Problem

The Karcher Creek Wastewater Treatment Plant in Port Orchard, Wash., needed to control odors and had no room to expand.

Solution

Engineers chose a biofilter system from Bohn Biofilter Corp. that treats 200 ppm hydrogen sulfide. The biofilter, built on the roof of the solids storage tank, accommodates large mixers penetrating through the roof into the tank below.

Result

The system provides odor control and was shut down only once in seven years for fan maintenance. 520/624-4644; www.bohnbiofilter.com.

Insulated cover seals in odors

Problem

Odors from the Southwest Water Reclamation Facility in Bradenton, Fla., bothered golfers on a nearby course and local residents.

Solution

The Manatee County Public Works Department selected the LemTec modular insulated cover from Lemna Technologies to cap the 244-foot circular equalization tank. Individual casings of 1-inch closed-cell insulation sealed between two sheets of 40 mil HDPE geomembrane minimizes odors while adjusting to fluctuating water levels.

Result

The product proved cost-effective and maintenance-free. 612/253-2000; www.lemna.com.

Ozone chamber controls odors

Problem

Engineers at the 333 mgd North Side Water Reclamation Plant in Skokie, Ill., proposed ozone to reduce odor complaints.

Solution

They chose an odor control system with corrosion-resistant fiberglass contact chamber from Ozonology. The chamber, sized for the exhaust air volume, detains hydrogen sulfide for 30 seconds, in which time it reacts with ozone and controls odor. A monitor regulates ozone production to match odor loads.

Result

The system has controlled odors for six years. 866/998-8808; www.ozonology.com.

Oxidation technology controls odor

Problem

For 20 years, hydrogen sulfide odor from 8.5 miles of sewer made life unpleasant for neighborhoods and small businesses in Clarksville, Ind. Wastewater Treatment Department personnel struggled to find a cost-effective solution.

Solution

A Source Technologies representative recommended the VSP superoxide process. It combines the VSP catalyst, a complex organic compound, with oxygen generated on site using a molecular sieve and the two chemistries combine to oxidize the sulfide in the water within minutes, preventing the formation of hydrogen sulfide in the lines.

Result

Since its installation in February 2010, the area has been odor free. Clarksville town council president Greg Isgrigg received the 2010 Collection Systems Small Facility Award from the Indiana Water Environment Association for solving the problem. 859/223-1444; www.sourcetechnologiesllc.com.

Activated carbon ensures fresh air

Problem

A 30 mgd municipal wastewater treatment facility in a Connecticut neighborhood wanted to minimize odor breakthrough while reducing activated carbon changeout frequency to lower costs.

Solution

Operators chose DARCO H2S, a nonhazardous lignite-based activated carbon from NORIT. The product’s natural catalytic capabilities required no impregnation to achieve optimal porosity and maximum hydrogen sulfide absorption.

Result

The facility extended its carbon filter bed life from four to more than 18 months, and the initial fill was still usable. Over five years, operators eliminated more than 12 changeouts, saved more than $360,000, and reduced odor-testing expenses by nearly 50 percent. 800/641-9245; www.norit-americas.com.

System stops odors, reduces FOG

Problem

Residents complained of sewer odors in neighborhoods near the Howell Avenue pump station in Riverhead, N.Y. The two wet wells also had large amounts of fats, oils, and grease.

Solution

Parkson Corp. proposed an OHxyPhogg V80 system with one standard nozzle per wet well. The Sewer District installed it in July 2011.

Result

Odor complaints ceased and FOG was reduced despite additional grease being diverted from other pump stations. Operators found the system easy to operate and maintenance requirements minimal. 888/727-5766; www.parkson.com.

Device controls odor and corrosion

Problem

A southern Arizona municipality had a two-mile force main with hydrogen sulfide peaking at 3,400 ppm and averaging 340 ppm at its outfall. Daily temperatures reached 110 degrees F.

Solution

Operators installed the FORSe 5 odor and corrosion control system from Anue Water Technologies in the line at the wet well and downstream from the check valve. The device diverts a fractional flow, infuses it with oxygen and ozone, then returns it to the force main.

Result

Five days after installing the device, hydrogen sulfide levels dropped from 17 mg/L to less than 0.2 mg/L. Vapor measurements decreased from greater than 3,400 ppm to less than 10 ppm. 760/476-9090; www.anuewater.com.

It’s not surprising that a community in the Sonoran Desert would place a high value on water. Chandler, a Phoenix suburb, gets about nine inches of rain a year. Even in March, the wettest month, it only gets about an inch. All new developments are required to use reclaimed water whenever possible. Reclamation is also cost-effective, as it would cost millions to build an effluent pipeline to the nearest river more than 20 miles away.

The Ocotillo facility, one of three wastewater plants in the city, has been operated by Severn Trent Services since 1999. In 2007-08, the plant used the company’s Site Energy Management Plan (SEMP) to improve its energy efficiency, leading to the 2010 Large Wastewater Treatment Plant of the Year award from the Arizona Water Association.

“SEMP evaluates the treatment process as a whole to see where efficiencies can be achieved,” explains Severn Trent senior area manager Keith Greenberg.

Aeration improvements

Continued effort toward efficiency at the Ocotillo biological nutrient removal plant was a key factor in winning the award. Of special note was an aeration blower replacement in 2010 that earned an $86,300 rebate from Salt River Project, the local electrical utility. Three existing aeration blowers were replaced with high-efficiency blowers from HSI of Houston.

Using air bearings and high-efficiency motors, the blowers are 30 to 35 percent more efficient than the plant’s original 25-year-old blowers, according to Greenberg. Replacing the 300 hp conventional centrifugal blowers with the same size high-speed turbo blowers is projected to reduce overall plant energy use by 1 million kWh or more. With a total cost of $720,000, the project has an expected payback of 7.7 years. That doesn’t include the $30,000 annual savings from decreased maintenance on the blowers.

“The original plant blowers were very mechanical with a lot of moving parts, and they required ongoing service from an outside vendor for routine maintenance,” says Greenberg. The bearings on the new blowers are cushioned by air, which reduces friction. The motors are also made of rare earth metals, whose magnetic characteristics and light weight reduce energy use and wear.

Increasing revenue

“Determining the exact effect the blowers had on reducing the overall use of electricity is very complex,” notes Greenberg. “However, there is no doubt that we have reduced energy costs through the implementation of the SEMP and by installing high-efficiency blowers. The total plant electric use is substantially less than it would have been had the original blowers not been replaced.”

Another aeration improvement was switching to LDO probes from Hach Company in place of older membrane probes. “They’re much more efficient and much more accurate,” says Greenberg. “They allow better control and better utilization of the air that is available, and you don’t have to replace the membranes.”

