News from Schwing Bioset

Biosolids Plant Up and Running at Paragould WWTP

 

Published in Paragould Daily Press, August 2020

 

Thanks to a newly completed $5.15 million biosolids plant, not all the waste at Paragould Light, Water and Cable’s Wastewater Treatment Plant is actually going to waste. 

“We send out two 12-[cubic] yard trucks of biosolids a day, Monday through Thursday,” said plant Operations Manager David Romine on Monday. 

Romine said the biosolids, a byproduct of wastewater treatment and processed by the plant’s new Schwing Bioset equipment, go out to area farmers at a cost to them of $5 a cubic yard delivered, such that a fully loaded truck would cost $60.

In addition, the new equipment enables a savings of about $100,000 a year on the cost to operate and maintain the equipment, compared to the old system.

The Schwing Bioset system enables sludge produced to receive a rating of Class A EQ biosolid under the EPA 40 CFR 503 regulation. “The EQ means it’s ‘exceptional quality,’” Romine said, “which means you don’t have to do anything special in order to use it anywhere [as fertilizer].”

 

Click here to read the full article in the Pargould Daily Press

 

The Bioset Process allows the product to be used as a fertilizer under regulation for Class A EQ. Pictured is the Bioset unit, dewatering screw presses, piston pump, and truck loading operation. 

20200831_110158 (2)  20191003_134927

 

 

Tags: Class AA/EQ Biosolids, Dewatering, Wastewater Treatment Plant

Schwing Bioset, Inc., Acquires Assets of Custom Conveyor Corporation

 

 

Custom Conveyor, A Division of Schwing Bioset

 

August 2020

Schwing Bioset, Inc. (SBI) is proud to announce that it has acquired substantially all of the assets of Custom Conveyor Corporation (CCC) of Rogers, MN. In connection with the acquisition, SBI has:

- Retained all of the CCC staff with their decades of experience.

- Acquired all of the equipment for the production of their products.

- Acquired all existing project files to continue to provide on-going after-market support.

 

Additionally, SBI has taken over the greater than 20,000 square feet of office and production space for the continued manufacturing of Custom Conveyor and Schwing Bioset products.

CCC had over 30 years of experience in the manufacturing of conveyance and storage systems with primary products consisting of:

- Shafted Conveyors

- Shaftless Conveyors

- Live Bottoms

- Belt Conveyors

- Gates

- Augie Dumpster Loaders

 

The acquisition increases SBI’s manufacturing capacity and vertically integrates our supply chain to shorten delivery schedules and enable more competitively priced products in the market.

For more than 30 years, Schwing Bioset, Inc. has been helping wastewater treatment plants, mines, and industrial users by engineering solids handling solutions. Schwing Bioset’s custom-engineered solutions can be found in over a thousand facilities across North America and around the world.

Schwing Bioset’s products include, among others, sludge, industrial, and tunnel piston pumps, screw presses, nutrient removal and management, membrane bioreactors, sliding frame and push floor silos, fluid bed drying products, Bioset process for Class A Biosolids, container wagons, and screw conveyors. The company also offers on-site demos, spare parts and equipment maintenance services, and training seminars. 

 

To learn more about Custom Conveyor, a Division of Schwing Bioset, visit here or contact us.

 

Belt Conveyor   Augie Dumpsters

 

Tags: Conveyors, Live Bottoms, Custom Conveyor, Augie Dumpsters

Pima County, AZ, Tres Rios WRF Biosolids System Upgrades - Part Two: Live Bottom Cake Bins

 

Written by Josh DiValentino

 

Background: The district of Pima County, AZ, operates a total of eight wastewater treatment plants. The Tres Rios Water Reclamation Facility (WRF) is the centralized biosolids processing facility for all Pima County plants. Tres Rios WRF currently operates 24/7/365 at a 30 MGD capacity, with a projected flow of 50 MGD in 2030. The facility process is; BNR, Anaerobic Digestion, Dewatering, Pumping, Truck Loading, and Land Application of biosolids (cotton is common use). For nearly 20 years, Schwing Bioset, Inc. has provided solids handling solutions at Tres Rios with projects ranging from biosolids cake pumping and cake storage bins, to most recently, nutrient recovery and temporary Screw Press dewatering equipment.

 

Live Bottom Cake Storage: In 2012, the facility completed a Regional Optimization Master Plan expansion, which included upgrades to the centrifuge building and a new truck loading building. Prior to this expansion, dewatered cake was pumped (using the original Schwing Bioset Piston Pump) directly through a pipeline to the truck loading area. There was no intermediate storage capacity in the system on the dewatered cake side. Further, trucks could only be filled as fast as the cake pump could deliver cake, significantly reducing truck fill times.

 

Tres Rios Storage w-caption 2During the 2012 expansion, Schwing Bioset, Inc., supplied the new truck loading cake bins. Three (3) live bottom bins were provided, each with a capacity of 3,000 cubic feet of cake storage.

  • Bin Silo Sizing Details (each): Circular Design, 12’ diameter and 33’ tall storage area. Total height of 51’ including truck loading area.

Each bin utilizes a live bottom to deliver biosolids cake to the trucks below. The live bottoms are center discharging.

  • Bin Live Bottom Details (each): 18” diameter shafted, Twin Screws. Complete with 36” x 36” pneumatically actuated slide gates to control cake fill.

