Water Environment & Technology (WE&T) is the premier magazine for the water quality field. WE&T provides information on what professionals demand: cutting-edge technologies, innovative solutions, operations and maintenance, regulatory and legislative impacts, and professional development.
Dynamic modeling of cyclic aeration process for biological nutrient removal
The Hampden Township Roth Lane Wastewater Treatment Plant in Mechanicsburg, Pa., developed and calibrated a dynamic model to predict the performance of a cyclic or intermittent aeration process for its extended aeration activated sludge process. The water resource recovery facility automatically cycled aeration on and off to create oxic, anoxic, and anaerobic conditions within the reactor’s biomass. Sequencing these conditions in the same order enabled nitrification, denitrification, and biological phosphorus removal in a single reactor.
A state of urgency
“Out of sight, out of mind” has been the normal approach in thinking (or not thinking) about buried underground sewer infrastructure, at least until there is a collapse in the street, the public is affected, and the unseen is revealed. The Albuquerque Bernalillo County (N.M.) Water Utility Authority experienced this phenomenon in the early 1990s with the sudden and seemingly random collapse of large-diameter sewer pipelines in various areas of its collection system. Collapses of the authority’s large interceptor pipes in major roadways occurred again in March and April 2011, and again in May and June 2012.
A careful evaluation of these collapses pointed to aging pipes whose useful lives had been reached or exceeded. Staff predicted that these collapses were only the beginning; more pipes would fail unless steps were taken to rehabilitate or replace them.
The water authority’s solution was to select a methodology that takes a thorough inventory of the condition of interceptors using risk-based, asset-management principles.
A greener permit
Milwaukee is first U.S. sewer district to add green infrastructure to wastewater discharge permit
Coming in the next issue:
Whether the cause is severe weather, changing climates, or the effects of aging infrastructure, it seems that Mother Nature is taking a harsher toll on water sector services. Floods, heavy rainstorms, and tornadoes all require preparation and, later, recovery.
Likewise, the Water Environment Research Foundation (Alexandria, Va.) and several partners documented the experiences of water service agencies dealing with extreme weather events in six areas across the nation. Agency representatives shared their experiences, and researchers synthesized their collective knowledge and identified the lessons learned that would help other water service agencies increase their resilience for future extreme weather events.
It is critical that water sector personnel assess the potential risks from these hazards and use the findings to update emergency response plans and enhance infrastructure resilience. To support this, the U.S. Environmental Protection Agency collaborated with water sector partners to update the Water Health and Economic Analysis Tool. The tool now includes assessment and consequence analysis for loss of a water or wastewater system operating assets, a hazardous gas release component, and a contamination event in a drinking water distribution system.
Also in this issue:
From manual to automatic at Spring Creek.
Designers and operators team up to smooth the transition.
New Zealand facilities find a culturally sensitive solution in biological trickling filters as the sole means of wastewater treatment.
A coalition of researchers uses oysters to filter and clean California’s waters naturally.