The Ocotillo facility also takes part in a utility program called PowerPartner, designed to reduce energy use during times of high demand. By agreeing to curtail its energy use, the plant receives an incentive payment from Salt River Project both for participating and for its actual performance during curtailment events.

“It brings in $10,000 to $11,000 per year, and the savings are shared with the city,” says Greenberg. “If called upon, we have to reduce our power use by 300 kW.”

That is achieved in several ways, including shutting off pumps, reducing dissolved oxygen to the minimum needed for treatment, and cutting demand throughout the plant by minimizing the use of lights and other electrical equipment.

The agreement with the electric utility restricts the number of curtailment events to one a day, no more than three times in seven days, up to four hours at a time, and no more than 60 hours per year. There is no penalty if Ocotillo can’t cut its use by 300 kW, but that would reduce its incentive payment. Greenberg says anything more than two hours becomes difficult for the plant to meet, but most curtailment events haven’t lasted that long. In 2011, the plant was asked to reduce its power consumption only once.

The details of such curtailment programs vary with the utility. One limiting factor for a wastewater plant is the time of peak flows compared to the peak demand for the electric utility. “Our flow starts picking up about 10 a.m. and we peak from about noon to 3 p.m.,” says Greenberg. “We usually get called for curtailment early in the morning.”

Using rebates

The electric utility also offers a wide variety of energy rebates. “All of our lighting projects are upgraded to the Salt River Project rebate standards for high efficiency,” says Greenberg. That includes a recent project that relit an entire building with LED lights. The city also takes part in the utility’s premium efficiency motor rebate program and looks for applications for variable-frequency drives.

In the planning stages is a total upgrade of the plant’s HVAC system to switch to high-efficiency air conditioners and control valves. “We use as much of the utility program as we possibly can to achieve lower electrical costs with high-efficiency equipment and lighting,” says Greenberg.

The plant’s odor control system has also been improved to reduce impact on the neighborhood. “We optimized our system with hydrogen sulfide detectors for direct gas sampling that will trigger sodium hypochlorite use instantaneously, so that we use the right amount and use it only when we have to,” says Greenberg.

The plant also uses a “green” bioremediating parts washing system, the ChemFree SmartWasher, which combines a biodegradable solvent with microbes to eliminate parts washer waste. Greenberg says it all shows that energy efficiency is just one aspect of green operation. A holistic approach has helped the plant conserve critical water resources in the desert while reducing its impact on the planet.

“Each group that comes through gets a Touch Tank demonstration,” says Jocelyn O’Neill, environmental education coordinator at the Loxahatchee River Center. “We’ve got sea urchins, sea cucumbers, snails, sea stars, and hermit crabs that they can touch and hold.”

The Touch Tank is just one of the attractions at the River Center, opened in 2008 and operated by the Loxahatchee River Environmental Control District (LRECD) in Jupiter, Fla. It’s a place where the public can learn about the importance of the Loxahatchee River and preserving its waters. The LRECD Wastewater Facility treats up to 11 mgd (design) and serves about 80,000 people. The reclaimed wastewater is used for irrigation.

Protect and preserve

“The LRECD was put in place to protect and preserve the river, which is one of only two designated Wild and Scenic Rivers in Florida,” says O’Neill. “That was the whole mission of the district when it was formed 40 years ago.”

The staff of three educators at the 5,000-square-foot River Center teach students and adults how water in the river is used and reused within the community and why it needs to be protected.

“The River Center has evolved within the LRECD to become an environmental education program,” says O’Neill. “None of us are operators, but we’re all educators.

“We bring people in to learn about the river and what we can do to protect it. That means treating wastewater to prevent pollutants from entering the river. It also means reusing that water in our community as an alternative source of water — again protecting the river and reducing the amount of water taken out of the watershed.”

Hands-on learning

The River Center gets about 20,000 visitors each year. Different exhibits show and tell the public how wastewater treatment works and how it relates to them. Says O’Neill: “We have a nice, big exhibit that shows how the people in the community get their water, how they use it, and then what happens to it after they use it, which gets into wastewater and reuse.

“The water balance display discusses water resources and how they’re used, and the balance between the two. That includes using reuse water as an alternative resource.”

Both displays are interactive, creating a hands-on learning experience. “We also have several aquariums and each one of them represents a different habitat on the Loxahatchee River,” says O’Neill.

Operations staff members were involved in planning and designing the displays. “When they were first designing it, we gave all the artists a tour of the plant and told them about the processes, and helped them with the photos and the captions,” says plant superintendent Sheldon Primus. “I designed a schematic they could use for the displays.”

Individual learning

The staff at the River Center provides group-specific education based on the students’ ages and their reason for visiting.

“For the Girl Scouts, we have a great program called the Eco-Action Interest Patch,” says O’Neill. “One of the components is always science and technology. That’s when we get into the specifics about wastewater treatment, what’s involved with certain steps, why it has evolved into the technology we’re using today, and the advancements we’re still making.”

Groups use a range of skills to understand how wastewater treatment works. “For each student field trip group that comes through here, we provide a component that specifically takes them through each one of the exhibits and gets them to interact in a direct way using math skills and word skills,” says O’Neill.

Operators join in

The three River Center staff members can’t do it all by themselves, so the operators at the LRECD play a big role in helping the citizens of Jupiter understand why their water is important.

O’Neill notes: “Whenever we’re doing an outreach in the community, Sheldon and all of his operators are always available for us.

“At the Jupiter Jubilee annual community event, we set up our table with a big display, and the operators are there so people have a way to be involved with the Loxahatchee River on a more personal level.”

Primus adds: “At the Jubilee, we have a display that shows the reuse portion of the system and we give out materials so people understand the difference between their drinking water supply and the reuse supply. We educate the public that the more they use the reuse water, the less they’re taking away from the drinking water supply.

“We gear a lot of the handouts toward the kids, like coloring books. We want to catch them early so they start thinking environmentally.”

Primus also participates in local events distinct from the River Center. “Envirothon, a two-day event held locally in Jupiter, is a science competition between high school environmental students,” he says. “The district was one of the key sponsors last year. I talked to the youth about the process of wastewater and what the field is like for those who are interested in staying in environmentalism as they go through college and graduate. Our Jupiter High School won the Envirothon in 2011.”

Seeing and hearing from the plant staff gives the public a chance to see what the operators are all about. “We’re not like the Ed Norton types from ‘The Honeymooners,’” Primus jokes.

Getting the word out

O’Neill and her staff do not just wait for visitors at the River Center. They are proactive in getting information out.