 

The top of the bins extend through the roof of the truck loading building. The bins provide storage capacity for dewatered cake and can fill trucks in less than 15 minutes when needed. The systems came complete with access ladders, safety railing, and ventilation connections for odor control. The bins have been in operation for nearly a decade, requiring only regular upkeep and maintenance to bearings and drive systems.

 

Click here to read more about our Products, then contact us to learn more about this project or find out how we can help your plant too.

 

Read Part One: Cake Pumping

Stay Tuned for More on Pima County Projects:

Part Three: Temporary Screw Press Dewatering

Part Four: NuReSys Struvite Management Project

 

 Download Our Brochures    or Application Reports

Read More Schwing Bioset  News and Blog Articles

 

Tags: Biosolids, Wastewater Treatment, Water Reclamation Facility, Live Bottom Bins

The Maine Solution

 

When an upgrade to the biosolids dewatering component at the Westbrook/Gorham Regional WWTP was needed, a screw press has helped the facility dramatically reduce their sludge hauling/handling costs.

Written by Larry Trojak, Trojak Communications

Version also published in WaterWorld, June 2020

 

Schwing Bioset Dewatering Screw Press

 

When an upgrade to the biosolids dewatering component at the Westbrook/Gorham Regional WWTP was needed, plant personnel looked at several different available technologies. Handling secondary sludge alone is challenging, and after an extensive trial and evaluated bid process, they opted for a screw press from Schwing Bioset, Inc. Today, sludge leaving the plant is averaging just above 20 percent solids, and the Westbrook/Gorham Regional WWTP has dramatically reduced costs associated with hauling and landfilling their material. Are they pleased? To quote the locals: “Ayuh.”

 

Diversity in the District

The Portland, Me., Water District (PWD) manages its wastewater treatment through four facilities: East End, the largest plant in the state, which handles wastewater for the Portland metro and surrounding areas; Westbrook/Gorham Regional WWTP, which serves Westbrook, Gorham and a portion of Windham; Cape Elizabeth, which handles wastewater from 3,100 residents in the southern part of the town of Cape Elizabeth; and Peaks Island, which serves 600 island residents — a number that can swell to more than five times that in the summer tourist season. While the Westbrook/Gorham Regional facility is an extended aeration plant, each of the others utilizes a different technology for dealing with their biosolids, according to Steve Picard, the operations foreperson at the plant.

“Within the District, we are certainly varied in our approaches to wastewater treatment,” he said. “East End is a conventional aeration-type plant using clarifiers; Peaks Island is a sequencing batch reactor facility, and Cape Elizabeth is an oxidation ditch plant — they are all similar in many ways but different in others. The Westbrook/Gorham Regional plant was built in 1978. An upgrade to the plant’s aeration system is planned for later in 2020.”

Picard added that three-quarters of the existing plant will be upgraded — a move that will include the addition of new clarifiers mechanisms, a blower facility, and diffused air-type aeration equipment. To show how things have changed, the original plant’s price tag was $14 million; this modification alone is $10 million.

 

Planning Ahead

About two years prior to the plant upgrade, the Portland Water District saw the sludge disposal costs Westbrook was incurring and committed to improving the plant’s dewatering capability. Up until then, the facility, which is rated for 4.54 MGD but treats an average flow of about 3.2 MGD, took sludge from the bottom of the final clarifiers, pumped it to a gravity belt thickener where it was thickened to approximately 4 percent solids, and sent it to a 2.5 meter belt press.

“On a good day, that belt press would give us maybe 17–18 percent solids,” said Picard. “Unfortunately, because we deal strictly with an inflow of secondary sludge here at Westbrook, there weren’t many of those good days. To make matters worse, because we were sending that sludge to a trailer for transport to a landfill about three hours away, we were paying to haul a lot of water that didn’t need to be there. That had to change.”

For Schwing Bioset, finding out about the project was a classic case of being in the right place at the right time. For nearly 30 years, Westbrook has been using a Schwing Bioset KSP 10 piston pump to move sludge from the belt press out to the trailers — a distance of more than 70 feet. Word that they were actively seeking equipment to enhance their dewatering effort got the attention of a technician who happened to be on site.

“When I mentioned that we were about to go out to bid for dewatering equipment, the tech said that Schwing Bioset also made a screw press that could be a good fit,” said Picard. “He went back, told his people, and they were suddenly in the running for the bid along with several other manufacturers. Their timing couldn’t have been better.”

 

Natural Solution

After extensive testing of four manufacturers’ products and a competitive bid process, PWD selected an FSP 1003 screw press from Schwing Bioset.

“Because we already had the piston pump and power pack from Schwing Bioset, we thought that having a screw press from the same manufacturer — a company that we were already very satisfied with — could only work to our advantage,” said Picard. “However, they also outperformed the others we tested and were within our budget, so we felt confident that we’d made a good decision.”

Features that helped make the case for Westbrook included the unit’s low-speed operation — which enhances its lifespan — and automated control. Ease of regular maintenance was also key, including a split screen casing to simplify access for any maintenance activities such as replacing the sealing lip and eventually the screens. Both items can be replaced without having to remove the screw.

“In addition, because the entire operation is now enclosed, all the odor associated with dewatering is contained,” said Picard. “And finally, we liked the fact that the Bioset press could be cleaned while in use, so the dewatering operation would not be impacted by it. All these played a role in our decision.”

 

Getting the Numbers Up

Once the new press was in place (the installation was completed by the same contractor that handled their belt press 28 years ago), Picard and his team were initially stymied trying to find the polymer that would give them the numbers they were anticipating. Using the same product they ran with the belt press resulted in no change: solids in the 17 percent range.

