A Permit by Rule (PBR) Evaluation for Painting Operation Facility

MEE 6501, Advanced Air Quality Control 1

Course Learning Outcomes for Unit V Upon completion of this unit, students should be able to:

5. Evaluate health risks of air pollution exposure. 5.1 Discuss the air pollution variables causally related to adverse health effects on ecological

systems. 5.2 Discuss the air pollution variables causally related to adverse effects on physical structures. 5.3 Calculate operational air emission rates for a selected scenario.

Course/Unit Learning Outcomes

Learning Activity

5.1 Unit Lesson Chapter 6, pp. 203-236 Unit V Mini Project

5.2 Unit Lesson Chapter 6, pp. 203-236 Unit V Mini Project

5.3 Unit Lesson Unit V Mini Project

Reading Assignment Chapter 6: Welfare Effects, pp. 203–236

Unit Lesson In this unit, we consider Godish, Davis, and Fu’s (2014) presentation of a unique perspective of air quality as they address pollution impacts from a comprehensive systems approach. Pollution effects are clearly distinguished as being health (as in our previous unit reading) or welfare (in this unit reading). The authors are clear to articulate welfare effects in non-health effects, to include natural vegetation and cultivated crop damage, materials deterioration (such as acid rain corroding steel structures and limestone architecture and monuments), and odors. Further, they spend a limited amount of time reminding us of visibility issues, the potential for ecosystem changes, and trends in rising temperatures across the globe. These welfare effects are of particular importance to us as air quality engineers, given that we must first be able to anticipate the effects of industry activities on ambient air quality. As Godish et al. (2014) demonstrate, we must take a comprehensive systems approach to engineering air quality to protect ecosystems, structures, and overall human and ecological life. Pollution Concern Categories In this unit, we are going to quickly summarize the work of Godish et al. (2014) into four main categories as air pollution issues of concern: agricultural, ecological systems, structures, and odors. For the purposes of this lesson, agricultural considerations include cultivated crops, natural vegetation (plants, grasses, and trees), and domesticated animals (livestock and horses). Phytotoxicity involves the toxic effects to plants that are often at the base of the majority of documented air quality variables, causally related to negative agricultural impacts. Heavy metals, sulfur dioxide (SO2), hydrogen fluoride (HF), hydrogen chloride (HCl), nitrogen dioxide (NO2), chlorine (Cl2), ammonia (NH3), and particulate matter (often termed PM in air

UNIT V STUDY GUIDE

Engineering Air Quality for Ecological and Structural Health

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quality literature) are featured as some of the most significant and well-documented phytotoxins (Godish et al., 2014). However, other compounds are also damaging to vegetation through photochemical oxidation, with one of the most notable being ozone (O3). Contemporary studies have demonstrated that two additional compounds— less studied photochemical oxidizers—are becoming of more interest to air quality engineers with spreading urbanization. These are the compounds hydrogen peroxide (H2O2) and peroxyacetyl nitrate (PAN). Chemically, photochemical oxidizers are the resulting products of nitrous oxides (NOx) and a rather wide range of volatile organic compounds (VOC) that seem to be sourced from major cities with elevated levels of O3 and other oxidants (Gurjar, Molina, & Ojha, 2010). One of the most notable implications of polluted air’s acidic deposition is in the form of acid rain. Godish et al. (2014) carefully describe the leaf and plant structural damage to vegetation, as well as the resulting soil fertility problems that result from acid rain negatively affecting soil microbe activities, elemental (micro and macro nutrient) composition within the soil, nutrient mobility, and nutrient bioavailability to plants. The correlated reduction of plant nutrition (such as leaching of amino acids, sugars, vitamins, and other essential minerals) have a devastating impact on plants used in animal feed composition, as well as animal grazing pastures (Godish et al., 2014; Gurjar et al., 2010; Brady, 1990; Tisdale, Nelson, & Beaton, 1985; Cullison & Lowrey, 1987). Documented problems have included fluoride (F) toxicity with most incidences being chronic, given that F disrupts calcium (Ca) metabolism in both the rumen (four-compartment fermenting stomach, such as in cows) and the simple stomach. The instances of F toxicity (flourosis) are more often found in less developed countries, and seem largely to negatively impact skeletal development and create dental changes in cattle teeth, creating grazing and mastication (chewing) problems, as well as decreased dairy cattle milk production (Godish et al., 2014). As might be expected, lead (Pb), molybdenum (Mb), arsenic (As), and selenium (Se), toxicity are also discussed with acute poisoning in grazed cattle and dairy cattle, including a wide range of symptoms in production cattle health and conformation (Godish et al., 2014; Acker & Cunningham, 1991). Ecological considerations include the same phenomena of phytotoxicity, atmospheric depositions (such as acid rain), increased ultraviolet (UV) radiation, and global warming. Godish et al. (2014) carefully explain the implications of chemically impacting the aquatic and terrestrial ecosystems. They also discuss select pesticide run-offs, over-sprays, and reuptakes in ambient air that affect both aquatic and terrestrial ecosystems. Carefully read this material, as it will largely inform our predictive air quality models that we will consider and evaluate in Unit VII. Structural considerations are not as frequently studied and discussed as health and ecological effects. However, Godish et al. (2014) are careful to include air quality considerations for the pollutants known to have negative impacts on metals, paints, carbonate building stones, monuments and architecture, glass, and other materials associated with construction and structures. Further, the chemical reactions associated with these impacts are discussed, taking us all the way back to Unit I material. A careful review of these chemical reactions is important for us in this reading because it will inform our understanding of how to evaluate air quality monitoring method options in our Unit VI work. Odor considerations are of particular interest to us, given our work with VOC compounds in our course project. Godish et al. (2014) not only discuss malodorous issues as annoyances, but also as symptomatic air quality indicators that are causally related to some of the previous information discussed (human health, ecological health, and structural health). As you may have experienced in your own industry setting, malodorous environments are often common. This may be due to the fact that air quality engineers become

