Case Studies: Clarifiers, Digesters, Water Towers, Structures and Components

Case Studies: Clarifiers, Digesters, Water Towers, Structures and Components
Rotary press ideal in retrofit situation

Press moves discharge permit approval, reduces costs

Problem

Dave Hapchuk owns and operates a septage receiving facility where he pretreats septage from his operation and seven others southwest of Pittsburgh. With tightening restrictions, effluent quality was threatening his permit renewal: “I was lying awake trying to figure out how to make sure we’d get our discharge permit renewed. I wanted to lower my surcharges by sending a better quality of water to the city plant.”

Solution

The solution came with a Fournier Rotary Press. After screening, grit removal and settling in tanks, sludge is pumped to the dewatering system. The cake comes out as 30-44% solids bricks, which drop from the press in a roll-off container for trucking to landfill.

RESULT:

The press captures over 95% of suspended solids. “That was one of the things that moved our new permit for discharge along a lot faster,” Hapchuk reports. 800-463-6328; www.fournierdewatering.com


Combined gravity settler and continuous backwash sand filter provide enhanced nutrient removal

Problem

With increasing population and tighter nutrient regulations, a municipal wastewater treatment facility in Georgia needed help to meet a discharge permit level of 0.14 mg/L phosphorus. The facility treats an average of 5 mgd of primarily domestic wastewater along with influent from a poultry processing plant. Effluent is discharged to the Little River.

Solution

After on-site pilot testing, the community chose an integrated design with a Lamella Gravity Settler and DynaSand Continuous Backwash Media Filter (Parkson Corp.) Chemically conditioned wastewater from a sequencing batch reactor is directed to four basins with four sets of Lamella plate packs. The settler in the plate pack configuration serves as a secondary clarifier and has a small footprint. With EcoFlow technology, a 25% increase in settling area can be realized due to 100% utilization of the plate surface area. Clarified is water essentially free of TSS, and phosphorus removal exceeds 91%. The water then flows by gravity to the DynaSand deep-bed filter modules for polishing. The filter requires low power and eliminates ancillary backwash equipment.

RESULT:

The integrated design delivers water at less than 0.1 mg/L ammonia and less than 0.07 mg/L phosphorus with turbidity less than 0.5 NTU. The plant consistently outperforms its NPDES limits on BOD, total nitrogen, phosphorus, and turbidity. 888-727-5766; www.parkson.com


City increases daily water capacity from 80 to 400 million gpd

Problem

Serving one of the fastest-growing metro areas in the United States, the Houston Northeast Water Purification Plant needed to drastically expand its water capacity to support residential and commercial growth and reduce dependency on groundwater.

Solution

The Houston Waterworks team chose Jim Myers & Sons for the expansion. The design of the Mega-SETTLER plate settler system enables increased water capacity in 50-75% less space than conventional settling tanks.

RESULT:

The technology increased capacity from 80 to 400 mgd while dramatically reducing the footprint of the sedimentation basin. This is the largest plate settler project in the world. When complete, it will have used over 4 million pounds of stainless steel to build over 50,000 individual settling plates. 704-554-8397; www.jmsequipment.com


Mixer installed in reservoir to maintain equal temperatures

Problem

The Reading Area (Pennsylvania) Water Authority in sought to mix a 15 million-gallon water reservoir (300 feet in diameter) to maintain equal temperature and chlorine residual throughout. The system needed to be in its own all-weather enclosure.

Solution

Pulsed Hydraulics designed a system with 16 bubble-forming plates located in the tank as determined by the CFD model. The system included two PHI-500 enclosures that each house PHI 360 components and a 15 hp compressor. Two compressors connected and controlled by the company’s software limit the start surge power to keep the plant’s outdated electrical infrastructure from overloading.

RESULT:

Temperature readings from predetermined test points showed a differential of 0.1 degree F between all test locations. Before mixer installation and start-up, the reservoir water was stratified and readings showed a 6 degree F temperature variance. 800-641-1726; www.phiwater.com


City seeks cake storage solution for water reclamation facility

Problem

When designing a new biosolids drying facility, the Des Plaines (Illinois) Water Reclamation Facility staff wanted the ability to process dewatered cake from their own facility and from external sources. With limited space and specific volume requirements, they needed a custom cake storage solution.

Solution

Schwing Bioset worked with the community to meet the challenges of receiving, moving and storing dewatered biosolids for the dryer. The company manufactured a custom-designed receiving bin with a push floor design to receive the outside cake. The bin includes a safety screen to keep large tramp material from entering and a bifold cover to contain odors. A hydraulically driven push floor feeds cake to the pumps with. The main storage silo in the plant collects dewatered cake from the receiving bin and from dewatering to feed to the dryer. The main storage silo uses sliding frame technology similar to the push floor but with a single frame constructed of carbon steel to feed cake to the discharge.

RESULT:

The dryer operates continuously and smoothly with buffering storage provided by the receiving and storage bins without additional operators or maintenance staff. 715-247-3433; www.schwingbioset.com


Design-build approach includes cost-effective media

Problem

East Cherry Creek Valley in Colorado sought a cost-effective media and filter system to provide groundwater treatment.

Solution

Tonka Water, a Kurita America Brand, installed a groundwater treatment plant with a fully automated OptaCell Plus horizontal pressure filter system for the removal of iron and manganese. The facility includes two high-rate 1,400 gpm media filters with Iron-Man media pre-conditioning,  providing operational flexibility, allowing operators to isolate individual cells within the vessel when needed. This also enables a cell to be taken offline for backwash while keeping the plant operating at full capacity. A Simul-Wash backwash system saves up to 50% of backwash water waste. The filters have isolated cell compartments above and below the underdrain, with a total of four individual filter cells. This enables individual cells to be backwashed or taken completely offline while the others remain in service.

RESULT:

The plant has performed beyond expectations since its startup. 866-663-7633; www.kuritaamerica.com


Belt dryer reduces 1,300 miles of biosolids hauling risks

Problem

The city and bureau of Juneau, Alaska, produces 7,000 wet tons of dewatered biosolids per year. The material hauled 1,300 miles via truck, barge and train to the Columbia Ridge landfill in Arlington, Oregon. This transport poses multiple risks and costs, and the city faced uncertainty over environmental regulations.

Solution

With geographic challenges, limited transportation options, an unpredictable climate, and lack of specialized support services, the city needed a stable, long-term biosolids solution to meet U.S. EPA guidelines. The city chose the BioCon medium-temperature belt dryer (Veolia Water). The resulting Class A EQ material provides pathogen reduction and diversifies the range of end uses including reuse as landfill cover, fertilizing community sites and parks, erosion control, and topsoil replacement. These options also offer potential for much lower end-to-end cost versus shipping wet solids to landfill.

RESULT:

The dryer is designed for 36 wet tons per day and produces 5.5 tons of dried product, an 85% reduction in volume and weight. Other benefits include less truck traffic, lower emissions and reduced noise. 919-677-8310, www.veoliawatertech.com   



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