Acid Rain - Monitoring SO2 in a Flue Gas Desulfurization Unit

by Applied Analytics


From the 1970s through the 1990s, acid rain was the main environmental concern. Lakes1, vegetation2 and animals3 were affected.

The New York Times reported in 1979:“The rapid rate at which rainfall is growing more acidic in more areas has led many scientists and governmental officials to conclude that acid rain is developing into one of the most serious worldwide environmental problems of the coming decades.”4

What is acid rain?
 
Acid rain simply refers to rain or other precipitants that have uncommonly high acidity. This is a result of SO2 in the air that dissolves in water creating sulfuric acid. The source of this SO2 is largely power plants that burn fossil fuels.
 
EPA
 
The EPA, under the 1990 Clean Air Act amendments, created the Acid Rain Program (ARP). The aim was to reduce the amount of NO2 and SO2 emissions, while allowing for the industry to employ cost-effective technology to achieve this goal. As the following graph shows, the program was a remarkable success.

Figure 1. SO2 Emissions from CSAPR and ARP Sources, 1980–2016 (ARP- The Acid Rain Program; CSAPR -Cross-State Air Pollution Rule)5

The EPA reports concluded that experience with the Clean Air Act since 1970 has shown that protecting public health and building the economy can go hand in hand.6 Furthermore, “The emissions reductions have led to dramatic improvements in the quality of the air that we breathe. Between 1990 and 2017, national concentrations of air pollutants improved... 88 percent for sulfur dioxide”7


Figure 2. Note. Data for SO2 concentration from SO2 Air Quality, 1980-2017 (Annual 99th percentile of Daily Max 1-hour Average) National Trend based on 42 sites. 90% decrease in national average8

The Technology
 
Flue gas desulfurization units are used to remove SO2 from flue gas; the process is also called scrubbing. The most common type is limestone scrubbing, in which the flue gas is stripped by dissolution into water. The stripped gas reacts with the limestone (CaCO3) resulting in solid residue, in this case calcium sulfite (CaSO3). The scrubbing efficiency is usually higher than 90%. To achieve this level of efficiency, the concentration of SO2 must be monitored both before and after the process.
 
The Analysis
 
The OMA-300 measures a full, high-resolution spectrum. This allows for both applications to be monitored continuously by the same analyzer, from 4000 ppm to 10 ppm full scale. Hence, it provides an indication of the process’ effectiveness by measuring the SO2 before and after the flue gas desulfurization unit.


Figure 3: Absorbance spectra of SO2 40 ppm and 4000 ppm, demonstrating that one analyzer can be used for both applications simultaneously. The absorbances at different wavelengths are correlated to the SO2 concentration.

The Future
 
While controlling industrial SO2 emission in North America and Western Europe has been largely successful, acid rain is still a problem in rapidly growing economies such as China and India. Even the famous Taj Mahal in Agra is facing corrosion of its marble9. Hopefully, in the very near future, these burgeoning regions will implement the same technology and regulations that worked so well in more established countries.
 
References
 
1. WILLIAM K. STEVENSJAN , ‘Study of Acid Rain Uncovers a Threat To Far Wider Area’, New York times, 16, 1990.
2. WILLIAM K. STEVENSAPRIL, ‘The Forest That Stopped Growing: Trail Is Traced to Acid Rain’ New York Times, 16, 1996 .
3. LES LINEMARCH ‘Acid Rain Leading to Moose Deaths’ , New York Times, 12, 1996.
4. (BAYARD WEBSTERNOV. “Acid Rain: An Increasing Threat” New York Times 6,11, 1979).
9. Henry Fountain and John Schwartz ‘Have We Passed the Acid Test?’ New York Times May 2, 2018


EPA restores common sense to overaggressive water regulations

by Tim Huelskamp and James Taylor


The Environmental Protection Agency announced Tuesday it is rolling back some of the excessive, and possibly illegal, water regulations imposed by the Obama administration. EPA’s announcement is a welcome relief for homeowners and property owners impacted by overly aggressive EPA officials.

As a federal executive agency, EPA can only enforce laws that have been passed by Congress. While EPA has some rule making authority, it cannot make up laws of its own and then decide to enforce them. This is a very important check against a dictatorial presidency or executive branch. Regarding water regulations, Congress, via the Clean Water Act, has given the executive branch authority to regulate only those bodies of water that are “navigable waters of the United States.”

EPA has always asserted a broad definition for navigable waters. Dating back to the 1980s, EPA has asserted it can regulate smaller, streams and tributaries that cannot be navigated but that flow into navigable waters. EPA has also asserted it can regulate wetlands that are adjacent to navigable waters.

