News from Schwing Bioset

Water Reclamation Facility Steps Up its Approach to Biosolids

 

Written by Larry Trojak, June 2018

 

Central Florida is One “Class A” Place

Much like the State of Florida itself, the Water Conserv II facility, located in Orlando, is all about change. Almost since its inception in 1961, Water Reclamation Facility  (WRF) has been undergoing periodic upgrades, process changes and, at times, major overhauls to keep pace. So it should come as no surprise that, when confronted with the need to replace major anaerobic digestion components that were impacting capacity, all options were on the table. And when the Florida Department of Environmental Protection (FDEP) indicated that newer, tougher regulations would be impacting continued production of their Class B biosolids product, a range of alternatives was examined. The end result of those efforts is a new Class A Exceptional Quality (EQ) product created through use of the Bioset Process from Schwing Bioset, Inc. (SBI, Somerset, Wisc.) which effectively creates 120,000 lbs. of field-ready fertilizer product per day.  

Silo_Small

 

Use Then Reuse

Originally constructed in 1961 as the 4 mgd McLeod Road Treatment Plant, the Orlando facility was upgraded to 12 mgd in 1972 to deal with the area’s rapidly growing population and then further expanded to 25 mgd. Then, in the early 1980s, a number of factors, including the realization that the plant’s discharge was adversely affecting the health of nearby waterways, prompted the City of Orlando and Orange County to team up and create what is today called the Water Conserv II Distribution Center (DC) in west Orange County, about 20 miles from the Water Conserv II WRF. The DC reuses about 35 mgd of treated wastewater (reclaimed water) in west Orange County for agricultural, residential and commercial uses, as well as rapid infiltration basins (RIBs) to help with aquifer recharge. According to Paul Deuel, assistant division manager for the City of Orlando Water Reclamation Division, the scope of what was planned for the newly revised treatment plant was impressive.

“Much of this was driven by the growth we were seeing in the early 1980s and the projected impact on the aquifer that serves this area,” he said. “In addition, the EPA was mandating that discharge issues at nearby Shingle Creek be resolved. So, the Water Conserv II DC, which combined newly improved processes with the use of reclaimed water for area irrigation, was born. That last point is huge: up until then, very little agriculture involved the use of reclaimed water. The Water Conserv II DC went that route and for a long time was the largest citrus irrigation project in the world to do so.”

The move to make the resource available resulted in a contract which provided early participants access to free reclaimed water for a period of 20 years. For some, according to Deuel, the benefits proved invaluable.

“In the case of the citrus growers, this agreement provided a guaranteed water source, even in times of shortages or drought,” he said. “In addition, it could be used for frost and freeze protection when the lives of the trees themselves were at risk. Once we became established, additional users joined in over the years, including several area golf courses, Valencia Community College, Universal Studios’ theme park (which uses it both for site irrigation and in their cooling towers), the Mall at Millennia, even apartment complexes and single-family homes. It has really proven itself an invaluable resource.”

 

Time Takes a Toll

As mentioned, Conserv II WRF has been undergoing change of one sort or another since its inception. When major components in the anaerobic digestion area began to show signs of wear — and failing on an increasingly regular basis — the facility team started running the numbers to weigh the cost of shoring up the Class B biosolids operation or going in a new direction entirely.

“We started looking at the costs needed to rehab the anaerobic digesters to achieve [Class B] biosolids,” said Steve Shelnutt, Water Conserv II WRF plant manager. “At about the same time, FDEP advised us that new regulations, specific to the generation of a Class B product, were being implemented. It was obvious that continuing to do Class B was going to be more challenging and more costly. So, we began looking at alternatives available to us.”

Shelnutt said they contracted with engineering firm Black & Veatch and considered a combined heat and power process that still relied on anaerobic digestion but, because it went into the thermophilic range, it would give them the Class A EQ product they desired  “However, it also added a nutrient load back to the plant,” he said. “So, they sought to remedy that by recycling the gas it created, treating the side streams, and so on. Unfortunately, the project costs started growing into the $40-60 million capital range — far beyond what we had envisioned.”

 

Let the Games Begin

As is so often the case in any industry, word that Water Conserv II WRF was seeking alternative processing methods traveled quickly. One of the first to call upon them, according to City project manager Kristi Fries P.E., was Brian Schuette, vice president of Moss Kelly, Inc., SBI’s Florida sales representative.

“Brian came in and, based on equal parts: what the Bioset Process could do for us and its estimated costs, quickly got our attention,” said Fries. “He told us that he could take us into a Class A EQ fertilizer-grade product for about $1.8 million. Compared with the other proposal which seemed to be growing more expensive by the day, this seemed almost too good to be true. At the same time, we were hearing from other manufacturers who pitched their processes, each of which had some good points, but ultimately didn’t give us what we really needed.”

The alternatives examined included upgrading the anaerobic digesters, a process that employed a high-pressure steam pre-treatment, another which used a technique to accelerate the composting process, and others.

“We did an evaluation of capital costs for each, measured it against the proposed end-product, and decided that we would move forward with the Bioset Process,” said Shelnutt. We also took a ‘field trip’ to two different Florida locations where the process was already in operation and liked what we saw. In fact, our chief operator and I spent a good deal of time talking to the staff discussing the process and hearing how they felt about it. That really helped us make our decision.”

