WATER REUSE OF EFFLUENT ON A LARGE SCALE – WHAT WE CAN LEARN FROM OTHER COUNTRIES?

Valentine Environmental Engineers has been an advocate for water recycling technology for years and is at the forefront of grey water reuse and water reuse.  They have designed and managed multiple projects over the past decade blazing a trail for others to join this ideal.  “Preserving our fresh water supplies is important but eventually we will have to adjust our technology and how we view our water.  Water engineers and water companies need to collaborate and understand the need to recycle water from tap to toilet back to tap again,” says Dr. Teresa Valentine, managing principal.

Many countries are already doing this in large quantities because of the short water supplies in their region such as: Australia, Singapore, and Israel.

Whether water recycling is something you are doing today or plan to do in the future, the critical element for success is communication and education.  The tools NDEEP developed are based on research findings around perceptions and beliefs of stakeholders regarding recycled water.

There are three key questions we need to ask ourselves and we need to consider for the future of water in our communities especially here in our own backyards in the Southwest.

  1. What is the big picture? Being transparent and thinking about the complete water scenario is critical to give our communities and our citizens the facts they need to determine what is best for them.  NDEEP research shows that we cannot just communicate about water recycling, we need to help the public understand the entire urban water cycle, and how drinking water is produced, and primarily the risk in drought-stricken areas and the risk we face.
  2. What are others doing – what’s working, what’s not? It is our responsibility to learn from other best practices in our field and use those to improve our master plans and design philosophies.
    Another tool NDEEP created was a Global Connections Map showing information featuring expert and citizen commentary about potable water recycling schemes all over the world – including more than 50 videos featuring interviews with key personnel from the plant engineer and regulators of a particular scheme, to local politicians and citizens.
  3. How can we work together? We understand the importance of collaborating with municipalities, private companies, the public, other engineers, other planners, and the list goes on.  When all constituents are brought together to create a plan, it works – from operators in a plant to community leaders.

Water recycling is not new to our field but how we evolve it and talk about it can change how it is perceived and how we develop communities.  Water preservation is Valentine’s sole purpose, and a future of pure water is our vision.

Laundry washing units for water recycling

Laundry washing units

Laundry water treatment

Laundry water treatment

One example of the impact water recycling can have is Valentine’s water recycling projects with Corrections Corporation of America.  They utilize laundry water recycling which reduced water consumption by 80-90%, and shower water recycling for toilet flushing which reduced potable water demand by over 70%.  See the complete case study.

OPEN HOUSE FOR CEUs: SCREWSUCKER PUMPS & MOTORS

In October, Valentine held an open house to give the opportunity for participants to earn Continuing Education Units (CEU) and network with peers and colleagues.  The presentations covered self-cleaning wet wells and new advances in motor technologies.

Self-Cleaning Wet Wells

The screwsucker technology was in action with two types of self-cleaning wet wells including the Fairbanks Morse Trench wet well.   Hennesy Mechanical focused on different solutions that:

  • Provide unique hydraulic solutions for improved wet well cleaning
  • Overcome problems with non-biodegradable wipes
  • Provide a true safety backup with a portable high solids pumping system.
Screwsucker Demonstration

Screwsucker Self-Cleaning Wet Well

Screwsucker Demonstration -Self-Cleaning Wet Well

Screwsucker Self-Cleaning Wet Well

 

 

 

 

 

 

 

 

Download the full presentations for these self-cleaning wet wells.  1: ScrewSucker Presentation 2: Wastewater and Self Cleaning Wetwells

Motor Technology for Water and Wastewater Applications

There are so many options for motors that can satisfy a number of different problems and complex specifications.  US Motors talked about the latest and greatest motor designs and the plethora of capabilities for:

  • Efficiency improvements for energy savings and maintenance ease
  • New applications involving VFDs
  • New advances and industry standards for various motor applications.

Download the full presentation for detailed information on these motor technologies. Motor Technology

Every situation should be fully evaluated to determine the most optimal solution for specific challenges and wanted outcomes.  Valentine would be happy to further discuss what your needs are and recommend the proper design and technology to fit your operation and meet your goals.  Call Teresa or Mike Valentine at 480.283.8991.

Stay tuned for Valentine’s next Open House in 2014.

WHAT USES 40% OR MORE OF YOUR ANNUAL ENERGY USE AND HOW CAN YOU CHANGE IT?