“Going to events is a big pull for us to get the word out about the River Center,” O’Neill says. “We get a lot of people that way who haven’t been exposed to us before. We also use Facebook and we have a website (www.loxahatcheeriver.org).

“Through our school program, every student goes home with a personal invitation to return to the River Center with their family. We tell them, ‘You’ll be the tour guide.’”

The Loxahatchee River Center is a central location for people to come and learn, but the staff reaches out beyond those four walls. Says O’Neill: “Our objective is for people to understand why wastewater treatment is necessary and how it functions in their community.”

While frequent bridge derailments annoyed the operators, a bigger problem was the sand sucked up by the backwash pump. The return process deposited it at the headworks, where the material ruined the impellers on influent pumps. It also accumulated on the bottom of the digester, affecting the diffusers’ ability to aerate and circulate the material.

To resolve these and other related issues, the plant team selected partially submerged disc filters supplied by WesTech Engineering.

Clogging issues

“We have a lot of inflow and infiltration problems,” says plant manager Chuck Fonte. “At 8 or 9 mgd, sand clogged our grit system and blinded the bridge filters, causing the excess flow tanks to fill sooner than necessary.”

Sludge commingling with the sand in the bays also blinded the filters. “No matter how much we chlorinated, we couldn’t get them clean,” says Fonte. “We’d have to drain the 5 mgd bays and scoop out the small cells by hand every five or six years.”

The sand also had to be replenished annually. Operators risked back injuries when leaning through the handrails to pass 50-pound bags of sand to their co-workers down in the bays. Maintaining the bridge filters took 15 labor hours per week.

In 2011, officials hired Chicago engineering firm Baxter & Woodman to upgrade the tertiary treatment. They suggested the disc filters because they would fit in the 74- by 12.5- by 6.81-foot bays and came closest to matching the plant’s hydraulic profile.

“After evaluating the bids, we selected WesTech Engineering,” says Fonte. “Besides offering a substantial savings, the filters would provide additional filtration area to handle 21 mgd, which was 3 mgd more than requested in the bid.”

Manusos General Contracting installed three units in two months. “Since March 2011, the plant hasn’t gone to high flow,” says Fonte. “But the best thing is that we no longer have sand issues, nor do we have to replace the material.” The filters lowered TSS from 4 mg/L to 2 mg/L and use 2 kWh per day less electricity than their predecessors.

Look at the space

The 10.52 mgd (design) activated sludge plant operating in extended aeration averages 3.5 mgd with 21 mgd maximum flow. The sand filters have a solids loading rate of 30 mg/L. Effluent discharges to the DuPage River and biosolids are land-applied.

Construction began on Bay 3 in November once rain was no longer a concern. Using a Bobcat excavator, Manusos workers removed the sand filter and charcoal filter beneath. Scooping out the material left the floor uneven, so they applied a layer of thin-set concrete to level it. The process was repeated in each bay.

“Doubling up units in the first bay enabled Manusos to convert the third bay into a storage/meeting room,” says Fonte. “We gained 600 square feet.”

Meanwhile, workers built a knee wall in Bay 1 to divert all the flow to it, then removed the sand filter in Bay 2. Other workers cut a hole in the wall of the building large enough to slide in a 7 mgd filter assembly. It included a support frame with trough, motor, backwash pump and piping, rotor drum with discs, and a fiberglass cover with hatches. “They look like large beer cans on their sides,” says Fonte.

Inside the units is a row of 20 eight-foot rotating discs. Each one holds 10 removable filter cartridges with 10-micron polyester woven media. During operation, liquid feeds into the center of the drum, passes through the media, and is discharged.

As captured solids collect on the discs, the influent level increases and signals a backwash cycle. A high-pressure spray then cleans the filter and discharges solids into the reject flume.

50 percent reduction

After workers lowered the filter assembly into Bay 2, they anchored it to the floor and connected the piping and electrical. Once it was online, they opened the bypass gate and directed flow from Bay 1 into it.

Workers prepared the first bay like the others and cut a hole in the wall opposite it to slide in two 7 mgd units. “Previously, it took three bays to treat 15 mgd,” says Fonte. “Now we can handle 21 mgd in one-and-a-half bays.” Before leaving, Manusosalso installed an actuated bypass gate and SCADA system.

That summer, algae growth in the uncovered clarifiers caused its usual problems, only this time large clumps of it threatened to clog the filter media. Operators tried chlorinating the clarifier, but it didn’t work. “We have two trough weirs and had to chlorinate both sides,” says Fonte.

Lead operator Al Fajardo had a simpler solution. He built screens ahead of the units to catch the scum. Every morning, an operator pulls the screens and sprays them to remove the algae. “That’s the only maintenance other than greasing the drum bearings once a week,” says Fonte. The units are chemically cleaned annually. All work is done at floor level.

Popular attraction

Many Great Lakes municipalities have visited Fonte to look at the filters. Last September, the facility was host to a monthly gathering of the Fox Valley Operators Association in the new storage/meeting room. “Everybody toured the units and were amazed at how they work,” says Fonte. “We are very pleased with them and will show them to anyone who is interested.”

This state college, based in Lake City, now offers a two-year Associate of Science degree in environmental science technology that includes preparation for state wastewater treatment and water treatment licensing. Its proponents say the associate degree provides an opportunity for aspiring and veteran operators to earn greater recognition and attain personal and professional pride.

While created for Florida residents, the program is offered online and so is accessible to anyone in the country, and even worldwide. John Rowe, Ph.D., professor of water resources, and Tim Atkinson, director of water resources training programs, talked about the offering in an interview with Treatment Plant Operator.

TPO: What was the rationale for creating this degree program?

Rowe: About 10 years ago, we started teaching a 15-week wastewater treatment class that is required by the State of Florida for an operator to become certified. We offered classroom instruction, generally meeting in the evenings, four days a week.

Over time, we saturated the market here. When I visit wastewater plants in our area, most operators are people we trained. About four years ago, with encouragement from the state Department of Environmental Protection (DEP), we began teaching the course online, so that now we can offer it not only for our area but for the entire state. In fact, we’ve had operators come in from all over the United States.

Now we have a two-year Associate of Science degree in environmental science technology that has embedded within it the pre-licensing course for wastewater treatment and water operations. It includes the training that’s required to sit for the licensure exam, along with the hands-on experience needed to get the license.

TPO: How does a Florida-based licensure course help prospective operators from other states?

Atkinson: The pre-licensure courses are specifically approved by the Florida DEP. Since Florida uses the Association of Boards of Certification (ABC) Need-to-Know Criteria, our course would be helpful to any student in any state that uses those criteria in its exams. That includes 46 states, all Canadian provinces, and several foreign countries.