Bioset_Edited_Small

 

Feeling the Heat

The Bioset Process which Water Conserv II WRF has embraced takes biosolids that have been dewatered to about 15% dry solids and, using Schwing KSP-25 piston pump, routes it to a twin-screw mixer in which quicklime and sulfamic acid are added and blended. This type of mixing ensures a homogeneous product and alleviates issues such as unreacted lime in the final product — and the associated costs associated with it.

“At that point, the Schwing KSP-25 piston pump feeds material into the reactor in which heat from the acid and quicklime raises the pH level, thereby stabilizing the biosolids mixture and creating a product that meets EPA 503.33 requirements,” said Shelnutt.

Because the ammonia that is generated through addition of the lime is entrained with the biosolids inside the reactor, thereby killing the pathogens, the Bioset approach has been approved as a process to further reduce pathogens (PFRP). This approval allows the Bioset process to operate at 55°C (131°F) with a residence time of 40 minutes (versus 70°C (158°F) for 30 minutes) lowering operating costs by approximately 35%.

The stabilized Class A EQ product exits the reactor and is pumped directly to a pair of waiting trailers. Even though it is discharged from the process above 25% dry solids, the new product has very little surface tension until it cools, improving its flow characteristics and making it self-leveling in the trucks. According to Deuel, having SBI involved took care of an important step in the upgraded biosolids process: finding a customer for the end-product.

“We are fortunate in that Schwing Bioset has arrangements worked out with customers here in Florida who are anxious to take the Class A EQ material,” he said. “In this case, it is an organization called the Deseret Ranch which runs a cattle operation on about 295,000 acres (450 square miles) in Central Florida. And while they are happy to take the product in its raw form, Bioset will also accommodate customers who demand a pellet or finer product. Not having to deal with [the disposition of] the biosolids has been a nice bonus for us.”

 

Weathering the Storm

Schwing Bioset’s sister company, Biosolids Distribution Services (BDS) provided the first six months of hauling and marketing of the Class A EQ material .  Utilizing more than 15 years’ experience, BDS was able to add the production from the Water Conserv II WRF to their current operation. 

The benefit of having BDS haul Water Conserv II WRF’s Class A EQ product was felt soon after the equipment was installed, as Hurricane Irma struck in September of 2017. Due to the high-water table levels after the hurricane’s passage, virtually all sites available for Class B land application couldn’t be utilized and it wasn’t until three months later, when groundwater levels dropped, that those fields could be accessed again. The plant would likely have incurred substantial additional disposal costs taking Class B material to either landfills or longer-distance application sites that could still receive Class B biosolids. BDS and the city only missed one day of scheduled hauling — the actual day the hurricane struck. Otherwise it was business as usual leading up to and immediately after the storm.

 

The Need for Feed

Making the switch from a Class B biosolids product to a Class A EQ was not without its challenges. For example, at 371 cu. ft., the reactor installed at the Orlando site is quite large, yet the footprint in which the major components had to be installed was extremely tight. In addition, one of Water Conserv II WRF’s primary stipulations said that that their new process needed to be fully automatic.

David Bass P.E., Water Reclamation Division manager added. “We needed to automate everything. So the programming needed to achieve that was intricate and demanding. But Schwing Bioset, working with our own programmers, was able to make it happen.”

A good example of that automation at work can be found in the system’s lime feed process. At Water Conserv II WRF, should the temperature in the reactor drop, the lime feed will automatically increase; conversely, if the process is found to be running too hot, the lime feed will decrease. The program also monitors the output of the transfer pump and — whether they are running one or two dewatering presses — if the pump starts adding more sludge to the outside hopper it will also speed up the lime.

“This has taken our biosolids process to a whole new level,” says Shelnutt. ”We’ve gone from a situation in which the staff felt they needed to monitor things constantly, to one in which they are totally comfortable letting it operate as designed. Everything is now controlled by the HMI (human machine interface) on the control panel and, despite a few hiccups at the outset, it has proven an outstanding solution for us.”

 

All About the Change

In its previous Class B biosolids scenario, four belt filter presses discharged the dewatered biosolids onto two belts that led to an incline conveyor, then to a traveling conveyor which deposited it into trucks below. True to Water Conserv II WRF’s spirit of continual improvement, those two belts are in the process of being converted to screw conveyors and rather than converging in the center, will go in opposite directions and dump into a pair of Schwing KSP-25 transfer pumps.

“Those pumps take the biosolids to the Bioset unit outside,” said Shelnutt. “While it would have been great to have the entire biosolids process under one roof, size constraints made that impossible. This plant is on an area that measures less than 40-acres — relatively small for a plant of this size — and any open space we have remaining has already been slated for other use such as new clarifiers, additional aeration, etc.  However, this does allow us to keep the Bioset process close to the trailer loading area, which was also important for us.”

Shelnutt added that the system design features a pair of Schwing Bioset bulk storage silos for redundancy in the lime storage area. They will also be keeping the traveling and incline conveyors as a backup, should there be anything that results in a service interruption to the Bioset system. In that case, they can simply send material through the belt presses and haul it to another facility for processing. “It’s an option, albeit an expensive one, but it is better than being completely out of business,” he added.