City of Mesa SEWRP Turbo Blowers

City of Mesa SEWRP Turbo Blowers

Municipal water and wastewater plants, pumps, and lift stations can consume more than 40% of a city’s energy in a year to distribute, disinfect, treat, and pump water for their customers.  The City of Mesa realized this and took action to make improvements to their systems.

The City of Mesa Southeast Water Reclamation Plant (SEWRP) aeration improvements project represents a unique application of different technologies brought together to achieve two main goals; reduce energy use and optimize aeration and process control in the activated sludge process. The different technologies installed at the Mesa SEWRP include fine bubble aeration, high speed turbo blowers, and real time analyzers for nutrients (ammonia and nitrate) and dissolved oxygen.  The blend of these technologies as well as the cutting edge high speed turbo blower technology is a unique application in the State of Arizona.

Collectively, the turbo blowers and the fine bubble aeration saved the city more than 2 million kilowatt-hours annually which equates to more than 60% savings in energy use, or approximate $166,000.  Check out City of Mesa video and learn about their SRP rebates.

The heart of this unique aeration system is the high speed turbo blower.  The new high speed turbo blowers (200hp) provide additional 30% energy efficiency over the existing centrifugal blower (400hp) technology due to several key benefits of this cutting edge technology.  The benefits include:

  • Lower installed motor horse power (HP) due to a more efficient blower design
  • Efficient blower design components include the direct drive impeller to motor configuration coupled with an air bearing design and the more efficient permanent magnetic synchronous motor
  • Up to 40% turndown capability due to variable frequency drive

Like many WRPs, the Mesa SEWRP experiences diurnal swings in influent flow and loading.  A conventional aeration system consisting of constant speed centrifugal blowers, dissolved oxygen analyzers and modulating or manually operated airflow control valves is typically utilized and was the original method installed at the facility.  The conventional system has two main shortcomings, limited ability for airflow turndown on centrifugal blower, and thus limited ability to optimize energy consumption and process control. Furthermore it lacked the partial optimization of energy use and process control that can be realized with dissolved oxygen only control.

Due to the shortcomings of the existing aeration system, the Mesa staff at the SEWRP found the existing centrifugal blowers to be limited in their turndown capabilities, resulting in high devolved oxygen (DO) concentrations during low flows and forcing staff to blow off air excess to maintain DO concentrations.  The generally higher DO concentrations consequently also increase the DO concentration in the anoxic zone due to internal mixed liquor return flows, resulting in inefficient nitrogen removal.  Mesa operations staff had devised an interim control strategy for inlet valve modulation which achieved some turndown, but it could not provide significant energy savings.

The combination of fine bubble aeration, high speed turbo blowers, and both dissolved oxygen and nutrient analyzers offers a combined solution that optimized energy use while at the same time improved process control.  The fine bubble aeration alone has resulted in approximately 30% greater oxygen transfer efficiency over the existing coarse bubble diffusers.  The fine bubblers were designed with a tapered heads allowing for minimal transfer of oxygen from final aerated zone back to the anoxic zone.

Although fine bubble aeration is not a new technology, coupling it with nutrient/DO controls provided for a unique application with this project.  The fine bubble aeration control valves at each of the aeration basin zones will now modulate and control both the DO set point and an overriding ammonia set point.  Thus, even when the optimum DO requirement is met and ammonia set point indicates treatment to be complete, the control strategy will further decrease the DO set point to further optimize energy usage.

In addition to the energy, control and technology benefits, the high speed turbo blowers required less overall maintenance than conventional blowers and operate at a significantly reduced noise level.  The operational noise is a real added tangible benefit for plant staff that has to work in close proximity with the system on a daily basis.

Bringing together new technologies and blending it with various applications has provided the City of Mesa with an innovative solution to accomplish major financial and operational goals.  The techniques that have now been applied provide a significant energy savings which reduces overall operational costs and CO2 emissions.  This project has been a great example of how technology and the use of variable control techniques in the application of that technology can solve many of our greatest wastewater challenges.

ODOR CONTROL TECHNOLOGY

Finished oxygenation project

Photo compliments of Anue Water Technologies

Finished ECO2 project
Photo compliments of ECO2 Laguna Beach LS, CA

The Odor Control Struggle and What To Do About It

BENEFITS OF A NO-CHEMICAL ODOR CONTROL SOLUTION:

      • Improves odor and corrosion control
      • Reduces operating and maintenance costs
      • Improves overall performance

 

Oftentimes in sewage collection systems that utilize forcemains, there is a wide range in diurnal flow which causes sewage to sit or flow slowly in the forcemain for extended periods of time.  The onset of anaerobic activity and hence production of sulfides from sulfate occurs during these time periods resulting in high hydrogen sulfide odors at downstream lift stations or treatment plants.

