Wastewater treatment plants (WWTPs) are facing many challenges. Permits on nitrogen and phosphorus in effluent water are progressively becoming stricter in order to protect surface waters from eutrophication. At the same time, plants are required to reduce both energy and chemical consumption, and often are challenged with limited time and staff. In total, they are required to do more with less.
Chemical treatment, biological treatment, and combinations of both are common methods for removing phosphorus in a wastewater treatment plant (WWTP). When using chemical treatment, metal salts that react with soluble reactive phosphate (i.e., orthophosphate) are added to form solid precipitates that are removed by physical processes such as clarification and filtration. The required chemical dosing rate depends on factors such as the targeted effluent phosphorous concentration, the influent phosphorus load and the amount of phosphorus that is being removed biologically.
When a broken shaft caused a malfunction in one of the brush aerators at the Village of Liberty, N.Y., wastewater treatment plant (WWTP), the village worked with its engineers, Delaware Engineering, to develop a plan for repair and upgrade.
In the late 1970s, the old Tullahoma, Tenn., wastewater treatment plant (WWTP), built in 1955, was overloaded and deteriorating. The City of Tullahoma and its consultants—Barge, Waggoner, Summer and Cannon—began an extensive evaluation of different treatment options for the new plant, including an oxidation ditch, in-channel clarifiers and the Sanitaire Intermittent Cycle Extended Aeration System (ICEAS) for a sequencing batch reactor (SBR) process.
Driven by compliance with more stringent water treatment standards, the Fond du Lac (Wis.) Wastewater Treatment Plant leveraged an upgrade opportunity to improve beyond limiting ammonia effluent levels. The plant improved energy efficiency, reduced maintenance and operating costs, and eliminated bypasses into Lake Winnebago during high rainfall.
The Village of Johnson Wastewater Treatment Facility (WWTF) was among the first in the state of Vermont to meet newly enacted secondary treatment requirements when it began operation in 1970. After legislative changes more than two decades later called for stricter discharge limits on phosphorous, ammonia and residual chlorine, the Village of Johnson sought to increase the facility’s flow capacity—especially its ability to handle the high seasonal flows associated with storm events.
A recent $10.2-million upgrade at the regional wastewater treatment plant operated by the Portage (Pa.) Area Sewer Authority doubled the facility’s daily flow rating to 2 million gal per day (mgd) and brought the previously deficient peak rating up to 6 mgd. Added peak capacity was a primary goal of the project to correct hydraulic limitations that previously required repeated bypasses during heavy rainfall events caused by inflow and infiltration (I&I) into the collection system.
City officials in Sullivan, Mo., were notably proud in 1988 when their new aerated wastewater treatment lagoon began operation. Within five years, however, the plant was essentially obsolete due to the reclassification of the effluent-receiving stream by the state’s regulatory agency and apprehensions about the stability of the site’s underpinning geology.
The Newville Borough Water and Sewer Authority (NBWSA) in Newville, Pa., has over 6.5 miles of sewers in the borough, serving a population of 1,326. An additional 5.7 miles of gravity sewers and one pumping station serves surrounding municipalities.
The city of Portage is a former borough within Portage Township in Cambria County, Pa. Before a $10.2 million upgrade, the Portage Area Sewer Authority was operating in a facility built in 1972.
Xylem Inc. has been awarded a contract to work with Essar Projects (India) Limited to install its Sanitaire ICEAS biological treatment system in a wastewater treatment plant in Jamnagar, in the Indian state of Gujarat. Xylem will be responsible for the new installation, as well as for providing ongoing service and maintenance for the 70-million-Lpd-capacity wastewater treatment plant for the Jamnagar Municipal Corporation.
Xylem Inc. has been awarded a contract to supply treatment technology and systems for a new wastewater treatment plant in Brazil that will serve 60,000 people. Construction is currently underway with Xylem providing its Sanitaire brand ICEAS biological technology to treat wastewater in the city of Campo Grande in the Mato Grosso state of Brazil.
Xylem Inc. has released the results of a full-scale study showing a 65% reduction in energy consumption at a municipal wastewater treatment plant in Sweden when more efficient equipment and improved systems were incorporated. The results of the study indicate a four-year payback, with the new system decreasing the total energy consumption of the entire plant by 13%.
Contract covers the design and supply of an additional eight of ITT’s Sanitaire sequence batch reactorsITT Corp. announced it has been awarded a $32 million contract by Larsen & Toubro (L&T) for the Phase II extension of Qatar's Doha South Sewage Treatment Works. The contract covers the design and supply of an additional eight of ITT's Sanitaire sequence batch reactors (SBRs), which will increase the wastewater treatment capacity of the Doha South plant by 92 million liters per day.