The biosolids process now in place at Water Conserv II WRF is capable of processing 20 dry tons/day and Deuel said that under normal conditions they would do about half that. “Right now, however, we are pulling material that has been stored from the shutdown of the anaerobic digesters,” he said. So we are doing between three and six trailers a day, depending on hauling and plant variables.”

 

Solid Relationship

According to Shelnutt, the relationship between the Water Conserv II WRF team and Schwing Bioset has been a good one, based equally on the product’s proven performance and the company’s quick, consistent response to their needs.

“It seems like such basic business sense, but while far too many companies don’t seem to get it, Schwing Bioset does,” he said. “By way of an example: we had a problem with an acid hopper, determined that we caused the problem, and went back to the manufacturer to order a new one. They wanted more details and were dragging their feet on the replacement. SBI found out about it and interacted with that manufacturer directly to make things right. We felt that was over and above what is expected of an equipment supplier — but it’s solidified our relationship.”

Obviously, given the savings cited and the market for the product, Water Conserv II WRF’s decision to go with the Bioset process was largely based on economic concerns. However, according to David Bass, they were also committed to the idea of having a usable, in-demand product leaving their facility.

“It seems like so many biosolids management facilities are coming and going; people are losing their permits, others are opting to leave the industry, and so on,” he said. “And to a certain extent, I can see that. If we were still generating a Class B product, the increasingly stricter regulations that the FDEP and EPA are now promulgating require a much larger application setback than previous regulations. We wanted to eliminate issues like that, create a viable product, and feel good about our operation. The Bioset Process was definitely the right solution for us at this facility.”

 

To learn more about this project or how we can help your plant, contact a regional manager or email us.

  

 Download Our Brochures    or Application Reports

Read More Schwing Bioset  News and Blog Articles

 

Tags: Wastewater Treatment Plant, Bioset Process, Class AA/EQ Biosolids, Pumps, Biosolids Storage

Schwing Bioset is Exhibiting at WEFTEC 2017

 

Schwing Bioset, Inc. (SBI) is looking forward to exhibiting at the 2017 WEFTEC Event in Chicago on October 2-4. 

Please be sure to stop by our booth (#2007) while you're on the exhibit floor. We will be displaying a dewatering screw press, as well as two new pieces of equipment.

Our new Membrane Bioreactor (MBR) filtration systems for water and wastewater utilize hollow fiber membranes. The unique end-free cartridge design provides an economical alternative to traditional longer fibers.

We are also debuting our new SBI Solutions system. This pre-packaged system is configurable to produce either Class A or B Biosolids in a convenient, pre-engineered skid mounted unit. The system is a compact, modular unit including a piston pump combined with the Bioset process, and optional screw press dewatering capabilities for an all-in-one package.    

MBR.png  SBI Solutions.png

 

 

 

 

 

 

 

The SBI team members attending the show include Executives, Regional Sales Managers, Aftermarket Support personnel, and more. If you'd like to meet with one of our team members, please email us and we'll put you in touch with the appropriate person.

Read about our Nutrient Removal and Struvite Harvesting, Dewatering Equipment, Piston Pumps, Bioset Process and Class A Biosolids, our new products, and other products hereand then stop by booth 2007 to learn more!

Visit the conference website to view the event details and exhibition map: http://www.weftec.org. Here is the Schwing Bioset listing for the show.

We hope to see you at WEFTEC 2017!


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.

Our 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. We also offer on-site demos, spare parts and equipment maintenance services, and training. 

 

Read More Schwing Bioset  News and Blog Articles

 Download Our Brochures    or Application Reports

 

 

Tags: WEFTEC, Events, Membrane Bioreactor, Piston Pumps, Bioset Process, Screw Press

Schwing Bioset Onsite Demonstrations Help Find Solutions

 

Written by Dan Anderson

The past year has been full of onsite demonstrations and we are looking forward to another busy year for our demo fleet.

In 2016, we completed several successful onsite demos for solids pumping, the Bioset process for Class A Biosolids, nutrient removal/struvite recovery, and screw press dewatering.

Our demo program is a great way to see first-hand how our equipment can help your plant. Demos can run anywhere from a few days to a few months, depending on the needs of the plant.

Whether it is pumping material with ease, producing a beneficial re-use product, dewatering sludge efficiently, or removing unwanted nutrients to help your plant and the environment, Schwing Bioset has a vast array of knowledge, tools, and equipment to help your plant find the right solution.

For more information on our demos, please contact Chuck Wanstrom at cwanstrom@schwingbioset.com or 715.247.3433.

Schwing Bioset Class A Biosolids Demo Unit  Schwing Bioset Screw Press Demo Unit

 

 

Tags: Screw Press, Bioset Process, Bioset Demo, Screw Press Demo, Biosolids Handling

City of Orlando WWTP Utilizes Schwing Bioset Piston Pumps in Class AA Process

 

City of Orlando, FL, Conserv II WWTP Utilizes Schwing Bioset KSP 25 Piston Pumps in Class AA Biosolids Process

Written by Tom Welch, December 14, 2016

The City of Orlando, FL, Conserv II WWTP became aware of the Schwing Bioset process and immediately saw the potential it had to meet all of their requirements for both short and long-term implementation.  In addition, Schwing Bioset could offer conversion of the stabilized Biosolids to a licensed commercial fertilizer product.  The City staff visited current Bioset operations in Florida and were impressed with what they saw and with the simplicity of the process.  The City conducted an in-house feasibility study that considered Bioset and other technologies and concluded that Bioset was the preferred treatment process.