Many municipalities utilize chemicals such as chlorine, ferrous salts, peroxide, bioxide, etc., to reduce the production of hydrogen sulfide downstream.  They are challenged with these methods to provide effective odor control at a reasonable cost to operate and maintain.   These methods are band aid solutions that do not address the real issue – the onset of an anaerobic condition.  As a result, they are dissatisfied with the impact on their wastewater treatment and the release of odors into the atmosphere.

Valentine has conducted studies to examine old and new technologies to evaluate real time situations, and determine more sustainable and efficient solutions.


CASE STUDY:  OXYGEN/OZONE TECHNOLOGY IS SUSTAINABLE CURE

THE SOLUTION

If the anaerobic conditions are removed from the forcemain, there is no possibility for sulfides to form.  Oxygen or a combination of oxygen and ozone is used in place of chemicals, forcing the environment in the forcemain to go from anaerobic to aerobic.  Once in the aerobic state, the bacteria that reduce sulfates to sulfides can no longer survive.  Several companies have developed oxygen/ozonation feed systems for injection into the sewer to solve the odor control problem – Anue, BlueInGreen, ECO2.  These methods replace the traditional treatment chemicals to offer a safer and more environmental sustainable solution.
BENEFITS OF OXYGEN/OZONATION TECHNOLOGY

Besides treating the systemic problem of H2S formation, the use of oxygen/ozone offers many other benefits:

      • Delivers proven odor control or H2S removal – better removal than other technologies, and in some cases there is virtually no H2S at discharge point, and continued odor control through downstream processes.
      • Eliminates handling of hazardous chemicals
      • Reduces corrosion of equipment
      • Reduces the system footprint
      • Reduces the overall life cycle cost – energy, operations, and maintenance

Valentine provides turnkey water and wastewater systems development from program management to permitting and design, from operations support to construction phase services, their “waves of excellence” delivers the right water solutions specific to your facility.

WHICH IS MORE EFFICIENT – Suspended Air® Flotation (SAF™) or Dissolved Air Flotation (DAF)?

 

Skid mounted SAF unit

Skid mounted SAF unit

 

SAF generators

SAF generators

Which is more efficient – Suspended Air® Flotation (SAF™) or Dissolved Air Flotation (DAF)?
Suspended Air® Flotation (SAF™) is the next generation of solids removal for industrial and municipal waste streams.  This process is capable of greater solids removal than a conventional dissolved air flotation (DAF) system while using a footprint up to ten times smaller.  How does SAF achieve these better efficiencies?  The process uses an externally-generated bubble suspension with high air content. Each bubble is covered with a chemically active film which strongly attaches to the flocculated solids in the water being treated, achieving high rate and efficient flotation. DAF, by contrast, uses high pressure to dissolve a small amount of air in water with no chemically active agent, and depends on physical entrapment and a weak surface bond to float the flocculated solids.

Benefits of SAF™ = Increased Efficiency:

  • Smaller footprint
  • Less energy use
  • Removes more solids
  • More flexible operationally
  • More cost effective

This technology can be a stopgap for many clients who need a cost effective, easy to operate solution to their solids handling problems.  Whether you are a municipal client seeking to treat in-plant waste or recycle streams or improve your DAF’s performance; or an industrial client requiring pretreatment before sewer discharge, this technology offers many advantages for each unique scenario.

Learn more about SAF™ and watch these videos:

  1. Trade Show Float – demonstrates the separation of solids to the surface
  2. UC Davis – shows the actual system working with the flow of raw water that have separated from the solids that have floated to the surface

For more information, please visit www.heroninnovators.com.

VALENTINE EVALUATING INNOVATIVE ODOR CONTROL TECHNOLOGIES

Experiencing long detention times and sewer odors in your sewer force mains?

Troubled with high H2S gas concentrations at the downstream manhole or WWTP?

Tired of excessive chemical use to control the situation?

ECO Oxygen Technologies offers an innovative, energy efficient technology that cuts hydrogen sulfide gas production at the source.  This simple technology involves the superoxygenation of the force main, raising dissolved oxygen levels thereby removing the conditions in which dissolved sulfides form.

