MONROE — Monroe is updating it ozone system to control potential taste-and-odor problems with replacement one of two ozone generators for a cost of nearly $1,000,000. The new ozone generator is to become operational by Aug. 15. The ozone generators were installed in 1997 and 2001, but the 1997 ozone generator has failed and is being replaced with a larger generator. Design modifications will allow the Monroe to eventually install a third ozone generator to help increase the plant’s treatment capacity.
Monroe is Michigan’s only city to draw its water from Western Lake Erie. The main part of the water plant opened on March 1, 1924. Toledo and Port Clinton also draw their water from the shallow western basin.
Injecting ozone into the water after it’s been pulled from the lake is part of Monroe’s first-treatment process to improve taste and remove odors. The plant’s ozone capacity also is being increased to help fend off toxins found in western Lake Erie’s most prevalent form of harmful blue-green algae, microcystis. The main toxin in that algae is called microcystin.
One of Lake Erie’s worst algae outbreaks occurred this summer. It wasn’t as large as the record 2011 bloom. But the toxin was so concentrated in the Oak Harbor area that it overwhelmed a water-treatment system that serves 2,000 residents of Ottawa County’s Carroll Township. That event was the first in Ohio history to cause an emergency closure of a water plant because of algae toxins. Residents were provided bottled water until the township was able to get uncontaminated tap water from Port Clinton. The township flushed out its system and put its plant back into service after the threat subsided.
A new printed circuit board (PCB) etching process uses with ozone to replace hydrogen peroxide used in the etching solution. The invention is said to be environmentally more friendly while also producing traces just 20µm in width. H2O2 processes are seen as having broad process windows, making etching harder to control.
The new process from AKON tightens the process window and accurately measures the etching solution, resulting in better walls, finer structures and increased signal quality.
AKON’s OXIjet technology replaces H2O2 with ozone (O3) using ambient air from a generator. Ozone is introduced into the production cycle directly at the point it is required (in situ). The volume of ozone generated is of the order of a few grams; excess ozone is converted to oxygen in a catalytic converter and discharged back into the air. The new process eliminates H2O2 handling.
An annual saving of over 15 million liters of hydrogen peroxide my be achieved by the switch. The process should improve the environmental and safety foot print of PCB etching while also offering the industry reduction in the surface area of printed circuit boards in series production. AKON’s process has undergone successful beta testing in Europe.
Clearwater Florida is installing a system to convert 6.5 MGD of brackish water into drinking water. The process involves using RO to remove the dissolved solids. The RO water is then treated with ozone. Poole & Kent Co of Florida has been awarded a contract for the installation of the equipment.
Ozone water treatment is used extensively in Florida and the US for drinking water treatment to remove various contaminates and to disinfect drinking water to make it safe for human consumption. Ozone is produced using ozone generators from air or oxygen. Onnce it disinfects the water, the ozone reverts back to oxygen leaving no residual chemicals. It is also one of the strongest disinfectants used by municipal drinking water facilities killing all the major desease causing organisms.
In previous posts we have noted work on the use of ozone in ballast water treatment. IMO rules will require ships to treat ballast water to prevent the transport of invasive species across the globe. As an example of invasive species brought to the US via ballast water are zebra mussels.
The new rules will require the use of ozone, UV or other chemicals to treat the water. The US EPA ETV project has already identified ozone and UV as viable technologies. Currently, a few hundred ships have been equipped with such systems including ozone water treatment systems, but in the next decade over 50,000 systems will be needed at a cost of up to $1,000,000.
To be accepted for this application, manufacturers need to pass IMO certification for their systems. An expensive and time consuming process that can cost millions of dollars. Many ozone generator manufacturers and others are aggressively pursing this course.
If ozone becomes the primary biocide for this application, it is likely to be the largest single application for ozone.
Ashland and Hopkinton, MA are towns of about 16,000 and 14,000 residents, respectively. They are situated midway between Boston and Worcester in eastern Massachusetts. The Howe Street facility uses clarification, carbon filtration, and ozonation to treat groundwater.
Ashland experiences seasonal increases in manganese in its ground water supply. In Ashland’s water, the manganese is organically bound with an organic molecule such as humic, fulvic or tannic acid. Manganese in such a complex is more difficult to remove because the organic molecule provides a protective shell. Treatment of organically bound manganese leaves increased levels of disinfection byproducts in the finished water.
To address the issue, the Howe Street facility was originally designed to use two ozone generators to oxidize the manganese. Unfortunately, the system was difficult to operate and was taken off line for a couple of years. To bring the ozone generators back on-line, the dielectric modules were cleaned and rebuilt. A number of other improvements were made as well: relocating several valves for easier adjustment and maintenance, installing blow-down valves and drain lines for the degas system, and modifying the degassing and destruct units to vent to the entrained water separator without the need for vacuum pumps. Once the maintenance and upgrades were complete the results were dramatic and the project met the goal of having high quality water.