The current dewatering facility has four belt filter presses that discharge onto two belt conveyors that converge onto one common belt conveyor that takes the dewatered Biosolids to truck loading.  The decision was made to move away from the common belt conveyor to make the process more robust.  A KSP 25 piston pump was added at the end of each belt conveyor.  The two pumps are utilized to transfer the dewatered cake to the Bioset (Class A alkaline process).  The Bioset process also utilizes a third KSP 25 pump as the heart and soul of the system to blend the chemicals needed for the Class A process and pumps the end product into a plug flow reactor and ultimately out to two truck loading areas.  These pumps are programmed to work together to make sure that a consistent flow of Biosolids can be treated to Class A status through the reactor.

To learn more about our pumps and Bioset process, or this project specifically, contact this blog’s author, Tom Welch, and/or visit our Products page. For other inquiries, call 715.247.3433, visit our website, or find us on social media.

Schwing Bioset Piston Pump

 

Read More Schwing Bioset  News and Blog Articles

 Download Our Brochures    or Application Reports

 

 

Tags: Piston Pumps, Wastewater Treatment, Bioset Process, Class 'AA' Biosolids

Orlando Selects Schwing Bioset over Anaerobic Digestion for Class AA Biosolids

 

Authored by Tom Welch, Southeast Sales Manager for Schwing Bioset, Inc., and Vic Godlewski Jr., PE, Wastewater Division Manager, City of Orlando

May10, 2016

The City of Orlando has been working for several years to move away from Class B land application of Biosolids.  The City explored use of an experimental technology that would almost fully oxidize Biosolids leaving very little residuals for disposal.  While investigating this experimental technology, the City delayed renovations to the anaerobic digestion systems at their Conserv II Water Reclamation Facility (WRF).  Ultimately it was determined that the oxidation technology was not yet commercially viable, at which point they could no longer postpone biosolids treatment improvements.  Orlando engaged the services of a Consulting Engineer to evaluate the digesters and prepare project cost estimates from simple renovation to Class A TPAD with sidestream treatment and combined heat and power.  The estimated project costs were over $40 million and climbing.  Since Orlando believes that the market is going to deliver better options than anaerobic digestion in the future, they began to look for interim options that could be implemented relatively quickly at low capital cost investment; improve their Biosolids treatment, potentially eliminate the need for land application, and not substantially increase O&M costs.  That was a tall order!

The City became aware of the Schwing Bioset process and immediately saw the potential it had to meet all of their requirements for both short and long-term implementation.  In addition, Schwing Bioset could offer conversion of the stabilized Biosolids to a licensed commercial fertilizer product.  The City staff visited current Bioset operations in St. Petersburg as well as other locations in Florida and were impressed with what they saw and with the simplicity of the process.  The City conducted an in-house feasibility study that considered Bioset and other technologies and concluded that Bioset was the preferred treatment process.

Schwing Bioset offered a Design Build approach that was very appealing.  However, due to the City’s procurement constraints this path was not available. To speed up project delivery the Bioset process equipment was purchased directly by the City and installation was competitively bid.

Orlando_Conserv_II_image_3.jpg

Orlando_Conserv_II_image_2.jpg

As shown in the photos above, the Bioset equipment is currently being installed at the Conserv II facility and is scheduled for startup in the summer of 2016.  Schwing Bioset has a sister company, Biosolids Distribution Services (BDS), that manages Class AA Fertilizer Grade Biosolids in the state of Florida.  They have marketed in excess of one-million wet tons of Class AA fertilizer in the state of Florida over the last 10 years.  BDS will be managing the Biosolids produced at the Orlando Conserv II facility when the Bioset process becomes operational.

To learn more about our Bioset process or this project specifically, contact this blog’s author, Tom Welch, and/or visit our website here: SBI Bioset Process. For other inquiries, call 715.247.3433, visit our website, or find us on social media.

 

Download Our  Bioset Process Brochure

 

Tags: Bioset Process, Class 'AA' Biosolids, Wastewater Treatment, Biosolids Distribution Services, Commercial Fertilizer

Bioset Demo Confirms Direction for New Class A Biosolids Equipment at Russellville WWTP

 

Written by Lance Bartlett, Utility Engineering Manager for City Corporation and Tom Welch, Southeast Regional Sales Manager for Schwing Bioset, Inc.

April 25, 2016

 

In early 2015, City Corporation, the commission established by the City of Russellville to operate the municipal water system, completed a construction project to abandon existing fixed film treatment facilities and convert the wastewater treatment plant to a denitrifying activated sludge facility.  Activated sludge technologies produce more sludge than fixed film and initial calculations predicted an increase of 6 to 7 times the current production rate when operated at the design capacity of the facility.

