Post Point Wastewater Treatment Plant
Bellingham, Washington
The paper describes an approach to design and control of high purity oxygen (HPO) activated sludge treatment systems incorporating anaerobic zones for settleability control, efficient oxygen transfer, and control of dissolved oxygen concentration through variable speed drives. A case study from an upgrade project in Bellingham, Washington is used as an example of the approach. Results from upgrade of the Post Point WWTP provide proof that significant improvements can be made in the process control and energy efficiency of HPO plants. Improvements to sludge settleability can result from conversion from fully aerobic to anaerobic selector operation. Continuing improvements in oxygen transfer can make upgrade of impellers economical. Provision of variable speed drives reduces waste of DO, drive power, and HPO gas. Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: Waste Water Treatment | Tags: Energy Savings, Improved Oxygen Transfer, Improved Plant Efficiency, Improved Sludge Settleability, Reduced Loss of DO in the Effluent | No Comments »
Mill Creek WWTP and MWRD's Robert W. Hite Treatment Facility
Cincinnati, Ohio and Denver, Colorado
The business novel The Goal was used as guidance for the optimization/continuous improvement work at the Metropolitan Sewer District of Greater Cincinnati (MSD) and greater Denver’s Metro Wastewater Reclamation District (MWRD). The work at both utilities has been successful. Increased capacity and better and more stable performance has been realized at MSD’s Mill Creek Wastewater Treatment Plant while decreasing operating expenses; better and more stable performance has been realized at MWRD’s Robert W. Hite Treatment Facility. Source: WEFTEC 2008 Proceedings
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Posted: August 27th, 2010 | Filed under: Waste Water Treatment, Water Treatment | Tags: Cost Savings, Energy Savings, Improved Effluent, Improved Sludge Quality, Increased Plant Capacity, Plant Optimization | No Comments »
City of Taft POTW
Taft, California
One solution to address overloaded collection and treatment systems is to develop satellite units for wastewater treatment. The challenge is to implement a treatment system of such efficacy that these satellite units can exist throughout an area without a large footprint. Membrane bioreactors are one option; electrocoagulation is another. Ecolotech systems are designed to meet effluent criteria that allow the non-potable reuse of the effluent, while solids are transmitted to the centralized wastewater treatment plant. The system can create an unobtrusive water recovery facility by replacing tradition treatment equipment. A small footprint can be used to effect a 95% reduction in wastewater effluent to the collection system, an odor-free system, rapid implementation, and a source of emergency non-potable water. This paper describes the electrocoagulation process, Ecolotech system components, and case study results providing proof of concept for use in small wastewater treatment and water recovery facilities. Pilot testing of the Ecolotech system has demonstrated that that electrocoagulation is a viable technology and that each unit can treat up to 250 gallons per minute (gpm) of wastewater. The Water Recovery Treatment Center is a viable option for communities that want to offer wastewater treatment to new development without having to invest heavily in new or upgraded infrastructure. Reusing treated wastewater will reduce the use of potable water for non-human consumption uses, therefore conserving a valuable resource for the community. Small-scale (<2 mgd) MBR systems typically cost about $10 million per mgd capacity. The Ecolotech system is estimated to be approximately 40% to 60% of the MBR cost, depending upon site conditions and other factors. Source: WEFTEC 2008 Proceedings
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Posted: August 27th, 2010 | Filed under: <50K, Waste Water Treatment | Tags: Achieving Greater Throughput, Cost Savings, Energy Savings, Improved Treatment, Increased Treatment Capacity | No Comments »
Mt. Gilead WWTP
Mt. Gilead, Ohio
The Mt. Gilead WWTP, an activated sludge facility, expanded capacity to include revisions to both primary and secondary treatment processes as well as the biosolids handling for the proposed .82 MGD facility. The Poggemeyer Design Group was asked to evaluate various design alternatives for mixing and aeration of the (2) 62’ and (1) 45’ diameter aerobic digester/sludge holding tanks included in the expansion and upgrade. The Engineer compared complete aeration systems with aeration / hydraulic mixing systems with various combinations of hydraulics and aeration rates. After reaching a decision on his final design, the mixing system manufacturer completed a final design layout after analyzing placement of the diffuser grids in relation to the hydraulic flows required. The final design is now in operation with lower than anticipated operating costs which have resulted in substantial yearly savings along with other significant advantages that will be discussed in this paper. Source: WEFTEC 2008 Proceedings
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Posted: August 27th, 2010 | Filed under: Waste Water Treatment | Tags: Energy Savings, Increased Digester Loading Capability, Operation Savings, Reduced Greenhouse Gas Emissions | No Comments »
Tennessee Valley Authority
Knoxville, Tennessee
National estimates indicate that approximately 80-90% of the electricity utilized at water and wastewater facilities is attributable to pumps and blower motors. The Tennessee Valley Authority and our power distributors are helping our water and wastewater customers and other industrial users save energy by assessing their pumping systems using the US Department of Energy (DOE) Pumping System Assessment Tool (PSAT) which was developed by Don Casada. TVA has partnered with DOE to provide in-depth training in utilizing PSAT at several locations throughout the TVA service region. TVA is also conducting assessments at customer facilities at their request. PSAT identifies energy savings opportunities in pumping systems and quantifies those opportunities in both dollars and electrical energy savings. Although PSAT does not tell how to improve systems, it does prioritize improvement opportunities. When the opportunities are implemented, the results are often decreased maintenance and repair costs and increased production and energy savings. Source: WEFTEC 2008 Proceedings
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Posted: August 27th, 2010 | Filed under: Waste Water Treatment, Water Treatment | Tags: Cost Savings, Energy Savings, Increased Plant Efficiency, Pump Optimization, Reduced Greenhouse Gas Emissions | No Comments »
San Jose/Santa Clara Water Pollution Control Plant
San Jose, California
The San Jose/Santa Clara Water Pollution Control Plant (“Plant”) is an advanced wastewater treatment facility with a rated capacity of 167 MGD. Over the past year it implemented three major energy savings projects: optimization of pump station operation, optimization of operation of the dissolved air floatation system and replacing continuous aeration of mixed liquor channels and anaerobic/ anoxic compartments of the BNR process with pulsed (intermittent) aeration (Patent pending). Estimated energy savings is $1.3 million dollars. Cost of the projects was less than $300,000. Project cost was refunded to the Plant by the Electrical Utility. The following results were achieved: 1. More than 20% energy savings was achieved by optimization of scheduling of pumps and speeds of VFD motors.
