Wastewater Treatment with Algae

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Municipal Wastewater
The algaewheel® system is an advanced biological process for conventional wastewater treatment facilities. Because algaewheel is only one component of the system, the conventional treatment process is not completely replaced. The following diagram illustrates the wastewater process flow in an algaewheel system versus a conventional plant.  It may be noted that many of the components of traditional treatment systems are still used in the algaewheel system.

Algaewheel can be used in new construction or added to an existing plant to increase its capacity, efficiency, and environmental friendliness. The algaewheel system provides conventional biological wastewater treatment as well as advanced nutrient removal utilizing algae. The algae also serve to supply the oxygen required by the bacteria and likewise the bacteria supply the carbon dioxide required by the algae. Thus, an ecological balance is established in the algaewheel system making it very stable and resistant to the fluctuations normally experienced with bacteria-based wastewater treatment systems.  In addition to ecological balance, algaewheel systems have several other advantages.

Energy Efficiency: The U.S. EPA has estimated that conventional wastewater treatment plants account for 3 percent of the entire U.S. electrical demand and that the demand for electricity at these plants is expected to grow by approximately 20 percent over the next 15 years. Algaewheel systems, however, require 50 to 75 percent less energy to operate than other biological processes which is equal to producing the same amount of energy. Additionally, algaewheel systems typically generate 95 percent less solids that would otherwise require energy intensive handling and disposal transportation costs. Thermal biorefining processes can be used in conjunction with the algaewheel system to generate significant amounts of renewable energy. Depending on the scale of the system, a wastewater treatment plant utilizing algaewheel technology will realize renewable energy benefits ranging from 50 percent energy savings to production of excess power for sale to the electric power grid.

Solids Handling: By design, algaewheel systems generate more solids than traditional systems. Algaewheel systems basically leverage the nutrients in the wastewater to maximize biomass production, with the ultimate goal being to generate enough biomass to make thermal processing economically feasible for large and small wastewater treatment plants. Thermally processing this btu-rich algae and solids mixture generates significant amounts of energy (e.g. steam, heat, electricity), while reducing the solids by 95 percent or more and leaving valuable byproducts. More becomes less, and overall solids handling expenses and risks are dramatically reduced or eliminated.

Elimination of Greenhouse Gas (GHG) Emissions: Recent studies have shown that conventional wastewater treatment plants account for 3 to 4 percent of all greenhouse gas emissions in the world. Algaewheel systems, however, are extremely efficient at capturing CO2 because they generate a lot of algae, which take up significant amounts of CO2. Unlike other biological processes that emit enormous amounts of CO2, either directly or indirectly through biological processes or energy use, the algaewheel system enables a wastewater treatment plant to become carbon neutral or even carbon negative. The algaewheel system also converts ammonia directly to plant life unlike conventional systems that create nitrous oxide (N2O) during nitrification. Scientists have determined that N2O emissions from nitrification/denitrification processes in conventional systems are 300 times more potent as a greenhouse gas than CO2.  This is important because greenhouse gases are a significant concern, and because the EPA has specifically identified conventional wastewater treatment plants as major contributors to greenhouse gases.

Nitrogen & Phosphorous Removal: Algae can metabolize sewage far more rapidly than bacterial treatment. Treatment is more complete and more rapid since bacteriological treatment is a process of decay whereas algae treatment is one of conversion of organic matter to live, healthy plant life.  Current bacteriological treatment plants discharge nitrates, phosphates, sulfates, etc. into a natural body of water for dilution and continued treatment by naturally occurring plant and animal life. It is recognized that nutrients in treated effluent water have increasingly become a problem because they cause an increase in the amount of algae in our lakes and streams. The algaewheel technology approaches the desired function of discharging water with only its natural mineral elements because of the productive plant life cycle associated with algae.  Nitrates, phosphates and their antecedents are plant foods, and as such, are assimilated by the algae through photosynthesis.  Most regulatory agencies are either considering or have enacted stricter limits on nitrogen and phosphorous in effluent and industry is calling for innovative, cost-effective technologies for dealing with this problem.

Cost: Algaewheel based wastewater plants, including thermal bio-refining equipment, cost the same or less to build than plants that use traditional technologies. More importantly, algaewheel based treatment plants cost 25 to 50 percent less to operate and maintain because they are designed to be low maintenance, energy efficient, and nearly chemical independent. Our analyses of many scenarios indicates that up to three quarters of the cost to build a treatment plant can be recovered through the savings in operation and maintenance costs. The many benefits of algaewheel facilities represent an enormous value proposition.

How does algaewheel differ from differ from a conventional plant in regards to sludge handling and greenhouse gas emissions?  Follow the comparison below.

 
Onsite Wastewater
Algaewheel developed the bacpac^® system for onsite wastewater treatment applications. Our bacpac system provides a single pass, flow-through process in which balanced bacterial and algal populations provide treatment and filtration. Algaewheel has licensed the bacpac system to Oldcastle Precast, which has incorporated the technology into its precast concrete components to provide a modular treatment system that fits many onsite treatment applications. For further information on the Oldcastle's Onsite System using the bacpac unit please contact Oldcastle Precast at 765-331-0085 or visit them on the web at http://oldcastleprecastonsite.com/index.htm

Other Applications
There are numerous potential applications for the algaewheel to serve as a nutrient recovery system. Agricultural wastewater, industrial process water, and environmental water remediation are examples of other applications for which the algaewheel system may be used. Naturally, applications beyond standard wastewater would require testing and a potential pilot system to determine effectiveness and full scale system sizing. If you have questions regarding a particular application please contact us. We may have experience and/or data regarding an application that is comparable to yours.