City Corporation had processed sludge through aging aerobic digesters and produced a Class B biosolid under 40 CFR 503 that was then dewatered and land applied to three nearby fields.  Two of the three permitted fields were no longer available, leaving only 49 acres for use.  The increase of sludge production was predicted to require around 160 acres.

The expected increase in sludge production and lack of land available for land application prompted staff to explore options.  The alternatives explored included composting, additional aerobic digesters, dryers, and the Bioset process from Schwing Bioset, Inc. (SBI). The Bioset process was selected for piloting in February and March of 2015 due to its low cost, simple operation, and the high quality Class A product that it produces.  The lone concern was with respect to the increase in volume due to the addition of chemicals, and staff wanted to get the new process up and running to obtain empirical data on sludge volume.  The engineering firm performing the preliminary study had built in a large contingency due to not being familiar with the Bioset technology and the uncertainty in sludge volume, thus raising concerns that the Bioset technology would be the proper process for the future of the Russellville WWTP.  Ultimately the volumetric increase was less than 10%, and with the Class A designation the number of outlets and demand for the material exceeds production rates.

Russellville_Bioset_3.jpg Russellville WWTP_Bioset Process_Schwing Bioset

Following that successful pilot test, in April of 2015, Schwing Bioset agreed to continue to lease the pilot machine under a monthly contract basis for the sludge handling process.  By the fall, City Corporation had a good feel for their solids production and had a great experience with the Bioset full scale pilot equipment.  Given the years of struggling with the Class B sludge process, management and staff were very pleased with the Class A process and end product and the thought of returning to a Class B process was taken off the table. With all the uncertainty taken out of the equation, staff was ready to make a decision and chose to move forward with a permanent Bioset installation.  City Corporation and Schwing Bioset continue to operate under a contract that allows City Corporation to operate the pilot unit until the permanent unit is installed and operational.  This arrangement allows City Corporation to manage their sludge and operate the plant in accordance with the design parameters, keeping the facility in compliance with the ADEQ, which otherwise would not be possible.  The new facility is anticipated to be operational in mid-October 2016.  The current digester will only be used as a sludge holding tank, thus reducing the power consumption needed for complete aerobic digestion to meet Class B standards, and allowing just WAS sludge to be converted to Class A EQ fertilizer through the Bioset process.

To learn more about our Bioset process or this project specifically, contact this blog’s author, Tom Welch, and/or visit the SBI Bioset Process page. For other inquiries, call 715.247.3433, visit our website, or find us on social media.

Download Our  Bioset Process Brochure

 

Tags: Bioset Process, Class AA/EQ Biosolids, Wastewater Treatment, Lime Stabilization, Bioset Demo

How Transitioning to Class A Biosolids Saves Money

 

Published in TPO Magazine, February 2016. Written by Larry Trojak.

 

A southwest Florida treatment plant turns to lime stabilization to create Class A biosolids for land application and cuts handling costs significantly.

Cost-effective handling of biosolids is essential to clean-water plants’ economic and environmental performance.

The Immokalee Water and Sewer District in Florida faced a biosolids challenge in 2006. The district had been using drying beds to create Class B biosolids and spending about $500,000 a year to dewater and haul excess material from that process to a landfill.

Facing a change in regulations on land application of Class B material, and wanting to reach the biosolids’ full economic potential, the district looked at alternatives. The ultimate solution was a facility redesign centered on using the Bioset process (Schwing Bioset) to create Class A biosolids. As a result, the district has reduced handling costs by more than two-thirds and produces a Class A product for beneficial use.

Anticipating change

Located about 30 miles southeast of Fort Myers, the heavily agricultural Immokalee district is home to about 24,000 residents. Its wastewater treatment plant was expanded in 2013 from 2.5 mgd to 4.0 mgd design capacity. Until fairly recently, it generated 23,500 gallons of Class B biosolids per day at 1 to 1.5 percent solids.

Gary Ferrante, P.E., an engineer with the Greeley and Hansen engineering firm, says a number of factors in 2006 led the district to review its biosolids operation. “Immokalee’s plant was originally designed with a half-dozen drying beds in which a Class B biosolids was created and used on permitted area farms,” he says.

“While that was effective, the facility is next to a school, which repeatedly complained about students’ health risks and odor. The district later learned that the U.S. Department of Agriculture and the Florida Department of Environmental Protection were considering changes to biosolids land application regulations (passed in 2010 as Florida Biosolids Regulation Chapter 62-640 F.A.C.). All that prompted the district to hire a consultant to look at alternatives.”

Lots of options

Based on recommendations from the consultant’s report, in 2007 the district contracted with Synagro Technologies to dewater the Class B biosolids and haul it to a landfill more than 100 miles away. In time, rising prices and an increase in biosolids volume raised annual costs from $309,000 to more than $470,000, providing incentive for the district to pursue other options.

“Working with the district, we put together a couple of proposals and a couple of scenarios within each proposal,” says Ferrante. “The first one covered the design/build/finance of a biosolids facility at the existing location. Options under this plan included handling material from Immokalee only, as well as accepting material from Collier County and making Immokalee a regional processing facility. The second proposal had an outside entity leasing land from the district and constructing a Class A regional processing facility on it.”