From other states, we’re finding experienced operators who want to come to Florida but have to take the pre-licensure course and the examination, because Florida doesn’t offer reciprocity. So we have students all across the country who were referred to us because they can take the entire pre-licensure course online and qualify to sit for the Florida exam.

Speed is highly valued by folks who are trying to get to Florida for job opportunities, particularly in South Florida. We also have students from other states who are preparing to sit for their own state exams and who choose to take our course as part of their exam preparation.

TPO: Why would there be demand among wastewater operators for an associate degree program, rather than simply operator training?

Atkinson: It was our theory from the time we introduced the noncredit pre-licensure courses that there would be a percentage of operators who would value an Associate of Science degree for their own personal and professional satisfaction. We found that to be the case.

We established our credibility as a provider of water and wastewater training. And when we announced that the associate degree was available, we began to get responses from operators. Often the response was that finally someone had come up with a college degree recognizing that what operators do is rigorous, involving heavy science, heavy math and heavy technology. A number of people entering the associate degree program are seasoned operators.

Rowe: Several folks entered the associate degree program after they had their licenses with the aim of enhancing their advancement opportunities where they work. We are also promoting it as a means of succession planning for utilities and operating companies.

TPO: What exactly does the associate degree include?

Rowe: It’s a general view of environmental technology that includes soils and air but is directed primarily toward water. There are core general education requirements that go with a two-year degree program. The courses required for our particular degree are Introduction to Environmental Science, Chemistry and Biology of Natural Water, Introduction to Water Treatment Systems, Treatment of Water and Wastewater, Water Analysis and Monitoring, and Environmental Sampling and Analysis I and II.

We also offer some electives, including the pre-licensing courses for water and wastewater. A person doesn’t have to enter this program and come out as a water or wastewater operator, but that is really our focus.

TPO: Do you see interest in the associate degree among high school students?

Atkinson: That is part of the strategy we are now enacting. The early strategy with the licensure course was directed primarily at adults in the field who didn’t have a license or who, because of the recession, needed to retool and reinvent themselves and get into a sustainable career. It was for adults whose personal circumstances didn’t lend themselves to keeping a college student’s schedule.

We then activated the associate degree program. When we first started at this, we had no young people interested. If I were to speak to a person under age 25 about a career in wastewater operations, there was no connection whatsoever.

Now we have agreements with high schools in our area — and for that matter outside our area because the program is online — that will be attractive to high school students. We helped the state Department of Education create three high-school-level courses that are approved so that any high school in the state can use them. These courses will prepare a person to sit for the state exam.

We have worked out an agreement between our college and the high schools so that if a student successfully completes those three courses, passes the state exam, and enrolls in our associate degree program, we will give them 12 college credit hours. So we’re helping to create a pipeline of high school students into the associate degree program by way of water and wastewater operator training.

Rowe: This was something the industry was asking for. People in the industry were concerned that young people weren’t coming into the field.

Atkinson: Another way we’re taking this to the high schools is by offering dual enrollment. This allows high school students with certain grade level attainment who have passed a basic college preparatory test to take college credit courses and get college and high school credit. We are offering our associate degree in environmental science technology to high school students, and we have at least one and perhaps two high schools ready to enact that program.

TPO: Are there future plans to offer more advanced degrees?

Rowe: From the associate degree program, as we create a pool of folks who have that degree and are interested in moving on, we will roll out a Bachelor of Science degree in environmental management. That would involve additional licenses, such as solid waste management, pesticide management, and probably upper levels of water and wastewater licensing.

TPO: Speaking strictly about the pre-licensing course, how would an operator from outside Florida be able to complete the work experience component of licensing through your program?

Rowe: For those who don’t live in Florida, we would certainly make it available to them where they are. I would contact a wastewater facility in their region and see if we could institute the internship with them.

We’d tell them that the student has passed our pre-certification course for wastewater treatment and our courses in environmental science. We’d be able to give them a resume of who they would be getting. It certainly takes some of the guesswork out of whether a new hire is going to make it or not.

Atkinson: The practicum course calls for 10 to 40 hours of on-the-job experience per week during the 15-week term. In Florida, we are finding very positive response to this from treatment plants eager to take on trainees whom they will be able to evaluate and possibly consider for future employment. They see it as a recruitment mechanism. Some of the treatment plants are actually hiring the practicum students as entry-level workers. For others, it’s unpaid practicum experience.

TPO: How is the online course structured?

Rowe: Our online course is accessible anytime. No student has to go online at any particular time because we use a learning platform where students post their work online, so that all students in the class as well as the instructor can review it. Part of the course requirement is for each student to critique responses from other students. That helps create a virtual classroom environment.

Atkinson: You are in a class with other students. The course has a start date and an end date. The only time requirement is that you keep up with the weekly assignments so that you start and finish with your class.

TPO: How many students are enrolled in the licensure course and associate degree program now?

Atkinson: There are about 80 students enrolled, of whom 25 are in the associate degree program.

McCrometer added Live Chat to its website, www.mccrometer.com, enabling customers to directly communicate with flow measurement experts in the oil/gas and municipal water and wastewater industries during regular business hours. The chat icon can be found on the product pages.

Pasteurization Technology secures $1 million investment

Pasteurization Technology Group secured a $1 million investment from EIC Ventures, an early-stage venture capital investment fund. PTG’s innovative disinfection process uses digester gas, a natural byproduct of wastewater treatment, as fuel to drive a turbine that generates electricity.

Standard Methods manual updated

Standard Methods for the Examination of Water and Wastewater has been expanded and revised. Published by the American Public Health Association, the American Water Works Association and the Water Environment Federation, the publication is in its 22nd printing. One change in the edition is an emphasis on quality assurance/quality control practices. The book is available by calling 888/320-2742, emailing apha@pbd.com or visiting www.aphabookstore.org.

Koch Membrane hires commercial manager

Koch Membrane Systems hired Ravichandran Subramanian as regional commercial manager. He will be responsible for developing the markets for all KMS products in Southeast Asia for both the Water & Wastewater and the Industrial & Life Sciences divisions. Subramanian has 15 years of industry experience in sales, management and product management.

Participants of the SSPMA forum in Indianapolis included, from left, David Frame, Bob Frame Plumbing; Charles White, vice president of technical and code services for Plumbing Heating Cooling Contractors National Association; Jeff Hawks, Champion Pump and SSPMA’s moderator; Stephen Pfendler, P.I.P.E. Inc., and William Ciriello, Wm. J. Ciriello Plumbing Co.