2. More than 60% energy saving was achieved by optimization of operation of dissolved air floatation.
3. More than 50% energy savings was achieved by implementing pulsed aeration in the anaerobic compartments.
4. No deterioration of treatment performance was observed. Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: >1M, Waste Water Treatment | Tags: Cost Savings, Energy Savings, Plant Optimization | No Comments »
23rd Avenue Wastewater Treatment Plant
Phoenix, Arizona
Monitoring of influent loading and plant operating conditions, together with a real-time feedforward control model, allows dissolved oxygen (DO) set-points to be matched in real time to the influent loading. Adjusting DO set-points based on load results in a significant reduction in aeration energy. This paper discusses the monitoring technology, and optimization and control techniques used in an energy savings project at the 23rd Avenue Wastewater Treatment Plant (23rd Avenue WWTP) in Phoenix, Arizona. The plant treats an average of 48 MGD using an MLE process, with a goal of complete nitrification. Load-based feed-forward control of dissolved oxygen in an activated sludge wastewater treatment plant can provide measurable and consistent energy savings through reduced aeration requirements without jeopardizing effluent quality. In the case presented here, aeration energy savings were in the range of 11% to 18%, despite constraints on the controller that prevented it from lowering the DO set-point below an operator defined limit. At Phoenix 23rd Avenue WWTP this represents a savings of 2000 MWh per annum and a carbon footprint reduction of 1,400 metric tons. The results are consistent with savings achieved using the same control methods at plants in different climate zones (Liu, 2003). Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: 100K-500K, Waste Water Treatment | Tags: Cost Savings, Energy Savings, Environmental Impact, Plant Optimization, Reduced Carbon Footprint | No Comments »
California
In 2001 California spent 18,600 Gwh per year only on agricultural and water pumping (http://www.energy.ca.gov / electricity/ consumption_by_sector.html). In addition, pumping is widely used in power industry, HVAC, etc. Considering that each kw*hr of energy saving causes 0.537kg of carbon emission reduction, decrease of energy usage helps not only to improve the bottom line but also leads to reduction of carbon footprint. A new methodology has been developed for pump stations optimization. The methodology uses simultaneously generalized reduced gradient and genetic algorithms. The methodology allows optimization of any combination of constant speed and variable speed pumps. Implementation of this methodology at one pump station yielded reduction of energy usage as much 25% that was equal to more than $50,000 a year. Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: Sanitary Sewer, Stormwater | Tags: Cost Savings, Energy Savings, Environmental Impact, Reduced Carbon Footprint | No Comments »
United Utilities
United Kingdom
This paper will describe the results achieved by applying a Model Predictive Control (MPC) system to an Activated Sludge Plant (ASP) in the UK, with the objective of reducing energy consumption, whilst maintaining compliance within permitted environmental standards. Installation of the MPC system was initially an R&D project to assess if the suppliers performance expectations were valid. The successful outcome of the trial allowed the project to move to a permanent installation assessing the benefits over a longer period. During the R&D Phase the system demonstrated a high availability with an average of 20% energy reduction and peaks of 40% energy reduction when compared to conventional control. To date the system has reliably demonstrated energy savings and offers the potential to contribute significantly to United Utilities objective to reduce its Carbon emissions by 8% by 2012 if the benefits are replicated across the companies asset base of large ASP’s. Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: 50k-100k, Electric, Sanitary Sewer, Stormwater, Waste Water Treatment, Water Treatment | Tags: Cost Savings, Energy Savings, Environmental Impact, Reduced Carbon Footprint | No Comments »
Southwest WWTP and Dillman Road WWTP
Conroe, Texas and Bloomington, Indiana
Studies conclude the aeration process in an activated sludge wastewater treatment plant consumes 40 to 60 percent of a plant’s power usage. With the dramatic impact of the aeration process on the overall operational expenses of a plant, the last three decades has seen increased focus on the design, implementation, and operation of high efficiency single-stage centrifugal blowers and aeration control systems. State and local agencies offer a variety of funding options that favor energy-minded aeration systems due to the increased global emphasis on energy conservation. This paper will discuss the different types of high efficiency single-stage centrifugal blowers used in wastewater treatment plants, along with blower and aeration system control methodologies to maximize the overall aeration process efficiency. In addition, this paper will detail two case studies where alternative funding options allowed the implementation of high efficiency single-stage centrifugal blowers and aeration control systems, which yielded significant energy and operational savings. Source: WEFTEC 2009 Proceedings
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Posted: August 27th, 2010 | Filed under: <50K, Waste Water Treatment | Tags: Cost Savings, Energy Savings, Environmental Impact, Plant Optimization, Reduced Carbon Footprint | No Comments »