An option under that proposal included a continuation of the contract dewatering program while the regional facility was taking shape. In the end, the district chose to establish a turnkey processing facility for its own biosolids sludge only and selected the Bioset process to deliver Class A material.

Schwing Bioset - Bioset Process  Schwing Bioset - Bioset Process

Class A operation

At the new facility, material exits the primary treatment facility’s sludge holding tanks at 1.5 percent solids and is fed directly to a high-performance screw press, selected for a number of reasons, including its relatively compact design.

“Because of the limited availability of usable land, a small footprint for the entire biosolids system was a major consideration, and the Bioset screw press fit in nicely,” Ferrante says. “We’ve found it to be an outstanding dewatering tool, yet extremely efficient in power usage.

“The belt press we looked at would have taken the material from 1.5 or 2 percent solids up to 8 to 10 percent. A centrifuge might get that up to 20 percent, but the electricity costs would be much higher. The screw press takes the material up to 16 percent solids. It uses twin augers and a changing pitch on the screws to advance the material and remove the water. Because it takes far less energy to turn those two screws than to power a centrifuge, the savings in power consumption can be significant.”

Another feature is that district personnel can wash the screw press down while it remains operational, says Michael Castilla, service technician 1: “The Bioset screw press has an automated self-cleaning function which in itself is nice. However, when we have a situation that calls for additional cleaning, we can simply push a button and a cleaning cycle will start. That’s a bonus. To shut a press down for maintenance or repair could cost us a half-day’s performance.”

Positive reaction

After dewatering, untreated biosolids are taken via screw conveyor to a twin-screw mixer in which quicklime and sulfamic acid are added. The mixing resolves issues such as unreacted lime in the final product and yields a highly homogeneous material. From the mixer, a Schwing Bioset KSP-10HKR pump feeds material into a 56 1/2-cubic-foot reactor in which heat from the acid and quicklime reaction raises the pH, stabilizing the mixture and creating a product that meets both Florida Chapter 503.33 and U.S. EPA Class A requirements.

“Retention time in the reactor is about 30 to 45 minutes at temperatures in the range of 122 degrees Fahrenheit,” says Ferrante. “The plant wastes sludge for 16 hours a day, consistently generating about­­­­­ 11 dry tons of the Class A material weekly and doing so at a markedly lower cost than for outright hauling and landfilling.”
Castilla adds that the system’s ease of operation was also key to getting up to speed quickly.

“It is very intuitive and simple to operate,” he says. “However, Schwing Bioset still went to great lengths to ensure that people involved in day-to-day operation are comfortable with it, have a handle on the maintenance routines, and so on. Ian Keyes from their Wisconsin office spent time here mentoring me to such a degree that there’s very little about the system I don’t understand.”

The Class A material exits the system, is loaded onto a manure spreader and taken to an area field where it is applied in place of fertilizer. Eliminating those fertilizer costs alone has saved about $50,000 per year.

In addition to lower costs, the district benefits from a much cleaner, less maintenance-intensive, more environmentally friendly operation. Dust from the lime-based process is controlled using hard-piped or totally enclosed components. Odorous air is contained by the pressurized reactor and then captured and scrubbed under a collection hood before release.

Schwing Bioset - Biosolids Hauling    Schwing Bioset - Biosolids Hauling

Room to grow

The district’s biosolids plant was designed with ample space to install a second identical processing line in case the regional concept becomes a reality. “One of the most important aspects of this system is its ability to accommodate the changes a regional operation would entail,” says Ferrante. “Things like fluctuations in the percentage of solids, increases and decreases in throughput, and compatibility with biosolids from aerobic or anaerobic digestion processes without modification, are all within its design capability.

“Simply put, the district is well positioned to have its wastewater treatment needs met for the foreseeable future. After the $2 million design/build/finance contract was awarded, the district, seeing itself in a good financial position, opted to pay that cost out of pocket, rather than financing it over 20 years.”

The annual operating cost for the new system is about $130,000 a year, including chemicals and electricity. With estimated savings of $370,000 per year over landfilling, the system will pay for itself by about mid-2019.

“This was a case in which Immokalee, a small independent special district with a serious financial headache, took real initiative in getting things done,” says Ferrante. “They will be the beneficiaries of those sound decisions for decades to come.”

 

To view this story on TPO Magazine's website, click here.

To learn more about Schwing Bioset and the Bioset Process, click here.

 

 

Tags: Class 'A' Biosolids, Bioset Process, Piston Pumps, Bioset System, Wastewater Treatment, Fertilizer, Screw Press

Screw Press and Bioset Demo Leads to Treatment Plant Expansion

 

Written by Tom Welch, September 10, 2015

The Springfield, IL, Metro Sanitary District (SMSD) Sugar Creek Plant is going to be expanding over the next two years.  They currently have no dewatering capability and they treat their liquid sludge with lime and liquid land-apply on their own fields onsite at the plant.  In June of 2013, Schwing Bioset was invited to run a dual demo of their screw press and Bioset systems.  The pilot study was conducted for two weeks where the Waste Activated Sludge (WAS) was dewatered with the screw presses and then converted to a Class A EQ product through the advanced alkaline stabilization Bioset process.  Crawford, Murphy, and Tilly Engineers coordinated the pilot study for the District.