The Obama administration attempted in 2015 to further expand the definition of navigable waters to include such entities as isolated ponds, dormant stream beds that are dry most of the year, and minor depressions in the land that hold water only in the immediate aftermath of significant rainfall.

The consequences of the 2015 regulatory overreach can, and have been, devastating. Overly aggressive EPA officials tell farmers they cannot manage or cultivate farmlands that hold isolated puddles merely a few days of the year. Homeowners are told they cannot landscape or fill in nuisance depressions in their property that hold water briefly after a heavy rain. Federal bureaucrats have stripped homeowners and families of practical ownership rights to property they have purchased and managed for generations. Property owners who defy the EPA and other federal bureaucrats face steep penalties and fines.

Citizen lawsuits have been moderately successful challenging the Obama administration’s overreach. Courts have blocked enforcement of the Obama administration’s 2015 regulations in 28 states. Still, homeowners and landowners in the remaining 22 states remain subject to the oppressive 2015 regulations. The issue has been a likely candidate for eventual Supreme Court review, but in the meantime, people remain subject to the unfair policy.

The Trump EPA is thankfully proposing to restore common sense to EPA regulatory authority. The agency proposes to walk back the Obama administration’s asserted authority to regulate stream beds and land depressions that are usually dry. EPA will no longer regulate wetlands unless they are “physically and meaningfully connected” to waters under EPA jurisdiction. EPA will also eliminate subjective criteria for determining whether land or water features qualify under navigable waters jurisdiction, granting individuals more certainty about how they can use their property. These corrections are long overdue, and represent another example of President Trump keeping campaign promises to reduce environmental and regulatory overreach.

Environmental activists are sounding an alarm about potential environmental harms, but their arguments are weak. EPA will still regulate all navigable waters, as well as meaningful permanent and intermittent tributaries to navigable waters. Also, very importantly, all 50 states have their own environmental laws and regulations, allowing regulation above and beyond navigable waters as defined by EPA. For normally dry streambeds, isolated depressions that only occasionally hold water, and other land features that the Obama administration sought to regulate, regulations will once again come from state and local governments that are more responsive and accountable to the people and communities being regulated.

EPA’s proposed rule will continue to provide strong environmental protection for the waterways Congress authorized EPA to regulate. At the same time, the proposed rule will roll back executive branch overreach and protect the rights of homeowners and landowners.


Google Caught Misleading Users About Tracking Location Data

by Jack Davis


Google can always find you.

Contrary to claims Google was making to consumers, The Associated Press reported that some Google apps “automatically store time-stamped location data without asking.”

According to the AP, when a user simply opens the Maps app, that user’s location is stored.  Asking for weather updates means that a phone will note where the user was when the request was made.

But the AP also found random searches for subjects such as  “chocolate chip cookies,” or “kids science kits,” resulted in the phone tracking a user’s latitude and longitude.

Jonathan Mayer, a Princeton computer scientist, had his lab test and verify the AP’s findings. The AP reported that whether the apps were installed on iPhones of Android phones, the results were the same. Mayer said that’s a problem.

“If you’re going to allow users to turn off something called ‘Location History,’ then all the places where you maintain location history should be turned off,” Mayer said. “That seems like a pretty straightforward position to have.”

The company said users are informed of what their phones are up to.

“Location History is a Google product that is entirely opt in, and users have the controls to edit, delete, or turn it off at any time,” the company said in a statement, Bloomberg News reported.

.“… we make sure Location History users know that when they disable the product, we continue to use location to improve the Google experience when they do things like perform a Google search or use Google for driving directions.”

Google needs to know where users are, one commentator said.

“They build advertising information out of data,” said Peter Lenz, the senior geospatial analyst at Dstillery, an advertising technology company. “More data for them presumably means more profit.”

After the report revealed Google’s practices, the Electronic Privacy Information Center wrote to the Federal Trade Commission saying that Google’s action “clearly violates” a 2011 settlement with the government over Google’s privacy practices, the AP reported.
12:04 PM - 15 Aug 2018
WIRED‏Verified account @WIRED

If you use Google Maps, Google is tracking you right now. Even if you turned off Location History, the search giant still tracks and stores your location. There's a way to stop it—but it takes a lot of digging. Here’s a handy step-by-step guide Here

Google also responded to the report by making a change in what it told consumers, according to a follow-up AP report

Google formerly told users that “with Location History off, the places you go are no longer stored.”

Google now says, “This setting does not affect other location services on your device.” It adds that “some location data may be saved as part of your activity on other services, like Search and Maps.”

Google is owned by Alphabet Inc.

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