“We suspected that was because, unlike the screw press, the belt press had little to no agitation to it and it held the floc together easily,” he said. “However, by the time we tested our fourth polymer, we started getting solids numbers up in the 19–20 percent range. Connecting the screw press to the polymer injection system we had used with the belt press — then adding two more injection points — got us a bit closer.”

In addition to polymer optimization, there was a period of learning how the new system could be successfully operated at the plant. Doing minor adjustments to the injection system prior to running the screw press for several days without making any changes allowed workers at the plant to verify what worked and what didn’t.

“We were closely tracking our polymer feed rate and the cake coming out of the system and, when we started to break 20 percent solids, knew we were on to something,” Picard said. “We learned that, where the polymer is injected into the system is hugely important. Here, in an area one level down from the press, the polymer goes into a check valve which gives it a good primary mix with the sludge, then comes up and into a huge reaction tank equipped with a variable speed mixer. Using that configuration, the difference was impressive: the 2.5–3 percent feed rate at which we used to feed the belt press didn’t even tax the screw press. Instead, we found out the screw press runs great at 4–4.5 percent, which was a nice plus for us.”

 

Biosolids  Westbrook Wastewater Treatment Plant

 

The Better Choice

With their tweaks in place, Picard and his team at Westbrook saw a continued uptick to the point where they’ve averaged just over 20 percent solids out of the screw press for just over a year now and have seen that number climb as high as 22.5 percent or 24 percent on some days. That has resulted in a net savings — even with added polymer costs factored in — of about $40,000 annually. To the uninitiated, an increase in solids of up to 5.5 percent might not seem substantial. However, that number still represents a 25 percent increase in performance.

And, said Picard, context is key.

“The difference between the two processes is particularly significant when you remember that we are dealing with a straight secondary sludge which is very hard to dewater,” he said. “Even Schwing Bioset rated the screw press at only 19–20 percent under these conditions.

 

Anticipating Change

Today, Westbrook is producing about 30 tons of a better dewatered product every day they dewater during their five-day-a-week operation. By reducing the amount of water in each load, the three-hour trip to the landfill for disposal is far more cost-effective.

“Disposal for us is a costly operation and the Schwing Bioset press has helped significantly knock down those costs,” said Picard. “In addition, there was a good deal of belt spraying, wash water, etc., associated with the previous process, resulting in a constant mist in the air. The place was continually wet where today, things are clean and dry.

He adds that, throughout this conversion process, PWD leadership was outstanding in working with them — giving them support and encouragement all along the way.

“On that note, when we did the screw press install, we kept the belt press here for a year as a backup in case the Bioset didn’t work,” said Picard. “Eventually that belt press was sold for scrap — I guess that says it all.” 

 

Click here to read more about our Products, then contact us to learn more about this project or find out how we can help your plant too.

 

 Download Our Brochures    or Application Reports

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Tags: Biosolids, Screw Press, Dewatering, Wastewater Treatment Plant

Pima County, AZ, Tres Rios WRF Biosolids System Upgrades - Part One: Cake Pumping

 

Written by Josh DiValentino

 

Tres Rios Storage w-caption 2Background: The district of Pima County, AZ, operates a total of eight wastewater treatment plants. The Tres Rios Water Reclamation Facility (WRF) is the centralized biosolids processing facility for all Pima County plants. Tres Rios WRF currently operates 24/7/365 at a 30 MGD capacity, with a projected flow of 50 MGD in 2030. The facility process is; BNR, Anaerobic Digestion, Dewatering, Pumping, Truck Loading, and Land Application of biosolids (cotton is common use). For nearly 20 years, Schwing Bioset, Inc. has provided solids handling solutions at Tres Rios with projects ranging from biosolids cake pumping and cake storage bins, to most recently, nutrient recovery and temporary Screw Press dewatering equipment.

 

Cake Pumping:  Since the early 2000’s to 2012, the Tres Rios WRF had used a piston pump for biosolids cake conveyance to truck loading. In 2012, the facility completed a Regional Optimization Master Plan expansion, which included an upgrade to the centrifuge building and loading building. The upgrade design replaced the existing piston pump with progressive cavity pumps dedicated to each of the three new centrifuges.

After 6 years of struggling with excessive downtime associated with the progressive cavity pumps, the 10+ year-old piston pump was pulled from storage, sent to Schwing Bioset, Inc. to be rebuilt and reconfigured to fit the existing building, and installed to replace one of the progressive cavity pumps.

Since its reinstallation, the plant has used the piston pump as its primary pump, reducing the downtime and maintenance costs associated with the progressive cavity pumps. The facility no longer needs to de-rate the centrifuges and has been able to dewater the biosolids to a higher percent solids content when using the piston pump, significantly reducing hauling costs. The subsequent uptime and increase in dry cake solids production justified the capital cost of buying an additional Piston Pump, as the payback was determined to be 2 years. One progressive cavity pump will remain in service as an emergency backup for pumping thickened sludge, which is usually thickened from 6% to 8% solids.

The second new Piston Pump will come online in 2020. The Schwing Bioset, Inc. Engineering Team also worked with the district to perform a complete pipeline analysis of the existing cake pipeline. This identified the pipeline upgrades required to re-certify the pipeline for higher pumping pressures, resulting from higher cake solids and higher flow via the Piston Pumps to Truck Loading. This pump technology conversion clearly illustrates that while the initial capital expense of a piston pump is higher than a progressive cavity pump, the long-term expenses over the operating life of the equipment, when factoring in hauling expenses, maintenance costs, and operational downtime, heavily favor piston pump technology.