SSPMA welcomes Superior Pump, holds spring meeting

The Sump and Sewage Pump Manufacturers Association (SSPMA) welcomed Superior Pump of Minneapolis, Minn., to its membership. Superior manufactures sump, sewage, effluent, utility and backup pumps.

The association also held its spring meeting in February in Indianapolis. The program featured four plumbing contractor representatives from the Indiana Plumbing Heating Cooling Contractors Association. Topics included industry trends, pump distribution, training and education needs for employees and time demands for handling service calls.

Pump Solutions acquires the Maag Group

Pump Solutions Group, a business unit within the Engineered Systems segment of Dover Corp., acquired the Maag Group, headquartered in Zurich, Switzerland, for $285 million. The acquisition includes Maag Pump Systems, Automatik Pelletizing System and Maag Filtration Systems. The Maag Group will operate as a business unit within PSG.

AWWA publishes water, wastewater design-build book

The American Water Works Association published Design-Build for Water and Wastewater Projects. The book provides utility managers, operators and water quality staff, city officials and others with information on when design-build project delivery is a good choice for a water or wastewater utility. It also outlines how to plan, procure and execute a DB project. Black & Veatch senior water process engineering manager Holly Shorney-Darby, Ph.D., P.E., managed and edited the book.

Emerson Bearing forms wastewater division

Emerson Bearing of Boston formed a dedicated wastewater division. Richard Furtado, a senior sales expert who has been with the company for 30 years, will head the division.

Atchia, SJE-Rhombus recognized for technical leadership

Julian Atchia, director of engineered products for SJE-Rhombus, was recognized by the Hydraulic Institute for technical leadership and contributions to the creation of ANSI/HI standards. Atchia worked to update the standard for Rotodynamic Submersible Pumps for Hydraulic Performance, Hydrostatic Pressure, Mechanical and Electrical Acceptance tests, ANSI/HI 11.6-2011. The revised standard changes direction and represents a departure from the previous standard (ANSI/HI 11.6-2001) in that the submersible pump is guaranteed and tested as a complete close-coupled unit.

RedZone receives investment funds

RedZone Robotics Inc., designer and manufacturer of wastewater inspection technologies, received a $6.5 million investment from Waste Resources Fund L.P., managed by FourWinds Capital Management, and a $2 million investment by Smithfield Trust Co. FourWinds’ Valerie Daoud Henderson will join RedZone’s board of directors.

Metrohm creates young chemist award

Metrohm will present $10,000 to a graduate, post-graduate or doctoral student in North America performing research in the fields of titration, ion chromatography and/or electrochemistry. Candidates can submit their research abstract/summary for consideration at www.metrohmusa.com/youngchemist.

Parkson appoints Turpin vice president

Parkson Corp. named Mark Turpin vice president of strategic marketing and business development. Turpin joined the company in 2007 and most recently served as vice president and general manager of aftermarket and services.

CSI Controls’ representative expands territory

The 419 Group LLC expanded its CSI territory, becoming the wholesale factory representative for CSI customers in North and South Carolina. The group also serves as a CSI representative in Virginia.

VerderGPM becomes Verder Inc.

VerderGPM changed its name to Verder Inc. The company sells Verderflex brand hose and tubing, Verderair air-operated diaphragm pumps and SSP Alfa Laval rotary lobe and dual disc pumps.

Synagro appoints Zimmer president, CEO

Synagro Technologies Inc. appointed Eric Zimmer president and chief executive officer. Zimmer has 22 years experience in the environmental services industry. He joined the company in 2011 as executive vice president of Synagro’s services division and succeeds Bill Massa who resigned in October.

Microsol acquires SOLON and subsidiaries

Microsol, a United Arab Emirates-based solar cell manufacturer, acquired components of the insolvent SOLON SE and its subsidiaries, including U.S.-based SOLON Corp. The main sites in Germany, the United States and Italy will be maintained. The purchase price was not disclosed.

American Flow Control names sales manager

American Flow Control, division of American Cast Iron Pipe Co., named John Hagelskamp division sales manager. He will work with current sales manager Walter L. Cooper, who is retiring in 2013.

Netzsch Pumps names vice presidents

Netzsch Pumps North America named Julio C. Ferreira vice president of sales and John Maguire vice president of operations and product management. Ferreira has 30 years of industry experience. Maguire has been with the company for 20 years, most recently as vice president of sales.

The operator said the plant had been running well, producing quality effluent with discharge values well below the state permitted levels. When the operator came in to service the facility after a recent weekend, the effluent looked cloudy, with a hazy brown coloration.

He described the aeration tank’s appearance: The mixed liquor suspended solids (MLSS) looked thin, as if most of the solids had disappeared. The return activated sludge (RAS) flow from the clarifier was also thin and watery. He noted that sludge clumps were seen in the aeration tanks that looked gray, like shaggy mop heads rising and sinking again (Figure 1).

Solids washout?

The Lab Detective arrived at the plant and found the operator’s description accurate. One theory discussed with the operator was the possibility of a hydraulic washout of the mixed liquor solids, but further investigation of the chlorine contact tank and the effluent discharge into a percolation pond found no evidence of such an event.

There were several sludge clumps in the corner of an aeration tank near the surface. The detective picked up a long-handled pool-cleaning brush and broke up the clump releasing a massive number of small red worms. Acting on a hunch, he assembled his core sampler, a clear plastic device for measuring the sludge blanket.

Using the sampler in various locations around the actively mixing aeration tanks, he located the missing mixed liquor solids. As the Lab Detective poked the sludge core sampler all around the bottoms of the tanks, large amounts of bubbles were released, and clumps of dark brown to gray sludge rose to the surface.

As the clumps surfaced, the detective stirred the clumps with the pool brush, again releasing large numbers of red worms that began wiggling throughout the tank. He identified the worms as midge (Chironomid) fly larvae. These larvae, commonly called bloodworms, range from a few fractions of an inch to as long as one inch, depending on where they are in their life cycle (Figure 2).

Short life cycle

Like most flying insects, Chironomids go through metamorphosis from egg to adult. Male midges gather in a mating swarm that can be readily seen near standing water, ponds, creeks and streams, and there may be 100 or more males flying around in the group. When a female enters the swarm, a male and the female will mate.

As they descend together to the water surface, the female deposits her clutch of fertilized eggs onto the still water surface (most likely a secondary clarifier in this case). The egg mass sinks into the settled sludge or clings to the algae that grow on the tank walls. As the eggs incubate, they become tiny larvae.

