respirator Articles
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Model R OXIGEST - Petroleum Refinery - Case Study
A large, Midwestern oil refinery installed two identical, 110’ diameter S&L Model R OXIGEST® treatment systems to solve a groundwater treatment problem on-site. Each plant incorporates aeration, clarification, and effluent holding, treating peak flows of 7.2 MGD combined; 4.3 MGD in each plant. The plant operates with a Food-to-Mass (F/M) typical of extended aeration conditions ...
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Soil carbon dynamics and carbon budget of newly reconstructed tall-grass prairies in south central Iowa
Received for publication February 16, 2009. In addition to their aesthetic and environmental qualities, reconstructed prairies can act as C sinks and potentially offset rising atmospheric CO2 concentration. The objective of this study was to quantify C budget components of newly established prairies on previously cultivated land. Net ecosystem production (NEP) was estimated using a C budgeting ...
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Getting the Most Out of the KN95 Respirator
If you are a respiratory therapist, your job will involve a lot of tasks, including using a Knee Knot Respirator to help you in your job. A Knee Knot Respirator is used by health care professionals such as doctors and other physicians, nurses and respiratory therapists to help them keep their patients comfortable while they are breathing. This is important because patients with respiratory ...
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A biofilm microreactor system for simultaneous electrochemical and nuclear magnetic resonance techniques
Nuclear magnetic resonance (NMR) techniques are ideally suited for the study of biofilms and for probing their microenvironments because these techniques allow for noninvasive interrogation and in situ monitoring with high resolution. By combining NMR with simultaneous electrochemical techniques, it is possible to sustain and study live biofilms respiring on electrodes. Here, we describe a ...
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Ecology of Sulfate-reducing bacteria in an Iron-dominated, mining-impacted freshwater sediment
Received for publication October 31, 2007. A legacy of lead and silver mining in its headwaters left Lake Coeur d'Alene, Idaho with a sediment body that is highly reduced and contains up to 100 g kg–1 iron and a smaller fraction of chemically active sulfide phases. The dynamic character of these sulfides and their importance for the sequestering of contaminating trace elements prompted this study ...
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Sewer Collection System Bioaugmentation Reduces Influent Load and Improves Plant Performance
Abstract The effectiveness of In-Pipe Technology (IPT) patented sewer collection system engineered bioaugmentation on i) influent wastewater loads to wastewater treatment plant (WWTP), ii) WWTP performance, and iii) effluent quality, was a demonstrated at a domestic sequencing batch reactor (SBR) WWTP (Sewer District #20) in Suffolk County, Long Island, New York in collaboration with the Suffolk ...
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How changes in F/M impact microbial populations
Did you know that microbial populations in wastewater are constantly changing? F/M or influent organic makeup and concentrations are a major influence as to what microbes are present. Other factors influencing microbial populations include temperature, pH, D.O., inhibitory compounds, and macronutrients. An underused tool in wastewater treatment is to check your system against the growth curve. A ...
By Aster Bio
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Soil-mixing effects on inorganic nitrogen production and consumption in forest and shrubland soils
Abstract Soils that are physically disturbed are often reported to show net nitrification and NO3 – loss. To investigate the response of soil N cycling rates to soil mixing, we assayed gross rates of mineralization, nitrification, NH4+ consumption, and NO3 – consumption in a suite of soils from eleven woody plant communities in Oregon, New Mexico, and Utah. Results suggest that the common ...
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Microbial community structure and functioning along metal pollution gradients
Toxic effects of heavy metals on soil microorganisms have been confirmed in a number of laboratory studies. However, most real‐field studies do not allow for strong general conclusions due to a range of problems, such as pseudoreplication and confounding factors, which are almost impossible to control for with the most commonly used polluted‐vs.‐unpolluted or random sampling designs. Effects ...
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Kinetics of heterotrophic biomass and storage mechanism in wetland cores measured by respirometry
Although oxygen uptake rate has been widely used in activated sludge for measuring kinetic and stoichiometric parameters or for wastewater characterization, its application in constructed wetlands (CWs) cores has been recently proposed. The aim of this research is to estimate the kinetic and stoichiometric parameters of the heterotrophic biomass in CW cores. Respirometric tests were carried out ...
