Ocean Cuisine International, a Danvers, MA, fish processor, found itself under pressure recently, for a number of reasons. It had an onsite trickling filter that was undersized and that would occasionally plug with biosolids. When Ocean Cuisine consolidated in 1996, the company had two plants. The old plant with its trickling filter was treating approximately 15,000–18,000 gallons of wastewater per day. After consolidation, the amount of wastewater being treated increased to about 40,000–50,000 gallons per day. The trickling filter kept up with this increase for a time, but eventually the growing strain on the older system resulted in a great output of odor. The construction of the filter system made it difficult to clean, especially during the cold months of the year.
As a result of these conditions, the odors and vectors coming off the old system became a problem. In the summertime the odor problem grew especially troublesome.
Frank Gochakowski, wastewater treatment supervisor with Ocean Cuisine, says that the old system and its trickling filter with a fixed media had far more water running through it than it was designed for. “As the media clogged with biomass, the old system simply wasn’t filtering properly any longer. The dead bacteria, remaining largely in place created a lot of odor in the pockets between the media film.”
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| Ocean Cuisine has been reviewing various systems for four or five years. |
Ocean Cuisine had been reviewing various systems for four or five years. Gochakowski was able to search online for companies that may have been able to help Ocean Cuisine with its problem. The Westport, MA-based Hydroxyl Systems Inc. caught his eye with its moving media. “This was something different,” says Gochakowski. “I didn’t know they had something like this out there. I liked the explanation of how it worked. I ended up eventually calling Dan Turner with Hydroxyl Systems,” says Gochakowski. “He came out and showed me the literature on the new system they offered. I then traveled down to New Jersey to look at one of their systems.”
Though the plant that he and his chemical representative visited in New Jersey was a pharmaceutical plant, much different from Ocean Cuisine with its food industry slant, the principles of how things worked in both wastewater systems were still the same. Gochakowski was impressed by the way the New Jersey system looked and operated. He did get quotes from one other company, but he was most impressed with the Hydroxyl Systems setup.
Turner, who is vice president of sales for Hydroxyl Systems, continued to stay in contact with Ocean Cuisine from the fall of 2003 until the spring of 2004, when he was able to meet with Gochakowski.
From there Turner continued speaking with Jonathan Arena, director of manufacturing for Ocean Cuisine. “During one of the calls I made to discuss the system, Jonathan finally said: ‘If you can do the installation during the annual two-week shutdown period, getting everything ready and staged, I am willing to talk.”
After observing the system already in place, Hydroxyl Systems knew it had to design something that could fit the pad that Ocean Cuisine already had in place.
Hydroxyl Systems offered Ocean Cuisine its unique approach to biological treatment using a fluidized-bed bioreactor process with continuous sloughing action in just one pass.
The design called for extreme compactness, operating and residing on the single pad where the previous, 30,000-gallon-per-day system had resided—as well as providing three times the overall operation capacity. “The price was right, and we were extremely responsive to their needs,” says Turner. “I think they have been pretty happy overall so far.”
The work order for the project was received in April. Hydroxyl Systems then had everything ready for staging and implementation by the first week in July 2004.
Out With the Old, In With the New
Ocean Cuisine’s old system involved a fixed-film process with substrate media that remained mostly static, not moving.
“Our technology features a moving and fluidized system for a dynamic sloughing action of the media to remove the dead biomass,” says Turner.
“Static systems do not remove that biomass, and it accumulates, building up until it creates a septic system where you are generating methane gas,” he says. “That is the odor being generated. When Ocean Cuisine took apart the trickling filter with its static media packs—eventually having to dismantle it with a welding torch to remove the sides—there was a buildup, nearly to the top, with eight feet of sludge deposits.”
Gochakowski recalls the dismantling of the old system. “We knocked it down and apart with a crane-like setup. The media that was originally in there was clogged solid. Much of the sides were made of plastic, and when we hit the unit it simply shattered everywhere and black sludge was present on the media. Since our pad had a curb around it, the waste material did stay within the pad. The demolition crew we employed worked during our normal shutdown period in July. The waste material was placed in a container as the system was knocked down. Everyone did a tremendous job, considering the mess it made. They all pulled together as a great team.”
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During that two-week shutdown the goal for Hydroxyl was to install an equalization tank and take out the old trickling system. There was some uncertainty if these goals were going to be able to be met during that time frame. “We had laid it out very carefully as far as how we were going to execute it within that two week period,” says Turner. “But the installation ended up proceeding flawlessly.”
Two 11,000-gallon, vertical tanks were installed with a blower for aerating the tanks. An area was also set aside for placing a spare blower for backup in the case of failure of the first blower.
Everything is insulated with stainless steel jackets on all the pipes. “I consider our new system virtually maintenance-free, though I do have to keep an eye on it too,” says Gochakowski.