Agricultural

Ecological Systems

Structures

Odors

Figure 1. Four main air pollution areas of concern

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too focused on air quality permit limits and other quantitative limits and may fail to effectively utilize one of the quickest qualitative measures of air quality (in addition to visibility): the smell of the environment for contaminants. Airflow Rates and Filter Velocities Now that we have a solid grasp on the welfare effects of air pollution and poor air quality, let’s turn again to our course project to evaluate yet another aspect of our produced air quality by calculating our airflow rates and filter velocities for our scenario work system designs. First, we reference our scenario for the engineering specifications for the air makeup unit and see that there is only one unit. For this calculation, we are going to assume the basic 3.0 ft air intake opening radius. Next, we square 3.0 ft and multiply by pi (3.14) to derive a value for ft2 intake area. For example, for a 4.0 ft air intake, [Note: The actual scenario assumption needs to be calculated at 3.0 ft]:

Air intake (in ft2) = (ft opening radius)2 x 3.14

= (4.0 ft)2 x 3.14

= 16.0 ft2 x 3.14

= 50.24 ft2 Second, we reference our scenario for the engineering specifications for the spray booth equipment’s air makeup unit and exhaust fan. Then, we subtract our 5760 ft3/min air makeup unit air flow from our 10,000 ft3/min exhaust fan flow rate to derive a value for ft3/min flow rate. For example, for an air makeup unit air flow of 6,000 ft3/min and an exhaust fan flow rate of 12,000 ft3/min [Note: The actual scenario tabulated data is 5760 ft3/min air makeup unit air flow from our 10,000 ft3/min exhaust fan flow rate]:

Flowrate (in ft3/min) exhaust fan flow rate - air makeup unit flow

= 12,000 ft3/min - 6,000 ft3/min

= 6,000 ft3/min Third, we divide our calculated flow rate (ft3/min) by our calculated intake area (ft2 intake area) to derive a value for ft/min face velocity. We can check our regulatory face velocity minimum of 100 ft/min to decide whether or not our design is actually in compliance with the state permit requirements. If the face velocity is above the regulatory minimum, then this is wonderful news for us! That means that we could now move on to calculating the filter velocities for the booth. If the face velocity were to be below the 100 ft/min minimum, we would have to make modifications to our planned exhaust fan capacities. For example, for a calculated value of 6,000 ft3/min flow rate and a calculated 50.24 ft2 intake area [Note: The actual scenario data is now 4240 ft3/min flow rate and 28.26 ft2 intake area]:

Face velocity (in ft/min) = flow rate / intake area

= 6,000 ft3/min / 50.24 ft2

= 119.43 ft Assuming that we have an adequate face velocity, we are now ready to calculate our filter velocities for the booth. First, we reference our scenario for the engineering specifications for the filter openings and see that there are actually two openings for the booth. Now, we sum the filter area (ft2) of both filters to derive a value for ft2 total filter area.

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For example, for a filter area of 25.0 ft2 and two filters [Note: The actual scenario tabulated data is a filter area of 2 0.0 ft2]:

Total filter area (in ft2) = Σ (filter area per filter)

= 25.0 ft2 + 25.0 ft2

= 50.0 ft2 Next, we divide our calculated flow rate (ft3/min) by our calculated total filter area (ft2) to derive a value for ft/min filter velocity. We can check our regulatory filter velocity maximum of 250 ft/min to decide whether or not our design is still within regulatory compliance for the permit. If we are under the maximum filter velocity regulatory limit, then we our ventilation equipment vendor has done a wonderful job of keeping us out of trouble during the spray booth design phase! If we are over the 250 ft/min maximum, then we would need to sit back down with the ventilation equipment vendor and discuss alternative fan options. For example, for a flow rate of 6,000 ft3/min, and a total filter area of 50.0 ft2 [Note: The actual scenario data is now 4240 ft3/min and 40.0 ft2]:

Filter velocity (in ft/min) flow rate / total filter area

6,000 ft3/min / 50.0 ft2

= 120.0 ft/min The entire focus of these two final calculations is to ultimately decide whether or not the spray booth is in compliance with the state-level regulatory requirements as it is currently engineered. If it is in compliance with the state limits, and without a full Title V air permit being required at this phase, this facility is still on target for being able to submit a Permit by Rule (PBR) to the state and feel confident of it being approved for operational use. We now have only two more sets of calculations to perform before we complete the quantitative portion of this permit application. We will tackle these two additional measurements over the next two units together. Let’s keep engineering our air quality for this facility!

References

Acker, D., & Cunningham, M. (1991). Animal science and industry (4th ed.). Englewood Cliffs, NJ: Prentice Hall.

Brady, N. C. (1990). The nature and property of soils. (10th ed.). New York, NY: Macmillan. Cullison, A., & Lowrey, R. (1987). Feeds and feeding (4th ed.). Englewood Cliffs, NJ: Prentice Hall. Godish, T., Davis, W. T., & Fu, J. S. (2014). Air quality (5th ed.). Boca Raton, FL: CRC Press. Gurjar, B., Molina, L., & Ojha, C. (2010). Air pollution: Health and environmental impacts. Boca Raton, FL:

CRC Press. Tisdale, S., Nelson, W., & Beaton, J. (1985). Soil fertility and fertilizers (4th ed.). New York, NY: Macmillan

Publishing Company.