Prior to the pilot study, the plant operations team was leaning toward using belt presses for their future dewatering needs.  They had familiarity with belt presses and they were concerned that screw press technology did not have the capability to meet their requirements of 2660 dry pounds per hour without having to install a large number of screw press machines.  They were basing their concerns on historical screw press throughput capability based on their market research.

Springfield_Demo_Image_1-1

(Pilot Study Setup at SMSD Sugar Creek Plant)

During the pilot study, the Schwing Bioset team brought their FSP 600 screw press machine to dewater the partially aerobically digested WAS.  The goal was to dewater the material to the highest percent solids, with an excellent capture rate, and also with the least amount of polymer consumption.  The dewatered product would then be passed along to the mobile Bioset operation, which is an advanced alkaline stabilization process that can produce a Class A EQ Biosolid end product that can be utilized as a fertilizer or a soil amendment. 

The first week of the demo was utilized to optimize the screw press performance, and the second week to monitor continued performance of the screw press while utilizing the Bioset operation to produce a Class A EQ product. The purpose of this was to monitor the product over a couple month period to determine the stability of the Class A EQ product at the Springfield plant.  Over the two weeks, the FSP 600 screw press unit produced a dewatered product of 30% solids on average, even while operating the machine at 130-150% of design throughput capability.  After polymer optimization, the end result was realized with 14 pounds of active polymer per ton and the capture rate was above 95% during the entire two week period.  During the second week of the pilot, the Bioset system was utilized the entire time and was successful in producing the Class A EQ product.

Based on the successful results of the pilot, SMSD gave Crawford, Murphy, and Tilly the direction to design the new biosolids handling facility to include two high-performance screw presses, each capable of dewatering 1330 dry pounds per hour.  Although they liked the simplicity of the Bioset Class A operation, they were uncertain if the need for Class A was justified for the new facility.  They settled on a Class B Bioset system that utilizes all of the components of the Class A design, except for the reactor.  Space was left in the building to install the reactor in the future should Class A become necessary.  The job bid in December of 2014 and Schwing Bioset received an order for the two high-performance screw presses and the Class B alkalization system in early 2015. 

These FSP 1102 screw presses showcase the capabilities of high-performance screw presses and offer larger plants an appealing alternative to traditional belt filter press or centrifuge dewatering.

To learn more about our screw presses, Bioset process, and/or this project specifically, contact a Schwing Bioset Regional Sales Manager, call 715.247.3433, email us, and/or visit our website here.

Springfield_Demo_Image_2-1

(Class A EQ product at 44% solids)

 

 

Tags: Class 'A' Biosolids, Bioset Process, Alkaline Stabilization, Class AA/EQ Biosolids, Biosolids, Wastewater Treatment, Screw Press, Dewatering

When WWTP Says "No Tanks," Innovative Bioset Process Fills the Gap

 

Schwing Bioset Application Report 17, St. Petersburg, Florida

Written by Larry Trojak, Trojak Communications

Version also published in WE&T Magazine, November 2013

 

Pumps_Snapshot

 

Wear is the unflagging enemy of every wastewater treatment plant. Plant operators can defend against it to the best of their ability; but in the end, time will win out, resulting in breakdowns and the occasional interruption in service. To cope with such occurrences, forward-thinking plants will always have a solid contingency plan in place. For the Southwest Water Reclamation Facility (WRF) serving the Water Resources Department’s southwest sector (including St. Petersburg, FL), their contingency - designed to deal with a pair of worn, aging digester tanks - involved bypassing the tanks entirely and processing biosolids through a Bioset sludge treatment process. Doing so is not only helping them avoid an operational nightmare and additional maintenance and expense, it is allowing them to improve the by-product of that biosolids operation - all at a time when costs to land-apply their “standard” product have skyrocketed. Timing, it seems, really is everything.

 

Decades of Wear

Originally built in 1955 as a four million gallon per day (mgd) facility, the Southwest Water Reclamation Facility (WRF) was literally replaced at the same location with a 20 mgd plant in 1978. It is one of four which serve the greater St. Petersburg area: Plant #1, for the southeast section of the area which includes downtown St. Petersburg; Plant #2, to serve the northeast section of town; Plant #3, for the northwest section of the area and the beach communities; and Plant #4, for the southwest section of St. Petersburg, as well as the incorporated towns of Tierra Verde and Gulf Port. According to Ken Wise, chief plant operator for the Southwest WRF, volumes at each plant are pretty much equal.

“Plant #1 is called the Albert Whitted WRF and it’s a little smaller since there are fewer residents downtown than in other parts of the city,” he says. “But each of the other three plants are 20 mgd facilities and treat roughly the same amount of sewage. Since the upgrade in 1978 we’ve all been running an anaerobic digestion process and creating a Class B product from the biosolids. For us, that approach worked well until time caught up with us in the form of badly-worn digester tanks which were causing odor issues for an adjacent college and residential developments in the area.”

Given that two of the tanks were built in 1955 with the original plant, and the third was added with the expansion more than 35 years ago, the wear factor is not surprising. Wise says other plants in the area were also seeing failures in both the covers and in their structures as a whole.

