BAFs (Biologically Aerated Filters) are compact treatment processes, which combine filtration and aerobic/anoxic/anaerobic treatment using a fixed-film biodegradation. They consist of an immersed biological filter operating either in down flow or upflow hydraulic condition. They are used to remove TSS, COD, BOD5, NH4-N and NO3-N, either as a secondary or tertiary stage. Their filtering properties can also be used to remove phosphorus. The filter medium is periodically backwashed to remove suspended solids retained during the filtering interval and excess biomass produced within the filter bed. Their development has spanned the last 20 years. This paper presents the very last innovation in the application of BAFs for carbonaceous pollution abatement.
Environmental Sciences & Engineering_January 2008.PDF
Articles
Recent Developments In Carbon Pollution Abatement
Small Towns with Big Problems: Finding Solutions to More Stringent Wastewater Discharge Limits
Aerated lagoons use mechanical aeration to provide dissolved oxygen for biological treatment of wastewater. These systems efficiently remove carbonaceous pollution (whether measured as BOD or COD) from the effluent but nitrification is not readily accomplished giving poor ammonium removal.This situation is even more critical in cold, Canadian winter conditions, where nitrification is almost non-existent at temperature near the freezing point (<5oC).
Canadian Water Treatment_March, April 2008.PDF
High-rate ballasted flocculation technology for mining effluent treatment
Increasingly stringent environmental regulations pertaining to discharges containing total suspended solids (TSS) and heavy metals (Zn, As, Cu, Ni, etc.,) are being imposed on effluents from the mining industry. Coupled with often-limited available site area to install process equipment, the development of technically and economically feasible processes for removal of these contaminants from industrial wastewater prior to discharge becomes a necessity.
Environmental Sciences & Engineering_May 2008.PDF
Feeding sodium hypochloride using innovative drinking water disinfection technology
Water disinfection is the most critical process in the treatment of water and wastewater. The world's most universal and reliable means of water and wastewater disinfection is chlorination. Two fundamental methods include gas chlorination (Cl2) and liquid chlorination (NaOCl), otherwise known as sodium hypochlorite. Chlorination was introduced as a commercial water purifier in 1908 and has since been acknowledged as the optimum method for water disinfection due to its ability to provide residual protection throughout the water distribution system.
Environmental Sciences & Engineering_July 2008.PDF
(MBBR): a compact technology for upgrading Canadian municipal aerated lagoons
Aerated lagoons are used extensively throughout Canada for treatment of municipal wastewater. In fact, by far, lagoons are the most popular wastewater treatment technology, representing 67% of all existing wastewater treatment plants (WWTPs) across Canada. Aerated lagoons use mechanical aeration to provide dissolved oxygen for biological treatment of wastewater. These systems can efficiently remove carbonaceous pollution, whether measured as BOD or COD, and play an essential role in pollution control.
Watermark, Fall 2008.PDF
Magnetically driven, seal-less gear pumps improve chemical dosing systems
Chemical dosing systems are used in various water treatment applications, such as polymer feed (sludge dehydration, flocculation and coagulation), caustic soda (neutralization and pH control), sodium hypochlorite (water disinfection) and more.
Environmental Sciences & Engineering_Nov.2008.PDF
Innovative municipal water softening using high-rate sand-ballasted technology
Sand-ballasted settling is a highrate coagulation/flocculation/
sedimentation process that uses microsand as a seed for floc formation. The microsand provides a surface area that enhances flocculation and acts as a ballast or weight. The resulting floc settles quickly, allowing for compact clarifier designs with high overflow rates and short detention times.
Environmental Sciences & Engineering_January 2009.PDF
Special Treatment: City of Calgary Water Services
Unlike most large cities in Canada, which are subdivided into municipal districts, Calgary, Alberta, has a single municipal administration for its roughly one million people, and it supplies potable water to the city as well as some neighboring municipalities in the region. The city is also unique in that it has two water treatment plants located on two different water sources: the Bearspaw treatment plant is on the Bow River, and the Glenmore plant is on the Elbow River.
Business Excellence May 2009.PDF
How a global approach to wet weather can improve water quality
Wet weather issues have evolved greatly over the last generation. From a side issue 40 years ago, they have reached the forefront of environmental concerns. Initiatives such as the Great Lakes Water Quality Agreement and directives from the Canadian Council of the Ministers of the Environment indicate that stormwater and combined sewer overflows (CSOs) can no longer be considered as inoffensive as initially thought.
Environmental Sciences & Engineering_May 2009.PDF
Kingston chooses biological aerated filters for wastewater treatment plant upgrade
The Ravensview Water Pollution Control Plant (WPCP) currently provides primary level wastewater treatment from the City of Kingston, Ontario, including Pittsburgh Township and the Canadian Armed Forces Base in Kingston. The existing process at Ravensview WPCP includes: mechanical screening for pre-treatment, primary treatment with chemical enhancement, sodium hypochlorite dosing for disinfection and sodium bisulphite dosing for dechlorination. The treated effluent is then discharged into the St. Lawrence River.
Canadian Environmental Protection, May/June 2009.PDF
A Compact and Efficient Technology for Upgrade of Canadian Municipal Aerated Lagoons
Aerated lagoons are extensively used throughout Canada for treatment of municipal wastewater. In fact, lagoons are, by far, the most popular wastewater treatment technology: they represent 67% of all existing WWTP's (wastewater treatment plants) across Canada.
Influents Magazine, Summer 2009.PDF
Small Footprint Technologies Combine For High-Rate Treatment Efficiency
Stricter treatment and discharge regulations are forcing wastewater treatment plants in urban and high-growth areas to consider expanding or upgrading their systems. The challenge? Even if extra land is available, it's often not affordable. Fortunately, certain small footprint technologies now provide efficient high-rate treatment.
ES&E Magazine, Summer 2009.PDF
New Tailings Water Management System Supports Expansion, Helps Safeguard Environment
A recent tailings water management overhaul provides increased capacity for high volume tailings water and significantly reduces treatment time. The new system also ensures the operation maintains low impact to the environment.
Canadian Mining Magazine, Fall 2009.PDF
Novel processes for reducing phosphorus and SS levels down to tertiary discharge standards
Large population increases in rural areas, stricter discharge regulations, blue-green algae blooms and high phosphorus loads in watersheds are forcing wastewater treatment plants (WWTP) to consider upgrading their systems to include tertiary treatment of phosphorus.
ES&E Magazine, March 2010.PDF
Small (wastewater treatment plant) is beautiful
Population growth and stricter discharge regulations are forcing wastewater treatment plants (WWTPs) in urban and high-growth areas to consider expanding or upgrading their treatment systems. These plant expansions often require extra land, where, sometimes, none is available. Also, expanding the WWTP may mean infringing on pristine land or already occupied land (farmland, reserve, etc.), making the expansion a bureaucratic nightmare.
Watermark, Sring 2010.PDF
Treatment Tech Combos: The one, two, three punch.
Population growth and stricter treatment and discharge regulations are forcing wastewater treatment plants in urban and high-growth areas to consider expanding or upgrading their systems. All too often, these new discharge limits require a complete rethinking of the wastewater process, with all the complexities that it may involve and new regulations that might be put in place.
Water Canada Magazine, November - December 2010.pdf
A Green, Sustainable, Sefl-Sufficient Wastewater Treatment Plant: the Upcoming (R)evolution
As municipalities and industries strive towards sustainable development, the wastewater treatment plant (WWTP) is on the verge of being entirely transformed.
Influents Magazine, Fall 2011.PDF (1595 Kb)