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Soil formate regulates the fungal nitrous oxide emission pathway
Fungal activity is a major driver in the global nitrogen cycle, and mounting evidence suggests that fungal denitrification activity contributes significantly to soil emissions of the greenhouse gas nitrous oxide (N2O). The metabolic pathway and oxygen requirement for fungal denitrification are different from those for bacterial denitrification. We hypothesized that the soil N2O emission from ...
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Laboratory tests describing the biological reactivity of pretreated residual wastes
In Austria as well as in Germany, several ideas have been put forward on how to describe the biological activity of waste. Gas-generation potential, respiration activity and analysis of material groups ('Stoffgruppenanalysen' according to Van Soest, 1963) and eluate parameters like TOC, NH4-N, COD and BOD were discussed. The use of the Incubation Test (developed by the Department of Waste ...
By ORBIT e.V.
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Impact of barrages on downstream air entrained in water and on upstream river water quality
This research studies the effect of barrages on upstream river water quality and on its self-assimilative. Also, the impact of barrages on upstream water temperature profile is studied. The amount of entrained air in water at river downstream side as a result of barrage existence is also studied. Constructing barrages in river reaches will alter its hydraulics and thus its water quality and ...
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Safety Stand-Down Puts Safety First
An unfortunate event resulting especially from carelessness or ignorance” or “an unforeseen and unplanned event or circumstance” is how merriam-webster.com defines an accident. No one plans an accident. You don’t leave your house in anticipation of a fender bender; nor do jobsite and workplace accidents schedule a time — they happen. Unfortunately, you can be doing ...
By CETCO
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What Limits the Productivity of Acid Mine Drainage Treatment Ponds?
Acid mine drainage (AMD) treatment ponds are very common in the U.S. Appalachian coal region and are the main source of many headwater streams. Though the water that discharges from these ponds generally meets state and federal water quality standards, there is a distinct lack of productivity in most of these ponds. Our first objective was to compare the productivity of chemically-treated, ...
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The adaptation of nitrifying microorganisms to inhibiting substances at meso- and psychrophilic temperature conditions
This paper deals with adaption capacity of nitrifiers to allylthiourea (ATU) as a model inhibitor at two temperature levels. Nitrifying communities were developed at 15 (BM15) and 30 °C (BM30). The activity of the nitrifiers was determined by using short-time respiration (STR) tests, oxygen monitoring and in-situ measurements. The oxygen monitoring provided information about the ...
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Treatment of distillery anaerobic effluent in a hybrid biological reactor
The treatability of anaerobic effluent from a molasses-based distillery was studied in a shaft-type hybrid bioreactor under purely suspended growth and hybrid system containing 5 mm tyre-tube beads. The Ks, k, Y and k found as 111.29 mg/l, 0.026/h, 0.4607 and 0.0040/h respectively. The maximum COD removal was 51.7% at a loading rate of 5.250 kg d−1 m−3. The overall removal rate was 0.0431, ...
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Gene expression, glutathione status, and indicators of hepatic oxidative stress in laughing gull (Larus atricilla) hatchlings exposed to methylmercury
Despite extensive studies of methylmercury (MeHg) toxicity in birds, molecular effects on birds are poorly characterized. To improve our understanding of toxicity pathways and identify novel indicators of avian exposure to Hg, the authors investigated genomic changes, glutathione status, and oxidative status indicators in liver from laughing gull (Larus atricilla) hatchlings that were exposed ...
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A two-stage soil infiltration system incorporated with heterotrophic denitrification (TSISHD) for urban runoff treatment
To enhance denitrification performance of soil infiltration, a soil infiltration system incorporated with heterotrophic denitrification (TSISHD) for urban runoff treatment was developed. Sawdust and grass powders were added in the anaerobic stage (ANS) to provide organic carbon sources for the denitrification process, and the reduction environment was improved by iron addition in the ANS. ...
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Crystalline Silica: Sampling/Testing of Workers for Respirable Silica
Crystalline silica has been classified as a lung carcinogen. OSHA issued its final rules for controlling worker exposure to crystalline silica on March 23, 2016. The specific OSHA regulation is 29CFR1926.1153 (Construction Standard) and 29CFR1910.1053 (General Industry/Marine). Sampling of workers that handle sand (silica) such as concrete mixing, paving, gravestones, countertops, marble ...
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