The larval midge has a sticky outer layer covering its body, and the very fine suspended solids surrounding the young midge begin to accumulate on its exterior, forming a kind of tube. The young midge also feeds on decaying organic matter, so it grows and grows as it collects the silt-like organic material that enters the tube.

As the midge larvae mature (anywhere from two to seven weeks), they transform into pupae. After several days, the pupae emerge from the tube and swim to the surface, where they become adults after a few hours. The adult midge flies up into the air, enters a mating swarm, and the whole cycle begins again.

Adult midges live only a few days. Each adult female can lay an enormous number of eggs, from 100 to 3,000, depending on the species of Chironomid. The adult midge looks very similar to a mosquito (some folks call them blind mosquitoes), but they do not bite, and male midge flies have distinct feather-like antennae (Figure 3).

Time to pump

The operator of this small wastewater treatment plant had experienced a midge fly invasion. As the midge eggs were laid in the clarifier, the return activated sludge (RAS) airlift pump sent the egg-filled sludge into the aeration tank. Since the solids were so thick with sticky egg masses, the end result was like adding a coagulant (polymer) to the basins.

Piles of settled solids were gathered in the aeration tanks and clarifiers. A condition known as coning had been occurring in the clarifier, where thick solids would not move toward the airlift return sludge pump suction. That allowed a thin sludge to flow over and around the thick sludge to the pump suction.

To remedy the situation, the operator called in a sludge hauler to pump out the thick, midge-infested solids from the aeration tank bottoms and clarifiers. He re-seeded the treatment plant with fresh, healthy return activated sludge from another nearby treatment plant. The facility recovered quickly and began producing a good-quality effluent within a few days.

Nuisance on the wing

Midge flies can be a significant nuisance. Operators can breathe them in or get them in their eyes or mouths while walking around treatment plant grounds. Swarms can affect residents of surrounding neighborhoods. Midges provide food to spiders and other insects, so equipment, handrails, pumps, motors and light fixtures can quickly become filthy. So how can midge flies be controlled? There are several methods:

• Minimize plant lighting at night. Operate outdoor lighting at treatment units, filters and tanks only when needed. This may save a few dollars on the electric bill, too.

• Keep treatment units clean. Control algae buildup and keep areas of standing water clean.

• Use a product that contains Bti (Bacillus thuringiensis israelensis), a group of bacteria that produce toxins that only affect the larva of flies. Bti is an active ingredient in a product called Mosquito Dunks, produced by Summit Chemical. This product can be found at most home-improvement stores or by contacting a local aquatic insect control agency near you. It has been used to control all kinds of mosquitoes and midges.

• Use a product containing methoprene, a chemical that mimics a juvenile growth hormone that inhibits midge larvae from becoming adult midges, breaking the life cycle. Methoprene is found in a product called Strike by Zoëcon. It has been used successfully in the wastewater treatment industry to control trickling filter flies and midges.

• Use a product that forms a monomolecular film (MMF). A thin film spray-applied to standing water, reducing the surface tension. Mosquito and midge larvae, pupae and adults cannot cling to the liquid surface (Figure 4) and essentially drown. Cognis Corporation produces a product called Agnique MMF that has been used for this purpose.

• Introduce a natural predator, the Gambusia, better known as the mosquitofish (Figure 5). They can be found in most shallow freshwater habitats, where they are safe from larger predators. Gambusia feed on mosquito and midge fly larvae, pupae and adults. They are resilient to harsh environments (such as low dissolved oxygen and temperature variations) and are considered by some to be the most widespread freshwater fish.

Mosquitofish can be harmful to native fish in streams and ponds, but for use in a wastewater secondary clarifier, that probably won’t be an issue. The Lab Detective has used this method at a small package-type treatment plant with some success. He released 20 mosquitofish into a midge- and mosquito-infested clarifier. Several days later, most all the larvae were gone, and the fish looked as if they had gained 10 pounds.

Whatever the method of Chironomid control you choose, it’s always a good idea to check with your local and state regulatory authorities to be sure it is approved and will not harm the environment, the treatment plant or the public in any way. Check with other users of the chosen products to get their input on dosage and efficacy. As always, use chemicals with care and practice safe handling.

About the author

Ron Trygar is senior training specialist in water and wastewater at the University of Florida TREEO Center and a certified environmental trainer (CET). He can be reached at rtrygar@treeo.ufl.edu.

References

1. “Chironomid Midges,” Ernest C. Bay, Emeritus Urban Entomologist, Washington State University Cooperative Extension, Puyallup, 2003.

2. “Biology and Control of Non-Biting Midges,” Charles Apperson, Michael Waldvogel and Stephen Bambara, Extension Entomology, North Carolina State University, North Carolina Cooperative Extension, 2006.

After college, before landing a job in my field (journalism), I worked on the banquet setup crew at a high-end hotel. One day the maitre’d asked my colleagues and me to polish some silver sugar-packet holders for the banquet tables.

I was indignant; I was hired to muscle tables, chairs and room partitions around, not to do sissy work like shining up table doo-dads, and in not quite in so many words, I said so. After a closed-door “discussion” with the boss, I had to decide if I wanted to do whatever I was asked from then on or find my college-educated self on the street looking for another stopgap, near-minimum-wage job.

I decided my pride could stand polishing some silver, and in the few months I was there my pride stood doing various other non-macho things that just needed to get done. I taught myself to take pride in being part of the team and doing what it took to give customers a great banquet experience. Although I never polished silver again after I left there, the lesson stood me in good stead.

Pitching in

In TPO articles we meet a lot of people who apparently learned a similar lesson somewhere along the line. That’s true in Tacoma, Wash., where operators have helped in various ways to launch and sustain the TAGRO biosolids program.

Their contributions included brainstorming about and tinkering with the production process and the recipe, more or less within their realm, as well as lending a hand in less technical areas like marketing and public communication — likely not disciplines they learned in their job-related training and schooling.

No one had to twist their arms. They believed in the product, and they believed in beneficial use of biosolids, and so they did whatever it took to make the program successful — and it is.

Embracing change

Then there’s the crew at the treatment plant in Willmar, Minn. They spend countless hours, on top of their regular duties, helping to plan and design a new plant with a process they hadn’t run before.

It started with a leadership team taking part in planning and design workshops long before construction started. It extended to many hours of classroom and hands-on training on new equipment and procedures. It extended to making the switch from the old plant to the new, running both during the transition period. Then there was the matter of fine-tuning the new process until everything was running smoothly.

One can only imagine the extra hours the Tacoma and Willmar team members put in and the stress they added to their lives. But I am willing to bet that if you asked them, all would say they loved the challenge and, if asked, would do it again.

