Case Studies - November 2023

Case Studies - November 2023
Thickening centrifuge has multiple advantages

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Reclamation district implements phosphorus removal to achieve strict environmental standards

Problem: The Fox River Water Reclamation District in South Elgin, Illinois, needed to comply with an NPDES permit requiring a reduction of phosphorus discharges.   

Solution: Black and Veatch provided a comprehensive feasibility study of the district’s three water reclamation facilities and reviewed multiple nutrient removal processes. The district chose biological phosphorus removal along with MagPrex, a system from Centrisys/CNP able to precipitate phosphorus in the biosolids stream as struvite and substantially reduce soluble phosphorus in the digested solids stream and plant effluent.

Result: Implemented in 2021, the system consistently removes over 90% of orthophosphate in the solids stream and improved dewatering: cake total solids increased from 13% to 16%. Ed Brown, operations superintendent, commended the system, emphasizing exceptional dewatering performance. 262-747-2384;

Filtration system helps dairy operation get runoff under control

Problem: Raw manure from dairy operations challenged to a Wisconsin county, creating significant nutrient runoff, digestate transportation expense, and the risk of anaerobic degradation in the open lagoons, emitting methane and contributing to global climate change.  

Solution: After laboratory and pilot scale studies the Scepter technology from Graver Technologies was chosen. This crossflow filtration technology combines 316 L porous stainless steel tubes with a sinter-bonded titanium oxide membrane. Modules were incorporated to concentrate the solids from the digester. The technology withstands the aggressive cleaning and provides long-term economical operation.

Result: Scepter is deployed in state-of-the-art treatment plant designed to process nearly 1 mgd of digested dairy manure and return over 400,000 gpd of clean water to the environment. It reduces digestate volume to store and helps farmers better manage the application based on weather conditions and achieve optimal crop nutrient uptake. The process enables capture of methane for conversion to renewable natural gas. 888-353-0303;

MBBR allows facility to handle the increased flow capacity

Problem: A small but fast-growing city in New Jersey needed to expand its wastewater treatment plant capacity. One requirement was to keep the existing plant in service during construction. The design also had to consider a limited budget based on state revolving fund financing. Site limitations did not allow for an additional activated sludge train.

Solution: The client, consultant and Headworks International chose an integrated fixed film activated sludge process, which reduced the tank footprint by 50%. The moving bed bioreactor media shortened retention time by half so reduced the reactor load dramatically.

Result: The dramatically reduced retention time delivered the needed capacity increase within the space limitations. The system also produces less biosolids, reducing costs greatly. 713-647-6667;

Venturi sidestream injection brings ozonation to treatment plant

Problem: The Geren Island Water Treatment Plant in Salem, Oregon, draws its supply from the North Santiam River. In 2018 that source had elevated concentrations of cylindrospermopsin and microcystin, which appeared earlier than in previous years. 

Solution: Ozone was chosen as the best treatment option. The water goes through the primary slow sand filtration to remove cyanobacteria, a primary source of cyanotoxins. Remaining cyanotoxins are then destroyed by ozonation. Ozone also breaks down other contaminants that could impart taste and odor, improves secondary filtration, and reduces chlorine usage for disinfection. To optimize performance, ozone is forcefully mixed with source water. For mixing and ozone contact, venturi sidestream injection from Mazzei Injector was chosen for effective control and thorough mixing and contact capabilities in a small footprint.

Result: The Frank Mauldin Ozone Treatment Facility, coupled with expanded filter capacity, enables Salem to meet its water quantity and quality needs for today and the future. 661-363-6500;

Nanobubble generator reduces surfactants at recovery facility

Problem: The 9.5 mgd Goleta Sanitation District Water Resource Recovery Facility near Santa Barbara, California, faced high surfactant concentrations due to low-flow drought conditions and pandemic-level surfactant use. The surfactants made biological treatment inefficient and expensive, risking permit violations. The district faced millions of dollars in upgrades to address the problem conventionally.

Solution: The facility piloted the NBG 6 nanobubble generator from Moleaer after learning about its successful surfactant removal at a nearby facility. Nanobubbles produce hydroxyl radicals that partially oxidize the surfactants and FOG in wastewater and reduce upsets in the biological process. The NBG 6 was installed between the headworks and primary clarifier to treat degritted and screened wastewater.

