon concentrations decreased during rush hour and in the time of severe winter biomass burning. By observing the results, it could be concluded that black carbon persists longer in higher altitudes than near ground level. Black carbon concentration oscillations were also seen as more pronounced on main roads with higher traffic density. The more the traffic decreases and becomes steady, the more black carbon concentrations oscillate.

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