This is the norm

Stories like these shatter the stereotype of the public employee who just arrives at 7:30, does the bare minimum, and goes home at 4. We have many reasons to recognize and respect wastewater operators. This sort of diligence, which seems much more like the rule than the exception, is just one more.

Faced with too much inflow to the agency’s 3.6 mgd biotower/trickling filter wastewater treatment plant during the winter rainy season, officials created two dry ponds for temporary storage of wastewater. The ponds were built between the plant and the entrance to a nearby multi-use community park. Although plant general manager Steve Danehy wasn’t on the staff at the time, he knows of the ensuing controversies and the results.

“No one could have predicted this kind of outcome,” says Danehy. One pond serves the dual purpose of providing temporary storage of wastewater, while normally holding clean effluent to sustain plants and wildlife habitat.

Built for storage

Effluent leaves the plant through a 36-inch pipe near the ponds, starting a 6-mile trip to final discharge in San Francisco Bay. However, during a dry season just after a plant upgrade, a break developed in the effluent pipeline. While the leak was being repaired, final effluent was diverted and temporarily stored in the dry south pond.

“It took a while to sort out the cause of the leak, which was attributed to an outside contractor,” Danehy says. “During the time it took to negotiate action on the repair, waterfowl and shorebirds discovered the pond, and it turned into a nesting habitat.” Cattails and other native plants took hold, and suddenly the pond became a popular destination for birdwatchers and nature lovers, who unofficially called it Gem Pond.

Usage conflicts

Controversy erupted in the early 1990s when a group asked the plant to create a skateboard park by cementing over the dry north pond area. But those who enjoyed the south pond objected to the potential for noise and disturbance to wildlife. The dispute was settled when the sewerage agency found it could not get insurance for a city-sponsored skateboard park.

Over time, vegetation began to overrun the south pond, and the agency’s board reconsidered whether the 2-acre pond was suited for dual use. A proposal to drain it and return it to its original purpose drew another public outcry. This time the agency created a management plan for maintenance of the pond that includes mowing and periodic clearing of cattails.

In 2000, the board was confronted with the need to increase the pond’s wastewater storage capacity. “The ponds are earthen, and over the years the sides settled,” says Danehy. With little objection from activists, they decided to raise the berm around the pond instead of permanently lowering the normal level of treated water and threatening the wildlife habitat.

Since then, a sign has been installed in a kiosk that lists more than 120 species of native and migratory birds pond visitors have seen there. And a change in insurance regulations has allowed a skateboard park to be built near the Mill Valley Middle School, away from the pond.

F-Series premium carbon adsorption systems from Advanced Carbon Systems are engineered to maximize carbon life and minimize operational costs. They feature complete FRP construction from premium vinyl-ester epoxy resin with inner corrosion liner and exterior UV-resistant gel coat. Carbon life is extended with more than 99.9 percent grease and mist particulate elimination.

The FRP fan is designed for long bearing life and maximum efficiency. Optional sound enclosures reduce noise to less than 55 dBA. The enclosures also maintain cool fan operation while allowing full access for greasing bearings and changing belts. Standard VFD control allows for precise airflow control while minimizing power draw. Adsorber vessels are available in deep-bed and radial flow configurations. 866/834-5674; www.advancedcarbonsystems.com.

Chlorine dioxide kits

AquaDry kits from Beckart Environmental are designed for on-demand preparation of chlorine dioxide (ClO2) without a generator. The kits offer quick, safe and simple preparation of ClO2 to control, reduce or eliminate odor in a variety of applications. The kits include one pouch each of reactor and activator that mix in water and are ready to use within about 10 minutes.

The system produces variable liquid concentrates by adjustment of the amount of water in the recommended formula. Applications include treatment plants, industrial wastewater processes, water reuse and recycling systems, and septic/sanitary treatment facilities. The kits are available in 100-gram and 5,000-gram pouches. Material can be prepared and stored in any suitable container following manufacturer recommendations, or mixed and dispensed using the company’s optional mix and feed unit. 262/656-7680; www.beckart.com.

Aluminum domes

Clear-span aluminum domes from CST Covers provide cover to above-ground and in-ground wastewater storage tanks. Aluminum’s corrosion resistance makes the domes well suited for corrosive wastewater environments. Lightweight dome structures are easy and fast to install.

The domes provide odor control, low maintenance and construction cost, and design flexibility. Structurally efficient, the domes meet site-specific load requirements while accommodating process equipment underneath or above the covers. They accommodate snow loads up to 300 psf and wind speeds exceeding 200 mph. Domes can be designed up to 1,000 feet in diameter. 913/621-3700; www.cstcovers.com.

Odor control system

The OdorDigest Duo system from Enduro/Bay Products is a staged compartment system that removes odorous compounds from a variety of sources. It is primarily used for applications with medium to high levels of hydrogen sulfide along with other odors that require a high degree of treatment. The system consists of an FRP vessel (round or rectangular) in a variety of sizes with an integral bioscrubber on the front end. This removes most of the hydrogen sulfide and is followed by a biofilter section. The first stage promotes autotrophic bacteria, and the second stage is designed for heterotrophic bacteria. 800/707-8655; www.endurocomposites.com.

Tank covers

Defender tank covers from Environetics are custom manufactured from industrial-grade materials to fit new or existing wastewater treatment tanks or portable water tanks. The odor control covers contain volatile organic compounds at their source. The low-profile structurally supported covers minimize emission treatment volume to reduce the cost of air filtration equipment. 815/838-8331; www.environeticsinc.com.

Energy-efficient UV

The Amalgam UV system from Engineered Treatment Systems (ETS) uses energy-efficient 800-watt lamps for disinfection. The chambers are designed using CFD models that predict performance. The units contain an inspection hatch, and automated wipers that keep the quartz sleeves free from fouling. The chambers can be installed vertically or horizontally, and will deliver a UV dose from 30 to 120 mJcm-2, depending on the application. 920/885-4628; www.ets-uv.com.

Vapor odor control

NoMask from Advanced Odor Controls is converted from a super-concentrated liquid to a vapor phase by equipment specified according to where in the wastewater process the odors are generated, from pump stations to biosolids handling. It is designed as an effective, safe and low-cost alternative to masking agents and scrubbing chemicals for stopping year-round, sporadic and project-related odor complaints. Emergency systems are available.

NoMask is biodegradable, environmentally friendly and reduces part-per-million levels of common odors such as hydrogen sulfide, ammonia, sulfur dioxide, and methyl mercaptan. The product complies with EPA guidelines 81-1, 2, 3, 4, 5, 6. Its LD50 rating is 0 and it is USDA approved. 410/421-9180; www.odorcontrols.com.