Result: In a three-month pilot the technology removed 40% of total quaternary ammonia compounds, 54% of total nonionic surfactants, and 51% of total anionic surfactants from raw influent. Aeration power draw was reduced by 43% and chemical costs and odor fell while TSS removal at the primary clarifier increased by 10%. The disinfection process saw chlorine demand fall 43%, and the facility was able to discontinue its bioaugmentation program. The nanobubble system reduced operation and maintenance costs by $87,000 per year and produced better-quality effluent. 424-558-3567;

Water reclamation facility employs phosphorus management for nutrient recovery and equipment protection 

Problem: In designing a new anaerobic digestion and dewatering facility, the Michigan city of Grand Rapids also wanted to protect process equipment downstream of the new digester from struvite scaling, break the recycle loop of phosphorus back to the plant, and recover phosphorus for beneficial use. With limited space available and specific project requirements, the city needed a customized and multifaceted solution. 

Solution: Schwing Bioset met the challenges with a two-stage phosphorus management system using NuReSys technology. The first stage drives crystal formation downstream of anaerobic digestion, lowering struvite-forming potential and preventing dewatering equipment scaling. The second stage used on post-dewatering centrate adds struvite crystallization and harvests the struvite from the centrate stream for beneficial use.  

Result: The system operates continuously with sidestream treatment, protecting the plant from struvite buildup. It reduces the phosphorus return load and creates a marketable product. 715-247-3433;

Geomembrane protects wastewater treatment plant

Problem: The Haikey Creek Wastewater Treatment Plant in Tulsa, Oklahoma, receives wastewater through 36-, 30- and 24-inch force mains. The Broken Arrow Municipal Authority needed a geomembrane for a flow equalization basin designed to reduce sanitary sewer overflows.

Solution: XR-5 geomembranes from Seaman Corporation/XR Geomembranes were chosen for durability and low thermal expansion and contraction. The membranes are compatible with harsh liquids and offer high UV resistance and tensile strength. They can be prefabricated with fewer field seams than rigid alternatives, shortening installation time and cost and improving membrane integrity.

Result: These properties along with toughness from the base fabric enable the authority to leave the liner exposed so that there are lower construction and operating costs and no slope maintenance. 800-927-8578;

Customized solution provided to treat varying water quality

Problem: The Illinois city of Lexington needed of a new water treatment plant as residents were experiencing tinted water caused by organic materials. Water is sourced from multiple wells, creating unstable water quality. 

Solution: A customized solution was provided by Tonka Water, a Kurita Brand for the removal of TOC, iron, manganese and hardness. It includes a fully automated combination of four processes from a single manufacturer. Treatment begins with forced-draft aeration, providing iron oxidation. Water then flows to detention, allowing time for the iron to oxidize. Next comes an OptaCell Plus pressure filter for removal of iron and manganese. The filter, with isolated cell compartments above and below the underdrain, enables individual cells to be backwashed or taken completely offline while the others remain in service. Each cell includes the Simul-Wash backwash system, which reduces backwash waste and lowers costs. In the next stage water flows through four RidION ion exchange softener vessels to treat water hardness, followed by an Organix system for TOC removal before distribution.

Result: The Lexington plant is meeting expectations since commissioning in 2017. 866-663-7633;

Dredge helps improve water quality in lake 

Problem: Outbreaks of blue-green algae in a 1,616-acre natural lake created a call to action in Powers Lake, North Dakota. The water analysis measured the lake as hypereutrophic. Meeting state water quality standards required reducing nutrient loads to Powers Lake by 75% and nutrient cycling within the lake by 50%.

Solution: Agricultural producers adopted soil and water conservation Best Management Practices. Data showed that their efforts significantly reduced nutrient loadings to the lake, but blue-green algae blooms continued. In 2015, the city bought a SRS Crisafulli Rotomite hydraulic dredge. For seven seasons it has been used to dredge nutrient-heavy sediments from the lake. 

Result: The combination of dredging and conservation activities proved highly effective in enhancing water quality. 800-442-7867;  


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