The conversion of raw sewage sludge into valuable biosolids for beneficial reuse requires a
suitable pre-treatment process. However, traditional technologies are causing high investment
costs, operation costs, and energy demand; or are not fully meeting the demands of the market.
As recent experiences from the world’s largest solar drying and solar-assisted drying plants in
Palma de Mallorca, Spain and Oldenburg, Germany show, solar drying is an effective alternative
for large facilities. Drying costs and energy consumption are less than half, maintenance is low,
and operation is simple and safe at these facilities when compared to traditional thermal dryers.
Also, carbon dioxide (CO2) emissions are reduced by a factor of seven when compared to
conventional dryers. By using waste heat from other processes, the area requirement can be
reduced by a factor of three to five. The final product is suitable as fuel for Waste-to-Energy
(WTE) plants, coal power plants, or cement kilns. It can also be used as a Class-A fertilizer for
agricultural use, or land application.
Posted: May 20th, 2011 | Filed under: Waste Water Treatment, Water Treatment | Tags: Cost Savings, Decreased Energy Consumption, Plant Sustainability, Smaller Carbon Footprint | No Comments »
Magna Water District
Aeration accounts for up to 60% of the total energy required for a typical activated sludge wastewater plant. A new process was developed that decreases aeration demand during secondary wastewater treatment. This process, called BIOBROx, blends oxidant-laden residuals with screened municipal wastewater followed by treatment in a fixed-bed (FXB) bioreactor. Pilot testing showed that the BIOBROx process was effective at removing perchlorate and nitrate from membrane residuals. Considerable biochemical oxygen demand (BOD) and suspended solids were also removed across the process. A 3.8-mgd BIOBROx demonstration facility is now operating at the Magna Water District. The BIOBROx train treats 1/3 to 1/2 of Magna’s total wastewater flow, uses no aeration, has an empty-bed contact time of 10 minutes, and has a footprint that is one-twentieth the size of the conventional secondary processes. Preliminary data show effluent that even under these conditions, BOD5 and TSS levels in the effluent from the BIOBROx process are similar to those in Magna’s conventional secondary treatment effluent.
Posted: May 20th, 2011 | Filed under: <50K, Sanitary Sewer, Stormwater, Water Treatment | Tags: Cost Savings, Decreased Aeration Demand, Decreased Energy Consumption, Plant Sustainability, Smaller Carbon Footprint | No Comments »
Before the recession, Metro Atlanta and its surrounding counties were one of the fastest growing
regions in the United States. In order to reduce the impact of treatment plant discharges on its
limited water supply and to offset water demands on potable water systems, they were
increasingly looking at water conservation and water reuse. Paulding County was one of those
fast-growing counties, consistently ranked between the 12th and 15th fastest growing counties in
the United States. Wastewater treatment facilities are among the most critical to support the
County’s rapid population increase. With tighter effluent limits on the way and a halt on surface
water discharge permits, the County had to look at alternative uses for the treated wastewater.
Several technologies were evaluated, and based on this evaluation, MBR technology became the
apparent leader. This paper provides an overview of the selection process, the procurement
process, and the performance of four MBR systems currently operating in Paulding County.
Posted: May 20th, 2011 | Filed under: 100K-500K, Waste Water Treatment | Tags: Improved Plant Efficiency, Plant Sustainability, Reduced Carbon Footprint, Water Reuse | No Comments »
Green Bay Metropolitan Sewerage District (GBMSD)
Green Bay, Wisconsin
The Green Bay Metropolitan Sewerage District (GBMSD) is a public utility, established in 1931,
that reclaims 38 million gallons of wastewater per day at two treatment facilities in Green Bay
and De Pere, WI. Its service area covers 285 square miles and serves more than 219,000 people.
GBMSD’s mission is to promote public health and welfare through the collection, treatment, and
reclamation of wastewater, while assessing stable, competitive rates. In conjunction with others,
the organization will encourage pollution prevention and support programs to help ensure that
water contaminated by human activity is returned clean to the environment. GBMSD conducts
its business using a sustainable approach within the social, environmental, and economical
values of our customers and stakeholders.
