Digester and cogeneration system combine to eliminate odor, create energy

Problem: ECB Enviro North America, a bioenergy startup, needed to control odor from manure produced by intensive livestock operations in Lethbridge, Alberta, Canada, home to nearly 100,000 residents.

Solution: The company installed a PlanET anaerobic digester and efficient combined heat and power system. For an anaerobic digestion facility close to city limits, regulatory authorities required a state-of-the-art odor control system. The digester eliminates odors and produces stable biogas. Its biological filtering system uses tree bark to filter 17,657 cfm of contaminated air. Two Avus cogeneration systems from 2G – CENERGY Power System Technologies, with a capacity of 1,426 kW, convert the biogas to energy.

Result: The operation now uses manure and food processing waste to produce 388.5 million cubic feet of biogas annually, yielding 23.5 million kWh of electricity and 100,000 GJ of thermal energy per year. The stable electricity powers 2,500 homes. Odors and 45,000 tons of emissions are eliminated annually. 904/579-3217; www.2g-cenergy.com.

UV system helps city reclaim wetlands

Problem: Carnation, a city of about 1,900 residents in King County, Washington, had relied on septic systems for wastewater treatment. However, soil surveys in 1987 revealed that the septic systems had become insufficient for the growing population and threatened to contaminate the local aquifer.

Solution: Officials installed a membrane bioreactor system with UV disinfection. Reclaimed water is discharged to the 59-acre Chinook Bend Natural Area to foster wildlife and restore wetlands. Aquionics installed two parallel trains of InLine 7500+ UV units after the MBR system. The closed-vessel units flange directly to the MBR piping. The system uses medium-pressure, high-intensity lamps and has a compact footprint.

Result: One UV train treats up to 1.4 mgd and the second provides backup capacity. The low-maintenance units have automatic mechanical cleaning to keep quartz sleeves surrounding the UV lamps deposit-free. They continue to perform without failure. 859/341-0710, www.aquionics.com.

Biostimulant used to resolve odor problem

Problem: Homeowners in a neighborhood in Talbotton, Georgia, had experienced significant hydrogen sulfide odors for years. The source was a manhole where all four homes discharged, as well as an upstream pump station.

Solution: Each homeowner received a small metering pump and began to feed Byo-Gon PX-109 biostimulant into drainlines below bathroom sinks. The OMRI-certified organic product increases microbial respiration and eliminates the source of odors naturally.

Result: In less than a month, odors were under control. The city then began treatment of the upstream lift station and has now greatly reduced biostimulant feed rates at the homes. The addition of less than 1 ppm of biostimulant virtually eliminated the odor. 800/580-5509; www.byogon.com.

Microbes clean food-process wastewater

Problem: A premium U.S. ice cream company was seeing high TSS and BOD in process wastewater and therefore was paying surcharges for discharge to the municipal treatment plant. The company could not change the ingredients or the production process.

Solution: CoreBiologic created a scalable treatment system consisting of batch processing with pH adjustment and the addition of FogPro microbial blend, mineral nutrients and aeration. Samples were taken after 12 and 24 hours.

Result: The microbes effectively consumed the wastewater material, significantly reducing TSS, BOD and odor. After 12 hours, BOD was reduced by 37 percent and TSS by 46 percent. After 24 hours, BOD was further reduced by 57 percent and TSS by 76 percent. Waste byproducts of the process are being used for agricultural fertilizer. 888/390-8838; www.corebiologic.com.

Solution eliminates odors from stored biosolids

Problem: The Solon, Ohio, water reclamation facility processes approximately 5.8 mgd. As a good neighbor, the Solon Water Reclamation Department wanted to ensure that H2S and other mercaptan odors from stored biosolids wouldn’t impact the community.

Solution: Solon’s staff, working with Jack Doheny Companies, reached out to D3W Industries to help mitigate potential odor issues. Using a U.S. EPA-approved Planet Breeze solution, the product was dosed at a rate of 37.15 mg/L into the sludge feed line prior to the belt filter presses and polymer addition, targeting the sulfate-reducing bacteria that were plaguing the facility’s biosolids.

Result: The cake solids remained odor free after treatment, saving the workers and surrounding community from the toxic smells. 248/465-9841; www.planetbreeze.com.

Valveless piston pump cures priming issues for methanol metering 

Problem: A suburban college wastewater treatment plant in New York needed a cost-effective method to remove nitrate from wastewater effluent. The denitrification process required the low-rate addition of methanol.

Solution: The college installed a QDX valveless ceramic piston pump from Fluid Metering. The CeramPump technology relies on only one moving part, a rotating and reciprocation ceramic piston, to accomplish pumping and valving functions. For metering methanol, the pump head is close-coupled to a QDX hazardous-duty drive.

Result: The pump eliminated low-flow priming issues and self-primes even between long periods of downtime. Sapphire-hard ceramic internals are chemically inert and wear-resistant for long-term drift-free accuracy without calibration. 800/223-3388; www.fmipump.com.