Valentine is currently evaluating this technology for a local municipality and is excited about its potential benefits.  For more information on this technology visit www.eco2tech.com.

ENERGY SAVINGS WITH TURBO BLOWERS

 

40% REDUCTION in energy costs

 

Energy Savings with Turbo Blower Technology

 

BENEFITS TO YOUR WASTEWATER TREATMENT PLANT (WWTP):

  • 40% REDUCTION in energy costs
  • NO noise
  • SMALL footprint
  • MINIMAL Maintenance

The typical WWTP uses 40% of its overall energy consumption in its aeration process. Positive displacement or multistage centrifugal blowers are two technologies that are utilized for process aeration. These technologies, while proven, are energy intensive. These technologies are also noise and maintenance intensive.

Valentine Environmental Engineers designed the expansion and upgrades to the Arizona American Water Company Wishing Well Water Reclamation Facility (AAWC). The facility was equipped with a small blower room and conventional blower technology. The WRF aeration capacity was being doubled but the available space did not increase. The new conventional blowers to meet the increased capacity could not fit in the building, exceeded available electrical supply and would require HVAC modifications to the building to evacuate the additional heat load from the new, larger conventional blowers.

Valentine and AAWC investigated the problem from all angles and the challenges presented to determine the best use of space and more modern technology.


Case Study: Arizona American Water Company Wishing Well WRF

The Solution

The dawn of the Turbo Blower Technology has revolutionized the process air blower supply for WWTPs. Turbo blowers are not only quiet and require a small footprint, they are more efficient than conventional blowers and offer greater turndown capabilities.

Turbo blower technology has its roots from the aviation and aerospace industry. This technology relies on an air foil bearing supported on a shaft that is directly integrated with the variable frequency drive, motor and control system in a single enclosure. The air foil bearing eliminates friction between the bearing and the shaft and thus improves the efficiency of the blower while allowing 40% turndown capability.

Success with the Turbo Blower Technology

Valentine and AAWC investigated the Turbo Blower Technology to resolve all of the project issues:

  • Ability to install turbo blowers in existing space without having to expand the building
  • No requirement for additional electrical power due to the efficiency of the units and requires less installed hp overall
  • No HVAC retrofits required as blowers produce virtually no heat and can function at temperatures of 120 F

The blowers reduced overall construction and operations costs. Turbo Blower Technology is significantly more efficient than conventional blowers. You will save on energy costs, decrease noise, reduce your footprint and reduce your maintenance costs with newer methods.

Other turbo blower retrofits that Valentine Environmental Engineers designed:

  • Corrections Corporation of America Eloy Detention Center – three new 50 hp blowers
  • City of Scottsdale Gainey Ranch – replacing three existing 75 hp blowers with three new 50 hp turbo blowers, 6.7 year payback, $50,000 annual energy savings
  • City of Scottsdale Water Campus – replacing two existing 400 hp blowers with three new 250 hp blowers, 3.4 year payback, $200,000 annual energy savings
  • Other projects in the design phase for City of Tempe and City of Peoria

EXPERTS ON ENERGY AUDITS

Blower Energy Audits performed by Valentine Environmental Engineers at local WWTPs are continuing to prove successful from both an energy savings and rebate perspective for local municipalities.  Valentine has performed or is in the process of performing upgrades of the centrifugal blowers at four major WWTP facilities in the Phoenix area.

The blower technology will be upgraded to high speed air bearing turbo blowers and is estimated to realize nearly $1M annually in energy savings and garner over $700,000 in one time rebates from SRP and APS.

For more information on these projects see the Projects List or Energy Audits area of our website or call Teresa Valentine at 480-283-8991.

VALENTINE ON CUTTING EDGE OF WATER RECYCLING

Valentine Environmental Engineers recently acquired the first grey water permit in the state of Arizona for laundry water recycling. This innovative package treatment technology, manufactured by AquaRecycle, treats the laundry discharge and recycles it back to the washing unit for use in the next washing cycle.

Water savings of 60 to 85% are realized along with energy reduction benefits. The laundry recycling will be utilized in local prison facilities with a total savings of over 40,000 gallons per day or 14.6 MG annually.

For more information on the laundry recycling technology visit www.aquarecycle.com or call Teresa Valentine at 480-283-8991.