GBMSD initiated the development of a Solids Management Plan in 2008 to address aging solids
handling facilities and the solids loadings from recently acquired De Pere Facility. The existing
solids processing system consists of belt press dewatering followed by multiple hearth
incineration. The solids system is located at the Green Bay Facility. Solids from the De Pere
Facility are transferred by pipeline to the Green Bay Facility for processing. The solids system
was constructed in the 1970s and is reaching the end of its useful life. The multiple hearth
incineration process is now considered an outdated technology. Current incineration technology
uses fluidized beds, which consume less fuel and lower air emissions.
The solids management planning effort was undertaken to develop a long-term plan for handling,
processing, and disposing of solids. The plan included a comprehensive evaluation of numerous
solids management technologies and approaches. This paper describes the process used to
develop the plan, the alternatives that were considered, the alternatives evaluation process, and
the preferred solids management alternative.
Posted: May 20th, 2011 | Filed under: 100K-500K, Sanitary Sewer, Stormwater, Waste Water Treatment | Tags: Environmental Impact, Minimized Life-Cycle Cost, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
DC Water and Sewer Authority (DC Water)
The DC Water and Sewer Authority (DC Water) is implementing new sludge and biosolids
processing facilites at the 1.4 million cubic meters/day (370 million gallons per day [mgd]) Blue
Plains Advanced Wastewater Treatment Plant (AWTP) in Washington D.C. The program
involves thermal hydrolysis (TH) followed by anaerobic digsetion and includes a major
cogeneration facility to provide electric power for the treatment plant and steam for the TH
Decision and development criteria for DC Water’s biosolids program have evolved over recent
years and now include a broad range of factors with strong emphasis on sustainability criteria. A
major link between high-performance digestion and renewable energy production has been
forged. Key criteria for decision-making now include renewable power and energy production,
climate change issues, biosolids product quality, digestion performance, and site efficiency, as
well as capital constraints and economics.
Posted: May 20th, 2011 | Filed under: 100K-500K, Waste Water Treatment | Tags: Biosolids Minimization, Economic Benefits, Energy Management, Improved Digestion Performance, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
Spotsylvania County embarked up an aerated static pile composting program in 2002 to manage
undigested dewatered wastewater treatment plant (WWTP) residuals cake from their
Massaponax WWTP in conjunction with brush collected through a convenience center and at the
Livingston Landfill. The initial compost facility included a covered aerated static pile process
that provided intermittent positive aeration only. The quantity of dewatered residuals being
composted has increased from approximately 8,800 tons per year in 2003 to in excess of 12,600
tons per year in 2009. Even with this rapid increase in quantities, all regulatory process criteria
have been met and offsite odor impacts have been non-existent. Howeverer, residuals cake
continued to be landfilled from a second WWTP, the FMC plant, in the amount of 5,000 – 6,000
tons per year. The County embarked upon a compost facility expansion program in 2006 with
three main goals.
1. To manage the ever increasing quantities of residuals cake generated from both County
WWTP’s over the next 20 years.
2. To enhance and automate the compost process performance.
3. To accomplish this expansion with no offsite odor impacts.
Construction of the new facilities was completed in March, 2010. This paper presents data on the
process flow, process controls, and the odor management system of this successfully expanded
aerated static pile composting operation.
Posted: May 20th, 2011 | Filed under: Waste Water Treatment | Tags: Cost Savings, Environmental Impact, Plant Sustainability, Reduced Carbon Footprint, Reduced Odor | No Comments »
Polk County Utilities (PCU)
Polk County, Florida
To assure that Polk County Utilities (PCU) is ready for coming changes in regulations and ever
increasing solids production from ten treatment facilities geographically dispersed throughout the
County, the County wanted to develop a proactive long term biosolids management plan that
integrated residuals management approaches among the various treatment plants. Geographical
dispersion and capacity diversity combined with a desire for an integrated long-term
management plan gave rise to a number of possible alternatives to be included in the evaluation.