City Utilities of Springfield, Mo plans on capital improvements for their drinking water infrastructure. The water division plans to build a new million-gallon water tower in southeast Springfield to boost water pressure in that part of the city. In addition, it’s also moving ahead with a $7.2 million project to switch its water treatment facilities from using chlorine as a disinfectant to using ozone generators.
Ozone offers numerous benefits over chlorine as a primary disinfectant, most importantly, a reduction in the formation of chlorinated organic disinfection by products. These compounds are being more tightly regulated by the EPA in drinking water since they are suspected carcinogens.
African Oxygen, part of The Linde Group, is using ozone for the cyanide destruction process at gold mines. Ozone is generated on site, by using ozone generators and using oxygen. The ozone was injected using a specially developed contacting system to ensure that optimal reaction efficiency took place before the water was pumped into the tailings dam. Cyanide oxidation occurs quickly, with free
cyanide being reduced by more than 85%. The ozone consumption during the trial was about 2 g of ozone for every gram of cyanide.
The need for cyanide destruction has
increased over the years due to the growing demand for sustainable solutions to neutralize destructive cyanide in tailings dams as more mining companies voluntarily subscribe to the United Nation’s International Cyanide Management Code (ICMC). The fundamental aim of the code is to manage the use of cyanide throughout the gold beneficiation process, which limits the release of solutions containing cyanide into the environment from spillages and tailings disposal. Although compliance with the code is voluntary, it has been implemented by the world’s major gold producers.
The advantages of using the ozone-based process for cyanide destruction should, however, be a huge driver for mines when considering a cyanide destruction process.
The advantages associated with using this system include the fact that no adjustment to the tailings stream is required when installing ozone equipment and the reaction is rapid, complete, irreversible and by-product free.
Springfield Public Works (Missouri) is looking at making large-scale upgrades at sewage treatment facilities this year. The utility is seeking to replace old ozone generators and a sewer line. They have rolled out a proposal that asks the city to secure up to $13 million in special obligation bonds. Missouri DNR rated the ozone generator project the No. 1 “green project” in the state.
Ozone generators are extremely effective in disinfecting wastewater. In addition they potentially can remove pharmaceuticals and personal care products that can end up in drinking water by way of wastewater discharges. Ozone also helps to oxygenate the water before it is returned to rivers enhancing the overall health of the ecosystem.
Springfield Public Works wants to replace ozone generators at the Southwest Wastewater Treatment Plant. That would increase the facility’s capacity to disinfect from 65 million gallons a day to 100 million gallons a day. The generators are about 30 years old and replacement parts are expensive and difficult to come by. If the city had the new generators, it would likely save $4 million in operating costs in the next 20 years. Despite the increased difficulty to find parts, it is does demonstrate that high quality ozone generators can be expected to give extremely long lived operation.
The city of Springfield will receive $16.2 million to replace the Spring Branch trunk sewer line on the northwest side of town and replace an outdated ozone generator used to disinfect water at the Southwest Wastewater Treatment Plant, according to Steve Meyer, assistant director of public works.
Meyer said $3 million of the $16.2 million will be federal stimulus funds and the remaining $13.2 million will be a 20-year loan from the state’s revolving fund.
At the Southwest Wastewater Treatment Plant, money from the stimulus funds and state loan will be spent on a 24-month project to build a new ozone generator, expanding the facility’s capacity to disinfect up to 100 million gallons of treated water each day. Currently, the facility is limited to 60 million gallons, Meyer said.
“It’s a significant increase in what we can disinfect and treat,” Meyer said. “It will help up with our wet water flows and our peak flows.”
In a previous post, we noted that the EPA found that air purifiers that emit ozone either did not work or if they did emitted dangerous levels of ozone in the air. This area was not very well regulated, but recently California has taken steps to regulate ozone generators for home use.
Seventh grader Otana Jakpor was also concerned about this type of ozone generators after reading an article in Consumer Reports. The article indicated the potential dangers of these devices. While most seventh graders would have left it at that, Otana designed experiments to confirm the issues brought up in the Consumer Reports article.
Her work spanned a period of two years. Some purifiers, she found, emitted ozone levels equal to Stage 3 smog alerts. She provided her findings to the California Air Resources Board at the board’s invitation. Her testimony contributed to the regulations that were put into place to regulate ozone generators for home use.
Otana went on to be awarded the President’s Environmental Youth Award and the Action For Nature’s 2009 International Young Eco-Hero Award in the ages 8 to 16 category. She has met with senators and the head of the U.S. Environmental Protection Agency. She is now a volunteer spokesperson for the American Lung Association and will have her study published in the journal of the American Thoracic Society.
Besides the significant personal accomplishment, Otana research confirms work done by others and provides a warning to homeowners in states that do not regulate ozone generators for home use that they need to be very careful in the purchase decisions and use of these devices.
Spartan Environmental Technologies does not sell ozone generators for residential use.