Bioaerosols from the land application of biosolids in the desert southwest USA

2004 ◽  
Vol 50 (1) ◽  
pp. 7-12 ◽  
Author(s):  
J.P. Brooks ◽  
B.D. Tanner ◽  
K.L. Josephson ◽  
C.P. Gerba ◽  
I.L. Pepper

This study evaluated bioaerosol emissions during land application of Class B biosolids in and around Tucson, Arizona, to aid in developing models of the fate and transport of bioaerosols generated from the land application of biosolids. Samples were collected for 20 min at distances between 2 m and 20 m downwind of point sources, using an SKC BioSampler® impinger. A total of six samples were collected per sampling event, which consisted of a biosolid spray applicator applying liquid biosolids to a cotton field. Each application represented one exposure. Samples were collected in deionised water amended with peptone and antifoam agent. Ambient weather conditions were also monitored every 10 min following initiation of sampling. Concurrently with downwind samples, background (ambient) air samples were collected to compensate for any ambient airborne microorganisms. In addition, biosolids samples were collected for analysis of target indicator and pathogenic organisms. Soil samples were also collected and analysed. Significant numbers of heterotrophic plate count (HPC) bacteria were found in air samples collected during the biosolid application process. These could have arisen from soil particles being aerosolised during the land application process. Aerosolised soil may contribute significantly to the amount of aerosolised microorganisms. Soil particles may be able to more readily aerosolise, due to their low density, small particle size and low mass. Aerosolised HPC bacteria found during biosolids land application were similar to those found during normal tractor operation on non-biosolids applied fields. Coliforms and coliphages were not routinely detected even though they were found to be present in the biosolids at relatively high concentrations, 106 and 104/g (dry weight) of biosolids respectively. This could be due to the die-off rate of aerosolised Gram-negative bacteria or sorption to the solid portion of the biosolids. Low numbers of aerosolised coliphages may likewise be due to sorption phenomena. We theorise that only organisms in the aqueous phase of the biosolids were available to desorb and be aerosolised. Animal viruses, which were not detected in the biosolids, were likewise not detected in the aerosol samples. Clostridium perfringens was detected in only a small percent of aerosol samples although it was detected during all weather conditions; other microorganisms were detected during more favourable environmental conditions (relative humidity >10%). Despite the fact that many of these organisms were present in the biosolids at significant concentrations, their presence in bioaerosols generated during the land application of biosolids was limited to only a small percentage of samples. Bacteria as well as viruses may sorb to biosolids, which contain a high percentage of organic matter, and desorption during land application of biosolids may not readily take place; therefore, these microorganisms may not be readily aerosolised.

2019 ◽  
Vol 29 (3) ◽  
pp. 7
Author(s):  
Ramiz M. Shubbar ◽  
Abthal Jihad Suadi ◽  
Monim H. Al-Jiboori

In this study, the concentrations of sulfur dioxide (SO2) were emitted from the Daura oil refinery units and their effect on the surrounding areas of the refinery were investigated, and also, study the atmospheric stability effective by using the Screen View model, and check the effect of the wind speed and direction on the spread of pollutants. As indicated during this study, the physical factors of the sources of pollution, such as the height of the chimney, its diameter and the surrounding environmental conditions, contributed to the increase in the concentration of contaminants. It was generally observed that the concentration of SO2 increased by increasing the rates of airflow and ambient temperature. This work was prove the influences of weather conditions in the transmission and spread of pollutants such as wind speed, wind direction, atmospheric stability and ambient temperature, but the effect of ambient air temperature was lower than others variables. When the distance increases between the plume and the source of pollution, a heat exchange takes place with the surrounding atmosphere, the difference between the temperature of the emitted gas and the surrounding atmosphere decreases and the buoyant force increases. This leads to a lack of vertical movement that disperses the contaminants. In addition, the concentration of the pollutants decreases with the distance increases from the source of the pollution. In the present work, emission rate of SO2, and stack gas exit velocity calculated for all stacks (point sources) of the twelve production units during August 2013, and February 2014 by using the actual amounts of fuel consumed in Daura refinery in this period.