The landfill disposal alternative investigated met PCU’s objectives which were to identify a cost
effective method for managing current and future biosolids generated at PCU’s facilities that
would represent a viable plan for the next twenty years. An agreement developed between PCU
and Polk County’s Solid Waste Division to mutually address disposal of leachate and biosolids
resulted in significant cost savings for both these County agencies.
Posted: May 20th, 2011 | Filed under: Stormwater, Waste Water Treatment | Tags: Biosolids Management, Cost Savings, Environmental Impact, Plant Sustainability, Reduced Carbon Footprint | No Comments »
Aeration consumes about 60% of the total energy of a WWTP and therefore makes up for a
major part of its carbon footprint. Introducing advanced process control can help plants to reduce
their carbon footprint and at the same time improve effluent quality through making available
unused capacity for denitrification, if the ammonia concentration is below a certain set-point.
Measuring and control concepts are a cost-saving alternative to the extension of reactor volume.
However, they also involve the risk of violation of the effluent limits due to measuring errors,
unsuitable control concepts or inadequate implementation of the measuring and control system.
Dynamic simulation is a suitable tool to analyze the plant and to design tailored measuring and
During this work, extensive data collection, modeling and full-scale implementation of aeration
control algorithms were carried out at three conventional activated sludge plants with fixed predenitrification
and nitrification reactor zones. Full-scale energy savings in the range of 16-20 %
could be achieved together with an increase of total nitrogen removal of 40%.
Posted: May 20th, 2011 | Filed under: <50K, 100K-500K, 500K-1M, Waste Water Treatment | Tags: Ammonia Control, Cost Savings, Energy Savings, Environmental Impact, Plant Sustainability, Reduced Aeration, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
Two clean technologies, namely, “Anaerobic hydrogen production” and “Microbial fuel cells
(MFC)”, hold great potential for producing energy from wastewater, which can provide economic
and environmental benefits. Although 1 mole of glucose can theoretically produce 12 moles of
hydrogen, the experimental hydrogen yields obtained are only 0.9-2.0 moles [1, 2]. The liquid
fermentation products in the anaerobic treated wastewater cause the high chemical oxygen demand
(COD) in the effluent. It is desired to further treat these liquid products using MFCs to improve
effluent quality and harvest energy. By converting the chemical energy stored in wastewater to
electricity, MFCs can substantially reduce the operational cost in wastewater treatment plants .
Due to the limitation of current technologies, the operation of hydrogen bioproduction and MFC
individually in wastewater treatment is not suitable. Although hydrogen production is a good energy
resource, the COD removal efficiency remains low. On the other hand, MFC could achieve high
COD removal efficiency, but the power densities are low. In this study, the HPB and SCMFC were,
for the first time, operated in series to increase overall energy recovery from wastewater and enhance
COD removal efficiency for potential reclamation.
Posted: May 20th, 2011 | Filed under: Waste Water Treatment | Tags: Cost Savings, Energy Savings, Enhanced COD Removal Efficiency, Environmental Impact, Plant Sustainability, Reduced Carbon Footprint | No Comments »
Werribee Treatment Plant
Waste Stabilization Ponds are used extensively for sewage treatment in moderate and
tropical climates, and represent one of the most cost-effective, reliable and easily
operated processes for the treating domestic and industrial wastes. One of the biggest
problems associated with pond treatment, however, is the high algae concentrations in the
effluent. In many cases algae are not a desirable by-product and are themselves a source
of secondary pollution, rich in carbonaceous and nitrogenous algae matter. This puts an
environmental strain on the receiving waters. One of the recently improved ways to
control algae is to use trickling filters with a heterotrophic biofilm created by augmenting
readily available sustenance to the filter media. This paper examines some of the hybrid
facilities being used that combine existing stabilization ponds with trickling filters or
activated sludge for enhanced biological degradation and polishing of the final effluent.
Posted: May 20th, 2011 | Filed under: >1M, Waste Water Treatment | Tags: Algae Removal, Improved Plant Effluent, Improved Water Quality, Plant Sustainability, Reduced Carbon Footprint, Reduced Nitrogen Load, Reduced Nutrients, Reduced Solids | No Comments »