Covers help treatment plant meet odor control commitments

Problem: The James River Treatment Plant in Newport News, Virginia, is bordered on one side by the James River and on the other by houses and a park. Although it had installed odor control systems, the plant’s conventional aeration tanks were producing low-level odors that required additional control.

Solution: Plant management decided to capture the foul air under a cover system and feed it to a carbon treatment system. The team chose Geomembrane Technologies (GTI) retractable, structurally supported covers, tensioned over low-profile, arched aluminum frames and custom designed for the plant.

Result: “The covers provided access and odor control so well on the IFAS tanks that we chose them for the ANITA Mox tank too,” says Bob Rutherford, plant manager. The structurally supported covers have helped the plant reliably control odors, while retracting easily for access to tank internals.  506/449-0993; www.gticovers.com.

Chemical treatment reduces hydrogen sulfide

Problem: A 30 mgd municipal wastewater treatment plant in northern California was experiencing elevated H2S in its wastewater stream (average 7.7 ppm). This resulted in unacceptable atmospheric H2S (average 123 ppm) and a strong odor. The plant needed to reduce H2S in the waste stream to reduce odor and achieve an atmospheric H2S level of less than 10 ppm.

Solution: Hydritreat HS chemical treatment from Hydrite Chemical Co. was used upstream of the bar screens. It was metered into the wastewater pipe for proper mixing before exiting the headworks. The chemical injection point allowed for approximately three minutes of contact time.

Result: H2S in the wastewater stream was reduced to 3 ppm when measured at the bar screen, corresponding to a mass reduction of 1,200 pounds. The resulting atmospheric H2S level was reduced to an acceptable 4 ppm. 262/792-1450; www.hydrite.com.

Vacuum feed system eases maintenance burden

Problem: The 150 mgd Back River Wastewater Treatment Plant in Baltimore, Maryland, sought to replace its vacuum feeders with more advanced vacuum feed units for sodium hypochlorite treatment of plant effluent. “There were too many pieces that could go wrong and we had to redo the piping to the contact chamber,” says operator Prim Rambissoon. “There were certain eductors for certain feeders, so we had to go through a whole process of re-educting. That could take an hour or two for each occurrence, depending on operator availability.”

Solution: Plant operators chose chemical feeders from JCS Industries. With a capacity of 10,000 gpd each, they use real-time feed information via electronic flow sensors that allow for continuous monitoring and control of the chemical feed rates. Each feeder automatically regulates in both fixed and variable control modes, including fixed feed rate, flow-paced, residual control and compound loop. A vacuum injector safely introduces the liquid into the feedwater stream. A reversing servo motor coupled with a V-notch valve regulates the chemical feed rate, an electronic flow sensor monitors and regulates the feed rate, and a control module provides complete electronic control and communications.

Result: “Installation was easy, taking only a day for each unit,” says Rambissoon. “The units have a built-in electronic flowmeter with digital display that makes operation so much easier than before.” 281/353-2100; www.jcsindustries.us.com.

Treatment plant employs peracetic acid for effective disinfectant

Problem: A municipal wastewater treatment plant in Kentucky needed a disinfectant that was effective and highly reactive.

Solution: Solvay Chemicals conducted independent laboratory tests at the plant site using Proxitane WW-12 peracetic acid. It demonstrated rapid and effective disinfection, does not generate harmful DBPs even if overdosed and can be economically retrofitted or work in series with an existing disinfection system. The fast-acting disinfectant has a minimal effect on pH, its biodegradable residuals are nontoxic, it is stable under ambient conditions and it is not capital intensive.

Result: Final total fecal coliform numbers were all less than 21 CFU/100 mL, and no dechlorination step was necessary. 800/765-8292; www.solvaychemicals.us.

Bio-activator reduces odors at municipal wastewater lagoon

Problem: Two cheese plants and domestic wastewater from a Californian municipality (population 32,000) discharge into a 570-acre lagoon system. During a few weeks, the lagoons turned from a normal healthy emerald-green to gray, then black and red. Once this occurred, neighbors complained of an odor like rotten eggs from the lagoons. The speculation was that cleaning-in-place disinfectants and cleaners were entering the system in large quantities, upsetting the lagoon microbiology.

Solution: The plant supervisor began regular daily dosing of Bio Energizer and SuperPhos from Probiotic Solutions to control odors and re-establish a healthy microbial population. The broad-spectrum bio-activator contains over 30 microbial growth-promoting factors delivered by Micro Carbon Technology. It is a balanced formulation of vitamins, trace nutrients, organic acids and bio-stimulants that foster greater metabolic capacity and efficiency in the microbial community.

Result: Within two weeks, the lagoons began to turn green, and after three weeks the odors were gone. At four weeks, the lagoons were back to their usual emerald-green color. 800/961-1220; www.probiotic.com.

System clears the air at municipal pumping station

Problem: Foul odors from the neighborhoods surrounding two municipal pumping stations in L’Assomption, Quebec, Canada, were compromising quality of life for residents. H2S and mercaptan-type odors were concentrated at times throughout the day. Due to the turbulence in the pumping stations’ wet wells, it was also apparent that oils and grease in the foul air stream had to be removed along with the odors.