Author(s):  
Peter K. Mueller ◽  
Glenn R. Smith ◽  
Leslie M Carpenter ◽  
Ronald L. Stanley

At the present time the primary objective of the electron microscopy group of the Air and Industrial Hygiene Laboratory is the development of a method suitable for use in establishing an air quality standard for asbestos in ambient air and for use in its surveillance. The main concept and thrust of our approach for the development of this method is to obtain a true picture of fiber occurrence as a function of particle size and asbestos type utilizing light and electron microscopy.We have now available an electron micrographic atlas of all asbestos types including selected area diffraction patterns and examples of fibers isolated from air samples. Several alternative approaches for measuring asbestos in ambient air have been developed and/or evaluated. Our experiences in this regard will be described. The most promising method involves: 1) taking air samples on cellulose ester membrane filters with a nominal pore size of 0.8 micron; 2) ashing in a low temperature oxygen plasma for several hours;


2021 ◽  
Vol 2 (4) ◽  
pp. 1-20
Author(s):  
Ahmed Boubrima ◽  
Edward W. Knightly

In this article, we first investigate the quality of aerial air pollution measurements and characterize the main error sources of drone-mounted gas sensors. To that end, we build ASTRO+, an aerial-ground pollution monitoring platform, and use it to collect a comprehensive dataset of both aerial and reference air pollution measurements. We show that the dynamic airflow caused by drones affects temperature and humidity levels of the ambient air, which then affect the measurement quality of gas sensors. Then, in the second part of this article, we leverage the effects of weather conditions on pollution measurements’ quality in order to design an unmanned aerial vehicle mission planning algorithm that adapts the trajectory of the drones while taking into account the quality of aerial measurements. We evaluate our mission planning approach based on a Volatile Organic Compound pollution dataset and show a high-performance improvement that is maintained even when pollution dynamics are high.


2019 ◽  
Vol 1 (1) ◽  
pp. 79-89 ◽  
Author(s):  
Ajit Ghimire ◽  
Albert Leo N. dela Cruz ◽  
Roberto Wong ◽  
Panida Navasumrit ◽  
Stephania Cormier ◽  
...  

In the vicinity of a rendering plant it is very difficult to find a really unpolluted place for the olfactometric measurements. Although the most unpolluted site luff of the plant was chosen, another precaution was taken. As adaption of the panelists to the plant odour could cause one of the greatest errors, some minutes before and during the measurement the panelists inhale solely odourless air from the olfactometer. To prevent discomfort by inhaling completely dry air, the olfactometer Modell 1158 is supplied with a moistening device, fig. 1. Fig. 1. Moistening device. In a standard impinger, filled with destillated water, air is moistened close to saturation. An equal flow of moistened air is mixed to the olfactometer outlet, thus delivering to the panelist a rel. moisture content of nearly 50 %. The panel consisted of 4 persons. The samples are prediluted taken into plastic bags, simultaneously at the inlet (raw air) and at the outlet (cleaned air) of the air cleaners. To receive an unfalsified sample from the outlet of the biofilters, undiluted by ambient air, a "tent” of plastic foil, fig. 2, is placed on the filter surface. The cleaned air blows up the tent and escapes through the sample hole, large enough to prevent a significant increase of pressure. The form of the upblown tent indicates, wether a sample area with normal air flow is chosen, and over the space of the covered filter area of 6,25m2 an average sample is received. Fig. 2. Device for cleaned air samples from biofilter outlet.