 

Schwing Bioset Piston Pump

 

For more information on this project, read the paper below or contact us.  

 

Additional Info: Biosolids Cake Pumping Life Cycle Analysis - A True Operators Story

Stay Tuned for More on Pima County Projects:

Part Two: Live Bottom Bins

Part Three: Temporary Screw Press Dewatering

Part Four: NuReSys Struvite Management Project

 

 Download Our Brochures    or Application Reports

Read More Schwing Bioset  News and Blog Articles

 

 

Tags: Piston Pumps, Biosolids, Biosolids Piston Pump, Water Reclamation Facility

New Replacement Membrane Bioreactors Benefit Small Community

 

The Manor Water Reclamation Facility owned by Forsythe County located in Milton, GA, consisted of four trains utilizing Zeeweed 500D membrane bioreactors sized for a total of 500,000 gpd of flow. As the system aged, the County decided to replace the old membranes. Half of the existing membranes were replaced with Schwing Bioset’s Econity CF54D membrane bioreactors (MBRs) to process 250,000 gpd of flow. Due to the modular nature of Schwing Bioset’s Econity membranes, an easy, direct “in-kind” replacement of the old membranes was possible.

In the operator’s words regarding the retrofit, “the replacement was a breeze,” simply making pipe flange and hose connections. During replacement activities it was found that the existing membranes were fouled with debris, which revealed another advantage of the Schwing Bioset Econity membrane design.

Schwing Bioset’s Econity membranes are manufactured with an “end free” fiber (potted on bottom only) that eliminates fouling issues associated with membrane designs using top and bottom potting of the membrane fibers.

The Schwing Bioset Econity design is such that the fibers are contained in modular “cartridges” that are assembled into “cassettes” of more than one cartridge within a frame support. Unlike the existing MBR frames, the Schwing Bioset Econity frame is designed as a self-supporting structure. 

This modular design greatly simplifies installation and removal when necessary as the cassettes can be removed by a single operator in a couple hours, unlike the original equipment which required multiple staff members and a full day.

 

New MBR at Manor WRF   New Membrane Bioreactor at Manor Water Reclamation Facility

 

Based on the foregoing comparison, the following conclusions can be drawn about the Schwing Bioset Econity Membranes:

1. The modular design allows customization to fit virtually any basin shape or size.

2. The end free design solves the recurring problems of solids build up at the ends of the membrane fiber. The  membranes are not prone to fiber breakage and deterioration of effluent quality.

3. The construction is easier to maintain.

4. The end-free membrane design allows for more vigorous movement of the fibers requiring up to 40% lower air scour compared to the competitor.

5. The new MBR's have helped the community update its tertiary treatment system that treats sewage to re-use quality.

The advantages of Schwing Bioset Econity membranes are easily recognized by customers. It is for this reason that there well over 2000 installations world-wide.

 

Check out these photos of the old clogged membranes that were replaced!

Old MBR at Manor Water Reclamation Facility  Old Membrane Bioreactor at Manor WRF

 

To learn more about Schwing Bioset’s MBR systems, visit our website here or contact our Regional Manager closest to you.

 

 Download Our Brochures    or Application Reports

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Tags: Wastewater Treatment, Membrane Bioreactor

Big Changes at Pine Creek Wastewater Treatment Facility

 

Written by Larry Trojak, Trojak Communications

Version also published in TPO Magazine, February 2020

 

Alabama facility sets lofty goals for its upgrade; meets or exceeds them all.

When the City of Prattville, Alabama, recently chose to upgrade its Pine Creek wastewater treatment facility, it spared no effort in doing so. While they had made smaller, incremental modifications in the past, this time around they took the plant from simply adequate to boldly forward-thinking, designing it to be viable and effective for at least the next quarter century. Included in the wholesale changes was a rethinking of its solids handling capability which, up to that point, was both basic and costly. Today, the Pine Creek Clean Water Facility uses a new approach to aeration, dewaters through a pair of new screw presses, is generating a Class A biosolids for area land application, and is now accepting sludge from a nearby sister facility. In this case, being up a creek is definitely a good thing.

 

Dealing with Growth

Located 20 minutes northwest of Montgomery, Prattville is a city of 34,000 which has seen some impressive development of late. According to the local Chamber of Commerce, between 2014 and 2018 alone, more than 130 new businesses have opened in Prattville and immediate surrounding areas — a total of $760 million in capital investment. All that growth prompted city officials to look at existing infrastructure demands and determine that upgrades to their wastewater treatment effort were in order.

“This was a wholesale overhaul of the entire treatment process to help deal with the growth in the area,” said Greg
Thompson, project engineer with Engineers of the South. “We are a consulting engineering company and have been working with the City for more than 15 years now. So, we were actively involved in the research and planning leading to the upgrade. The original plant, built in 1979 as part of the Clean Water Act, had a 3 mgd capacity. In addition to options for dealing with the anticipated increases in volume, we talked with city officials about re-thinking the entire biosolids treatment and disposal process.”

 

Alabama Dream Sheet

Though a plant-wide change was in the cards, the evaluation criteria for that change were very ordered and specific. According to Dale Gandy, Prattville’s Director of Public Works, the desire to use state of the art technology headed up the list of desirables. 

