TechnologyAbout Our Wastewater Systems

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Decades of Research

An intensive and ongoing research program began in 1976 that was designed to resolve the common problems and limitations associated with traditional wastewater lagoons/stabilisation ponds including odour, short-circuiting, uneven loading, sludge accumulation and poor overall processing rates. 40+ years later, Gurney Environmental offers technology and designs based on this 4+ decades of intensive study of hundreds of municipal and industrial wwtp's from around the world.

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Mechanical vs. Biological

The more biological/biochemical removal of contaminants used in a treatment scheme, the lower the initial cost (CAPEX) and ongoing costs (OPEX) for a wwtp. 40+ years of research have defined the extraordinary capabilities of advanced biological/biochemical wastewater treatment.


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Truly Advanced Lagoon Design

Four decades of research based on solving problems with hundreds of wwtp's worldwide has resulted in a design philosophy that provides high rate processing, no odours and complete sludge digestion.

New-build lagoon systems are designed with the correct length-to-width ratio, parallel trains of cells to avoid large, poorly performing cells, and correct/optimal depth of cells to maintain perfect aerobic conditions while allowing for a smaller footprint. Experience does make a difference.


What Are Facultative Biological WWTPs Capable Of?

Gurney Environmental's advanced biological systems are well-proven and easily capable of very consistent performance with high processing rates, advanced treatment levels, no perceptible odours, no sludge accumulations and excellent accommodation of peak and shock flows. They can, in some cases, even be practical for very large population applications as well.

What has been the cause of misconceptions and myths about "lagoon-based" biological systems? Essentially, incorrect myths, wrong assumptions and poor design. Often lagoon systems are actually designed assuming that erratic, poor performance is "normal" operation.

The "Cardinal Sins" of Lagoon Design

In correct "advanced" facultative biological lagoon design, there are several key design factors that will affect various aspects of performance. Using Gurney Environmental's advanced design criteria – based on years of correcting and resolving problems with existing wwtp's – ensures superior performance.

Wastewater Design Considerations

  • Cell Geometry and Flow +

    An extraordinarily critical factor in the performance of lagoons is correct physical design. Based on experience with hundreds of lagoon-based municipal and industrial wwtp's, experience proved that better physical design results in superior, more reliable, robust and predictable performance of Gurney Environmental designed wwtp's.

  • Detention Time +

    The amount of time wastewater spends in each stage of treatment is highly critical and is temperature dependent. Modern lagoon-based systems are typically comprised of two or three stages of treatment — primary, secondary and possibly a tertiary or polishing stage. Each stage is designed for an approximately 80–85% reduction at summer water temperatures (20° C) taking a predictable amount of time at any given water temperature for the biology to establish and perform its reductions. Colder water temperatures are offset by longer detention times. However, note that historically systems successfully operate in 1- 2° C water temperatures. The warmer the average yearly water temperature, the faster the biological/biochemical removal rate.

  • Surface Organic Loading Rate +

    Nature can only provide a certain amount of natural aeration/oxygen production through photosynthesis and atmospheric absorption for a given climate. In colder climates, correct non-aerated/"accelerated" primary cell loadings typically run 20–25 kg/ha/day, while warmer climates can be loaded at up to 50–75 kg/ha/day.

    The Effects of Loading Rates That Are Too High

    Loadings in excess of these rates in non-accelerated systems will cause the biology to become dormant (anoxic) and sluggish resulting in odours, sludge accumulations and lower processing rates. Therefore, very specialised supplemental aeration and process "optimisation" equipment must be added to systems with higher loadings. Correct loading rates and detention times have been proven to provide strong, reliable and consistent performance in full-sized, commercially successful facilities — not just in "test" or experimental systems.

    Ignoring these basic design rules simply means that lagoon-based systems will not perform as well as correctly designed, optimised lagoons can and do.

  • "Real-World" Cell Loading +

    Correct cell loading is critical in order to maintain truly aerobic cells. Unfortunately, many lagoons are designed so that a bulk of the organic loading is concentrated within the influent zone and the waste then short circuits directly to the effluent structure reducing actual true detention time. Massive overloading occurs in that influent-to-effluent stream whilst huge areas of the cells are dramatically under-loaded and poorly utilised.

