Formulation consumes organic solids

Problem

Biosolids buildup in the anaerobic lagoons at the Mount Olive (N.C.) Wastewater Treatment Plant was lowering storage capacity.

 

Solution

Operators removed up to one-half of the biosolids with conventional equipment, then added ASI Maintenance Plus formulation from Agriment Services to remove another 25 percent. Each one-pound package contains nonpathogenic bacteria that digest and liquefy solids, reduce odors and control insects. The water-soluble packs are introduced directly into the lagoons.

 

Result

The lagoons’ storage capacity was restored along with the biological health of the waste management system. 252/568-2648; www.agrimentservices.com.

 

Probes recognize testing parameters

Problem

Membrane-style dissolved oxygen meters at the Loveland (Colo.) Wastewater Treatment Plant were time-consuming to set up, maintain and calibrate. Drifting test results made measurements unreliable.

 

Solution

The plant purchased the portable HQd meter with luminescent dissolved oxygen (LDO) probe from Hach. An intuitive user interface with guided self-calibration reduces calibration errors.

Besides measuring dissolved oxygen, different IntelliCAL plug-and-play probes simultaneously measure other parameters such as pH and ammonia. The probes store the last known calibration and the calibration history, reducing the need to recalibrate when moving from one meter to another. LDO technology eliminates membranes.

 

Result

Loveland runs five tests in the time it took to run one test with the older system, and the results are accurate. 800/227-4224; www.hach.com.

 

Meters improve field utility

Problem

The laboratory team from Greene County Sanitary Engineering in Beavercreek, Ohio, conducted monthly sampling on the Little Miami River and Massie Creek to monitor the county’s two wastewater treatment plants and comply with NPDES reporting requirements. Members carried separate meters for pH and dissolved oxygen (DO). Some sites were difficult to sample.

 

Solution

The team chose the Professional Plus handheld multiparameter meter from YSI. The Quatro cable allows them to measure pH, DO, and temperature quickly and reliably. The meter also measures oxidation reduction potential, conductivity, ammonium, and nitrate or chloride.

 

Result

The team even used the meter for testing BOD in the laboratory. 800/897-4151; www.ysi.com.

 

Vortex grit chamber enhances removal

Problem

The upgrade and expansion of the Soledad (Calif.) Wastewater Treatment Plant included a high-performance vortex grit chamber in the headworks. To prevent finer grit from wearing out pumping equipment, accumulating in clarifiers, and contaminating biosolids, officials looked for a grit removal system.

 

Solution

The facility installed the Mectan V variable-angle grit removal and separator from John Meunier. The tangential inflow velocity along the peripheral wall of the circular chamber helps remove grit. Paddles in the chamber maintain velocity, holding solids in suspension. As grit settles down the sloped transition between the upper chamber and grit well, circular and conical shapes reduce turbulence. A 360-degree flow path with separator plate ensures no short-circuiting. Air or water scours the bed of the well to fluidize the material before a pump or airlift transfers it to the classifier.

 

Result

Field tests revealed that the system removed more grit for each particle size analyzed than the specification requirements. The grit removal rate remains consistent for all flows. 888/638-6437; www.johnmeunier.com.

 

Scrubber transforms gases

Problem

As an operator at the Moccasin Bend Wastewater Treatment Plant in Chattanooga, Tenn., tried to switch 1-ton chlorine cylinders, a leak occurred. The worker escaped without injury as the facility implemented its emergency response plan.

 

Solution

Officials purchased a FOC-1 fiberglass emergency gas scrubber with Chlorosorb dry-scrubbing medium from Purafil ESD and installed it next to the chlorination room. The media neutralizes 400 pounds of chlorine in the first minute and additional gas at 80 pounds per minute thereafter. The chemisorptive process traps chlorine inside pellets where an irreversible chemical reaction changes the gas into a harmless solid.

 

Result

“The scrubber neutralized all the chlorine that leaked out,” says Jerry Stewart, director of Water Resources. “It turned a potentially major incident into a minor one, enabling us to shut off the gas before it escaped to surrounding areas.” 800/222-6367; www.purafil.com.

 

Cloth media filters improve performance

Problem

Intermittent flows from the Bear River Casino caused the continuous backwash sand filters at the Loleta (Calif.) Wastewater Treatment Plant to use much of the backwash effluent during low flows. Periodically, the filters even ran completely dry, causing maintenance issues and poor filtration.

 

Solution

In 2010, the plant purchased an FFP-90403 fixed-plate filter from Fluidyne Corp. to replace the sand filters. The FFP has four small cloth panels, each with three square feet of acrylic media, and no moving parts or pumps.

 

Result

The unit has a much smaller footprint than the sand filters, increased the system’s ability to handle peak flows, and minimized backwash during off-hours. 319/266-9967; www.fluidynecorp.com.

 

Filter reduces reject flow

Problem

Because the Pompano Beach (Fla.) Water Reuse Facility paid to process reject flow from the DynaSand continuous backwashing sand filter, officials looked for ways to reduce the volume of backwash water and optimize filter performance.

 

Solution

In a test project, workers converted one sand filter cell with an EcoWash filter from Parkson and left the other in its standard setup. The intermittent washing cycle in the test cell improved performance and shortened reject periods.

 

Result

The baseline reject flow averaged 28,800 gpd and the test cell averaged 2,880 gpd. The facility also saw a significant power savings due to the compressor’s reduced run times. Officials installed the system in the remaining cells. 954/974-6610; www.parkson.com.