“Obviously, we wanted to tap into the strengths of today’s newer technology,” he said. “However, we also wanted to try to utilize ‘green’ infrastructure within the plant; had our sights set on looking into a Class A biosolid; wanted to create an effluent that was cleaner than the environment into which it was headed; wanted the whole effort to be energy efficient; and needed the plant to gain an additional 25-30 years of viability. In addition, because we didn’t have unlimited funds to throw at the project, we had to be relatively cost conscious in our efforts. It was a long list to try to meet but we set out confident that it could get done.”

The new plant design that Thompson and his engineering team — working hand in hand with Gandy and Prattville’s
plant management — envisioned, would take the facility from 3.0 to 5.7 mgd — almost doubling in volume. That
increase in capacity, they felt, would give them the 25-30 year life expectancy they needed.

 

Schwing Bioset Screw Presses  Schwing Bioset - Bioset Process Reactor

 

Outdated Concepts

To get to that point, there was not one area of the Pine Creek facility that would be left untouched by the overhaul. Designed in the late 1970s as a conventional activated sludge facility, the plant utilized a coarse screen in a deep sump, prior to the raw sewage pump station, followed by aerated grit removal.

“Aeration in the original design consisted of three parallel basins with two fixed-mounted, low speed surface aerators per basin,” said Thompson. “Control of the aeration system consisted only of locally-mounted low/high-speed selector switches. Not only was the process energy-inefficient, the inability to aerate sufficiently or deal with varying flow rates and oxygen demands led to plant upsets and periodic effluent violations. The warm summer months, when effluent limits are lowest, made it particularly hard for operators to maintain compliance.”

At that time, once biosolids met Class B requirements, they were hauled off to a local field — with 100% of the liquid
— for land application. The facility averaged 10-15 tanker loads of the wet material per day. “But if it had rained and the field was wet, they couldn’t land-apply, so the plant had to be prepared to store material in the digesters,” added Thompson. “It’s not surprising they knew a change was needed.” Finally, the previous clarifiers utilized a mix of organ pipe and scraper blade solids-removal systems. Disinfection, which originally used gaseous chlorine, was updated to UV in a 1999 plant modification.

 

In With the New

Thompson and his group worked hard, not only to address all the issues with the existing design, but also to ensure
the plant’s viability for decades to come. In aeration, to deal with the high ammonia numbers caused by an inability to nitrify, they opted for a VertiCel solution (Evoqua Water Technologies, Pittsburgh, Pa.).

“VertiCel uses a combination of disk aeration followed by fine bubble diffused air,” said Thompson. “In that way, we
felt we could tap the efficiencies of both types of aeration to meet our need for an energy-efficient design and to get full biological nutrient removal.”

Conversely, changes to the plant’s digestion phase included taking them from using surface mechanical aeration to
diffused aeration. “Prattville always had issues getting enough oxygen transfer with the old system,” said Thompson. “This combination of disc aerators and fine bubble diffusers powered by Howden blowers (PD Blowers, Inc, Gainesville, Ga.) is both energy efficient and has great oxygen transfer.” Also covered in the expansion’s design were an all-new headworks, two new fine screens (Duperon, Saginaw, Mich.), and grit removal which incorporated Eutek HeadCell technology and WEMCO Hydrogritters.

 

Road Trip

With preliminary design considerations in place, representatives from both the City and Engineers of the
South, visited a number of wastewater treatment plants throughout the southeast U.S. to review various approaches
to dealing with biosolids. One of the things driving the city’s decision to create a Class A biosolid product was, again, growth in the area.

“We were seeing new industries coming in regularly and knew that we could soon be running out of industrial fields
like the one on which we’d been applying,” said Sam Russell, Pine Creek’s former plant manager who was brought on as a consultant during the upgrade. “So, we knew solids handling had to change and that dewatering would be a huge part of that discussion."

Evaluations of available dewatering options included visits to a half dozen facilities to view belt presses, screw presses and centrifuges, and conversations with operators about their experiences with each. With that growing volume of information at hand, the group started seeing the screw press as the best fit for Prattville, and a visit to a plant in Immokalee, Fla. confirmed that for them.

“Immokalee was an eye-opener for us,” said Thompson. “That installation utilizes a Schwing Bioset screw press
(Schwing Bioset, Somerset, Wisc.) for dewatering and creates a Class A product using the Bioset solution. We saw
so many similarities between what Immokalee had dealt with and our own situation at Prattville that we all felt we’d found our answer. ”

 

Pressing Issue

Coming online in August 2019, the biosolids treatment at Pine Creek now begins by taking material from WAS storage basins — where sludge is held, mixed and aerated — and fed to a pair of new Model FSP-1002 screw presses for dewatering. Each of Pine Creek’s screw presses is rated for 1,122 lbs. of dry solids per hour, with a minimum cake dryness of 17% and a 95% minimum system solids capture. With “tweaks” still being made to the process as operations stabilize, the facility is currently getting cake discharged up to 18%. While the performance stats proved key in making their decision, Prattville was also drawn by the self-cleaning function the Schwing Bioset screw press offered, where the units continue to dewater whenever a cleaning cycle is performed. This continuous operation ensures no equalization storage is necessary between dewatering and the Class A operations.

“We have each unit scheduled to clean itself every hour, but that function is flexible and easily changed,” said Napoleon Wilks, Pine Creek’s current plant manager. “We also like the fact that these presses are almost self-operating,” he said. “We have them programmed to run for only seven hours a day, five days a week, which allows us to keep staffing costs down.”

