Services

Process Studies and Optimization

Perhaps more than anything else, Hazen and Sawyer’s reputation is founded on the superior technical work we provide helping clients meet their water quality goals.

Combining innovative process design with our in-depth knowledge of regulatory requirements, we have amassed a valuable depth experience in evaluating and implementing pretreatment technologies to ensure water quality and protect public health.

Often, process optimization can achieve several desired outcomes at once, extending the useful life of a water or wastewater treatment plant and maximizing the return on the initial investment. We specialize in optimizing the process design of treatment plants to meet regulatory requirements, often reducing energy and other operating costs at the same time. Increasing capacity without significantly changing the infrastructure of a plant is another frequent outcome, delaying significant capital expenditure.

Process studies yield many of the same benefits, identifying alterations in treatment process that meet regulatory requirements while eliminating the need to construct costly new facilities. Studies can identify the need for advanced technologies, but just as often proven bench-scale testing coupled with utilization of innovative water quality computer modeling software identify more simple-to-implement and cost-effective solutions.

BioWin

We have developed a state-of-the-art, site-specific approach to process modeling, design, and optimization using BioWin simulations. This process model is used to simulate the performance of numerous unit processes, including primary settling tanks, aerobic, anoxic and anaerobic bio-reactors, IFAS bio-reactors, and final settling tanks, and can be used to simulate the infrastructure of a plant. The BioWin model also incorporates the flexibility to add chemical treatments, such as carbon (e.g. methanol), alkalinity, and metal salt addition.

BioWin provides a powerful interface for interactive steady-state and dynamic simulation of wastewater treatment systems. The dynamic simulations allow us to model the plant under wet weather flow conditions and determine the plant’s operational and effluent response to the high flow conditions. This approach ensures our clients of the most cost-effective, flexible, and robust solution for their needs. This approach has been used in the design of new treatment plants, facility upgrades for more stringent limits, plant expansions, facility re-ratings, and plant optimizations. We have used this approach at numerous plants, including several with treatment standards at the limits of technology (LOT), with requirements of Total Nitrogen effluent less than or equal to 3 mg/L, and Total Phosphorus effluent less than or equal to 0.15 mg/L.

The 2Dc Model

Hazen and Sawyer co-developed and currently uses the 2Dc CFD clarifier model. This model is a quasi three-dimensional clarifier model that can be used as an aid for designing and optimizing primary and secondary, circular and rectangular clarifiers. Developed at the University of New Orleans, the 2Dc model is a state-of-the-art tool that was built upon more than 30 years of experience on clarifier modeling.

The use of the 2Dc model requires extensive field calibration and close understanding of numerical methods, clarifier design, treatment process and the model itself; and Hazen and Sawyer has unequalled experience with its usage. With several modeling applications and the added capability of being able to modify the source code to match clarifier geometries not included in the original model release, Hazen and Sawyer’s staff have the knowledge and expertise required to apply this sophisticated tool to:

• Accurately predict ESS and sludge blanket depth from plant specific clarifier geometries
• Determine clarifier design and operational deficiencies not identified by traditional evaluation methods
• Validate the use of wet weather strategies to improve clarifier performance under extreme conditions
• Identify potential improvements to existing infrastructure and operating strategies that result in improved reliability in meeting stringent requirements and improved capital cost control through better use of existing facilities

Increasingly stringent regulatory standards, rising energy prices, and the cost of capital all threaten the successful operation of treatment plants large and small. Hazen and Sawyer can help you explore your alternatives and implement a solution that meets your water quality goals.