    The simple addition of the Gurney Environmental SERIES 3 windpowered aeration/optimisation units within the influent zone and throughout the cell does several critical things:

    Disperses the loading out from the influent zone, thereby uniformly loading the entire cell area;

    Increases true detention time by eliminating short circuiting, thus increasing removal rates;

    Improves the DO of the entire water column without disturbing the critical layering of the cell.

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Advanced Design Standards

Based on Decades of Research and Actual Successful Use

100% Complete On-site Treatment

Both Accel-o-Fac® and Aero-Fac® wwtp's provide complete on-site treatment including the removal and digestion of all biosolids. Energy and manpower requirements are a fraction of activated sludge plants. Maintenance is minimal and capital equipment lasts far longer. Using 40+ years of intensive research into lowering the total life cost of wastewater treatment, Gurney Environmental has the experience and proven track record of successes to provide extremely robust and low CAPEX, OPEX and TOTEX, truly sustainable systems unmatched in the industry.

Scalable, Modular Design For Any Size WWTP

Both Accel-o-Fac® and Aero-Fac® utilises multiple cells in parallel trains and in series. Each cell or stage reduces BOD by about 80-85% (water temperature dependent). Parallel trains provide for a modular approach to accommodate larger flows with complete and predictable scalability.

Examples of Modular Scaling

Comparison of OPEX in Wastewater

All Gurney Environmental systems come with design assistance and follow-on operational support.

  • Activated Sludge
  • OPEX 100%
  • High CAPEX
  • High initial cost and complex, expensive ongoing energy & operations costs
  • Shock & Peak Loads Can Upset Process
  • Prescreening Equipment Generally Required
  • Aeration Required for Both Oxygen & Mix
  • Clarifier Required
  • Can Have Odour Issues
  • Sludge Handling & Regulation Required
  • High Consumables/Chemicals
  • High Level of Operator Attention/Expertise
  • Annual Maintenance*
  • ?????
  • * 4000 m3
  • Aero-Fac®
  • OPEX –85%
  • Low CAPEX
  • Low initial cost and dramatically lower ongoing energy & operations costs
  • Easily Accepts Shock & Peak Loads
  • No Prescreening Equipment Required
  • Aeration Required only for Oxygen Demand
  • No Clarifier Required
  • Odour-Free wwtp
  • No Sludge Handling & Regulation Required
  • Few Consumables/Chemicals
  • Very Low Operator Attention/Expertise
  • Annual Maintenance*
  • £882/yr est.
  • * 4000 m3
  • Accel-o-Fac®
  • OPEX –95%
  • Lower CAPEX
  • Low initial cost and dramatically lower ongoing energy & operations costs
  • Easily Accepts Shock & Peak Loads
  • No Prescreening Equipment Required
  • Aeration Required only for Oxygen Demand
  • No Clarifier Required
  • Odour-Free wwtp
  • No Sludge Handling & Regulation Required
  • Few Consumables/Chemicals
  • Very Low Operator Attention/Expertise
  • Annual Maintenance*
  • £532/yr est.
  • * 4000 m3
  • WS Ponds
  • OPEX –97%
  • Lowest CAPEX
  • Low initial cost and low ongoing energy & operations costs, but several common problems
  • Problems With Shock & Peak Loads
  • Prescreening Equipment Sometimes Required
  • No Aeration used for Oxygen Demand
  • No Clarifier Required
  • Can Have Odour Problems
  • Possible Future Sludge Removal Required
  • Few Consumables/Chemicals
  • Very Low Operator Attention/Expertise
  • Annual Maintenance*
  • £200/yr est.
  • * 4000 m3

Both Aero-Fac® and Accel-o-Fac® can be designed as modular units and can accept a wide range of flows and loading. Both Systems can be designed as "new build" or retrofit to existing wwtp's.

Interested? Want to contact Gurney Environmental?

We'll be happy to work with you on ideas to solve your water and wastewater treatment problems.

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