“The discharge results coming out of the system have been completely acceptable. Everything has been great. Though the new Hydroxyl treatment system was designed to treat 80,000 gallons per day, it actually looks as if it took up less room than the older trickling filter system,” says Gochakowski. “The 11,000-gallon tanks are a little bit higher, but almost everything else is the same. They did a real nice job with the way they designed it.”
What Gochakowski likes about the new system is that the media is now completely aerated. “The media is moving around in the water, making things more aerobic instead of anaerobic,” says Gochakowski. “The bacteria grow on little structures in the media that look like macaroni ... [that are] just moving around in the water, actually eating the BOD. When the bacteria dies, the movement or agitation in that tank will cause it to fall off, and eventually the bacteria will come out with the water because the water is constantly recirculating. It will be picked up by our DAF [dissolved air-floatation] system. Since the new Hydroxyl system has been installed we haven’t had any complaints about odor.”
Gochakowski has been especially impressed with Hydroxyl Systems tech support. If he had any questions or problems with anything, the support team was always there for him. “I was dealing with people in Western Canada, and whenever I had some questions on things, they actually sent a technician down from Canada,” says Gochakowski.
“They would spend three days with me sometimes, and they are great people," he says. "I never had to wait for their callbacks, and we would actually have conference calls with other engineers trying to deal with my questions. They were very supportive and polite.”
Staying on Schedule
Ocean Cuisine held regular meetings with the contractor involved in assembling the system, Applied Water Management Inc. of Fall River, MA, hired by Hydroxyl Systems to be certain the setup proceeded smoothly during the rather narrow window of opportunity.
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| Two 11,000-gallon, vertical tanks were installed with a blower for aeration. |
Daniel Hankins, project engineer and construction manager with Applied Water Management on the Ocean Cuisine project, had actually worked with Dan Turner at another company nearly 10 years earlier, so the two were already acquainted with each other, which helped things go smoother. “We knew how Dan worked, and he knew how we worked,” says Hankins. “Therefore we were always on the same page as far as knowing what we still needed and how we could go about getting it for the project.”
Hankins encountered a major challenge when it was determined that the concrete pad at Ocean Cuisine was small for the amount of equipment and material that was to be used on it.
“Ocean Cuisine got rid of everything on that pad over a period of one or two days over the Fourth of July holiday weekend in 2004,” says Hankins. “On Monday morning we came in, with everything ordered prior to that day. We had everything onsite that weekend, ready to put it all together within a two-week time frame.
“It was a summer holiday weekend, and there were issues with getting major pieces of equipment moved there on that Saturday and Sunday because of trucking holiday constraints involved.
“Our greatest challenge was making sure that the equipment was ordered on time and that everything was onsite at the specific time it was scheduled for, based on the different phases of construction involved. Two weeks is not very much time for something involving construction of this type.”
The status of work and equipment on the project was monitored as it was being built. The staging and scheduling of assembly proceeded as planned, as not all the units could come together at the same time.
Applied Water Management’s role was to purchase all the equipment specified by Hydroxyl Systems, transport the equipment to the site and then make sure the project management happened in a timely fashion so that Hydroxyl’s design became a reality.
Hankins found the manner that the assembly of the DAF unit proceeded to be exceptional.
The DAF unit was huge, according to Hankins. It required a preconstructed building made for this specific piece of equipment and also for the housing of some of the electrical equipment.
“The challenge for us was how to get this piece in the building and then onsite,” says Hankins. “What we did was to actually send the DAF unit to the manufacturer of the building and then attach the roof. They also bolted in the DAF for us, installed and wired the lighting panel, lights, receptacles, heater, and ventilation system and then shipped the whole building with the unit already installed to the jobsite. We had a crane onsite to lower the building, with the DAF unit inside, into place with all major pieces of equipment already installed for the most part. This was critical to us, because if it would have taken us one whole day just to get the unit off-loaded and into the building onsite we would have lost an important day of work. All we had to do once the building and two 11,000-gallon tanks were in place was run wiring and piping to and from the Hydroxyl process equipment as well as connect the major process lines to and from the Ocean Cuisine plant process.”
Turner describes it as a fast-tracked project. Ocean Cuisine cleared the pad to get ready for the new system’s installation. Hydroxyl then went in with all the freight and equipment to the site, taking responsibility for coordinating all of those details as well as for the rigging and the tank placement. Local contractors and plumbers then did the actual integration of the system into the existing facility as far as connecting piping, wiring and heat tracing.
“Then we basically handed over the keys after the system was installed and commissioned,” says Turner. “From there we trained those at Ocean Cuisine on operation of the new system.”
Overall, Setup is a Success
Turner feels that the key to the project’s success, from his standpoint, lies in the fact that there was a dissolved air-floatation system provided within a building—all prewired, prepiped, and with all the controls, climate-control, vents, and lighting already in place. “That and the bioreactors and the way everything was pulled into place were excellent,” says Turner. “One thing we did learn from this project was that, based on the fact that we have a gravity-feed from the bioreactors that go down the dissolved air-floatation (DAF) feeders, for the removal of the bio-solids, because the elevations were slightly different from the DAF to their effluent discharge point for sewer discharge, we had to have a set of pumps on the DAF.”