Retractable cover

The structurally supported cover system from Geomembrane Technology consists of a retractable sheet of high-strength, UV-protected, coated fabric tensioned across a series of low-profile aluminum arches that span a tank opening, to control odor.

The cover is sufficiently airtight to capture odorous off-gas for removal by ventilation, yet it can be quickly detached on three sides and retracted to expose the tank contents for inspection or maintenance. Rain and snowmelt run off. Intermediate aluminum walkways divide long tank covers into sections for easy retracting. Hatches can be located in the walkways for inspection or sampling access. Off-gas removal piping connects directly to the cover system. 603/569-0676; www.gticovers.com.

Coated storage tanks

HydroTec epoxy-coated tanks and Aquastore glass-fused-to-steel coated tanks from CST Storage (formerly Columbian TecTank and Engineered Storage Products) are designed for all liquid applications including wastewater, sludge storage, leachate, aerobic/anaerobic digesters, potable water and industrial liquids.

The modular steel design allows tanks to be erected on-site with minimal environmental disruption. The tanks offer protection and durability, low maintenance requirements and simple, safe construction. 913/621-3700; www.cst-storage.com.

Fume hoods superstructure

The UniFlow Aire-Stream fume hoods superstructure from HEMCO features unitized dual wall construction for chemical resistance, strength and durability. It is performance tested to ASHRAE 110-1995, UL 1805 certified for fume hoods and cabinets, SEFA1 recommended practices for fume hoods, and greener product certified. Custom sizes can be modified to suit special needs. The hoods include low flow constant-volume and variable-air volume models. Process-specific models are PVC-, phenolic-, or stainless steel-lined for perchloric acid or acid digestion. 800/779-4362; www.hemcocorp.com.

Launder covers

Launder Cover Systems from NEFCO are designed to inhibit growth of algae on launder trough and weir surfaces by blocking sunlight. Without sunlight, the algae are largely eliminated or reduced to a light film easily washed away with a hose.

The covers contain odors produced when effluent breaks over the weir or can operate with scrubber systems that draw the trapped gases off and treat them. The covers are designed to meet specified load requirements with safety factors and can accommodate safety railings where necessary. The covers also keep ice, snow and debris from the launders. 561/775-9303; www.nefcoinnovations.com.

Maximized disinfection

The TrojanUVSigna from Trojan Technologies includes the TrojanUV Solo Lamp technology. It reduces cost of ownership and simplifies operation and maintenance. Disinfection is maximized with a staggered, inclined lamp configuration and bank walls. The unit is well suited for large facilities wanting to upgrade disinfection systems or convert from chlorine. 888/220-6118; www.trojanuv.com.

UV lamp and sleeves

4000L medium-pressure ultraviolet lamp and 4000Q quartz sleeve assemblies from UV Superstore, designed by First Light Technologies, for microbiological control are designed to fit model UV4000 UV wastewater treatment disinfection systems. The HID 3.2 kW lamps and sleeve assemblies are individually packaged for maximum protection. 770/307-3882; www.uvsuperstore.com.

Bio-oxidation system

Bio-sumpVENT from Met-Pro Environmental Air Solutions is a lightweight, modular bio-oxidation system for odor control at lift stations, sewer vents, and other small, contained processes. The exterior is fiberglass plastic (FRP) with a sealed lid that houses an internal framework to support BioAIRSpheres organic media for the adsorption and digestion of odorous compounds. The system can handle H2S and other odor compounds (mercaptans) in airflows up to 200 cfm. Single-stack or multi-vessel systems are available.

The system can be combined with a Bio-Pro bioscrubber when higher levels of H2S are present in applications such as headworks, clarifiers, biological and solids processing and collection facilities. The combination of the bioscrubber with the organic media-based bio-oxidizer provides complete odor control for H2S and organo-sulfur compounds. 503/691-2100; www.mpeas.com.

Tablet chlorination

The Accu-Tab tablet chlorination system from PPG Industries offers a safe, simple solution for disinfecting water and wastewater. The system combines engineered chlorinators with 3-inch controlled-release 68 percent calcium hypochlorite tablets to deliver consistent, controllable levels of chlorine residual. Solution output is controlled by a diaphragm valve. The system can be integrated with an existing system. Once in place, the tablet system runs with little or no maintenance. 800/245-2974; www.ppgaccu-tab.com.

Cyclonic separation unit

The Hurricane Filtration System from Harmsco combines cyclonic separation, cartridge filtration, and up-flow technology in a compact filter housing. The system separates dense solids before cartridge filtration for extended cartridge life, increased dirt holding capacity and reduced operating costs. The up-flow design prevents air entrapment, and rotational flow around the cartridge improves cartridge-load performance.

Liquid flows into the housing through a tangential entry and is channeled between the outer housing and the inner housing wall. The inner wall rises from the base to just below the top of the housing so that liquid must flow around and then over the inner wall before entering the cartridge-filtration area. The outer flow creates a cyclonic effect, and a combination of kinetic energy and centrifugal forces combine to make dense solids bounce along the outer casing and lose velocity. The tangential entry is located high on the housing to reduce the velocity of liquid flow in the bottom of the outer chamber and promote settling of the dense solids. 800/327-3248; www.harmsco.com.

Odor abatement

Biological Air Treater (BAT) from Purafil provides efficient and cost-effective odor abatement and VOC treatment. With blends of polyurethane-foam cubes and polypropylene spacers, the unit offers a fixed-film biotrickling filter technology. The mixture of cubes and spacers prevents plugging and channeling, providing a lower pressure drop. The natural biotrickling microbial process, with stable biofilms resistant to fluctuations, requires little maintenance. The mixed media has been proven in various odor-control applications.

The design offers a small footprint, and users can include a chemisorptive polishing media for higher contaminant and odor removal. Applications include wastewater treatment plants, food and agriculture, chemical and pharmaceutical, and petrochemical. 800/222-6367; www.purafil.com.

Noncontact disinfection

ENAQUA noncontact systems are nearly maintenance free, low-cost solutions designed for sequencing batch reactors with up to 24 on/off cycles per day.

Water is directed through Activated Fluoropolymer (AFP) tubes, with dry UV lamps on the outside. Banks of lamps surround the tubes so that each tube is exposed to UV light from all sides, allowing for rapid lamp changes without the need to clean the quartz tubes. There is no need to interrupt or remove any hydraulic seals during lamp maintenance. The tubes need never be replaced or removed from the system.

The AFP tubes ensure that algae does not grow in the system, making it well suited for lagoons. The systems do not require weirs. 800/321-4989; www.enaqua.com.