1996 ◽  
Vol 121 (4) ◽  
pp. 716-721 ◽  
Author(s):  
Gwendolyn Eason ◽  
Richard A. Reinert ◽  
James E. Simon

Three watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai] cultivars with different ozone (O3) sensitivities were grown in a charcoal-filtered greenhouse and exposed in continuous-stirred tank reactor chambers to five levels (0, 100, 200, 300, or 400 nL·L-1) of sulfur dioxide (SO2) in the presence (80 nL·L-1) or absence (0 nL·L-1) of ozone (O3) for 4 hours/day, 5 days/week for 22 days. In the presence of O3, SO2 increased foliar injury in all three cultivars, but the impact was greatest for the most O3-sensitive cultivar, `Sugar Baby,' moderate for `Crimson Sweet,' and least for the least O3-sensitive cultivar, `Charleston Gray.' For all cultivars, SO2 intensified O3 suppression of leaf area for the first seven mainstem leaves and of dry weights for aboveground and total plant tissues. Root dry weight was independently suppressed by both pollutants, and the root: top ratio was linearly suppressed by SO2 alone. Sulfur dioxide combined with O3 can be detrimental to crop species such as watermelon. Thus, the potential for SO2 phytotoxicity should not be summarily dismissed, especially in the vicinity of SO2 point sources where O3 co-occurs.


2021 ◽  
Vol 16 (2) ◽  
pp. 117-124
Author(s):  
Dodik Suprapto ◽  
Lilik Eka Radiati ◽  
Chanif Mahdi ◽  
Herly Evanuarini

The aim of this study was to evaluate the effect of ozone exposure to the physicochemical and microbial activity in dairy milk. The research material was fresh milk from dairy cows and ozone was produced by commercial ozone generator brand HANACO, production capacity up to 0.702 mg/min at 24-27ºC with oxygen source coming from ambient air in the nature. The experiment used ozone treatments for 0, 10, 20, and 30 min with variable of analysis such as density, protein, fat, electrical resistance, total plate count, and malondialdehyde which was analyzed using One Way Annova. The results showed that ozone treatment had no significant effect on the density, protein and fat in dairy milk, but had significant (P<0.05) effect on the electrical resistance, total plate count, and production of malondialdehyde. Electrical resistance and malondialdehyde were increased, while total plate count was decreased over time with the ozone exposure. Ozonation is possible to reducing yield loss on milk production that is caused by microbial activity without changing the physicochemical properties of dairy milk.


2020 ◽  
Vol 14 (1) ◽  
pp. 78-83
Author(s):  
Ali Shahryari ◽  
Charlotte D. Smith ◽  
Abolfazl Amini

Background: The consumption of bottled water globally, including Iran, has increased tremendously in recent years. This study was designed to assess the bacteriological quality of bottled water and its compliance with the drinking water regulations. In addition, we evaluated bottled waters for the presence of a variety of genera of bacteria and the effect of storage duration on the extent of bacterial contamination. Methods: Four hundred samples of bottled water belonging to ten different Iranian brands with various production dates were purchased from supermarkets in Gorgan, Iran, from 2017 to 2018. Bacterial quality of bottled water was assessed using heterotrophic plate count (HPC) followed by usual biochemical tests for identification of bacterial genera, and by the API system. Results: The average HPC of bottled water was 9974 colony-forming units per milliliter (CFU/ml). Twelve genera were isolated, among which Bacillus spp. and Escherichia coli were the most and least abundant, respectively. Statistical analysis showed that there was a positive association between water quality and storage duration so that the highest microbial load occurred within the first to third months after bottling. Furthermore, the highest rate of contamination was observed in May when ambient air temperatures commonly reached 40 °C. Conclusion: The bacterial quality of bottled water was not according to the standard of drinking water quality. This study demonstrated the variation in bacterial levels after bottling, which indicates the presence of waterborne heterotrophic bacteria, some of which can pose severe health risks to consumers.


2018 ◽  
Vol 20 (3) ◽  
pp. 544-552 ◽  
Author(s):  
Anteneh Assefa ◽  
Mats Tysklind ◽  
Jana Klanova ◽  
Karin Wiberg

A combination of PCDD/F patterns and metal source markers in ambient air samples together with stable air mass back trajectories can reveal the most significant atmospheric sources of PCDD/Fs.


Sign in / Sign up

Export Citation Format

Share Document