Hydroxyl also had some problems with a valve that was periodically closed inside the facility on the line that they were discharging into.
“The operator tried to get a handle on how to operate the system,” says Turner. “But there was a flow restriction, or he would even stop the flow from the large pumps to the sewage discharge point. Once that situation happened, though our pumps were still pumping—but against a deadhead—and because the DAF continues to fill with water, the DAF ended up overflowing. Despite having a lead pump and a lag pump ... we were pumping against a deadhead, and we had to replace a couple of pump motors.”
This happened within the first few weeks of operation.
To prevent further pump failures or a situation that could arise from a power outage, Ocean Cuisine decided it wanted assurances that no flow restrictions would happen again.
A fail-safe, automatic, flow-isolation valve was installed to keep this situation from recurring. The valve is a spring-loaded, pneumatically activated butterfly valve. This valve is normally open via a compressed air supply.
But if a power outage occurs, or if the level in the DAF increases, the valve would automatically close to prevent water flowing from the bioreactors from coming down and overflowing the DAF.
“Based on my understanding, the valve has never been activated due to an emergency event since it was first installed,” says Turner.
“In any case it is there more as a safety factor in assuring that the system operates properly and prevents any overflow condition from ever occurring. Another point that we discovered was that the DAF recycle pump’s strainers were operating without their screens,” he says.
Canadian-Developed System
This particular system was initially developed in the late 1990s by Environment Canada.
The system is 12 feet in width by 40 feet in length. The first step in the system is the collection of the wastewater in an equalization tank.
This effluent is fed with bacteria taken from another local publicly owned treatment works, specifically the Essex Wastewater Treatment System.
Next the effluent passes through a dissolved air flotation system for removal of fats, oils, grease, and any kind of solids, including clamshells or fish bones.
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| The DAF unit required a preconstructed building for housing. |
Following that, it is discharged into a below-grade sump pit. The sump has an overall capacity of approximately 3,000 gallons.
From there the pumping is done out of the pit through the pumps to parallel fluidized bioreactors. These discharge into dissolved air flotation systems for removal of the biosolids.
No chemicals are added to the involved tanks.
According to Turner, what makes Hydroxyl Systems’ immersed moving bed biological treatment different than standard conventional activated sludge treatment systems lies mainly in its volumetric efficiency, especially when compared to older systems.
The company is especially suited to retro-fitting existing systems, providing all the advantages of fixed film processes without any of the clogging, inefficient aeration, nuisance organisms, and, as was especially the case with Ocean Cuisine, none of the odor problems.
The Hydroxyl iMBR (immersed, moving-bed biological reactor) process requires no monitoring of food-to-mass (F/M) ratios or return-activated sludge (RAS) rates to maintain mixed-liquor suspended solids (MLSS) levels.
The iMBR process is a single-pass, fluidized, fixed-film process allowing the operators to monitor DO only and to maintain the solids-handling equipment as required. Because this system is a submerged, aerobic, biological treatment process, it essentially eliminates odors normally associated with other fixed-film processes, such as trickling filters or rotating biological contactors.
This iMBR process also effectively blocks excessive filamentous growth, worm infestations, and development of other nuisance organisms.
The constant motion and separation of the biomass carriers means these organisms do not plague this system.
The organisms are also not easily transported between carriers, thanks to the separation in space, and cannot tolerate the turbulence of the media. Therefore, they’ve not been a problem in the Hydroxyl systems.
Because the biomass is retained on the protected area of the carriers, this provides a buffer against toxic episodes.
Inner layers of the biofilm are protected by the diffusion barrier resulting in a system that’s less susceptible to damage during toxic shock conditions.
The toxic contaminant may kill the outer layer of biofilm, which will subsequently be soughed off or eroded off, revealing a new, untouched layer of biofilm.
Suspended growth systems will be severely exposed to any toxic contaminant that enters the system.
“In essence, with this project we are simply meeting our effluent discharge requirements for the city,” says Turner. “That is 350 ppm for BOD and TSS; but we don’t want to remove all of the solids, because that would require Ocean Cuisine to haul more sludge. We are within compliance at all times. The secondary DAF is reliable and the iMBR bioreactors are maintenance-free and effective—in fact, they surpass any design expectations of the system itself.”
In conclusion, Jonathan Arena, director of manufacturing for Ocean Cuisine, adds: “How the bioreactors are going to treat this wastewater itself and whether we are going to meet our goals and limits: Those are both the main challenges that we face. We met the goals and limits very well without a problem. Once the situation with the isolation valve was taken care of, there were no other problems. The pneumatically activated valve represented one small piece of insurance for us and Hydroxyl Systems. Now everyone’s breathing easier.”
PETE HILDEBRANDT is a writer specializing in science and engineering topics.
OW - March/April 2006 |
