Capture and treatment system controls odors

Problem

Residents in Bridgeport, Conn., complained of odors from a wastewater treatment facility.

Solution

The Water Pollution Control Authority selected retractable covers and a carbon system from Geomembrane Technologies. The durable coated fabric tensioned over low-profile aluminum arches covers the influent channel and primary clarifiers. The installation was done while the clarifiers were in service.

Result

Odors were controlled and budgets were met. 506/449-0993; www.gticovers.com.

Odor control system saves money

Problem

Structural failures in the chemical scrubbing odor control system at the Swansea Wastewater Treatment Plant in West Glamorgan, U.K., required operators to enter areas of the building wearing full breathing apparatus. The estimated cost for replacing the equipment was $2 million.

Solution

Welsh Water, the company operating and maintaining the facility, installed the Terminodour system from Kusters Water/CSO Technik in a pilot program. Seeing its low cost, simple retrofit and efficiency, the company made the selection permanent.

Result

The system saved the plant more than $1 million in capital expenditures. Operating expenses declined, and operators noticed a significant reduction in hydrogen sulfide corrosion. 205/987-8976; www.kusterswater.com.

Solar-powered mixers eliminate odors

Problem

Every spring, residents noticed odors from the seven lagoons at the Garretson (S.D.) Wastewater Treatment Plant. The containment system totals 35.2 surface acres and 46.8 million gallons, but the lagoons are only 5 feet deep.

Solution

SolarBee engineers recommended a solar-powered mixer from Medora Corp. for each of two lagoons. The units mix and oxygenate the top 3 feet of water, oxidizing sulfide gas to non-odorous sulfate. Constant circulation also removes surface film, allowing methane to escape more easily and increasing anaerobic digestion to reduce sludge.

Result

The mixers have been installed for five years. “We don’t detect any odors in spring anymore,” says utilities superintendent Craig Nussbaum. 866/437-8076; www.medoraco.com.

Mixing system manages pump station grease

Problem

The 1.5 mgd RCA Pump Station in Deptford, N.J., had FOG and odor problems. The Municipal Utilities Authority increased pump-outs from twice a year to quarterly at a cost of $600 per load, but that wasn’t often enough. Operators failed to control the odor with deodorizers and enzymes. Assistant superintendent Mike Cusick searched for solutions.

Solution

The authority purchased a PHI 300 Big Bubble mixer with two bubble-forming plates from Pulsed Hydraulics. After the plates were installed on the floor of the well, an electro-pneumatic valve that opened and closed in milliseconds released a massive, well-formed bubble every 30 seconds. The air burst powered liquid and sediment off the bottom, forcing them upward to smash into the grease. As the shock waves broke up the blanket, bubbles began breaking the surface, moving liquid and solids tangentially to the walls and down the sides to the bottom to complete the mixing cycle.

Result

The grease and odors were gone within a week and did not return. Annual savings in disposal fees provided a three-year return on investment. 800/641-1726; www.phiwater.com.

Closed-vessel UV system enables water reuse

Problem

An amendment to the Lahontan Region Basin Plan allowed recycled water for outdoor irrigation at elevations above 3,200 feet. The Grass Valley Wastewater Treatment Plant in Lake Arrowhead, Calif., needed an upgrade to comply with limits set on disinfection byproducts and residuals.

Solution

The plant installed four closed-vessel TrojanUVFit 32AL50 reactors (two are redundant). The reactor is approved for Title 22 applications by the California Department of Public Health and validated in accordance to the UV Disinfection Guidelines for Drinking Water and Water Reuse. A UV intensity sensor monitors output and ensures adequate dosing to optimize energy usage. The energy-efficient, affordable reactors have a small footprint.

Result

The reactors enabled the treated effluent to be used for irrigation. 519/457-3400; www.trojanuv.com.

Expansion project includes odor control system

Problem

An expansion project at the Wyoming (Mich.) Clean Water Plant required a new odor control solution.

Solution

Engineers chose truss-supported, extruded flat aluminum covers from CST Covers (formerly Conservatek and Temcor). They were installed on three biosolids storage tanks and four primary settling tanks. The settling tanks had open-top flow-splitting chambers with non-standard railings and manlift sockets at access hatches.

Result

The covers’ weight-bearing abilities gave operators a slip-resistant walkway. The project allotted 12 months for completion and was finished in nine. “The product’s design allowed us to use less labor and finish ahead of schedule,” says maintenance supervisor Tom Wilson. 936/539-1747; www.cstcovers.com.

Biofilter system reduces odor detection thresholds

Problem

Sanitation District #1 in Covington, Ky., a fast-growing area, was receiving odor complaints from its biosolids treatment system. The plant is in a valley, and the biosolids emitted intensely odorous gases. The problem could not be resolved by incinerating or chemically treating the gases.

Solution

The municipality contracted with PRD Tech to install a twin-biofilter system consisting of two vessels connected in series. Gas flows going down through one unit and then up through the other. Each biofilter is 14 feet in diameter and 20 feet high, with a gas residence time of 15 seconds. The biomedia has a large surface area and is randomly packed. It can be washed down automatically based on the gas-phase pressure drop across the biofilter beds, enabling the system to handle large loads of inlet volatile organics, which would clog a packed bed due to biomass growth.

Result

The system effectively removed odorous gases from the airstream, and odor complaints were nearly eliminated. 513/673-3583; www.prdtechinc.com.