 

A Stabilizing Presence

In addition to being a sound decision for the City, the fact that both Sam Russell and Dale Gandy own and operate
farms helped solidify Prattville’s decision to go with a Class A product. Their understanding of the benefits a soil
amendment product can bring, the ways it can be used and how positive it could be to the community, led to that
decision.

“We like what can be done with a good Class A product — whether it’s a resident needing it for flower beds, for grass in front of City Hall, or a farmer using it on crops. And, after seeing the success Immokalee was having, it made sense to go with the Bioset solution,” said Russell. “We also felt that there was a real up-side in accountability
to sourcing both the dewatering and the Class A process from the same company.”

The Bioset process uses a screw conveyor to take Pine Creek’s untreated biosolids from the screw presses to
a twin-screw mixer where quicklime and sulfamic acid are added and mixed. From the mixer, a Schwing Bioset
KSP-25VKL pumps material through a 22 ft. long reactor. There, the chemical reactions raise the temperature and
the pH level, stabilizing the mixture and creating a product that meets EPA Class A requirements.

According to Wilks, they are maintaining a minimum temperature of 131°F (55°C) in the reactor with a retention time of 40 minutes in accordance with the operating conditions approved by the Unites States Environmental Protection  Agency (USEPA) through the Process to Further Reduce Pathogens (PFRP) in the 503 regulations. “The way we process our biosolids today — pushing a lower quantity through there than our future design conditions — material is actually in the reactor far longer than that,” he said. “The results have been a consistently good Class A biosolid that we take to a field owned by the department, dump it, spread it a bit, and turn it for a few days until it dries to a point that we are able to pass it along to a local farmer — and right now he will take all that we can provide.”

 

Schwing Bioset Municipal Piston Pump  Schwing Bioset Truck Loading

 

No Mistake About It

In the past, a continual stream of trucks, each carrying roughly 6,800 gallons of liquid headed to the field to
land-apply as much as 81,600 gallons of liquid waste per day. Today’s disposal effort involves just two tri-axle
trucks loaded ¾ full per week. And that energy efficiency criteria? It’s been met to a degree they never imagined,
according to Gandy.

“This is amazing to even comprehend but, despite almost doubling the size of the plant in terms of capacity, when we ran the numbers we found that our energy consumption had only increased by 8%,” he said. “Thinking I must have missed something I checked the data several times and even had a representative from Alabama Power verify
it for me. There was no mistake — that’s how energy efficient this plant is.”

The new biosolids effort is working so well that Pine Creek CWF has already begun processing material from
its sister plant, the 4 mgd Autauga Creek CWF. To do that, the City hauls approximately 200,000 gallons of wet
sludge (at 1.75% concentration ) per month from Autauga Creek to Pine Creek for processing.

Said Gandy: “We set out with a pretty challenging to-do list. But tapping the innovative technology available to us,
we feel we accomplished it all — and then some.”

Click here to read more about our Products, then contact us to learn more about this project or find out how we can help your plant too.

 

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Tags: Class 'A' Biosolids, Bioset Process, Wastewater Treatment, Municipal Pumps, Screw Press

Capital Idea for Biosolids Processing at Springfield Wastewater Treatment Plant

 

Written by Larry Trojak, Trojak Communications

Version also published in WE&T Magazine, December 2019

 

Springfield, Ill., wastewater treatment plant supplements its sludge disposal effort with a pair of screw presses and alkaline stabilization.

Effective wastewater treatment is predicated on equal parts science and planning. The science element of that premise includes keeping abreast of the latest technology to best manage both the treatment and disposal of biosolids. For the Sangamon County (Illinois) Water Reclamation District, that has meant rethinking its approach to biosolids, particularly in the area of dewatering prior to land application. Once solely dependent upon liquid applying its Class B byproduct, the District’s Sugar Creek Wastewater Treatment Facility recently upgraded its process to include a pair of fully-automated screw presses and a Class B alkaline stabilization system from Schwing Bioset, Inc. (Somerset, Wis.). Today, with a viable option to that liquid process in place, the plant is generating more than 17,000 lbs. of Class B cake monthly, and has peace of mind that its biosolids effort is poised for future growth.

 

Schwing Bioset Screw Presses   Schwing Bioset Screw Presses

 

A Pair of Plants

In addition to being the state capital, the city of Springfield (and immediate surrounding areas) hosts scores of facilities related to a booming agribusiness industry. These include one of the nation's largest stockyards and feeder cattle facilities, as well as various creameries, meatpacking plants, flour mills, etc. To meet the demands these and other industries place on the area’s wastewater system, a pair of treatment plants were built: Spring Creek in 1928 and, to accommodate area growth, a sister plant, Sugar Creek, in 1972.

“Since that time, both plants have been retrofitted to better handle increased volumes,” said Steve Sanderfield, Sugar Creek’s plant supervisor. “Spring Creek is by far the larger of the two with an average flow of 32 mgd and a peak of 80 mgd. Here, we average 15 mgd and top out at 37.5 mgd, so our max is really only 5 million gallons more than their average. Spring Creek has been updated every couple of decades, but this plant had remained fairly constant until a 2017 upgrade which resulted in a 50% increase in both the average and peak flows. That upgrade also paved the way for the current change to the dewatering effort.”