“We hadn’t had a failure yet, but the Water Resources Department was spending a good deal of money on
upkeep with us,” says Wise. “Under normal circumstances that would have probably sufficed and bought us a few more years. However, due to changing Florida regulations surrounding the land application practices of the Class B biosolids they were producing at the time, the department started seriously looking into alternative biosolids treatment technologies hoping to avoid repairing something that was not only at the end of its life, but also might not be a fit for that new effort.”

 

Repeat Success

Bioset_Snapshot

To find that solution, the department looked at all possible alternatives, an initiative that included conducting pilot projects with various technologies at other locations in the city. One of those, at the Whitted plant, involved installing the Bioset Process sludge treatment system which uses a combination of pH and heat to stabilize the biosolids, thereby eliminating the need for digesters. 

In addition to being extremely low maintenance and operator friendly, Wise says that it had proven quick to implement and very successful there. “Ultimately the decision was made to install another system from Schwing Bioset here at Southwest,” he says. “Installation took place in July of last year (2012) and we were online by August.”

The installation, he adds, went smoothly, despite the fact that the Bioset Process had to be made to fit within the confines of an existing section of the plant rather than in a totally new site.

“The Bioset crew really worked with us to maximize use of the space we had and minimize disruption,” he says. “As a result, we probably have one of the few Bioset systems in which the reactor is raised some ten feet off the floor to fit with an existing opening. Now, sludge comes off the belt presses, is mixed with quicklime and sulfamic acid, and is pumped up into the reactor, where it spends at least 40 minutes at 135°F and achieves a pH of 12.5, before being discharged to the trailers.”

The newly-stabilized sludge is kept in the trailers on-site for 24 hours, at which point a sample is taken to ensure the pH is still in excess of 11.5 as required by Federal regulations. Since going online with the Bioset Process, Wise says the pH has never been less than 12.5.

 

Added Benefits

In addition to the elimination of virtually any odor and the complaints associated with it, it is the end product of the Bioset process - now a Class AA biosolid (the Florida equivalent of Class A-EQ) - which is the real benefit for Wise and his operation.

“In the past, our Class B material was suitable for use on sod farms and pasture lands, but because of its designation would have to be set back from any kind of food crops. By contrast, the Class AA product we get off the Bioset Process can be applied on golf courses, pastures, food crops - pretty much anywhere. In addition, because of a recent change in regulations, the other three area plants still generating the Class B biosolid are now paying an extra $300 more per trailer, while our costs dropped $100 per load. Granted, by adding the lime, the volumes are up about 10%, so the number of trailers we are shipping has increased. But even with that added into the equation, we are still saving 40 percent when compared to the Class B and have a much more usable product,” says Wise.

All of the Class AA material generated at the plant is currently either land applied at a site within an hour of the plant or sold as fertilizer to the local agricultural market. The previous Class B, by comparison, was hauled to sites more than three-hours away where it often found limited use.

 

Tanks for the Memories

The St. Petersburg WWTP has proven to be something of a case study in how to best deal with a set of unfortunate, challenging circumstances. Faced with a pair of failing digesters that were going to require a significant investment to rebuild, and which were creating odor issues for nearby residents, businesses, and students - the plant was able to solve the problems by abandoning the existing tanks and by adopting new technology in their operation. That solution from Schwing Bioset was implemented for less money than the tank rebuild project would have cost, it eliminated the odor issue, and includes the added benefit of processing cake directly to a Class AA biosolid (and gain more flexibility in the beneficial reuse of the end product), resulting in substantial net savings across the board.

"Since bringing in the Bioset System things have definitely settled down around here,” said Wise. “It’s been a great solution for us.” And, it would seem, all the issues created by the failing tanks are just fading memories.

 

To download the entire #17 application report for St. Petersburg, Florida, click here.

To learn more about Schwing Bioset, our products and engineering, or this project specifically, please call 715-247-3433, email marketing@schwingbioset.com, view our website, or find us on social media.

To view a version of this story published in WE&T Magazine, click here.

 

Tags: Class 'A' Biosolids, Bioset Process, Bioset System, Beneficial Reuse, Class AA/EQ Biosolids, Wastewater Treatment, Fertilizer

Schwing Bioset Exhibiting at WEF Residuals and Biosolids Conference

 

June 4, 2015

Schwing Bioset, Inc. will be exhibiting at the 2015 WEF Residuals and Biosolids Conference in Washington, DC, on June 8th and 9th.

Please be sure to stop by our booth (#106) while you're on the exhibit floor.

 

Visit the conference website to view the event details and exhibition map: http://www.residualsbiosolids-wefiwa.org/

Here is the Schwing Bioset listing for the show: http://app.core-apps.com/15rbwe/exhibitors/d4d3b4f759e0e3a5025efd0a3d0e4fc4

Learn more about our Bioset Process and Class 'A' Biosolids, Dewatering Equipment, Pumps, and other products here: http://www.schwingbioset.com/products

 

If you'd like to meet with one of our team members, please contact marketing@schwingbioset.com for the names of the team members who are attending the show.

We hope to see you there!

 

Bioset_Video_Screenshot

 

Tags: Class 'A' Biosolids, Bioset Process, Events, Biosolids, Wastewater Treatment, Pumps, Dewatering