November 2011, Vol. 23, No.11

How MBRs grew more efficient

Seven designs illustrate the technology’s evolution to a mature and costcompetitive component of wastewater treatment 

Menniti feature 1 art Adrienne Menniti, Zeynep Erdal, George Crawford, and Bruce Johnson

Evolving design philosophies have lowered the capital and operating costs of membrane bioreactors (MBRs) since the mid-1990s, increasing technology acceptance and application.

A comparison of seven MBR facilities helps to illustrate the design innovations driving the trend toward lower capital and operating costs. Read full article (login required) 


Blending green and gray 

A public works approach to rainwater harvesting

Carl feature 3 art Justin Carl, Vic Smith, and Harvey Brodsky
In 2008, New York City Mayor Michael R. Bloomberg developed a Sustainable Stormwater Management Plan, which in part, calls for reducing flow into the city’s combined sewer system. In keeping with this vision, the New York City Department of Sanitation (DSNY) is incorporating environmentally sustainable design elements into its new 40,736-m2 (438,498-ft2) Manhattan 125 Maintenance Garage. The facility will serve as a central location for DSNY vehicles and equipment to be parked, maintained, washed, and refueled. Read full article (login required) 


Operations Forum Features

Installation and startup of advanced process controls 

What went wrong and how to fix it 

Kestel feature 5 art Gregory Duffy, Steven Kestel, Matthew Gray, and George Lee
Advanced process controls do not come with a giant green button labeled “optimize.” Nor is installing and commissioning a system as simple as dropping some sensors around the plant and plugging all of the cords into the central control system. But the right methodology can provide successful approaches to time and project management, programming, and process troubleshooting. Read full article (login required) 


A next-generation external membrane technology 

The energy advantages of using an airlift MBR process

Sparks feature 2 art Michael Sparks and Dan Turner
Membrane bioreactors (MBRs) have proven to be a viable technology for treating both domestic and industrial wastewater. Although MBRs are considered the best available technology for the treatment of wastewater, there is additional energy cost associated with the upkeep of the membranes.

However, a Venezuelan brewery has discovered that using a sidestream, airlift MBR to process its wastewater can significantly reduce the energy required to keep the membrane’s transmembrane pressure stable when compared to more traditional immersed MBR systems. Read full article (login required) 


Ironing out the impacts of industrial wastewater 

A proven technology supports the growth of local industry and improves treatment plant operation 

Wilson feature 4 art Christopher Wilson, John McDonnell, Jennifer Hindel, Debby Martch, and David Hobbs
The Thorn Creek Basin Sanitary District (Chicago Heights, Ill.) provides wastewater treatment services in south suburban Chicago. In addition to treating domestic wastewater from the local area, the district has a substantial industrial base.

When the district’s largest industrial discharger requested permission to increase its discharge of sodium sulfate to the treatment facility by approximately 40%, the district evaluated the potential effects and created a ferric chloride dosing system to handle the extra loading. Not only does this solution enable a local business to expand, it also alleviates the extra operational and maintenance requirements at the treatment facility associated with the waste flow from this industry. Read full article (login required) 


Wasting pounds instead of gallons 

How one utility built a system to automatically control sludge age 

Kehoe feature 6 art Mike Kehoe, Shawn Griffith, and Bob Dabkowski
The Town of Morrison, Colo., owns and operates a 757,000-L/d (200,000-gal/d) conventional activated sludge plant to treat municipal wastewater. The operation of the plant is limited by a finite volume of aerobic digester capacity followed by sludge drying beds that can freeze in the winter. When the drying beds freeze, the plant is forced to skip drying and haul away the settled solids.
The creation of an automatic sludge age control system helped to better control the solids loading sent to the plant’s digester, simplify the wasting process, and increase operational consistency. Read full article (login required)

©2011 Water Environment Federation. All rights reserved.