Bottling plant eliminates odor with carbon-impregnated geomembrane

Problem: 

In 2017, a bottling plant in Brazil received frequent complaints about odors from its wastewater facility, especially from a neighboring hotel. At the same time, operators were looking to improve the safety of the wastewater tanks and seeking cost savings. The treatment plant had two rectangular reactors with rigid covers that still released odors even when odor-reducing chemicals were used.

Solution: 

The plant owners decided to install a reinforced membrane odor control system with integrated activated carbon filters. At the same time, a new glass-lined steel homogenization tank was to be built, and it made sense to cover that as well. Anue Water Technologies geomembrane covers, suspended above the liquid, are made to fit each tank precisely, providing a tight seal around the edges so that all gases are forced toward the filters. The filters’ porosity keeps pressure from building up under the covers to avoid dangerous gas buildup in confined spaces. The covers on the reactors were installed in a few days and the homogenization tank covers a month later. 

Result: 

Odors from the reactors were no longer detected. Since the homogenization tank covers were preinstalled, no odors from it were ever detected. 760-727-2683; www.anuewater.com

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Disinfection system enables plant expansion

Problem: 

The Santan Vista Water Treatment Plant serving Gilbert and Chandler, Arizona, gets its water from the Colorado River through a 14-mile, 48-inch pipeline as part of the Central Arizona Project canal. On-site sodium hypochlorite generation was selected for disinfection, mainly for safety. With on-site generation, the only chemical stored or transported is food-grade salt.

Solution: 

The plant installed two ClorTec units from De Nora Water Technologies that each produce 1,500 pounds of chlorine per day. One is always in use, and the other is for backup. When Phase II of the plant was completed in May 2018, capacity was increased to 48 mgd and a third ClorTec unit was added.

Result: 

“The decision to use the De Nora ClorTec generator was a simple one,” says Mike Schlabach of Sundt Construction, the installer. “The operators have been pleased with the performance, Sundt has extensive experience installing the components, and the value proposition offered through De Nora was significant.” 215-997-4000; www.denora.com

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Ozone treatment used to clear up tinted well water

Problem: 

When the Four Way Special Utility District drilled a 750 gpm well in Angelina County, Texas, color and odor management became a priority. The well water was tinted to 30 pcu (platinum-cobalt units) by tannic acid at 3.0 mg/L, contained 4.0 mg/L hydrogen sulfide, and also contained sulfur-reducing bacteria. The conventional treatment being used — aeration and chlorine injection — left potential for formation of disinfection byproducts, so managers turned to ozone. However, there was a concern that long ozone contact time and excess ozone in the contact tower could allow bromates to form. 

Solution: 

A precisely delivered dose of no more than 3.0 mg/L of ozone through a  Mazzei 3090 GDT ozone sidestream venturi injection system  with pipeline flash reactor provided the ozone mass transfer needed to remove color and odor while minimizing bromates. 

Result: 

With an ozone generator producing 730 grams of ozone per hour, the GDT system achieves its objectives with a rate of 2.8 mg/L of ozone. Pathogen control has allowed the district to reduce its chlorine dosage and discontinue the energy-consuming air stripping process used for VOC removal. The utility and its customers are pleased with the results. 661-363-6500; www.mazzei.net

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Plant-based odor atomization system ensures suburban wastewater facility is odor-free

Problem: 

The City of Crystal Lake, a Chicago suburb, is surrounded by commercial and residential neighbors, including a high school. Wastewater treatment plant managers wanted to reduce or eliminate odor issues.

Solution: 

Plant managers chose Ecosorb, a plant-based odor eliminating product, from OMI Industries. Two high-pressure atomization systems were installed. With 20 nozzles each for distributing Ecosorb liquid, one system is in the influent flume area and the other is in the aerated grit removal area. Vapor ducting feeds from the machine into the side of the building and creates a continuous loop surrounding the building. The equipment runs when the sludge centrifuge is run and sludge is being hauled outside of the facility.

Result: 

With Ecosorb products and customized equipment from OMI Industries, the plant was able to mitigate odor concerns. 800-662-6367; www.omi-industries.com

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On-site sodium hypochlorite generation maintains consistent disinfection at remote tank

Problem: 

Purissima Hills Water District provides chlorinated water to two-thirds of the town of Los Altos Hills, next to Palo Alto, California. With remote tank locations, low population density and low water demand (1.61 mgd), the utility is challenged to maintain consistent disinfectant residuals while balancing safe delivery of chemicals to its tank sites at an affordable cost.

Solution: 

Working together with PSI Water Technologies, >span class="s1">Microclor on-site sodium hypochlorite generation system. The input (salt) does not degrade over time or lose potency, and it can be safely transported through neighborhoods. Purchasing bulk salt also avoids the two- to three-week lead times for ordering bulk liquid hypochlorite.

Result: 

The utility was impressed with the system, which uses passive hydrogen evacuation for system safety. The electrolytic cell design means there are no internal baffles to trap hydrogen and no gaskets to wear. The skid-mounted design and easily accessible union connections allow quick access for routine cell maintenance and replacement. 888-774-4536; www.4psi.net