The most recent changes were improvements for flow control and diversion to wet weather treatment facilities that included mechanically cleaned perforated plate fine screens, grit removal tanks, and activated sludge tanks designed to meet both current and future effluent phosphorus limits.

 

A Better Alternative

In addition to the changes mentioned above, the biosolids area also underwent a significant upgrade, including those areas for thickening, stabilization, dewatering, and storage. Until those changes were made, Sanderfield said they had only one option for disposing of the sludge created in their treatment process.

“Since the mid 1990s, to meet 40CFR Part 503 requirements for Class B Biosolids, we post-stabilized liquid sludge (1.5% TS) by adding standard hydrated lime in a slurry,” he said. “Batches of the biosolids/lime mix were held in batch mixing tanks for 24 hours, after which (if they met 503 pH requirements) they were land-applied on a 30-acre farm owned by the District. If the batch pH dropped overnight below the acceptable standard, it would have to be “re-limed” and given another 24 hours to achieve the requirements within the standards. The stabilized liquid sludge was then pumped and spray-applied through a series of fixed irrigation nozzles installed throughout the farm. Because it is a liquid-sprayed application, large sludge storage tanks are required for times when field limitations (wet seasons, frozen ground, etc.) prevent application.”

While it was less expensive to apply the stabilized sludge in liquid form, those shortcomings prompted a re-thinking. Taking a page from their sister plant’s playbook, they began looking into options for dewatering prior to land application.

“Spring Creek was already dewatering with screw presses and sending the dewatered product to a pad for drying and eventual land application,” said Sanderfield.” However, because our process differs from theirs — aerobic versus anaerobic — and we saw some shortcomings in the presses they use, we decided to look at what else was out there. Vendors were invited to show us their products and, after an impressive two-week pilot test and subsequent bid process, we chose a pair of FSP 1102 screw presses from Schwing Bioset.”

 

Schwing Bioset Municipal Pump   Schwing Bioset Storage Silo

 

Two Are Better Than One

The model of presses in place at Sugar Creek represent one of the largest designs Schwing Bioset offers. Low speed by design, they offer dewatering results comparable to high speed centrifuges and — by nature of that slow speed and robust construction — provide a much longer lifetime of service. Sanderfield was particularly interested in one feature of the screw press: a split-screen cage that both simplifies screw removal and minimizes footprint requirements. The split cage allows the sealing lip and screen to be replaced with the screw in place — much simpler than removing the screw from one end of the machine.

“Once we knew the press would give us the product we needed, we tended to focus on the upkeep side of things,”
he said. “For example: how easy would the units be to repair if one of them went down? How self-cleaning is it? What kind of wear items does it contain? That last point was important to us. The presses at Spring Creek utilize brushes that wear down and, once they do, we have to pull the entire screw out to change them. That’s a huge undertaking we wanted to avoid over here.”

Immediately after the pilot test, Sanderfield was impressed with the self-cleaning process for the Schwing Bioset
presses. Unlike the units at Spring Creek which simply spray as the disc rotates and must be done when the unit is
not de-watering, these utilize a low-volume, high-pressure spray ring that tracks down the length of the screw — during operation.

“This approach is so much better than others we’ve seen,” he said. “Our dewatering operation does not need to be
interrupted for cleaning, and the cleaning cycle is typically only three to five minutes long, once per day. We’ve also
found that after a thorough cleaning the presses can sit for a while and, when they are needed, will be in operation
immediately — nothing hardens up in the lines. Because we don’t run the presses continuously here at Sugar Creek, that was important to us.”

 

Strength in Numbers

Although Sugar Creek never intended to run both presses at once, they nevertheless opted to go with two units rather than just one, based on equal parts the desire for redundancy and an eye toward future growth.

“For us, the purchase of the second press was definitely driven by the need for a backup,” said Sanderfield. “We
are in a situation here where a press failure or, more likely, one of the pumps we have feeding each press, would be
catastrophic to the process. That’s no longer a concern for us. In addition, as this area continues to grow, we are better poised to meet that growth without the need for any major overhaul.”

At Sugar Creek, sludge enters the press at roughly 1.3% solids, mixes with a polymer, and exits at 25 to 30%
dry solids. While they are extremely pleased with those numbers, Sanderfield is quick to point out that, as with any
press system, they have to take additional steps to deal with the filtrate. “The filtrate tends to be high in ammonia
and phosphorus, so it’s considered a side stream,” he said. “When we bring that back to the plant we have to be certain to do so slowly. So when the presses run, the filtrate that is getting squeezed out is pumped back at a slow rate and is controlled by the tank level. So, if we program it to start pumping when it’s at five feet and stop when it is at three feet, that’s what it will do.”

 

Push of a Button

Sanderfield’s allusion to equipment autonomy is telling. Automation of the presses was also a huge consideration
for Sugar Creek when making their purchase decision, and Sanderfield said they are very pleased with the level
of self-operation the 1102’s can maintain. 

“We start and stop it, monitor it, and run tests on the solids as it comes out,” he said. “But, for the most part, we are
able to hit ‘start’ and the sludge pump will control the feed rate that we set, the presses will do their thing, the
polymer will activate — it essentially runs itself and fits perfectly with the rest of the process which is also heavily
self-operating.”

From the screw press the biosolids still needed to be treated per the EPA 503 to Class B levels. The project
had already started down the path to utilize another technology, but after piloting the Schwing Bioset alkaline
stabilization technology with the screw press, the project switched gears. The biosolids are now routed from the
screw presses to the Class B lime system (also supplied by Schwing Bioset) where quicklime is introduced to
stabilize the dewatered biosolids by elevating the pH. 

