Washing system helps eliminate FOG problem

Problem: A large north Florida regional wastewater system was battling FOG buildups up to 4 feet thick blanketing lift station walls and equipment. Dry-weather spills exacerbated the problem.

Solution: The agency selected the EP-1100 well- washing and pretreatment system from Anue Water Technologies. 

Result: The system eliminated the FOG in two hours. Spills were nonexistent, and confined-space entry for cleaning was no longer necessary. Expenses for a boom truck and two operators for two hours on each occasion were also eliminated, reducing maintenance costs by up to 20 percent. The agency now operates 15 EP-1300s and plans to add more. 760-727-2683; www.anuewater.com

Bar screen provides long-term service

Problem: In 1997, the city of Adrian, Michigan, faced rising ownership cost for an aging bar screen. Sprockets below the water level needed frequent replacement requiring a three-person crew.

Solution: The equipment was replaced with a Duperon FlexRake FP full-penetration coarse bar screen, which has no lower sprockets, bearings, or tracks. Maintenance can be performed from the deck level. The simple design adapts to debris variations and has full-range flexibility. The site has experienced nontraditional debris like children’s toys, coffee cans and other odd-sized items.

Result: Running around the clock for more than 20 years (175,000 hours), the unit has managed flows from 7 to 21 mgd. The scraper has traveled the equivalent of 19 million feet, and the teeth and circumference show no wear. It has cost less than $6,000 in electricity. “This unit has run almost continuously since it was installed,” says Ryan White, plant superintendent. “Other than cleaning, we spend less than a couple of hours a year of maintenance on it.” 800-383-8479; www.duperon.com

Product reduces sulfides and helps control polymer usage

Problem: A large Midwestern wastewater treatment plant had hydrogen sulfide levels exceeding safe levels, posing hazard within the plant and the community, as well as potential corrosion of equipment. Daily spikes reached 180 ppm.

Solution: International Dioxcide / ERCO Worldwide initiated a two-week trial of Endimal DW to reduce airborne hydrogen sulfide levels in the solids-handling area and dissolved hydrogen sulfide in the belt press filtrate, to reduce polymer usage for dewatering while maintaining acceptable cake solids, and to establish an optimized dose rate. The product was dosed based on the dissolved sulfide levels of the incoming sludge and average sludge flow rate.

Result: The fast-acting, easy-to-use technology effectively controlled hydrogen sulfide levels and odors in the solids-handling building, bringing down the level to a safe range. Polymer dose rates were reduced while keeping the cake at acceptable dryness. 401-295-8800; www.idiclo2.com 

Screening system helps plant solve FOG issues

Problem: A regional wastewater treatment plant in Pennsylvania has had a truck waste-receiving program for many years. The percentage of FOG being discharged had grown significantly. Operators decided to establish a separate FOG receiving station.

Solution: A pilot test evaluated screens’ ability to accept gravity or pressurized flow from various size trucks, the amount of debris captured, truck unloading times, and the ability to perform without a rock trap or grinder. The plant team chose two FOG Beast 1400 screening systems (Enviro-Care) after the unit screened an average of 20 trucks per day for one month. Even mixed-load trucks with large quantities of rags and rocks were not a problem, and the unit didn’t require a rock trap or grinder.

Result: Feedback from the haulers and plant personnel was positive and so was the data collected on the four pilot parameters. 815-636-8306; www.enviro-care.com 

Dewatering presses prove to be the right fit 

Problem: The Brunswick (Maine) Sewer District sought a continuous dewatering solution to work with two existing Ashbrook 2-meter belt filter presses.

Solution: The district chose two six-channel rotary sludge dewatering presses from Fournier Industries. They were installed without process interruption and fit the existing footprint, avoiding a costly building expansion.

Result: Operations staff members are satisfied with the presses due to energy efficiency, reduced corrosive conditions, automated controls and less operator oversight. Since the dewatering process is contained within each machine, the ambient room conditions are exceptionally clean dry, requiring fewer air changes per hour. “The chemical usage and polymer efficiency have exceeded expectations,” says Jennifer Nicholson, treatment supervisor. “This is likely due to the compact design of the polymer conditioning arrangement that is part of the overall package.” 418-423-4241; www.rotary-press.com

Water reclamation facility upgrades system for struvite recovery

Problem: The Little Patuxent Water Reclamation Facility, a 29 mgd advanced plant in Savage, Maryland, sought to update biosolids processing by replacing lime stabilization with anaerobic digesters, centrate deammonification and associated solids screening, thickening, odor control and digester gas-handling improvements.

Solution: Centrisys/CNP supplied the AirPrex process. It improves biosolids processing by sequestering phosphorus and preventing the formation of struvite. Improvements in dewatering and other processes significantly reduce operating costs. The process either leaves struvite in the biosolids for land application or separates it for use as a slow-release fertilizer.