Solution: Newterra supplied two deep-bed scrubber systems with properly sized fans and prefiltration units for mist and grease removal. Each vessel was filled with high-yield carbon to target the odors.

Result: Removal of all odors was greater than 99.95 percent, with an undetectable level at the outlet side of the units. The air phase scrubber systems were quickly installed within a few hours and have required minimal maintenance. 800/420-4056; www.newterra.com.

Town installs chemical-free wastewater disinfection system that also creates energy

Problem: The northern California town of Graton in Sonoma County needed a new wastewater disinfection system that would reduce energy costs.

Solution: Town leaders purchased an M-500 system from Pasteurization Technology Group (PTG). The chemical-free disinfection system generates on-site electricity and can process almost 600,000 gpd, sufficient for Graton’s 1,700 residents. 

Result: The system uses natural gas to generate electricity at half the cost of grid power for use in the plant and associated buildings. It also eliminated the costs of purchasing and storing chlorine. 510/357-0562; www.pastechgroup.com.

Covering lagoon stops odor complaints

Problem: United Liquid Waste Recycling of Watertown, Wisconsin, recycles food and beverage waste into valuable byproducts such as fertilizer. Odors from the anaerobic treatment process needed to be stopped to enable the company to expand. Two lagoon anaerobic digesters needed an affordable odor control system, which had to function whether the lagoons were full or empty.

Solution: The owners selected Industrial and Environmental Concepts to cover the two 3.5-million-gallon lagoons. The 57,600- square-foot membrane covers collect the biogas and channel it to a draw-off location where it can be effectively controlled. The covers function at any water depth.

Result: The cover system has operated for three years with no problems, allowing the company to grow and expand into Illinois, Iowa, Michigan and Indiana. 952/829-0731; www.ieccovers.com.

Treatment plant uses photoionization to exceed odor control expectations

Problem: The Missoula (Montana) Wastewater Treatment Plant faced numerous complaints and a Corrective Action Order from the Department of Health for its ineffective odor control measures.

Solution: AMBIO Biofiltration installed a Neutralox photoionization system to decrease elevated concentrations of H2S and other odor-causing agents in its air emissions. Photoionization systems eliminate sulfide compounds through application of UV light in the presence of catalysts.

Result: The plant eliminated more than 99.8 percent of odor-causing contaminants. The technology reduced high concentrations of odorous compounds, especially sulfurous compounds, while having low maintenance requirements and a small environmental footprint. 312/377-6116; www.neutralox-inc.com.

Self-cleaning mixed oxidant on-site generation system replaces aging sodium hypochlorite system

Problem: To use a safer disinfectant and identify areas to reduce operational chemical costs and improve water quality, the Paducah (Kentucky) Water Works needed to upgrade its disinfectant system from a 12 percent bulk sodium hypochlorite system in its downtown water treatment plant.

Solution: A self-cleaning 900-pound-per-day MaximOS on-site-generated mixed oxidant generation system from Parkson Corporation was selected based on lab testing that showed, among other benefits, a 25 to 30 percent reduction in alum usage to achieve a better settling floc particle.

Result: The advanced on-site generation system uses a self-cleaning technology with a polarity reversal cycle so that calcium and magnesium particles are flushed from the cell automatically. The mixed oxidant chemistry improves overall water quality. 888/727-5766; www.parkson.com.

UV system allows plant to handle additional flow

Problem: To comply with a total maximum daily load set by the U.S. EPA and the Alabama Department of Environmental Management, the City of Auburn ceased discharge at its Northside Water Pollution Control Facility and transferred the discharge to the H.C. Morgan Water Pollution Control Facility, which treats the majority of the city’s wastewater. The decision required upgrading the plant to handle the additional flow.

Solution: Facility management converted the chlorine disinfection system to UV and chose the TrojanUVSigna for its suitability for seasonal operation, the low number of UV lamps required, the low capital and long-term operating costs, ease of retrofit and simplicity of operation.

Result: The system has consistently performed under the monthly average and daily maximum colony-forming units (CFU) limits. The monthly average for 2014 was 42 CFU/100 mL, with a daily maximum of 194 CFU/100 mL. 519/457-3400; www.trojanuv.com.

Auto-optimized dosing system used for odor control

Problem: The Town of Palm Beach, Florida, needed an optimized treatment system for fluctuating force main flows and dissolved sulfide levels at one of its lift stations.

Solution: Town leaders selected the Kemira S-Guard advanced remote contaminant control and monitoring technology, which uses real-time influent dissolved sulfide data to consistently auto-optimize a correct chemical dosage on a weight for weight basis, taking into account wastewater flow, temperature, and pH.

Result: The remotely operated system has lowered the site’s overall chemical usage, increased response time, and maintained a consistent level of <5mg/L total dissolved sulfides leaving the injection site. 480/227-4848; www.kemira.com.