“As with the liquid application, according to EPA 503 we cannot field apply the material until we’ve met the 24-hour
pH criteria,” said Sanderfield. “Doing so eliminates the risk of rodents, birds, animals, etc., coming in contact with
the sludge and possibly transferring diseases to other animals or people. Once we’ve stabilized it in the lime
system that’s no longer an issue.”

And, with an eye toward the future, Sugar Creek’s Class B lime system is also designed to facilitate expansion into a Class A Bioset alkaline stabilization process, should they choose. After treatment in the lime system, sludge — now with the consistency of a slightly wet modeling clay — is conveyed to a drying pad where it gets regularly turned using a skid-steer loader with a Brown Bear windrow turning attachment; once fully dried, it is ready for land
application.

 

Just Gets Better

If things seem to be going great for the team at Sugar Creek, it’s because they are. They just wrapped up a
well-attended open house for area residents and local officials, they are meeting all the necessary biological and
phosphorus thresholds without the use of chemicals, and they were just recently nominated for Plant of the Year in
Illinois.

“That last fact — a nomination for Plant of the Year — is mind-blowing, given that we’ve only been online for over a
year,” said Sanderfield. “Things were crazy here for quite a while, but we are now settling in to a nice routine and the Schwing Bioset presses and alkaline system have helped provide a lot of that peace of mind. We will still do both solid and liquid land applications of the sludge — that’s always been the plan. But, since we can press in five days what would probably take us three weeks to do otherwise, the process is far more efficient than it’s ever been.”

 

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Tags: Alkaline Stabilization, Wastewater Treatment Plant, screw presses

Schwing Bioset Exhibiting at Water & Wastewater, Mining, and Industrial Trade Shows in 2020

 

Schwing Bioset, Inc. is excited to be attending and exhibiting at several conventions and expos throughout 2020. If you'd like to meet with one of our team members at a show, please email us and we'll put you in touch with the appropriate person.

Below is a list of water, wastewater, mining, and industrial events that we are scheduled to attend for the coming year, and we will keep this information updated as we add shows throughout the year. 

Products that you can learn about at the trade shows include, among others, sludge, industrial, and tunnel piston pumps, dewatering screw presses, membrane bioreactors, Bioset process equipment for Class A biosolids, phosphorus removal and struvite recovery, sliding frame and push floor silos, fluid bed drying products, container wagons, and soil conditioners. We can also help you with equipment demos, mobile equipment, spare parts, equipment maintenance services, and customer pump and screw press training. 

For more than 30 years, Schwing Bioset, Inc. has been helping water and wastewater treatment plants, mines, and industrial customers by engineering solids handling solutions. Schwing Bioset’s custom-engineered solutions can be found in hundreds of wastewater treatments plants in North America, as well as mines and tunnels around the world.

Read about our company, our products, our aftermarket team, and more, and then stop by one of our booths to learn more! 

Trade Show Date Place
Arizona Water Biosolids Workshop 2020 Feb. 4 Pima County Water Campus, Tucson, AZ
Michigan Joint Expo 2020 Feb. 4-5 Lansing Center, Lansing, MI
Pacific Water Conference 2020 Feb. 4-6 Hawaii Convention Center, Honolulu, HI
SME MineXchange 2020 Feb. 23-26 Phoenix Convention Center, Phoenix, AZ
MRWA Technical Conference 2020 March 3-5 River's Edge Convention Center, St. Cloud, MN
Salon TEQ 2020 March 10-11 Quebec City Convention Center, Quebec City, QC
Texas Water 2020 July 13-16 Virtual Event
Arizona Water Annual Conference 2020 July 21-23 Virtual Event
PNCWA 2020 Sept. 13-16 Virtual Event
WaterJam Virginia 2020 Sept. 14-17 Virtual Event
WEFTEC Connect 2020 October 5-9 Virtual Exhibitor
CWEA (NWEA) Annual Conference 2020 October 19-22 Virtual Event
Paste 2020 November 2-6 Virtual Event


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Tags: Announcements, Events, WEFTEC, Expos

Schwing Bioset Trailer Mounted FSP 1103 Screw Presses Now Available for Contract Operations

 

Written by Kelly Kramer

 

Schwing Bioset is pleased to announce that we can now help solve your dewatering challenges with our fully automated trailer mounted FSP 1103 screw press dewatering systems. Available for onsite demonstrations and/or contract operations, the 1103 screw press is one of our largest models and is engineered for durability, reliability, ease of operation, and low power consumption, making the units an efficient method to dewater.

As with all of our screw presses, our mobile units are designed for quick set up, ease of use, and high-performance for dewatering all types of wastewater. 

One of the screw press features our customers are most excited about is the self-cleaning wash cycles. With low wash water requirements and automation, dewatering operations do not need to be suspended during cleaning and a cleaning cycle typically lasts less than five minutes.

Once dewatered, the solids can be treated, loaded, hauled away, and/or beneficially reused, depending upon the method of the end user.

For more information on our mobile screw press units, please contact our Regional Manager nearest to your plant. The screw press and Schwing Bioset’s full product offering can be viewed here.

 

Schwing Bioset Mobile Screw Press   Schwing Bioset Mobile Screw Press

 

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Tags: Wastewater Treatment, Screw Press, Dewatering, Mobile Screw Press