Result: The system was scheduled to go online in the third quarter of 2018. 262-654-6006; www.cnp-tec.com

Water reels enable plant to easily distribute effluent

Problem: In Fayetteville, Arkansas, the Noland Wastewater Treatment Plant lies next to the Midland Bermuda production area, which produces 230 tons of forage grass per year for sale to residents and farmers. The plant has a 670-acre nutrient water reuse site and uses up to 12.6 mgd of effluent on the crops. The plant sought an easy way to distribute the water.

Solution: The plant purchased four T40x1250 Water-Reels from Kifco. They apply water uniformly and eliminate soil compaction from tanker trucks. The units were equipped with hydraulic turntables, hydraulic jacks and five-wheel gun carts to decrease operating cost. 

Result: The Water-Reels enable plant personnel to distribute wastewater with up to 3 percent solids. 800-452-7017; www.kifco.com 

Screen achieves high capture efficiency

Problem: Ash Creek Special Service District in Utah regularly struggled with mechanical breakdowns in its lagoon aeration system from accumulation of wipes and rags around aerator drive shafts. The material reduced performance until the motors became completely bound, resulting in an over-amp fault.

Solution: Based on feedback from operators at other facilities, the Ash Creek team identified key requirements for a new screening system: very high capture efficiency, a full-penetration cleaning mechanism to eliminate screen blinding, and a single screening/washer/compactor unit. The district chose an all-stainless steel Raptor Fine Screen from Lakeside Equipment.

Result: When the upstream water level rises to a high-level setpoint, the unit’s rake arm begins to rotate to remove captured material. After a complete revolution, material falls into a collection trough. The unit has run trouble-free, removing rags and debris. 630-837-5640; www.lakeside-equipment.com

Mixing system helps eliminate ragging and FOG

Problem: A 100,000 gpd pump station in Aqua America’s Fort Wayne, Indiana, division was inundated with rags and FOG, creating large, bricklike masses of grease and rewoven fibers. Monthly removal with shovels and buckets was required because the station’s inaccessibility precluded use of a vacuum truck. In addition, there were frequent odor complaints from the neighborhood. 

Solution: The solution employed a protein-based degreasing formulation and a large-bubble mixer. Protein Matrix’s PM-1 plant-based, bacteria- and enzyme-free solution prevents FOG solidification, converting grease on a molecular level to a flowable and soluble byproduct that does not resolidify downstream. Pulsed Hydraulics’ Hydro-Pulse System enables complete mixing of the wet well contents without moving parts or entrainment of oxygen. 

Result: After 14 months, the wet well remains clean. The Hydro-Pulse System distributes the chemical throughout the wet well, facilitating contact with FOG molecules and increasing chemical efficiency by nearly 30 percent. The PM-1 prevents resolidification of wet well contents expelled by the mixer, reducing the risk of downstream overflows. 800-641-1726; www.phiwater.com 

Screw presses help reduce maintenance costs

Problem: The Bradenton (Florida) wastewater treatment plant processes 8 mgd. It had aerobically digested biosolids and dewatered them to 15 percent solids content using two 2-meter belt filter presses, which were aging and creating a maintenance burden.

Solution: After a successful pilot test, facility personnel chose the Schwing Bioset screw press. The process yielded biosolids at up to 21 percent solids. The presses fit within the available space on the second floor of the dewatering building. 

Result: The two FSP902 screw presses were commissioned early in 2018. The more completely dewatered biosolids reduce hauling and disposal costs while reducing the wash water required and significantly reducing maintenance. 715-247-3433; www.schwingbioset.com

Screening system saves company time and money

Problem: Aqua Engineers has served the water and wastewater needs of the Hawaiian Islands for 37 years. With limited space at sites the Oahu Wastewater System team services, it was not feasible to build a drying bed for debris. This meant driving an hour to the available drying bed and then returning to clear out the bed after the material dried.

Solution: The Mega Screen from ScreenCo Systems allows the company to dewater and clean debris on site at one of its pump stations. 

Result: The Mega Screen has saved time and increased productivity of the team, as it provides a quick and easy way to unload the Vactor vacuum truck. 208-790-8770; www.screencosystems.com

Hydrogen peroxide helps eliminate odor complaints 

Problem: The City of Boynton Beach, Florida, was experiencing severe hydrogen sulfide odors and corrosion at a lift station along heavily traveled Boynton Beach Boulevard near restaurants and other retail businesses. Two force mains that receive flow from 15 lift stations terminate at the station, and the turbulence created as the flow discharged into the station contributed greatly to the release of hydrogen sulfide. Odor complaints were common, and corrosion in the station wet well was severe.

Solution: USP Technologies (US Peroxide) provided a full-service solution using hydrogen peroxide, engineered equipment storage and dosing systems. The company began treating the two flows in 2017. Optimal hydrogen sulfide control was achieved by the strategic placement of the hydrogen peroxide systems, coupled with hour-by-hour chemical feed predicated on flow and historic hydrogen sulfide levels. 

Result: Dissolved hydrogen sulfide levels were reduced by 85 percent. In addition, hydrogen sulfide levels in the station wet well were greatly reduced, enhancing safety for city personnel. Odor complaints were nearly eliminated. 877-346-4262; www.usptechnologies.com